modified: blueprints/sync_server.py

modified:   core/sync.py

app.py

@@ -1,5 +1,7 @@
 import os
 import sys
+import json
+import uuid
 import time
 import threading
 
@@ -12,12 +14,14 @@ from flask_socketio import SocketIO
 from core.utils import get_bundled_path, get_persistent_path
 from core.db import init_db as init_db_core, get_db_connection
 from core.events import socketio
+from core.sync import SyncManager
 
 from blueprints.auth import auth_bp, init_login_manager
 from blueprints.finance import finance_bp
 from blueprints.inventory import inventory_bp
 from blueprints.pos import pos_bp
 from blueprints.sales import sales_bp
+from blueprints.sync_server import sync_bp
 
 # --- PYINSTALLER WINDOWED MODE FIX ---
 if getattr(sys, 'frozen', False) and sys.platform == "win32":
@@ -25,7 +29,7 @@ if getattr(sys, 'frozen', False) and sys.platform == "win32":
     sys.stdout = open(log_file, 'w', encoding='utf-8')
     sys.stderr = sys.stdout
 
-# --- FLASK INIT ---
+def create_app(mode=None):
     app = Flask(
         __name__,
         template_folder=get_bundled_path('templates'),
@@ -33,8 +37,17 @@ app = Flask(
     )
     app.config['SECRET_KEY'] = 'seki_super_secret_key_99'
 
-# --- DIRECTORY SETUP ---
-DB_DIR = get_persistent_path('db')
+    if mode is None:
+        mode = os.environ.get('SEKIPOS_MODE', 'desktop')
+
+    PORT = int(os.environ.get('PORT', 5000))
+    app.config['PORT'] = PORT
+
+    SYNC_SECRET = os.environ.get('SEKIPOS_SYNC_SECRET', '').strip()
+    if mode == 'server' and not SYNC_SECRET:
+        print("[WARN] SEKIpos_SYNC_SECRET not set — sync API is unprotected!")
+
+    DB_DIR = os.environ.get('SEKIPOS_DB_DIR', get_persistent_path('db'))
     os.makedirs(DB_DIR, exist_ok=True)
     DB_FILE = os.path.join(DB_DIR, "pos_database.db")
     app.config['DB_FILE'] = DB_FILE
@@ -43,6 +56,36 @@ CACHE_DIR = get_persistent_path(os.path.join('static', 'cache'))
     os.makedirs(CACHE_DIR, exist_ok=True)
     app.config['CACHE_DIR'] = CACHE_DIR
 
+    # --- INSTANCE CONFIG ---
+    INSTANCE_FILE = os.path.join(DB_DIR, 'instance.json')
+
+    if not os.path.exists(INSTANCE_FILE):
+        config = {
+            "instance_id": str(uuid.uuid4()),
+            "display_name": "Caja Principal",
+            "mode": mode,
+            "server_url": "",
+            "last_sync_at": None
+        }
+        with open(INSTANCE_FILE, 'w') as f:
+            json.dump(config, f, indent=2)
+    else:
+        with open(INSTANCE_FILE) as f:
+            config = json.load(f)
+        config['mode'] = mode
+        with open(INSTANCE_FILE, 'w') as f:
+            json.dump(config, f, indent=2)
+
+    INSTANCE_ID = config['instance_id']
+    DISPLAY_NAME = config.get('display_name', 'Caja Principal')
+    SERVER_URL = config.get('server_url', '')
+
+    app.config['INSTANCE_ID'] = INSTANCE_ID
+    app.config['DISPLAY_NAME'] = DISPLAY_NAME
+    app.config['SERVER_URL'] = SERVER_URL
+    app.config['MODE'] = mode
+    app.config['SYNC_SECRET'] = SYNC_SECRET
+
     # --- BLUEPRINT REGISTRATION ---
     app.register_blueprint(auth_bp)
     app.register_blueprint(finance_bp)
@@ -50,6 +93,9 @@ app.register_blueprint(inventory_bp)
     app.register_blueprint(pos_bp)
     app.register_blueprint(sales_bp)
 
+    if mode == 'server':
+        app.register_blueprint(sync_bp)
+
     init_login_manager(app)
     socketio.init_app(app, cors_allowed_origins="*", async_mode='threading')
 
@@ -62,18 +108,30 @@ init_db_core(DB_FILE)
     def index():
         return redirect(url_for('inventory.inventory'))
 
-# --- RUN FUNCTION ---
-def start_server():
-    socketio.run(app, host='127.0.0.1', port=5000, log_output=False, allow_unsafe_werkzeug=True)
+    # --- SYNC CLIENT ---
+    if mode == 'desktop' and SERVER_URL:
+        sync_secret = config.get('sync_secret', '')
+        sync_mgr = SyncManager(DB_FILE, INSTANCE_ID, SERVER_URL, DISPLAY_NAME, sync_secret)
+        sync_mgr.start()
+        print(f"[Sync] Desktop mode — syncing to {SERVER_URL}")
+
+    return app
+
+app = create_app()
 
 def run_standalone():
-    t = threading.Thread(target=start_server)
+    local_app = create_app(mode='desktop')
+    port = local_app.config['PORT']
+    t = threading.Thread(target=lambda: socketio.run(local_app, host='127.0.0.1', port=port, log_output=False, allow_unsafe_werkzeug=True))
     t.daemon = True
     t.start()
     time.sleep(2)
-    webview.create_window('SekiPOS', 'http://127.0.0.1:5000', width=1366, height=768, resizable=True, fullscreen=False, min_size=(800, 600), maximized=True)
+    webview.create_window('SekiPOS', f'http://127.0.0.1:{port}', width=1366, height=768, resizable=True, fullscreen=False, min_size=(800, 600), maximized=True)
     webview.start(private_mode=False)
 
 if __name__ == '__main__':
-    #run_standalone()  # Uncomment for desktop app
-    socketio.run(app, host='0.0.0.0', port=5000, debug=True, allow_unsafe_werkzeug=True)
+    if os.environ.get('SEKIPOS_MODE') == 'server':
+        port = app.config['PORT']
+        socketio.run(app, host='0.0.0.0', port=port, debug=True, allow_unsafe_werkzeug=True)
+    else:
+        run_standalone()

blueprints/auth.py

@@ -1,4 +1,6 @@
-from flask import Blueprint, render_template, request, redirect, url_for, flash
+import os
+import json
+from flask import Blueprint, render_template, request, redirect, url_for, flash, jsonify, current_app
 from flask_login import LoginManager, UserMixin, login_user, login_required, logout_user, current_user
 from werkzeug.security import check_password_hash, generate_password_hash
 from core.db import get_db_connection
@@ -56,5 +58,71 @@ def update_settings():
     flash('Configuración actualizada')
     return redirect(request.referrer)
 
+@auth_bp.route('/api/instance/config')
+@login_required
+def get_instance_config():
+    db_dir = os.path.dirname(current_app.config.get('DB_FILE', ''))
+    instance_file = os.path.join(db_dir, 'instance.json')
+    if os.path.exists(instance_file):
+        with open(instance_file) as f:
+            config = json.load(f)
+    else:
+        config = {}
+    return jsonify({
+        "instance_id": config.get('instance_id', ''),
+        "display_name": config.get('display_name', 'Caja Principal'),
+        "server_url": config.get('server_url', ''),
+        "sync_secret": config.get('sync_secret', ''),
+        "mode": config.get('mode', 'desktop')
+    })
+
+@auth_bp.route('/api/instance/config', methods=['POST'])
+@login_required
+def save_instance_config():
+    data = request.get_json()
+    db_dir = os.path.dirname(current_app.config.get('DB_FILE', ''))
+    instance_file = os.path.join(db_dir, 'instance.json')
+    if os.path.exists(instance_file):
+        with open(instance_file) as f:
+            config = json.load(f)
+    else:
+        config = {}
+    if 'server_url' in data:
+        config['server_url'] = data['server_url']
+    if 'display_name' in data:
+        config['display_name'] = data['display_name']
+    if 'sync_secret' in data:
+        config['sync_secret'] = data['sync_secret']
+    with open(instance_file, 'w') as f:
+        json.dump(config, f, indent=2)
+    return jsonify({"status": "ok"})
+
+@auth_bp.route('/api/sync/trigger', methods=['POST'])
+@login_required
+def trigger_sync():
+    from core.sync import SyncManager
+    try:
+        db_file = current_app.config.get('DB_FILE', '')
+        instance_id = current_app.config.get('INSTANCE_ID', '')
+        server_url = ''
+        display_name = ''
+        sync_secret = ''
+        if db_file:
+            instance_file = os.path.join(os.path.dirname(db_file), 'instance.json')
+            if os.path.exists(instance_file):
+                with open(instance_file) as f:
+                    cfg = json.load(f)
+                    server_url = cfg.get('server_url', '')
+                    display_name = cfg.get('display_name', 'Caja Principal')
+                    sync_secret = cfg.get('sync_secret', '')
+        if server_url:
+            sm = SyncManager(db_file, instance_id, server_url, display_name, sync_secret)
+            sm._push()
+            sm._pull()
+            return jsonify({"status": "ok"})
+        return jsonify({"status": "error", "message": "No server URL configured"}), 400
+    except Exception as e:
+        return jsonify({"status": "error", "message": str(e)}), 500
+
 def init_login_manager(app):
     login_manager.init_app(app)

blueprints/finance.py

@@ -1,9 +1,18 @@
-from flask import Blueprint, render_template, request, jsonify
+import uuid as _uuid
+from datetime import datetime, timezone
+from flask import Blueprint, render_template, request, jsonify, current_app
 from flask_login import login_required, current_user
 from core.db import get_db_connection
 
 finance_bp = Blueprint('finance', __name__)
 
