"""
Migration Script: Separate Databases for Admin & Commerce
=========================================================
Migrates collections from 'sahihislam' into:
- 'sahihislam_admin' (Control Plane & Telemetry)
- 'sahihislam_commerce' (Ads, Wallets & Financial Ledger)

Leaves intact in 'sahihislam':
- 'hadiths' (with vector search index)
- 'quran'
- 'quran_verses' (with vector search index)
- 'vector_memory' (with vector search index)
- 'users', 'chats', 'masjids', 'daily_progress', 'qaza_tracker', 'tasbeeh_records'
"""

import asyncio
import os
import sys

sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
from dotenv import load_dotenv

load_dotenv(os.path.abspath(os.path.join(os.path.dirname(__file__), "..", ".env")))
from motor.motor_asyncio import AsyncIOMotorClient

MONGO_URI = os.getenv("MONGO_URI")
if not MONGO_URI:
    print("❌ MONGO_URI missing!")
    sys.exit(1)

ADMIN_COLLECTIONS = [
    "system_settings",
    "platform_settings",
    "sendads",
    "audit_logs",
    "client_errors",
    "pending_approvals",
    "mufti_requests",
    "masjid_reports",
    "email_change_requests",
    "email_change_logs",
]

COMMERCE_COLLECTIONS = [
    "ads",
    "ad_analytics",
    "products",
    "orders",
    "wallets",
    "transactions",
    "payouts",
    "shop_settings",
    "subscriptions",
]


async def migrate_collection(src_db, dest_db, col_name):
    src_col = src_db[col_name]
    dest_col = dest_db[col_name]

    count = await src_col.count_documents({})
    if count == 0:
        print(f"   • {col_name}: 0 docs (initialized empty)")
        return True

    docs = await src_col.find({}).to_list(length=None)
    # Clear any previous migration attempts in target
    await dest_col.delete_many({})
    await dest_col.insert_many(docs)

    target_count = await dest_col.count_documents({})
    assert target_count == count, f"Count mismatch for {col_name}: {count} vs {target_count}"
    print(f"   • {col_name}: successfully migrated {target_count}/{count} docs")
    return True


async def main():
    print("=" * 60)
    print("🚀 MIGRATING TO SEPARATE DATABASES: ADMIN & COMMERCE")
    print("=" * 60)

    client = AsyncIOMotorClient(MONGO_URI)
    src_db = client["sahihislam"]
    admin_db = client["sahihislam_admin"]
    commerce_db = client["sahihislam_commerce"]

    # 1. Migrate Admin Collections
    print("\n1. Migrating to 'sahihislam_admin':")
    for col in ADMIN_COLLECTIONS:
        await migrate_collection(src_db, admin_db, col)

    # 2. Migrate Commerce Collections
    print("\n2. Migrating to 'sahihislam_commerce':")
    for col in COMMERCE_COLLECTIONS:
        await migrate_collection(src_db, commerce_db, col)

    # 3. Clean up migrated collections from source database
    print("\n3. Cleaning up old collections from 'sahihislam':")
    all_migrated = ADMIN_COLLECTIONS + COMMERCE_COLLECTIONS
    for col in all_migrated:
        await src_db[col].drop()
        print(f"   • Dropped {col} from sahihislam")

    # 4. Verification of final database state
    print("\n4. Final Database Breakdown:")
    dbs = await client.list_database_names()
    print("   Active Databases:", dbs)

    for db_name in ["sahihislam", "sahihislam_admin", "sahihislam_commerce"]:
        db_ref = client[db_name]
        colls = await db_ref.list_collection_names()
        print(f"\n   📁 [{db_name}] ({len(colls)} collections):")
        for c in sorted(colls):
            cnt = await db_ref[c].count_documents({})
            print(f"      - {c}: {cnt} docs")

    print("\n" + "=" * 60)
    print("🎉 DATABASE MIGRATION COMPLETED SUCCESSFULLY WITH 100% INTEGRITY!")
    print("=" * 60)


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