"""Background worker: processes queued/processing video generation jobs."""
import asyncio
import json
import logging
from datetime import datetime, timezone

import duckdb

from . import openrouter
from .models import mark_timed_out_video_jobs

logger = logging.getLogger(__name__)

# Interval between worker ticks (seconds)
WORKER_INTERVAL = 15
# Jobs to process per tick (prevents unbounded bursts)
BATCH_SIZE = 5


async def process_queued_jobs(conn: duckdb.DuckDBPyConnection, lock: asyncio.Lock) -> int:
    """Submit queued jobs to OpenRouter and transition them to 'processing'."""
    rows = conn.execute(
        """SELECT id, generation_type, request_params
           FROM generated_videos
           WHERE status = 'queued' AND request_params IS NOT NULL
           ORDER BY created_at ASC
           LIMIT ?""",
        [BATCH_SIZE],
    ).fetchall()

    processed = 0
    for row in rows:
        db_id, generation_type, raw_params = str(row[0]), row[1], row[2]
        try:
            params = json.loads(raw_params)
        except (json.JSONDecodeError, TypeError):
            logger.error("Bad request_params for video job %s", db_id)
            continue

        try:
            if generation_type == "image_to_video":
                result = await openrouter.generate_video_from_image(
                    model=params["model"],
                    image_url=params.get("image_url", ""),
                    prompt=params.get("prompt", ""),
                    duration_seconds=params.get("duration_seconds"),
                    aspect_ratio=params.get("aspect_ratio", "16:9"),
                    resolution=params.get("resolution"),
                )
            else:
                result = await openrouter.generate_video(
                    model=params["model"],
                    prompt=params.get("prompt", ""),
                    duration_seconds=params.get("duration_seconds"),
                    aspect_ratio=params.get("aspect_ratio", "16:9"),
                    resolution=params.get("resolution"),
                )
        except Exception as exc:
            logger.warning("OpenRouter call failed for job %s: %s", db_id, exc)
            now = datetime.now(timezone.utc).replace(tzinfo=None)
            async with lock:
                conn.execute(
                    "UPDATE generated_videos SET status = 'failed', error = ?, updated_at = ? WHERE id = ?",
                    [str(exc), now, db_id],
                )
            continue

        job_id = result.get("id", "")
        polling_url = result.get("polling_url")
        new_status = result.get("status", "processing")
        # Normalise terminal statuses returned immediately (rare but possible)
        if new_status not in ("queued", "processing", "completed", "failed", "cancelled"):
            new_status = "processing"

        urls = result.get("unsigned_urls") or result.get("video_urls")
        video_url = (urls or [None])[0]
        now = datetime.now(timezone.utc).replace(tzinfo=None)

        async with lock:
            conn.execute(
                """UPDATE generated_videos
                   SET job_id = ?, polling_url = ?, status = ?, video_url = ?, updated_at = ?
                   WHERE id = ?""",
                [job_id, polling_url, new_status, video_url, now, db_id],
            )
        processed += 1
        logger.info("Video job %s → %s (provider id: %s)",
                    db_id, new_status, job_id)

    return processed


async def process_processing_jobs(conn: duckdb.DuckDBPyConnection, lock: asyncio.Lock) -> int:
    """Poll in-progress jobs and update to 'completed' or 'failed'."""
    rows = conn.execute(
        """SELECT id, polling_url
           FROM generated_videos
           WHERE status = 'processing' AND polling_url IS NOT NULL
           ORDER BY updated_at ASC
           LIMIT ?""",
        [BATCH_SIZE],
    ).fetchall()

    updated = 0
    for row in rows:
        db_id, polling_url = str(row[0]), row[1]
        try:
            result = await openrouter.poll_video_status(polling_url)
        except Exception as exc:
            logger.warning("Polling failed for job %s: %s", db_id, exc)
            continue

        job_status = result.get("status", "processing")
        if job_status not in ("completed", "failed"):
            continue  # still in-progress — check again next tick

        urls = result.get("unsigned_urls") or result.get("video_urls")
        video_url = (urls or [None])[0]
        error_msg = result.get("error")
        now = datetime.now(timezone.utc).replace(tzinfo=None)

        async with lock:
            conn.execute(
                """UPDATE generated_videos
                   SET status = ?, video_url = ?, error = ?, updated_at = ?
                   WHERE id = ?""",
                [job_status, video_url, error_msg, now, db_id],
            )
        updated += 1
        logger.info("Video job %s → %s", db_id, job_status)

    return updated


async def worker_tick(conn: duckdb.DuckDBPyConnection, lock: asyncio.Lock) -> None:
    """Single worker tick: submit queued, poll processing, expire timed-out."""
    queued = await process_queued_jobs(conn, lock)
    polled = await process_processing_jobs(conn, lock)
    async with lock:
        timed_out = mark_timed_out_video_jobs(conn, timeout_minutes=120)
    if queued or polled or timed_out:
        logger.info(
            "Worker tick: submitted=%d polled=%d timed_out=%d",
            queued, polled, timed_out,
        )


async def run_worker(conn: duckdb.DuckDBPyConnection, lock: asyncio.Lock) -> None:
    """Infinite loop: run a worker tick every WORKER_INTERVAL seconds."""
    logger.info("Video worker started (interval=%ds)", WORKER_INTERVAL)
    while True:
        try:
            await worker_tick(conn, lock)
        except asyncio.CancelledError:
            logger.info("Video worker stopped.")
            return
        except Exception as exc:
            logger.exception("Unexpected error in video worker: %s", exc)
        await asyncio.sleep(WORKER_INTERVAL)