+def _log_deletion(conn, entity_type, entity_uuid):
+    conn.execute("INSERT INTO sync_deletions (entity_type, entity_uuid) VALUES (?, ?)",
+                 (entity_type, entity_uuid))
+
+def _instance_id():
+    return current_app.config.get('INSTANCE_ID', '')
+
 @finance_bp.route('/dicom')
 @login_required
 def dicom():
@@ -51,6 +60,8 @@ def pay_debtor_ticket(debtor_id):
     data = request.get_json()
     ticket_id = data.get('ticket_id')
     amount = float(data.get('amount', 0))
+    inst_id = _instance_id()
+    now = datetime.now(timezone.utc).isoformat()
 
     if not ticket_id or amount <= 0:
         return jsonify({"error": "Monto inválido"}), 400
@@ -58,17 +69,20 @@ def pay_debtor_ticket(debtor_id):
     with get_db_connection() as conn:
         conn.execute('''UPDATE debtor_tickets
                        SET amount_paid = amount_paid + ?,
-                           status = CASE WHEN (total - amount_paid - ?) <= 0 THEN 'paid' ELSE 'partial' END
-                       WHERE id = ?''', (amount, amount, ticket_id))
+                           status = CASE WHEN (total - amount_paid - ?) <= 0 THEN 'paid' ELSE 'partial' END,
+                           updated_at = ?,
+                           updated_by = ?
+                       WHERE id = ?''', (amount, amount, now, inst_id, ticket_id))
 
-        # Update status based on final values
         conn.execute('''UPDATE debtor_tickets
                        SET status = CASE
                            WHEN total - amount_paid <= 0 THEN 'paid'
                            WHEN amount_paid > 0 THEN 'partial'
                            ELSE 'unpaid'
-                       END
-                       WHERE id = ?''', (ticket_id,))
+                       END,
+                       updated_at = ?,
+                       updated_by = ?
+                       WHERE id = ?''', (now, inst_id, ticket_id))
         conn.commit()
 
     return jsonify({"status": "success"})
@@ -80,29 +94,29 @@ def dicom_pay():
     ticket_id = data.get('ticket_id')
     amount = float(data.get('amount', 0))
     payment_method = data.get('payment_method', 'efectivo')
+    inst_id = _instance_id()
+    now = datetime.now(timezone.utc).isoformat()
 
     if not ticket_id or amount <= 0:
         return jsonify({"error": "Monto inválido"}), 400
 
     try:
         with get_db_connection() as conn:
-            cur = conn.cursor()
+            conn.execute('UPDATE debtor_tickets SET amount_paid = amount_paid + ? WHERE id = ?', (amount, ticket_id))
 
-            # Update the debtor ticket payment
-            cur.execute('UPDATE debtor_tickets SET amount_paid = amount_paid + ? WHERE id = ?', (amount, ticket_id))
-            
-            # Update status based on final values
-            cur.execute('''UPDATE debtor_tickets 
+            conn.execute('''UPDATE debtor_tickets
                            SET status = CASE
                                WHEN total - amount_paid <= 0 THEN 'paid'
                                WHEN amount_paid > 0 THEN 'partial'
                                ELSE 'unpaid'
-                           END
-                           WHERE id = ?''', (ticket_id,))
+                           END,
+                           updated_at = ?,
+                           updated_by = ?
+                           WHERE id = ?''', (now, inst_id, ticket_id))
 
-            # Insert into sales table to track daily revenue
-            cur.execute('''INSERT INTO sales (date, total, payment_method) 
-                           VALUES (CURRENT_TIMESTAMP, ?, ?)''', (amount, payment_method))
+            conn.execute('''INSERT INTO sales (date, total, payment_method, uuid)
+                           VALUES (CURRENT_TIMESTAMP, ?, ?, ?)''',
+                         (amount, payment_method, str(_uuid.uuid4())))
 
             conn.commit()
 
@@ -121,6 +135,8 @@ def update_dicom():
     notes = data.get('notes', '')
     image_url = data.get('image_url', '')
     action = data.get('action')
+    inst_id = _instance_id()
+    now = datetime.now(timezone.utc).isoformat()
 
     if not name or amount <= 0:
         return jsonify({"error": "Nombre y monto válidos son requeridos"}), 400
@@ -129,14 +145,17 @@ def update_dicom():
         amount = -amount
 
     with get_db_connection() as conn:
-        cur = conn.cursor()
-        cur.execute('''INSERT INTO dicom (name, amount, notes, image_url, last_updated) 
-                           VALUES (?, ?, ?, ?, CURRENT_TIMESTAMP)
+        existing = conn.execute("SELECT uuid FROM dicom WHERE name = ?", (name,)).fetchone()
+        ent_uuid = existing[0] if existing else str(_uuid.uuid4())
+        conn.execute('''INSERT INTO dicom (uuid, name, amount, notes, image_url, updated_at, updated_by)
+                        VALUES (?, ?, ?, ?, ?, ?, ?)
                         ON CONFLICT(name) DO UPDATE SET
                         amount = amount + excluded.amount,
                         notes = excluded.notes,
                         image_url = CASE WHEN excluded.image_url != "" THEN excluded.image_url ELSE dicom.image_url END,
-                           last_updated = CURRENT_TIMESTAMP''', (name, amount, notes, image_url))
+                        updated_at = ?,
+                        updated_by = ?''',
+                     (ent_uuid, name, amount, notes, image_url, now, inst_id, now, inst_id))
         conn.commit()
     return jsonify({"status": "success"}), 200
 
@@ -145,6 +164,9 @@ def update_dicom():
 def delete_dicom(debtor_id):
     try:
         with get_db_connection() as conn:
+            row = conn.execute("SELECT uuid FROM dicom WHERE id = ?", (debtor_id,)).fetchone()
+            if row:
+                _log_deletion(conn, 'dicom', row[0])
             conn.execute('DELETE FROM dicom WHERE id = ?', (debtor_id,))
             conn.commit()
         return jsonify({"status": "success"}), 200
@@ -160,15 +182,6 @@ def gastos():
     with get_db_connection() as conn:
         cur = conn.cursor()
         
-        cur.execute('''
-            CREATE TABLE IF NOT EXISTS expenses (
-                id INTEGER PRIMARY KEY AUTOINCREMENT,
-                date TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-                description TEXT NOT NULL,
-                amount INTEGER NOT NULL
-            )
-        ''')
-        
         sales_total = cur.execute("SELECT SUM(total) FROM sales WHERE strftime('%Y-%m', date, 'localtime') = ?", (selected_month,)).fetchone()[0] or 0
         expenses_total = cur.execute("SELECT SUM(amount) FROM expenses WHERE strftime('%Y-%m', date, 'localtime') = ?", (selected_month,)).fetchone()[0] or 0
         
@@ -194,8 +207,8 @@ def add_gasto():
         return jsonify({"error": "Faltan datos"}), 400
 
     with get_db_connection() as conn:
-        cur = conn.cursor()
-        cur.execute("INSERT INTO expenses (description, amount) VALUES (?, ?)", (desc, int(amount)))
+        conn.execute("INSERT INTO expenses (uuid, description, amount) VALUES (?, ?, ?)",
+                     (str(_uuid.uuid4()), desc, int(amount)))
         conn.commit()
     return jsonify({"success": True})
 
@@ -203,8 +216,10 @@ def add_gasto():
 @login_required
 def delete_gasto(gasto_id):
     with get_db_connection() as conn:
-        cur = conn.cursor()
-        cur.execute("DELETE FROM expenses WHERE id = ?", (gasto_id,))
+        row = conn.execute("SELECT uuid FROM expenses WHERE id = ?", (gasto_id,)).fetchone()
+        if row:
+            _log_deletion(conn, 'expense', row[0])
+        conn.execute("DELETE FROM expenses WHERE id = ?", (gasto_id,))
         conn.commit()
     return jsonify({"success": True})
 
@@ -213,22 +228,17 @@ def delete_gasto(gasto_id):
 def get_debtors():
     try:
         with get_db_connection() as conn:
-            # Check if table exists
             cur = conn.cursor()
             cur.execute("SELECT name FROM sqlite_master WHERE type='table' AND name='debtors'")
             if not cur.fetchone():
-                print("Debtors table does not exist!")
                 return jsonify([])
 
-            cur.execute('SELECT id, name, contact_info FROM debtors ORDER BY name')
+            cur.execute('SELECT id, name, contact_info, uuid FROM debtors ORDER BY name')
             debtors = cur.fetchall()
-            print(f"Found {len(debtors)} debtors:", debtors)
 
-        return jsonify([{"id": d[0], "name": d[1], "contact_info": d[2]} for d in debtors])
+        return jsonify([{"id": d[0], "name": d[1], "contact_info": d[2], "uuid": d[3]} for d in debtors])
     except Exception as e:
         print(f"Error getting debtors: {e}")
-        import traceback
-        traceback.print_exc()
         return jsonify([])
 
