Phase 1: scaffold local backend — models, schemas, routers, printer service, Docker

local_backend/services/printer_service.py

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+"""
+ESC/POS printer service — Jolimark TP850UE confirmed configuration.
+
+Key findings from printer testing:
+- Code page n=29 (CP737) is the only working Greek code page on this model.
+- All Greek text MUST be sent as raw CP737 bytes via p._raw() — never p.text().
+- Set the code page immediately after connecting, before any output.
+- 80mm paper = 48 chars wide at standard font. Double-height keeps 48-char width.
+"""
+import json
+import logging
+import socket
+import datetime
+from typing import Tuple, List
+
+from escpos.printer import Network
+from sqlalchemy.orm import Session
+
+from database import SessionLocal
+from models.order import Order, OrderItem, PrintLog
+from models.printer import Printer
+from models.product import Product
+
+logger = logging.getLogger(__name__)
+
+LINE_WIDTH = 48
+PRINTER_TIMEOUT = 5
+
+
+# ── Low-level helpers ────────────────────────────────────────────────────────
+
+def _get_printer(ip: str, port: int) -> Network:
+    p = Network(ip, port, timeout=PRINTER_TIMEOUT)
+    p._raw(b'\x1b\x40')       # ESC @ — reset printer
+    p._raw(b'\x1b\x74\x1d')   # ESC t 29 — select CP737 (Greek) — confirmed n=29
+    return p
+
+
+def _gr(text: str) -> bytes:
+    """Encode text to CP737 bytes. Replaces unknown chars instead of crashing."""
+    return text.encode('cp737', errors='replace')
+
+
+def _raw_text(p: Network, text: str):
+    """Send text as raw CP737 bytes — the ONLY safe way to print Greek."""
+    p._raw(_gr(text))
+
+
+def _divider(p: Network):
+    p._raw(b'\x1b\x61\x00')
+    p._raw(_gr("-" * LINE_WIDTH + "\n"))
+
+
+def _item_line(name: str, qty: int) -> str:
+    """Build a dot-leader line: 'Club Sandwich . . . . 1' at 48 chars."""
+    qty_str = str(qty)
+    gap = LINE_WIDTH - len(name) - len(qty_str)
+    if gap < 3:
+        return f"{name} {qty_str}"
+    dots = (". " * ((gap // 2) + 1))[:gap]
+    return f"{name}{dots}{qty_str}"
+
+
+def check_printer(ip: str, port: int) -> bool:
+    """Quick TCP connect check — no data sent."""
+    try:
+        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        s.settimeout(2)
+        s.connect((ip, port))
+        s.close()
+        return True
+    except OSError:
+        return False
+
+
+def send_test_print(ip: str, port: int, name: str) -> Tuple[bool, str]:
+    try:
+        p = _get_printer(ip, port)
+        p._raw(b'\x1b\x61\x01')
+        p._raw(b'\x1b\x21\x30')
+        _raw_text(p, f"TEST — {name}\n")
+        p._raw(b'\x1b\x21\x00')
+        now = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
+        _raw_text(p, f"{now}\n")
+        p._raw(b'\n\n\n')
+        p.cut()
+        p.close()
+        return True, ""
+    except Exception as e:
+        logger.error("Test print failed for %s:%s — %s", ip, port, e)
+        return False, str(e)
+
+
+# ── Receipt formatting ───────────────────────────────────────────────────────
+
+def _print_kitchen_ticket(p: Network, order: Order, items: List[OrderItem], db: Session):
+    # Header
+    p._raw(b'\x1b\x61\x01')
+    p._raw(b'\x1b\x21\x38')   # bold + double height + double width
+    _raw_text(p, f"Παραγγελια #{order.id}\n")
+    p._raw(b'\x1b\x21\x00')
+    _divider(p)
+
+    # Meta
+    p._raw(b'\x1b\x61\x00')
+    p._raw(b'\x1b\x21\x10')   # double height only — keeps 48-char width
+    now = datetime.datetime.now().strftime("%Y-%m-%d  %H:%M")
+    _raw_text(p, f"Date:   {now}\n")
+    _raw_text(p, f"Table:  {order.table_id}\n")
+    _raw_text(p, f"Waiter: {order.opened_by}\n")
+    p._raw(b'\x1b\x21\x00')
+    _divider(p)
+
+    # Items
+    for item in items:
+        product = db.query(Product).filter(Product.id == item.product_id).first()
+        name = product.name if product else f"Product #{item.product_id}"
+
