"""
Backfill SLA response_due and resolution_due on all tickets that have
a category but no SLA dates set.
"""
import asyncio
import os
import sys
from datetime import timedelta

sys.path.insert(0, '/app')
os.chdir('/app')

from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession
from sqlalchemy.orm import sessionmaker
from sqlalchemy import text


async def run():
    database_url = os.environ.get(
        'DATABASE_URL',
        'postgresql+asyncpg://postgres:postgres@db:5432/servicemanager'
    )
    engine = create_async_engine(database_url)
    async_session = sessionmaker(engine, class_=AsyncSession, expire_on_commit=False)

    async with async_session() as session:
        # Find all tickets with a category but missing SLA dates
        result = await session.execute(text("""
            SELECT
                t.id,
                t.created_at,
                c.sla_response_hours,
                c.sla_resolution_hours
            FROM tickets t
            JOIN ticket_categories c ON c.id = t.category_id
            WHERE t.sla_response_due IS NULL
              AND t.sla_resolution_due IS NULL
        """))
        rows = result.fetchall()
        print(f"Tickets to update: {len(rows)}")

        updated = 0
        for row in rows:
            ticket_id, created_at, resp_h, res_h = row
            # Ensure naive datetime for DB compatibility
            if hasattr(created_at, 'tzinfo') and created_at.tzinfo is not None:
                from datetime import timezone
                created_at = created_at.astimezone(timezone.utc).replace(tzinfo=None)
            sla_response_due = created_at + timedelta(hours=float(resp_h))
            sla_resolution_due = created_at + timedelta(hours=float(res_h))

            await session.execute(text("""
                UPDATE tickets
                SET sla_response_due   = :sla_resp,
                    sla_resolution_due = :sla_res
                WHERE id = :ticket_id
            """), {
                "sla_resp":    sla_response_due,
                "sla_res":     sla_resolution_due,
                "ticket_id":   ticket_id,
            })
            updated += 1

        await session.commit()
        print(f"Updated {updated} tickets with SLA dates.")

        # Verify
        r2 = await session.execute(text("""
            SELECT ticket_number, sla_response_due, sla_resolution_due
            FROM tickets
            WHERE sla_response_due IS NOT NULL
            ORDER BY created_at
            LIMIT 10
        """))
        print("\nSample of tickets with SLA dates now:")
        for row in r2.fetchall():
            print(f"  {row[0]}: response_due={row[1]}, resolution_due={row[2]}")

    await engine.dispose()


asyncio.run(run())