 @finance_bp.route('/api/dicom/checkout', methods=['POST'])
@@ -240,6 +250,8 @@ def dicom_checkout():
         debtor_name = data.get('debtor_name', '').strip()
         contact_info = data.get('contact_info', '').strip()
         initial_payment = data.get('initial_payment', 0) or 0
+        inst_id = _instance_id()
+        now = datetime.now(timezone.utc).isoformat()
 
         if not cart:
             return jsonify({"error": "Carrito vacío"}), 400
@@ -249,36 +261,33 @@ def dicom_checkout():
         total = sum(item.get('subtotal', 0) for item in cart)
 
         with get_db_connection() as conn:
-            cur = conn.cursor()
-            
-            # Upsert debtor
-            cur.execute('''INSERT INTO debtors (name, contact_info) 
-                           VALUES (?, ?)
+            debtor_uuid = str(_uuid.uuid4())
+            conn.execute('''INSERT INTO debtors (uuid, name, contact_info, updated_at, updated_by)
+                           VALUES (?, ?, ?, ?, ?)
                            ON CONFLICT(name) DO UPDATE SET
-                           contact_info = excluded.contact_info''',
-                        (debtor_name, contact_info))
+                           contact_info = excluded.contact_info,
+                           updated_at = excluded.updated_at,
+                           updated_by = excluded.updated_by''',
+                        (debtor_uuid, debtor_name, contact_info, now, inst_id))
 
-            # Get debtor ID
-            debtor_id = cur.execute('SELECT id FROM debtors WHERE name = ?', (debtor_name,)).fetchone()[0]
+            debtor_id = conn.execute('SELECT id FROM debtors WHERE name = ?', (debtor_name,)).fetchone()[0]
 
-            # Insert debtor ticket
             status = 'partial' if initial_payment > 0 else 'unpaid'
-            cur.execute('''INSERT INTO debtor_tickets (debtor_id, total, amount_paid, status) 
-                           VALUES (?, ?, ?, ?)''',
-                        (debtor_id, total, initial_payment, status))
-            ticket_id = cur.lastrowid
+            ticket_uuid = str(_uuid.uuid4())
+            c = conn.execute('''INSERT INTO debtor_tickets (uuid, debtor_id, total, amount_paid, status, updated_at, updated_by)
+                               VALUES (?, ?, ?, ?, ?, ?, ?)''',
+                            (ticket_uuid, debtor_id, total, initial_payment, status, now, inst_id))
+            ticket_id = c.lastrowid
 
-            # Insert ticket items and deduct stock
             for item in cart:
-                cur.execute('''INSERT INTO debtor_ticket_items 
+                conn.execute('''INSERT INTO debtor_ticket_items
                                (ticket_id, barcode, name, price, quantity, subtotal)
                                VALUES (?, ?, ?, ?, ?, ?)''',
                             (ticket_id, item.get('barcode', ''), item.get('name'),
                              item.get('price'), item.get('qty'), item.get('subtotal')))
 
-                # Deduct stock (skip for manual products)
                 if item.get('barcode') and not item.get('barcode', '').startswith(('MANUAL-', 'VARIOS-', 'RAPIDA-')):
-                    cur.execute('UPDATE products SET stock = stock - ? WHERE barcode = ?', 
+                    conn.execute('UPDATE products SET stock = stock - ? WHERE barcode = ?',
                                 (item.get('qty'), item.get('barcode')))
 
             conn.commit()
@@ -294,13 +303,15 @@ def dicom_checkout():
 def delete_debtor(debtor_id):
     try:
         with get_db_connection() as conn:
-            cur = conn.cursor()
-            # Delete items first
-            cur.execute('DELETE FROM debtor_ticket_items WHERE ticket_id IN (SELECT id FROM debtor_tickets WHERE debtor_id = ?)', (debtor_id,))
-            # Delete tickets
-            cur.execute('DELETE FROM debtor_tickets WHERE debtor_id = ?', (debtor_id,))
-            # Delete debtor
-            cur.execute('DELETE FROM debtors WHERE id = ?', (debtor_id,))
+            row = conn.execute("SELECT uuid FROM debtors WHERE id = ?", (debtor_id,)).fetchone()
+            if row:
+                _log_deletion(conn, 'debtor', row[0])
+                tickets = conn.execute("SELECT uuid FROM debtor_tickets WHERE debtor_id = ?", (debtor_id,)).fetchall()
+                for t in tickets:
+                    _log_deletion(conn, 'ticket', t[0])
+            conn.execute('DELETE FROM debtor_ticket_items WHERE ticket_id IN (SELECT id FROM debtor_tickets WHERE debtor_id = ?)', (debtor_id,))
+            conn.execute('DELETE FROM debtor_tickets WHERE debtor_id = ?', (debtor_id,))
+            conn.execute('DELETE FROM debtors WHERE id = ?', (debtor_id,))
             conn.commit()
         return jsonify({"status": "success"}), 200
     except Exception as e:
@@ -312,11 +323,11 @@ def delete_debtor(debtor_id):
 def delete_ticket(ticket_id):
     try:
         with get_db_connection() as conn:
-            cur = conn.cursor()
-            # Delete items first
-            cur.execute('DELETE FROM debtor_ticket_items WHERE ticket_id = ?', (ticket_id,))
-            # Delete ticket
-            cur.execute('DELETE FROM debtor_tickets WHERE id = ?', (ticket_id,))
+            row = conn.execute("SELECT uuid FROM debtor_tickets WHERE id = ?", (ticket_id,)).fetchone()
+            if row:
+                _log_deletion(conn, 'ticket', row[0])
+            conn.execute('DELETE FROM debtor_ticket_items WHERE ticket_id = ?', (ticket_id,))
+            conn.execute('DELETE FROM debtor_tickets WHERE id = ?', (ticket_id,))
             conn.commit()
         return jsonify({"status": "success"}), 200
     except Exception as e:
@@ -328,28 +339,23 @@ def delete_ticket(ticket_id):
 def delete_item(item_id):
     try:
         with get_db_connection() as conn:
-            cur = conn.cursor()
-            # Get item info to update ticket total
-            item = cur.execute('SELECT ticket_id, subtotal FROM debtor_ticket_items WHERE id = ?', (item_id,)).fetchone()
+            item = conn.execute('SELECT ticket_id, subtotal FROM debtor_ticket_items WHERE id = ?', (item_id,)).fetchone()
             if not item:
                 return jsonify({"error": "Item no encontrado"}), 404
 
             ticket_id, item_subtotal = item
-            
-            # Delete item
-            cur.execute('DELETE FROM debtor_ticket_items WHERE id = ?', (item_id,))
-            
-            # Check if ticket has remaining items
-            remaining_items = cur.execute('SELECT COUNT(*) FROM debtor_ticket_items WHERE ticket_id = ?', (ticket_id,)).fetchone()[0]
+            conn.execute('DELETE FROM debtor_ticket_items WHERE id = ?', (item_id,))
+            remaining_items = conn.execute('SELECT COUNT(*) FROM debtor_ticket_items WHERE ticket_id = ?', (ticket_id,)).fetchone()[0]
 
             if remaining_items == 0:
-                # Delete ticket if no items left
-                cur.execute('DELETE FROM debtor_tickets WHERE id = ?', (ticket_id,))
+                row = conn.execute("SELECT uuid FROM debtor_tickets WHERE id = ?", (ticket_id,)).fetchone()
+                if row:
+                    _log_deletion(conn, 'ticket', row[0])
+                conn.execute('DELETE FROM debtor_tickets WHERE id = ?', (ticket_id,))
+                conn.commit()
                 return jsonify({"status": "success", "ticket_deleted": True}), 200
 
-            # Update ticket total
-            cur.execute('UPDATE debtor_tickets SET total = total - ? WHERE id = ?', (item_subtotal, ticket_id))
-            
+            conn.execute('UPDATE debtor_tickets SET total = total - ? WHERE id = ?', (item_subtotal, ticket_id))
             conn.commit()
         return jsonify({"status": "success", "ticket_deleted": False}), 200
     except Exception as e:
@@ -363,15 +369,14 @@ def pay_all_debtor(debtor_id):
         data = request.get_json()
         amount = float(data.get('amount', 0))
         payment_method = data.get('payment_method', 'efectivo')
+        inst_id = _instance_id()
+        now = datetime.now(timezone.utc).isoformat()
 
         if amount <= 0:
             return jsonify({"error": "Monto inválido"}), 400
 
         with get_db_connection() as conn:
-            cur = conn.cursor()
-            
-            # Get all unpaid/partial tickets for this debtor
-            tickets = cur.execute('''SELECT id, total, amount_paid, total - amount_paid as remaining 
+            tickets = conn.execute('''SELECT id, total, amount_paid, total - amount_paid as remaining
                                       FROM debtor_tickets
                                       WHERE debtor_id = ? AND status != 'paid' ''', (debtor_id,)).fetchall()
 
