"""Celery tasks: sync_inventory (every 5min), sync_tracking, recalc_prices.

Broker/backend from REDIS_URL (default redis://redis:6379/0 inside Docker).
"""
import os
from datetime import datetime, timedelta, timezone

from celery import Celery

REDIS_URL = os.getenv("REDIS_URL", "redis://redis:6379/0")

celery_app = Celery("polaris", broker=REDIS_URL, backend=REDIS_URL)
celery_app.conf.timezone = "UTC"
celery_app.conf.beat_schedule = {
    "sync-inventory-every-5m": {
        "task": "app.tasks.sync_inventory",
        "schedule": 300.0,
    },
    "sync-tracking-every-5m": {
        "task": "app.tasks.sync_tracking",
        "schedule": 300.0,
    },
    "recalc-prices-hourly": {
        "task": "app.tasks.recalc_prices",
        "schedule": 3600.0,
    },
}


@celery_app.task(name="app.tasks.sync_inventory")
def sync_inventory(supplier_id=None):
    from app.database import SessionLocal
    from app.engines.inventory import sync_inventory as _sync

    db = SessionLocal()
    try:
        return _sync(db)
    finally:
        db.close()


@celery_app.task(name="app.tasks.sync_tracking")
def sync_tracking():
    """MVP tracking progression:
    - confirmed + tracking   -> shipped
    - shipped, older than 7d -> delivered
    """
    from app.database import SessionLocal
    from app.models import AuditLog, Order

    db = SessionLocal()
    try:
        stats = {"checked": 0, "shipped": 0, "delivered": 0}
        now = datetime.now(timezone.utc)
        for order in db.query(Order).filter(
            Order.status.in_(["confirmed", "shipped"])
        ).all():
            stats["checked"] += 1
            if order.status == "confirmed" and order.tracking:
                order.status = "shipped"
                stats["shipped"] += 1
                db.add(
                    AuditLog(
                        actor="tasks.sync_tracking",
                        action="order_shipped",
                        entity="order",
                        entity_id=order.order_number,
                        detail={"tracking": order.tracking},
                    )
                )
            elif order.status == "shipped":
                age = now - (order.updated_at or now)
                if age > timedelta(days=7):
                    order.status = "delivered"
                    stats["delivered"] += 1
                    db.add(
                        AuditLog(
                            actor="tasks.sync_tracking",
                            action="order_delivered",
                            entity="order",
                            entity_id=order.order_number,
                        )
                    )
        db.commit()
        return stats
    finally:
        db.close()


@celery_app.task(name="app.tasks.recalc_prices")
def recalc_prices():
    from app.database import SessionLocal
    from app.engines.pricing import calculate_price
    from app.models import PriceHistory, Product

    db = SessionLocal()
    try:
        updated = 0
        for product in db.query(Product).filter(Product.status != "sold").all():
            quote = calculate_price(db, product.cost)
            if quote is None:
                continue  # no active rule -> leave alone, never publish invalid
            product.retail_price = quote["retail"]
            if product.min_price is None or quote["retail"] < product.min_price:
                product.min_price = quote["retail"]
            if product.max_price is None or quote["retail"] > product.max_price:
                product.max_price = quote["retail"]
            db.add(PriceHistory(product_id=product.id, price=quote["retail"], reason="auto"))
            updated += 1
        db.commit()
        return {"recalculated": updated}
    finally:
        db.close()