+        p._raw(b'\x1b\x21\x10')
+        p._raw(b'\x1b\x45\x01')   # bold on
+        _raw_text(p, _item_line(name, item.quantity) + "\n")
+        p._raw(b'\x1b\x45\x00')   # bold off
+
+        if item.removed_ingredients:
+            try:
+                removed_ids = json.loads(item.removed_ingredients)
+                if removed_ids:
+                    _raw_text(p, f"  - χωρις: {', '.join(str(i) for i in removed_ids)}\n")
+            except (json.JSONDecodeError, TypeError):
+                pass
+
+        if item.selected_options:
+            try:
+                option_ids = json.loads(item.selected_options)
+                if option_ids:
+                    _raw_text(p, f"  + επιλογες: {', '.join(str(i) for i in option_ids)}\n")
+            except (json.JSONDecodeError, TypeError):
+                pass
+
+        if item.notes:
+            _raw_text(p, f"  (i) {item.notes}\n")
+
+        p._raw(b'\x1b\x21\x00')
+
+    _divider(p)
+
+    if order.notes:
+        p._raw(b'\x1b\x21\x30')
+        _raw_text(p, "Σημειωσεις:\n")
+        p._raw(b'\x1b\x21\x10')
+        _raw_text(p, f"{order.notes}\n")
+        p._raw(b'\x1b\x21\x00')
+        _divider(p)
+
+    p._raw(b'\x1b\x61\x01')
+    p._raw(b'\x1b\x21\x30')
+    _raw_text(p, "Τελος Παραγγελιας\n")
+    p._raw(b'\x1b\x21\x00')
+    p._raw(b'\n\n\n')
+    p.cut()
+
+
+# ── Routing logic ────────────────────────────────────────────────────────────
+
+def route_and_print(order_id: int, item_ids: List[int]):
+    """
+    Background task: group items by printer zone, send to each printer.
+    Printer failures are logged but never raise — order is already saved.
+    """
+    db: Session = SessionLocal()
+    try:
+        order = db.query(Order).filter(Order.id == order_id).first()
+        if not order:
+            logger.error("route_and_print: order %s not found", order_id)
+            return
+
+        items = db.query(OrderItem).filter(OrderItem.id.in_(item_ids)).all()
+
+        # Group items by printer zone
+        zone_map: dict[int, List[OrderItem]] = {}
+        unzoned: List[OrderItem] = []
+        for item in items:
+            product = db.query(Product).filter(Product.id == item.product_id).first()
+            if product and product.printer_zone_id:
+                zone_map.setdefault(product.printer_zone_id, []).append(item)
+            else:
+                unzoned.append(item)
+
+        if unzoned:
+            logger.warning("order %s has %d item(s) with no printer zone — skipped", order_id, len(unzoned))
+
+        for printer_id, zone_items in zone_map.items():
+            printer = db.query(Printer).filter(Printer.id == printer_id, Printer.is_active == True).first()
+            if not printer:
+                logger.warning("Printer %s not found or inactive", printer_id)
+                continue
+
+            success = False
+            error_msg = None
+            try:
+                p = _get_printer(printer.ip_address, printer.port)
+                _print_kitchen_ticket(p, order, zone_items, db)
+                p.close()
+                success = True
+                # Mark items as printed
+                for item in zone_items:
+                    item.printed = True
+                db.commit()
+            except Exception as e:
+                error_msg = str(e)
+                logger.error("Print failed for printer %s (%s:%s): %s", printer.name, printer.ip_address, printer.port, e)
+
+            log = PrintLog(
+                order_id=order_id,
+                printer_id=printer_id,
+                item_ids=json.dumps([i.id for i in zone_items]),
+                success=success,
+                error_message=error_msg,
+            )
+            db.add(log)
+            db.commit()
+
+    except Exception as e:
+        logger.exception("Unexpected error in route_and_print for order %s: %s", order_id, e)
+    finally:
+        db.close()