@@ -380,14 +385,13 @@ def pay_all_debtor(debtor_id):
                 remaining = ticket[3]
 
                 if remaining > 0:
-                    # Pay remaining amount
-                    cur.execute('UPDATE debtor_tickets SET amount_paid = amount_paid + ? WHERE id = ?', 
-                                (remaining, ticket_id))
-                    # Update status
-                    cur.execute('''UPDATE debtor_tickets SET status = 'paid' WHERE id = ?''', (ticket_id,))
-                    # Record sale
-                    cur.execute('''INSERT INTO sales (date, total, payment_method) 
-                                   VALUES (CURRENT_TIMESTAMP, ?, ?)''', (remaining, payment_method))
+                    conn.execute('UPDATE debtor_tickets SET amount_paid = amount_paid + ?, updated_at = ?, updated_by = ? WHERE id = ?',
+                                (remaining, now, inst_id, ticket_id))
+                    conn.execute('UPDATE debtor_tickets SET status = \'paid\', updated_at = ?, updated_by = ? WHERE id = ?',
+                                (now, inst_id, ticket_id))
+                    conn.execute('''INSERT INTO sales (date, total, payment_method, uuid)
+                                   VALUES (CURRENT_TIMESTAMP, ?, ?, ?)''',
+                                (remaining, payment_method, str(_uuid.uuid4())))
 
             conn.commit()
 

blueprints/inventory.py

@@ -38,16 +38,22 @@ def upsert():
     cache_dir = current_app.config['CACHE_DIR']
     final_image_path = download_image(image_url, barcode, cache_dir)
     
+    from datetime import datetime, timezone
+    now = datetime.now(timezone.utc).isoformat()
+    instance_id = current_app.config.get('INSTANCE_ID', '')
+    
     with get_db_connection() as conn:
-        conn.execute('''INSERT INTO products (barcode, name, price, image_url, stock, unit_type) 
-                        VALUES (?,?,?,?,?,?)
+        conn.execute('''INSERT INTO products (barcode, name, price, image_url, stock, unit_type, updated_at, updated_by) 
+                        VALUES (?,?,?,?,?,?,?,?)
                         ON CONFLICT(barcode) DO UPDATE SET 
                         name=excluded.name, 
                         price=excluded.price, 
                         image_url=excluded.image_url,
                         stock=excluded.stock,
-                        unit_type=excluded.unit_type''',
-                     (barcode, name, price, final_image_path, stock, unit_type))
+                        unit_type=excluded.unit_type,
+                        updated_at=excluded.updated_at,
+                        updated_by=excluded.updated_by''',
+                     (barcode, name, price, final_image_path, stock, unit_type, now, instance_id))
         conn.commit()
     return redirect(url_for('inventory.inventory'))
 
@@ -82,6 +88,7 @@ def delete(barcode):
     cache_dir = current_app.config['CACHE_DIR']
     
     with get_db_connection() as conn:
+        conn.execute('INSERT INTO sync_deletions (entity_type, entity_uuid) VALUES (?, ?)', ('product', barcode))
         conn.execute('DELETE FROM products WHERE barcode = ?', (barcode,))
         conn.commit()
     
@@ -102,9 +109,12 @@ def bulk_price_update():
         return jsonify({"error": "Missing data"}), 400
 
     try:
+        from datetime import datetime, timezone
+        now = datetime.now(timezone.utc).isoformat()
+        instance_id = current_app.config.get('INSTANCE_ID', '')
         with get_db_connection() as conn:
-            params = [(float(new_price), b) for b in barcodes]
-            conn.executemany('UPDATE products SET price = ? WHERE barcode = ?', params)
+            params = [(float(new_price), now, instance_id, b) for b in barcodes]
+            conn.executemany('UPDATE products SET price = ?, updated_at = ?, updated_by = ? WHERE barcode = ?', params)
             conn.commit()
         return jsonify({"status": "success"}), 200
     except Exception as e:
@@ -124,6 +134,8 @@ def bulk_delete():
 
     try:
         with get_db_connection() as conn:
+            for barcode in barcodes:
+                conn.execute('INSERT INTO sync_deletions (entity_type, entity_uuid) VALUES (?, ?)', ('product', barcode))
             conn.execute(f'DELETE FROM products WHERE barcode IN ({",".join(["?"]*len(barcodes))})', barcodes)
             conn.commit()
         

blueprints/pos.py

@@ -1,5 +1,6 @@
 import os
 import time
+import uuid
 from flask import Blueprint, render_template, request, jsonify, current_app
 from flask_login import login_required, current_user
 from core.db import get_db_connection
@@ -81,7 +82,8 @@ def process_checkout():
         with get_db_connection() as conn:
             cur = conn.cursor()
             
-            cur.execute('INSERT INTO sales (date, total, payment_method) VALUES (CURRENT_TIMESTAMP, ?, ?)', (total, payment_method))
+            sale_uuid = str(uuid.uuid4())
+            cur.execute('INSERT INTO sales (date, total, payment_method, uuid) VALUES (CURRENT_TIMESTAMP, ?, ?, ?)', (total, payment_method, sale_uuid))
             sale_id = cur.lastrowid
             
             for item in cart:

blueprints/sales.py

@@ -130,6 +130,11 @@ def reverse_sale(sale_id):
         with get_db_connection() as conn:
             cur = conn.cursor()
             
+            sale_uuid = cur.execute('SELECT uuid FROM sales WHERE id = ?', (sale_id,)).fetchone()
+            if not sale_uuid:
+                return jsonify({"error": "Sale not found"}), 404
+            sale_uuid = sale_uuid[0]
+            
             items = cur.execute('SELECT barcode, quantity FROM sale_items WHERE sale_id = ?', (sale_id,)).fetchall()
             
             for barcode, qty in items:
@@ -137,6 +142,8 @@ def reverse_sale(sale_id):
                 
             cur.execute('DELETE FROM sale_items WHERE sale_id = ?', (sale_id,))
             cur.execute('DELETE FROM sales WHERE id = ?', (sale_id,))
+            cur.execute('INSERT INTO sync_deletions (entity_type, entity_uuid) VALUES (?, ?)',
+                        ('sale', sale_uuid))
             
             conn.commit()
             

