"""Automated pipeline scheduling.

Runs the parliamentary embedding pipeline and motion summarization
on a configurable schedule using the `schedule` library.

Usage:
    uv run python scheduler.py                    # start scheduler loop
    uv run python scheduler.py --once             # run once and exit
    uv run python scheduler.py --pipeline-time 03:00 --summarizer-every 6
"""

from __future__ import annotations

import argparse
import logging
import signal
import sys
import time
from typing import Callable

import schedule

from config import config

from pipeline.run_pipeline import run as run_pipeline
from summarizer import summarizer

_logger = logging.getLogger(__name__)


class PipelineScheduler:
    """Schedules and runs pipeline jobs."""

    def __init__(self, db_path: str = "data/motions.db"):
        self.db_path = db_path
        self._running = False

    def run_pipeline(self) -> int:
        """Run the full embedding pipeline.

        Returns the exit code from the pipeline run.
        """
        _logger.info("Starting scheduled pipeline run")
        try:
            args = argparse.Namespace(
                db_path=self.db_path,
                window_size="annual",
                start_date=None,
                end_date=None,
                svd_k=50,
                svd_workers=None,
                text_model=None,
                text_batch_size=200,
                skip_metadata=False,
                skip_extract=False,
                skip_svd=False,
                skip_text=False,
                skip_fusion=False,
                dry_run=False,
            )
            result = run_pipeline(args)
            _logger.info("Pipeline run completed with code %s", result)
            return result if isinstance(result, int) else 0
        except Exception:
            _logger.exception("Pipeline run failed")
            return 1

    def run_summarizer(self) -> None:
        """Run motion summarization for missing explanations."""
        _logger.info("Starting scheduled summarizer run")
        try:
            summarizer.update_motion_summaries()
            _logger.info("Summarizer run completed")
        except Exception:
            _logger.exception("Summarizer run failed")

    def schedule_daily(self, time_str: str = "02:00") -> None:
        """Schedule the pipeline to run daily at *time_str*."""
        _logger.info("Scheduling daily pipeline run at %s", time_str)
        schedule.every().day.at(time_str).do(self.run_pipeline)

    def schedule_summarizer(self, every_n_hours: int = 6) -> None:
        """Schedule the summarizer to run every *every_n_hours* hours."""
        _logger.info("Scheduling summarizer every %s hours", every_n_hours)
        schedule.every(every_n_hours).hours.do(self.run_summarizer)

    def _signal_handler(self, signum, frame) -> None:
        """Handle shutdown signals gracefully."""
        _logger.info("Received signal %s, shutting down", signum)
        self.stop()

    def start(self) -> None:
        """Start the scheduler loop.

        Blocks until :meth:`stop` is called or a signal is received.
        """
        self._running = True

        # Register signal handlers for graceful shutdown
        signal.signal(signal.SIGTERM, self._signal_handler)
        signal.signal(signal.SIGINT, self._signal_handler)

        _logger.info("Scheduler started")
        while self._running:
            schedule.run_pending()
            time.sleep(1)
        _logger.info("Scheduler stopped")

    def stop(self) -> None:
        """Stop the scheduler loop."""
        self._running = False


def build_parser() -> argparse.ArgumentParser:
    parser = argparse.ArgumentParser(
        description="Automated pipeline scheduler",
        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
    )
    parser.add_argument(
        "--db-path",
        default="data/motions.db",
        help="Path to the DuckDB file",
    )
    parser.add_argument(
        "--pipeline-time",
        default="02:00",
        help="Daily pipeline run time (HH:MM)",
    )
    parser.add_argument(
        "--summarizer-every",
        type=int,
        default=6,
        help="Run summarizer every N hours",
    )
    parser.add_argument(
        "--once",
        action="store_true",
        help="Run pipeline + summarizer once and exit (no scheduling loop)",
    )
    return parser


def main(argv: list[str] | None = None) -> int:
    parser = build_parser()
    args = parser.parse_args(argv)

    logging.basicConfig(
        level=logging.INFO,
        format="%(asctime)s %(levelname)s %(name)s %(message)s",
    )

    sched = PipelineScheduler(db_path=args.db_path)

    if args.once:
        _logger.info("Running in single-shot mode")
        pipeline_rc = sched.run_pipeline()
        sched.run_summarizer()
        return pipeline_rc

    sched.schedule_daily(args.pipeline_time)
    if args.summarizer_every > 0:
        sched.schedule_summarizer(args.summarizer_every)

    sched.start()
    return 0


if __name__ == "__main__":
    sys.exit(main())