"""
Persistent SQLite Queue & Checkpoint Manager for 24/7 Autonomous Operation.
Provides job scheduling, per-step progress tracking, crash resumption, and job status reporting.
"""

import os
import sqlite3
import json
import time
import logging
from typing import List, Dict, Any, Optional

logger = logging.getLogger("YTFactory.Queue")

class QueueManager:
    def __init__(self, db_path: str = "output/factory_queue.db"):
        self.db_path = db_path
        os.makedirs(os.path.dirname(os.path.abspath(self.db_path)), exist_ok=True)
        self._init_db()

    def _get_conn(self) -> sqlite3.Connection:
        conn = sqlite3.connect(self.db_path)
        conn.row_factory = sqlite3.Row
        return conn

    def _init_db(self):
        with self._get_conn() as conn:
            conn.execute("""
                CREATE TABLE IF NOT EXISTS video_jobs (
                    job_id TEXT PRIMARY KEY,
                    topic TEXT NOT NULL,
                    status TEXT NOT NULL DEFAULT 'QUEUED',
                    progress_step TEXT NOT NULL DEFAULT 'PENDING',
                    duration INTEGER,
                    created_at REAL NOT NULL,
                    started_at REAL,
                    completed_at REAL,
                    error_message TEXT,
                    job_dir TEXT,
                    output_bundle TEXT
                )
            """)
            conn.commit()

    def add_job(self, topic: str, duration: Optional[int] = None) -> str:
        """Enqueue a new topic for processing."""
        job_id = f"{int(time.time())}_{abs(hash(topic)) % 100000}"
        now = time.time()
        with self._get_conn() as conn:
            conn.execute("""
                INSERT INTO video_jobs (job_id, topic, status, progress_step, duration, created_at)
                VALUES (?, ?, 'QUEUED', 'PENDING', ?, ?)
            """, (job_id, topic.strip(), duration, now))
            conn.commit()
        logger.info(f"[QUEUE] Added job '{topic[:40]}' (ID: {job_id})")
        return job_id

    def get_next_job(self) -> Optional[Dict[str, Any]]:
        """Retrieve and lock the next pending or retriable job."""
        with self._get_conn() as conn:
            row = conn.execute("""
                SELECT * FROM video_jobs
                WHERE status = 'QUEUED'
                ORDER BY created_at ASC
                LIMIT 1
            """).fetchone()
            
            if row:
                job = dict(row)
                conn.execute("""
                    UPDATE video_jobs
                    SET status = 'PROCESSING', started_at = ?
                    WHERE job_id = ?
                """, (time.time(), job["job_id"]))
                conn.commit()
                return job
        return None

    def update_progress(self, job_id: str, step: str, job_dir: Optional[str] = None):
        """Update current active processing step."""
        with self._get_conn() as conn:
            conn.execute("""
                UPDATE video_jobs
                SET progress_step = ?, job_dir = COALESCE(?, job_dir)
                WHERE job_id = ?
            """, (step, job_dir, job_id))
            conn.commit()

    def mark_completed(self, job_id: str, output_bundle: Dict[str, Any]):
        """Mark job successfully completed."""
        with self._get_conn() as conn:
            conn.execute("""
                UPDATE video_jobs
                SET status = 'COMPLETED', progress_step = 'DONE', completed_at = ?, output_bundle = ?
                WHERE job_id = ?
            """, (time.time(), json.dumps(output_bundle, ensure_ascii=False), job_id))
            conn.commit()
        logger.info(f"[QUEUE] Job {job_id} marked COMPLETED")

    def mark_failed(self, job_id: str, error_msg: str):
        """Mark job as failed with error details."""
        with self._get_conn() as conn:
            conn.execute("""
                UPDATE video_jobs
                SET status = 'FAILED', error_message = ?, completed_at = ?
                WHERE job_id = ?
            """, (error_msg, time.time(), job_id))
            conn.commit()
        logger.error(f"[QUEUE] Job {job_id} marked FAILED: {error_msg}")

    def list_jobs(self, limit: int = 25) -> List[Dict[str, Any]]:
        """List recent jobs with their statuses."""
        with self._get_conn() as conn:
            rows = conn.execute("""
                SELECT job_id, topic, status, progress_step, duration, created_at, completed_at, error_message
                FROM video_jobs
                ORDER BY created_at DESC
                LIMIT ?
            """, (limit,)).fetchall()
            return [dict(r) for r in rows]

    def retry_failed(self) -> int:
        """Reset failed jobs back to QUEUED state."""
        with self._get_conn() as conn:
            cur = conn.execute("""
                UPDATE video_jobs
                SET status = 'QUEUED', progress_step = 'PENDING', error_message = NULL
                WHERE status = 'FAILED'
            """)
            conn.commit()
            return cur.rowcount

    def has_pending_jobs(self) -> bool:
        """Check if any jobs are waiting in queue."""
        with self._get_conn() as conn:
            count = conn.execute("SELECT COUNT(*) FROM video_jobs WHERE status = 'QUEUED'").fetchone()[0]
            return count > 0