blueprints/sync_server.py

@@ -0,0 +1,273 @@
+from datetime import datetime, timezone
+from flask import Blueprint, request, jsonify, current_app
+from functools import wraps
+
+sync_bp = Blueprint('sync', __name__)
+
+def require_sync_secret(f):
+    @wraps(f)
+    def decorated(*args, **kwargs):
+        secret = current_app.config.get('SYNC_SECRET', '')
+        if secret and request.headers.get('X-Sync-Secret') != secret:
+            return jsonify({"error": "unauthorized"}), 401
+        return f(*args, **kwargs)
+    return decorated
+
+@sync_bp.route('/api/ping')
+def ping():
+    return jsonify({"status": "ok"}), 200
+
+@sync_bp.route('/api/sync/push', methods=['POST'])
+@require_sync_secret
+def sync_push():
+    data = request.get_json()
+    if not data:
+        return jsonify({"error": "empty payload"}), 400
+
+    instance_id = data.get('instance_id', 'unknown')
+    synced_at = data.get('synced_at') or datetime.now(timezone.utc).isoformat()
+
+    from core.db import get_db_connection
+
+    with get_db_connection() as conn:
+        # 1. Deletions
+        for d in data.get('deletions', []):
+            et = d['entity_type']
+            eu = d['entity_uuid']
+            # Log to server's sync_deletions so other pulling clients see it
+            existing = conn.execute(
+                "SELECT id FROM sync_deletions WHERE entity_type = ? AND entity_uuid = ?",
+                (et, eu)
+            ).fetchone()
+            if not existing:
+                now = datetime.now(timezone.utc).isoformat()
+                conn.execute(
+                    "INSERT INTO sync_deletions (entity_type, entity_uuid, deleted_at) VALUES (?, ?, ?)",
+                    (et, eu, now)
+                )
+            if et == 'debtor':
+                conn.execute("DELETE FROM debtors WHERE uuid = ?", (eu,))
+            elif et == 'ticket':
+                row = conn.execute("SELECT id FROM debtor_tickets WHERE uuid = ?", (eu,)).fetchone()
+                if row:
+                    conn.execute("DELETE FROM debtor_ticket_items WHERE ticket_id = ?", (row[0],))
+                conn.execute("DELETE FROM debtor_tickets WHERE uuid = ?", (eu,))
+            elif et == 'dicom':
+                conn.execute("DELETE FROM dicom WHERE uuid = ?", (eu,))
+            elif et == 'expense':
+                conn.execute("DELETE FROM expenses WHERE uuid = ?", (eu,))
+            elif et == 'sale':
+                row = conn.execute("SELECT id FROM sales WHERE uuid = ?", (eu,)).fetchone()
+                if row:
+                    conn.execute("DELETE FROM sale_items WHERE sale_id = ?", (row[0],))
+                conn.execute("DELETE FROM sales WHERE uuid = ?", (eu,))
+            elif et == 'product':
+                conn.execute("DELETE FROM products WHERE barcode = ?", (eu,))
+
+        # 2. Sales
+        for sale in data.get('sales', []):
+            existing = conn.execute(
+                "SELECT id FROM sales WHERE uuid = ?", (sale['uuid'],)
+            ).fetchone()
+            if existing:
+                continue
+            cur = conn.execute(
+                "INSERT INTO sales (date, total, payment_method, uuid, synced_at) VALUES (?, ?, ?, ?, ?)",
+                (sale.get('date', synced_at), sale['total'], sale.get('payment_method', 'efectivo'),
+                 sale['uuid'], synced_at)
+            )
+            sale_id = cur.lastrowid
+            for item in sale.get('items', []):
+                conn.execute(
+                    "INSERT INTO sale_items (sale_id, barcode, name, price, quantity, subtotal) VALUES (?, ?, ?, ?, ?, ?)",
+                    (sale_id, item['barcode'], item['name'], item.get('price', 0),
+                     item.get('qty', 1), item.get('subtotal', 0))
+                )
+
+        # 3. Products
+        now = datetime.now(timezone.utc).isoformat()
+        for p in data.get('products', []):
+            existing = conn.execute(
+                "SELECT updated_at FROM products WHERE barcode = ?", (p['barcode'],)
+            ).fetchone()
+            if existing and existing[0] >= p.get('updated_at', now):
+                continue
+            conn.execute('''INSERT INTO products (barcode, name, price, image_url, stock, unit_type, updated_at, updated_by)
+                            VALUES (?,?,?,?,?,?,?,?)
+                            ON CONFLICT(barcode) DO UPDATE SET
+                            name=excluded.name, price=excluded.price,
+                            image_url=excluded.image_url, stock=excluded.stock,
+                            unit_type=excluded.unit_type, updated_at=excluded.updated_at,
+                            updated_by=excluded.updated_by''',
+                         (p['barcode'], p.get('name', ''), p.get('price', 0),
+                          p.get('image_url'), p.get('stock', 0), p.get('unit_type', 'unit'),
+                          p.get('updated_at', now), instance_id))
+
+        # 4. Debtors
+        for d in data.get('debtors', []):
+            conn.execute('''INSERT INTO debtors (uuid, name, contact_info, updated_at, updated_by)
+                            VALUES (?,?,?,?,?)
+                            ON CONFLICT(uuid) DO UPDATE SET
+                            name=excluded.name, contact_info=excluded.contact_info,
+                            updated_at=excluded.updated_at, updated_by=excluded.updated_by''',
+                         (d['uuid'], d['name'], d.get('contact_info', ''),
+                          d.get('updated_at', now), d.get('updated_by', instance_id)))
+
+        # 5. Dicom (legacy)
+        for d in data.get('dicom', []):
+            conn.execute('''INSERT INTO dicom (uuid, name, amount, notes, image_url, updated_at, updated_by)
+                            VALUES (?,?,?,?,?,?,?)
+                            ON CONFLICT(uuid) DO UPDATE SET
+                            name=excluded.name, amount=excluded.amount,
+                            notes=excluded.notes, image_url=excluded.image_url,
+                            updated_at=excluded.updated_at, updated_by=excluded.updated_by''',
+                         (d['uuid'], d['name'], d.get('amount', 0), d.get('notes', ''),
+                          d.get('image_url', ''), d.get('updated_at', now), d.get('updated_by', instance_id)))
+
+        # 6. Debtor tickets with items
+        for t in data.get('tickets', []):
+            existing = conn.execute(
+                "SELECT id FROM debtor_tickets WHERE uuid = ?", (t['uuid'],)
+            ).fetchone()
+            if existing:
+                continue
+            debtor_row = conn.execute(
+                "SELECT id FROM debtors WHERE uuid = ?", (t['debtor_uuid'],)
+            ).fetchone()
+            if not debtor_row:
+                continue
+            cur = conn.execute(
+                "INSERT INTO debtor_tickets (uuid, debtor_id, date, total, amount_paid, status, updated_at, updated_by) VALUES (?,?,?,?,?,?,?,?)",
+                (t['uuid'], debtor_row[0], t.get('date', synced_at), t['total'],
+                 t.get('amount_paid', 0), t.get('status', 'unpaid'),
+                 t.get('updated_at', now), t.get('updated_by', instance_id))
+            )
+            ticket_id = cur.lastrowid
+            for item in t.get('items', []):
+                conn.execute(
+                    "INSERT INTO debtor_ticket_items (ticket_id, barcode, name, price, quantity, subtotal) VALUES (?,?,?,?,?,?)",
+                    (ticket_id, item['barcode'], item['name'], item.get('price', 0),
+                     item.get('qty', 1), item.get('subtotal', 0))
+                )
+
+        # 7. Expenses
+        for e in data.get('expenses', []):
+            existing = conn.execute(
+                "SELECT id FROM expenses WHERE uuid = ?", (e['uuid'],)
+            ).fetchone()
+            if existing:
+                continue
+            conn.execute(
+                "INSERT INTO expenses (uuid, date, description, amount) VALUES (?,?,?,?)",
+                (e['uuid'], e.get('date', synced_at), e['description'], e['amount'])
+            )
+
+        conn.commit()
+
+    return jsonify({"status": "ok", "instance_id": instance_id}), 200
+
+@sync_bp.route('/api/sync/pull')
+@require_sync_secret
+def sync_pull():
+    since = request.args.get('since', '1970-01-01')
+    since_sales = request.args.get('since_sales', '1970-01-01')
+    since_debtors = request.args.get('since_debtors', '1970-01-01')
+    since_tickets = request.args.get('since_tickets', '1970-01-01')
+    since_dicom = request.args.get('since_dicom', '1970-01-01')
+    since_expenses = request.args.get('since_expenses', '1970-01-01')
+    since_deletions = request.args.get('since_deletions', '1970-01-01')
+
+    from core.db import get_db_connection
+    with get_db_connection() as conn:
+        # Products
+        products = conn.execute(
+            "SELECT barcode, name, price, image_url, stock, unit_type, updated_at, updated_by FROM products WHERE updated_at >= ?",
+            (since,)
+        ).fetchall()
+
+        # Sales with items
+        sales_rows = conn.execute(
+            "SELECT id, uuid, date, total, payment_method FROM sales WHERE date >= ? ORDER BY date",
+            (since_sales,)
+        ).fetchall()
+        sales_payload = []
+        for s in sales_rows:
+            items = conn.execute(
+                "SELECT barcode, name, price, quantity, subtotal FROM sale_items WHERE sale_id = ?",
+                (s[0],)
+            ).fetchall()
+            sales_payload.append({
+                "uuid": s[1], "date": s[2], "total": s[3], "payment_method": s[4],
+                "items": [{"barcode": i[0], "name": i[1], "price": i[2], "qty": i[3], "subtotal": i[4]} for i in items]
+            })
+
+        # Debtors
+        debtors = conn.execute(
+            "SELECT uuid, name, contact_info, updated_at, updated_by FROM debtors WHERE updated_at >= ?",
+            (since_debtors,)
+        ).fetchall()
+
+        # Dicom (legacy)
+        dicom_rows = conn.execute(
+            "SELECT uuid, name, amount, notes, image_url, updated_at, updated_by FROM dicom WHERE updated_at >= ?",
+            (since_dicom,)
+        ).fetchall()
+
+        # Debtor tickets with items
+        tickets = conn.execute(
+            "SELECT id, uuid, debtor_id, date, total, amount_paid, status, updated_at, updated_by FROM debtor_tickets WHERE updated_at >= ?",
+            (since_tickets,)
+        ).fetchall()
+        ticket_payload = []
+        for t in tickets:
+            ticket_id, ticket_uuid, debtor_id = t[0], t[1], t[2]
+            debtor_uuid = conn.execute("SELECT uuid FROM debtors WHERE id = ?", (debtor_id,)).fetchone()
+            items = conn.execute(
+                "SELECT barcode, name, price, quantity, subtotal FROM debtor_ticket_items WHERE ticket_id = ?",
+                (ticket_id,)
+            ).fetchall()
+            ticket_payload.append({
+                "uuid": ticket_uuid, "debtor_uuid": debtor_uuid[0] if debtor_uuid else '',
+                "date": t[3], "total": t[4], "amount_paid": t[5], "status": t[6],
+                "updated_at": t[7], "updated_by": t[8],
+                "items": [{"barcode": i[0], "name": i[1], "price": i[2], "qty": i[3], "subtotal": i[4]} for i in items]
+            })
+
+        # Expenses
+        expenses = conn.execute(
+            "SELECT uuid, date, description, amount FROM expenses WHERE date >= ?",
+            (since_expenses,)
+        ).fetchall()
+
+        # Deletions
+        deletions = conn.execute(
+            "SELECT entity_type, entity_uuid, deleted_at FROM sync_deletions WHERE deleted_at >= ?",
+            (since_deletions,)
+        ).fetchall()
+
+    return jsonify({
+        "products": [
+            {"barcode": p[0], "name": p[1], "price": p[2], "image_url": p[3],
+             "stock": p[4], "unit_type": p[5], "updated_at": p[6], "updated_by": p[7]}
+            for p in products
+        ],
+        "sales": sales_payload,
+        "debtors": [
+            {"uuid": d[0], "name": d[1], "contact_info": d[2], "updated_at": d[3], "updated_by": d[4]}
+            for d in debtors
+        ],
+        "dicom": [
+            {"uuid": d[0], "name": d[1], "amount": d[2], "notes": d[3], "image_url": d[4],
+             "updated_at": d[5], "updated_by": d[6]}
+            for d in dicom_rows
+        ],
+        "tickets": ticket_payload,
+        "expenses": [
+            {"uuid": e[0], "date": e[1], "description": e[2], "amount": e[3]}
+            for e in expenses
+        ],
+        "deletions": [
+            {"entity_type": d[0], "entity_uuid": d[1], "deleted_at": d[2]}
+            for d in deletions
+        ]
+    }), 200

core/db.py

@@ -66,6 +66,55 @@ def init_db(db_file):
                          subtotal REAL,
                          FOREIGN KEY(ticket_id) REFERENCES debtor_tickets(id) ON DELETE CASCADE)''')
         
