"""
Phase 2 — Step 2.3: crm_products  (Firestore → Postgres)

Reads the 'crm_products' Firestore collection. The Firestore schema is richer
than the Postgres target (has costs, stock, name_en, etc.) — we extract only
what the Postgres ORM model covers. The rest stays in Firestore until the
service is fully cut over.

Run on VPS:
    docker compose exec backend python -m migration.migrate_crm_products
"""

import asyncio
import sys
from datetime import datetime, timezone

from sqlalchemy.dialects.postgresql import insert as pg_insert

from crm.orm import CrmProduct
from shared.firebase import init_firebase, get_db as get_firestore
from migration.utils import AsyncPgSession, parse_dt, log_run, pg_count

SCRIPT = "migrate_crm_products"
COLLECTION = "crm_products"

_LEGACY_STATUS_MAP = {
    "active": True,
    "discontinued": False,
    "planned": True,
}


def _now_utc() -> datetime:
    return datetime.now(timezone.utc)


async def run() -> None:
    init_firebase()
    fs = get_firestore()
    if fs is None:
        print("ERROR: Firebase not initialised.", file=sys.stderr)
        sys.exit(1)

    docs = list(fs.collection(COLLECTION).stream())
    source_count = len(docs)
    print(f"Source (Firestore): {source_count} crm_products documents")

    if source_count == 0:
        print("Nothing to migrate.")
        await log_run(SCRIPT, 0, 0, notes="source empty")
        return

    records = []
    for doc in docs:
        d = doc.to_dict()

        # is_active: prefer 'active' bool field, fall back to 'status' string
        if "active" in d:
            is_active = bool(d["active"])
        else:
            is_active = _LEGACY_STATUS_MAP.get(d.get("status", "active"), True)

        # unit_cost: Firestore uses 'price'
        unit_cost = d.get("unit_cost") or d.get("price") or 0

        created_at = parse_dt(d.get("created_at")) or _now_utc()
        updated_at = parse_dt(d.get("updated_at")) or _now_utc()

        records.append({
            "id":           doc.id,
            "firestore_id": doc.id,
            "name":         d.get("name") or d.get("name_en") or "",
            "sku":          d.get("sku"),
            "category":     d.get("category"),
            "description":  d.get("description") or d.get("description_en"),
            "unit_cost":    unit_cost,
            "currency":     d.get("currency") or "EUR",
            "unit_type":    d.get("unit_type") or "pcs",
            "is_active":    is_active,
            "created_at":   created_at,
            "updated_at":   updated_at,
        })

    async with AsyncPgSession() as session:
        async with session.begin():
            stmt = pg_insert(CrmProduct).values(records)
            stmt = stmt.on_conflict_do_nothing(index_elements=["id"])
            await session.execute(stmt)
            dest_count = await pg_count(session, "crm_products")

    if dest_count < source_count:
        msg = f"Count mismatch: source={source_count}  postgres={dest_count}"
        print(f"ERROR: {msg}", file=sys.stderr)
        await log_run(SCRIPT, source_count, dest_count, success=False, notes=msg)
        sys.exit(1)

    print(f"Postgres: {dest_count} rows ✓")
    await log_run(SCRIPT, source_count, dest_count)


if __name__ == "__main__":
    asyncio.run(run())