+        conn.execute('''CREATE TABLE IF NOT EXISTS expenses 
+                        (id INTEGER PRIMARY KEY AUTOINCREMENT,
+                         date TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+                         description TEXT NOT NULL,
+                         amount INTEGER NOT NULL)''')
+        
+        conn.execute('''CREATE TABLE IF NOT EXISTS sync_deletions
+                        (id INTEGER PRIMARY KEY AUTOINCREMENT,
+                         entity_type TEXT NOT NULL,
+                         entity_uuid TEXT NOT NULL,
+                         deleted_at TEXT DEFAULT (datetime('now')),
+                         synced_at TEXT)''')
+        
+        # --- MIGRATIONS ---
+        for stmt in [
+            "ALTER TABLE sales ADD COLUMN uuid TEXT",
+            "ALTER TABLE sales ADD COLUMN synced_at TEXT",
+            "ALTER TABLE products ADD COLUMN updated_at TEXT DEFAULT CURRENT_TIMESTAMP",
+            "ALTER TABLE products ADD COLUMN updated_by TEXT",
+            "ALTER TABLE expenses ADD COLUMN uuid TEXT",
+            "ALTER TABLE expenses ADD COLUMN synced_at TEXT",
+            "ALTER TABLE debtors ADD COLUMN uuid TEXT",
+            "ALTER TABLE debtors ADD COLUMN updated_at TEXT DEFAULT CURRENT_TIMESTAMP",
+            "ALTER TABLE debtors ADD COLUMN updated_by TEXT",
+            "ALTER TABLE debtor_tickets ADD COLUMN uuid TEXT",
+            "ALTER TABLE debtor_tickets ADD COLUMN updated_at TEXT DEFAULT CURRENT_TIMESTAMP",
+            "ALTER TABLE debtor_tickets ADD COLUMN updated_by TEXT",
+            "ALTER TABLE dicom ADD COLUMN uuid TEXT",
+            "ALTER TABLE dicom ADD COLUMN updated_at TEXT DEFAULT CURRENT_TIMESTAMP",
+            "ALTER TABLE dicom ADD COLUMN updated_by TEXT",
+        ]:
+            try:
+                conn.execute(stmt)
+            except Exception:
+                pass
+
+        for tbl in ['products', 'debtors', 'debtor_tickets', 'dicom']:
+            conn.execute(f"UPDATE {tbl} SET updated_at = datetime('now') WHERE updated_at IS NULL")
+
+        for idx in [
+            "CREATE UNIQUE INDEX IF NOT EXISTS idx_debtors_uuid ON debtors(uuid)",
+            "CREATE UNIQUE INDEX IF NOT EXISTS idx_dicom_uuid ON dicom(uuid)",
+            "CREATE UNIQUE INDEX IF NOT EXISTS idx_expenses_uuid ON expenses(uuid)",
+        ]:
+            try:
+                conn.execute(idx)
+            except Exception:
+                pass
+
         user = conn.execute('SELECT * FROM users WHERE username = ?', ('admin',)).fetchone()
         if not user:
             from werkzeug.security import generate_password_hash

core/sync.py

@@ -0,0 +1,374 @@
+import threading
+import requests
+from datetime import datetime, timezone
+
+POLL_INTERVAL = 30
+BACKOFF_MULTIPLIER = 2
+MAX_BACKOFF = 120
+
+class SyncManager:
+    def __init__(self, db_file, instance_id, server_url, display_name="Desktop", sync_secret=""):
+        self.db_file = db_file
+        self.instance_id = instance_id
+        self.server_url = server_url.rstrip('/')
+        self.display_name = display_name
+        self._headers = {'X-Sync-Secret': sync_secret} if sync_secret else {}
+        self._stop = threading.Event()
+        self._last_push_at = None
+        self._last_sale_pull = None
+        self._last_debtor_pull = None
+        self._last_ticket_pull = None
+        self._last_dicom_pull = None
+        self._last_expense_pull = None
+        self._last_deletion_pull = None
+
+    def start(self):
+        thread = threading.Thread(target=self._run, daemon=True, name="sync-manager")
+        thread.start()
+
+    def stop(self):
+        self._stop.set()
+
+    def _run(self):
+        backoff = POLL_INTERVAL
+        while not self._stop.wait(backoff):
+            try:
+                if self._ping():
+                    self._push()
+                    self._pull()
+                    backoff = POLL_INTERVAL
+                else:
+                    backoff = min(backoff * BACKOFF_MULTIPLIER, MAX_BACKOFF)
+            except Exception as e:
+                print(f"[Sync] Error: {e}")
+                backoff = min(backoff * BACKOFF_MULTIPLIER, MAX_BACKOFF)
+
+    def _ping(self):
+        try:
+            r = requests.get(f"{self.server_url}/api/ping", headers=self._headers, timeout=5)
+            return r.ok
+        except requests.RequestException:
+            return False
+
+    def _push(self):
+        import sqlite3
+        conn = sqlite3.connect(self.db_file)
+        try:
+            now = datetime.now(timezone.utc).isoformat()
+            cutoff = self._last_push_at or '1970-01-01'
+
+            # Sales (immutable, synced_at IS NULL)
+            sales = conn.execute(
+                "SELECT id, uuid, date, total, payment_method FROM sales WHERE synced_at IS NULL"
+            ).fetchall()
+
+            sale_ids = [s[0] for s in sales]
+            sale_payloads = []
+            for s in sales:
+                items = conn.execute(
+                    "SELECT barcode, name, price, quantity, subtotal FROM sale_items WHERE sale_id = ?",
+                    (s[0],)
+                ).fetchall()
+                sale_payloads.append({
+                    "uuid": s[1], "date": s[2], "total": s[3], "payment_method": s[4],
+                    "items": [{"barcode": i[0], "name": i[1], "price": i[2], "qty": i[3], "subtotal": i[4]} for i in items]
+                })
+
+            # Products (mutable, by updated_at)
+            products = conn.execute(
+                "SELECT barcode, name, price, image_url, stock, unit_type, updated_at FROM products WHERE updated_by = ? AND updated_at >= ?",
+                (self.instance_id, cutoff)
+            ).fetchall()
+
+            # Debtors (mutable)
+            debtors = conn.execute(
+                "SELECT uuid, name, contact_info, updated_at FROM debtors WHERE updated_by = ? AND updated_at >= ?",
+                (self.instance_id, cutoff)
+            ).fetchall()
+
+            # Dicom legacy (mutable)
+            dicom_rows = conn.execute(
+                "SELECT uuid, name, amount, notes, image_url, updated_at FROM dicom WHERE updated_by = ? AND updated_at >= ?",
+                (self.instance_id, cutoff)
+            ).fetchall()
+
+            # Debtor tickets with items (mutable)
+            tickets_raw = conn.execute(
+                "SELECT id, uuid, debtor_id, date, total, amount_paid, status, updated_at FROM debtor_tickets WHERE updated_by = ? AND updated_at >= ?",
+                (self.instance_id, cutoff)
+            ).fetchall()
+            ticket_payloads = []
+            for t in tickets_raw:
+                debtor_uuid = conn.execute("SELECT uuid FROM debtors WHERE id = ?", (t[2],)).fetchone()
+                items = conn.execute(
+                    "SELECT barcode, name, price, quantity, subtotal FROM debtor_ticket_items WHERE ticket_id = ?",
+                    (t[0],)
+                ).fetchall()
+                ticket_payloads.append({
+                    "uuid": t[1], "debtor_uuid": debtor_uuid[0] if debtor_uuid else '',
+                    "date": t[3], "total": t[4], "amount_paid": t[5], "status": t[6],
+                    "updated_at": t[7],
+                    "items": [{"barcode": i[0], "name": i[1], "price": i[2], "qty": i[3], "subtotal": i[4]} for i in items]
+                })
+
+            # Expenses (immutable, synced_at IS NULL)
+            expenses = conn.execute(
+                "SELECT id, uuid, date, description, amount FROM expenses WHERE synced_at IS NULL"
+            ).fetchall()
+            expense_ids = [e[0] for e in expenses]
+
+            # Deletions (immutable, synced_at IS NULL)
+            deletions = conn.execute(
+                "SELECT entity_type, entity_uuid FROM sync_deletions WHERE synced_at IS NULL"
+            ).fetchall()
+
+            payload = {
+                "instance_id": self.instance_id,
+                "display_name": self.display_name,
+                "synced_at": now,
+                "sales": sale_payloads,
+                "products": [
+                    {"barcode": p[0], "name": p[1], "price": p[2], "image_url": p[3], "stock": p[4], "unit_type": p[5], "updated_at": p[6]}
+                    for p in products
+                ],
+                "debtors": [
+                    {"uuid": d[0], "name": d[1], "contact_info": d[2], "updated_at": d[3], "updated_by": self.instance_id}
+                    for d in debtors
+                ],
+                "dicom": [
+                    {"uuid": d[0], "name": d[1], "amount": d[2], "notes": d[3], "image_url": d[4], "updated_at": d[5], "updated_by": self.instance_id}
+                    for d in dicom_rows
+                ],
+                "tickets": ticket_payloads,
+                "expenses": [
+                    {"uuid": e[1], "date": e[2], "description": e[3], "amount": e[4]}
+                    for e in expenses
+                ],
+                "deletions": [
+                    {"entity_type": d[0], "entity_uuid": d[1]}
+                    for d in deletions
+                ],
+            }
+
+            has_data = any([
+                sale_payloads, products, debtors, dicom_rows,
+                ticket_payloads, expenses, deletions
+            ])
+
+            if has_data:
+                r = requests.post(f"{self.server_url}/api/sync/push", json=payload, headers=self._headers, timeout=15)
+                if r.ok:
+                    if sale_ids:
+                        conn.executemany(
+                            "UPDATE sales SET synced_at = ? WHERE id = ?",
+                            [(now, sid) for sid in sale_ids]
+                        )
+                    if expense_ids:
+                        conn.executemany(
+                            "UPDATE expenses SET synced_at = ? WHERE id = ?",
+                            [(now, eid) for eid in expense_ids]
+                        )
+                    if deletions:
+                        conn.executemany(
+                            "UPDATE sync_deletions SET synced_at = ? WHERE entity_type = ? AND entity_uuid = ?",
+                            [(now, d[0], d[1]) for d in deletions]
+                        )
+                    conn.commit()
+                    self._last_push_at = now
+                    print(f"[Sync] Pushed {len(sale_payloads)} sales, {len(products)} products, {len(debtors)} debtors, {len(dicom_rows)} dicom, {len(ticket_payloads)} tickets, {len(expenses)} expenses, {len(deletions)} deletions")
+                else:
+                    print(f"[Sync] Push failed: HTTP {r.status_code} {r.text[:200]}")
+            else:
+                print(f"[Sync] Push: nothing to push")
+        finally:
+            conn.close()
+
+    def _pull(self):
+        import sqlite3
+        conn = sqlite3.connect(self.db_file)
+        try:
+            last_pull = conn.execute(
+                "SELECT COALESCE(MAX(updated_at), '1970-01-01') FROM products WHERE updated_by != ?",
+                (self.instance_id,)
+            ).fetchone()[0]
+
+            params = {
+                "since": last_pull,
+                "since_sales": self._last_sale_pull or '1970-01-01',
+                "since_debtors": self._last_debtor_pull or '1970-01-01',
+                "since_tickets": self._last_ticket_pull or '1970-01-01',
+                "since_dicom": self._last_dicom_pull or '1970-01-01',
+                "since_expenses": self._last_expense_pull or '1970-01-01',
+                "since_deletions": self._last_deletion_pull or '1970-01-01',
+                "instance_id": self.instance_id,
+            }
+            print(f"[Sync] Pull: {params}")
+
+            r = requests.get(f"{self.server_url}/api/sync/pull", params=params, headers=self._headers, timeout=15)
+            if not r.ok:
+                print(f"[Sync] Pull request failed: HTTP {r.status_code} {r.text[:200]}")
+                return
+
+            data = r.json()
+            now = datetime.now(timezone.utc).isoformat()
+
+            # Apply deletions first
+            for d in data.get("deletions", []):
+                et, eu = d["entity_type"], d["entity_uuid"]
+                if et == 'debtor':
+                    conn.execute("DELETE FROM debtors WHERE uuid = ?", (eu,))
+                elif et == 'ticket':
+                    row = conn.execute("SELECT id FROM debtor_tickets WHERE uuid = ?", (eu,)).fetchone()
+                    if row:
+                        conn.execute("DELETE FROM debtor_ticket_items WHERE ticket_id = ?", (row[0],))
+                    conn.execute("DELETE FROM debtor_tickets WHERE uuid = ?", (eu,))
+                elif et == 'dicom':
+                    conn.execute("DELETE FROM dicom WHERE uuid = ?", (eu,))
+                elif et == 'expense':
+                    conn.execute("DELETE FROM expenses WHERE uuid = ?", (eu,))
+                elif et == 'sale':
+                    row = conn.execute("SELECT id FROM sales WHERE uuid = ?", (eu,)).fetchone()
+                    if row:
+                        conn.execute("DELETE FROM sale_items WHERE sale_id = ?", (row[0],))
+                    conn.execute("DELETE FROM sales WHERE uuid = ?", (eu,))
+                elif et == 'product':
+                    conn.execute("DELETE FROM products WHERE barcode = ?", (eu,))
+
+            # Debtors (upsert by uuid)
+            pulled_debtors = 0
+            for d in data.get("debtors", []):
+                conn.execute('''INSERT INTO debtors (uuid, name, contact_info, updated_at, updated_by)
+                                VALUES (?,?,?,?,?)
+                                ON CONFLICT(uuid) DO UPDATE SET
+                                name=excluded.name, contact_info=excluded.contact_info,
+                                updated_at=excluded.updated_at, updated_by=excluded.updated_by''',
+                             (d["uuid"], d["name"], d.get("contact_info", ""),
+                              d.get("updated_at", now), d.get("updated_by", "")))
+                pulled_debtors += 1
+
+            # Dicom (upsert by uuid)
+            pulled_dicom = 0
+            for d in data.get("dicom", []):
+                conn.execute('''INSERT INTO dicom (uuid, name, amount, notes, image_url, updated_at, updated_by)
+                                VALUES (?,?,?,?,?,?,?)
+                                ON CONFLICT(uuid) DO UPDATE SET
+                                name=excluded.name, amount=excluded.amount,
+                                notes=excluded.notes, image_url=excluded.image_url,
+                                updated_at=excluded.updated_at, updated_by=excluded.updated_by''',
+                             (d["uuid"], d["name"], d.get("amount", 0), d.get("notes", ""),
+                              d.get("image_url", ""), d.get("updated_at", now), d.get("updated_by", "")))
+                pulled_dicom += 1
+
+            # Debtor tickets (insert with items, dedup by uuid)
+            pulled_tickets = 0
+            for t in data.get("tickets", []):
+                existing = conn.execute(
+                    "SELECT id FROM debtor_tickets WHERE uuid = ?", (t["uuid"],)
+                ).fetchone()
+                if existing:
+                    continue
+                debtor_row = conn.execute(
+                    "SELECT id FROM debtors WHERE uuid = ?", (t["debtor_uuid"],)
+                ).fetchone()
+                if not debtor_row:
+                    continue
+                cur = conn.execute(
+                    "INSERT INTO debtor_tickets (uuid, debtor_id, date, total, amount_paid, status, updated_at, updated_by) VALUES (?,?,?,?,?,?,?,?)",
+                    (t["uuid"], debtor_row[0], t.get("date", now), t["total"],
+                     t.get("amount_paid", 0), t.get("status", "unpaid"),
+                     t.get("updated_at", now), t.get("updated_by", ""))
+                )
+                for item in t.get("items", []):
+                    conn.execute(
+                        "INSERT INTO debtor_ticket_items (ticket_id, barcode, name, price, quantity, subtotal) VALUES (?,?,?,?,?,?)",
+                        (cur.lastrowid, item["barcode"], item["name"], item.get("price", 0),
+                         item.get("qty", 1), item.get("subtotal", 0))
+                    )
+                pulled_tickets += 1
+
+            # Expenses (insert, dedup by uuid)
+            pulled_expenses = 0
+            for e in data.get("expenses", []):
+                existing = conn.execute(
+                    "SELECT id FROM expenses WHERE uuid = ?", (e["uuid"],)
+                ).fetchone()
+                if existing:
+                    continue
+                conn.execute(
+                    "INSERT INTO expenses (uuid, date, description, amount, synced_at) VALUES (?,?,?,?,?)",
+                    (e["uuid"], e.get("date", now), e["description"], e["amount"], now)
+                )
+                pulled_expenses += 1
+
+            # Products (upsert by barcode, skip if local is newer)
+            pulled_prods = 0
+            for p in data.get("products", []):
+                existing = conn.execute(
+                    "SELECT updated_at FROM products WHERE barcode = ?", (p["barcode"],)
+                ).fetchone()
+                if existing and existing[0] >= p["updated_at"]:
+                    continue
+                conn.execute('''INSERT INTO products (barcode, name, price, image_url, stock, unit_type, updated_at, updated_by)
+                                VALUES (?,?,?,?,?,?,?,?)
+                                ON CONFLICT(barcode) DO UPDATE SET
+                                name=excluded.name, price=excluded.price,
+                                image_url=excluded.image_url, stock=excluded.stock,
+                                unit_type=excluded.unit_type, updated_at=excluded.updated_at,
+                                updated_by=excluded.updated_by''',
+                             (p["barcode"], p["name"], p["price"], p.get("image_url"),
+                              p.get("stock", 0), p.get("unit_type", "unit"),
+                              p["updated_at"], p.get("updated_by", "")))
+                pulled_prods += 1
+
+            # Sales (insert with items, dedup by uuid)
+            pulled_sales = 0
+            for sale in data.get("sales", []):
+                existing = conn.execute(
+                    "SELECT id FROM sales WHERE uuid = ?", (sale["uuid"],)
+                ).fetchone()
+                if existing:
+                    continue
+                cur = conn.execute(
+                    "INSERT INTO sales (date, total, payment_method, uuid, synced_at) VALUES (?, ?, ?, ?, ?)",
+                    (sale.get("date", now), sale["total"], sale.get("payment_method", "efectivo"),
+                     sale["uuid"], now)
+                )
+                for item in sale.get("items", []):
+                    conn.execute(
+                        "INSERT INTO sale_items (sale_id, barcode, name, price, quantity, subtotal) VALUES (?, ?, ?, ?, ?, ?)",
+                        (cur.lastrowid, item["barcode"], item["name"], item.get("price", 0),
+                         item.get("qty", 1), item.get("subtotal", 0))
+                    )
+                pulled_sales += 1
+
+            conn.commit()
+
+            # Update pull timestamps
+            all_sales = data.get("sales", [])
+            all_debtors = data.get("debtors", [])
+            all_tickets = data.get("tickets", [])
+            all_dicom = data.get("dicom", [])
+            all_expenses = data.get("expenses", [])
+            all_deletions = data.get("deletions", [])
+
+            if all_sales:
+                self._last_sale_pull = max(s["date"] for s in all_sales)
+            if all_debtors:
+                self._last_debtor_pull = max(d["updated_at"] for d in all_debtors)
+            if all_tickets:
+                self._last_ticket_pull = max(t["updated_at"] for t in all_tickets)
+            if all_dicom:
+                self._last_dicom_pull = max(d["updated_at"] for d in all_dicom)
+            if all_expenses:
+                self._last_expense_pull = max(e["date"] for e in all_expenses)
+            if all_deletions:
+                self._last_deletion_pull = max(d["deleted_at"] for d in all_deletions)
+
+            if pulled_prods or pulled_sales or pulled_debtors or pulled_dicom or pulled_tickets or pulled_expenses:
+                print(f"[Sync] Pulled {pulled_prods} products, {pulled_sales} sales, {pulled_debtors} debtors, {pulled_dicom} dicom, {pulled_tickets} tickets, {pulled_expenses} expenses")
+            else:
+                print(f"[Sync] Pull: nothing new to apply")
+        except Exception as e:
+            print(f"[Sync] Pull error: {e}")
+        finally:
+            conn.close()

db_client/instance.json

@@ -0,0 +1,8 @@
+{
+  "instance_id": "f35f82c4-2cc7-4a29-bce7-9c8b0d451a0e",
+  "display_name": "Caja Principal",
+  "mode": "desktop",
+  "server_url": "http://192.168.1.87:5000",
+  "last_sync_at": null,
+  "sync_secret": "secetkey"
+}

db_server/instance.json

@@ -0,0 +1,7 @@
+{
+  "instance_id": "fc0f4545-53a4-4a03-a9fb-74d3f9adfe94",
+  "display_name": "Caja Principal",
+  "mode": "server",
+  "server_url": "",
+  "last_sync_at": null
+}

docker-compose.yml

@@ -0,0 +1,29 @@
+services:
+  sekipos-server:
+    image: sekipos:latest
+    container_name: sekipos-server
+    pull_policy: never
+    ports:
+      - "5000:5000"
+    environment:
+      - SEKIPOS_MODE=server
+      - SEKIPOS_SYNC_SECRET=${SEKIPOS_SYNC_SECRET}
+      - PYTHONUNBUFFERED=1
+    volumes:
+      - sekipos-db:/app/db
+      - sekipos-cache:/app/static/cache
+    restart: unless-stopped
+
+volumes:
+  sekipos-db:
+    driver: local
+    driver_opts:
+      type: none
+      o: bind
+      device: /home/sekidesu/dockerVolumes/sekipos-db
+  sekipos-cache:
+    driver: local
+    driver_opts:
+      type: none
+      o: bind
+      device: /home/sekidesu/dockerVolumes/sekipos-cache

templates/macros/modals.html

@@ -324,6 +324,31 @@
                         <option value="xlarge">Extra Grande</option>
                     </select>
                 </div>
+
+                <hr>
+                <h6 class="text-muted text-uppercase small mb-2"><i class="bi bi-cloud-arrow-up me-1"></i>Sincronización</h6>
+                <div class="mb-2">
+                    <label class="form-label text-muted small mb-1">Servidor (URL)</label>
+                    <input type="text" id="setting-server-url" class="form-control" placeholder="Ej: http://192.168.1.100:5000" autocomplete="off">
+                </div>
+                <div class="mb-2">
+                    <label class="form-label text-muted small mb-1">Nombre de esta caja</label>
+                    <input type="text" id="setting-display-name" class="form-control" placeholder="Ej: Caja Principal" autocomplete="off">
+                </div>
+                <div class="mb-2">
+                    <label class="form-label text-muted small mb-1">Clave de sincronización</label>
+                    <input type="password" id="setting-sync-secret" class="form-control" placeholder="Ingrese la clave del servidor" autocomplete="off">
+                </div>
+                <div class="d-flex justify-content-between align-items-center mb-2 p-2 rounded" style="background: var(--input-bg);">
+                    <div>
+                        <span id="sync-mode-badge" class="badge bg-secondary me-1">---</span>
+                        <small class="text-muted d-block mt-1" id="sync-status-text">Estado: <span id="sync-status-label">No configurado</span></small>
+                        <small class="text-muted d-block" id="sync-instance-id"></small>
+                    </div>
+                    <button class="btn btn-sm btn-outline-secondary" onclick="syncNow()" id="btn-sync-now" title="Sincronizar ahora">
+                        <i class="bi bi-arrow-clockwise"></i>
+                    </button>
+                </div>
             </div>
             <div class="modal-footer d-flex">
                 <button class="btn btn-secondary flex-grow-1" data-bs-dismiss="modal">Cancelar</button>
@@ -338,6 +363,48 @@
         document.getElementById('setting-sii-fields').classList.toggle('d-none', !isChecked);
     }
 
+    async function loadSyncConfig() {
+        try {
+            const res = await fetch('/api/instance/config');
+            const data = await res.json();
+            const isServer = data.mode === 'server';
+            const badge = document.getElementById('sync-mode-badge');
+            badge.textContent = isServer ? 'Servidor' : 'Cliente';
+            badge.className = 'badge ' + (isServer ? 'bg-success' : 'bg-primary') + ' me-1';
+
+            const urlInput = document.getElementById('setting-server-url');
+            const nameInput = document.getElementById('setting-display-name');
+            const syncBtn = document.getElementById('btn-sync-now');
+
+            urlInput.value = data.server_url || '';
+            nameInput.value = data.display_name || '';
+            document.getElementById('setting-sync-secret').value = data.sync_secret || '';
+            urlInput.disabled = isServer;
+            syncBtn.style.display = isServer ? 'none' : '';
+
+            document.getElementById('sync-instance-id').textContent = 'ID: ' + (data.instance_id || '').slice(0, 8) + '...';
+            document.getElementById('sync-status-label').textContent = isServer ? 'Activo' : (data.server_url ? 'Conectado' : 'No configurado');
+        } catch (e) {
+            document.getElementById('sync-status-label').textContent = 'Error al cargar';
+        }
+    }
+
+    async function syncNow() {
+        const btn = document.getElementById('btn-sync-now');
+        btn.disabled = true;
+        btn.innerHTML = '<span class="spinner-border spinner-border-sm"></span>';
+        document.getElementById('sync-status-label').textContent = 'Sincronizando...';
+        try {
+            const res = await fetch('/api/sync/trigger', { method: 'POST' });
+            const data = await res.json();
+            document.getElementById('sync-status-label').textContent = data.status === 'ok' ? 'Sincronizado' : 'Error';
+        } catch (e) {
+            document.getElementById('sync-status-label').textContent = 'Error de conexión';
+        }
+        btn.disabled = false;
+        btn.innerHTML = '<i class="bi bi-arrow-clockwise"></i>';
+    }
+
     document.addEventListener('DOMContentLoaded', () => {
         const modalEl = document.getElementById('settingsModal');
         if (modalEl) {
@@ -357,12 +424,13 @@
                 document.getElementById('setting-address').value = localStorage.getItem('seki_address') || '';
 
                 toggleSiiFields();
+                loadSyncConfig();
             });
         }
     });
 
 
-    function savePosSettings() {
+    async function savePosSettings() {
         const bizName = document.getElementById('setting-biz-name').value.trim() || 'SekiPOS';
         const autoPrint = document.getElementById('setting-auto-print').checked;
         const askDetails = document.getElementById('setting-ask-order-details').checked;
@@ -370,6 +438,9 @@
         const foodMode = document.getElementById('setting-food-mode').checked;
         const lastScanned = document.getElementById('setting-last-scanned').checked;
         const comandaSize = document.getElementById('setting-comanda-size').value;
+        const serverUrl = document.getElementById('setting-server-url').value.trim();
+        const displayName = document.getElementById('setting-display-name').value.trim() || 'Caja Principal';
+        const syncSecret = document.getElementById('setting-sync-secret').value.trim();
         localStorage.setItem('seki_biz_name', bizName);
         localStorage.setItem('seki_auto_print', autoPrint);
         localStorage.setItem('seki_ask_order_details', askDetails);
@@ -379,6 +450,16 @@
         localStorage.setItem('seki_last_scanned', lastScanned);
         localStorage.setItem('seki_comanda_size', comandaSize);
 
+        try {
+            await fetch('/api/instance/config', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ server_url: serverUrl, display_name: displayName, sync_secret: syncSecret })
+            });
+        } catch (e) {
+            console.error('Failed to save sync config', e);
+        }
+        
         if (showSii) {
             localStorage.setItem('seki_rut', document.getElementById('setting-rut').value.trim());
             localStorage.setItem('seki_giro', document.getElementById('setting-giro').value.trim());