"""Video Calendar — upcoming TV episodes for OWNED shows.

GET /api/video/calendar?days=N → episodes airing from today through today+N-1,
grouped client-side into the agenda view. Isolated: reads only video_library.db
via VideoDatabase, writes nothing, never touches the music side.
"""

from __future__ import annotations

from datetime import date, datetime, timedelta

from flask import jsonify, request

from utils.logging_config import get_logger

logger = get_logger("video.calendar")


def register_routes(bp):
    @bp.route("/calendar", methods=["GET"])
    def video_calendar():
        from . import get_video_db
        try:
            days = request.args.get("days", default=7, type=int) or 7
            days = max(1, min(days, 31))            # one week (or a few) per view
            today = date.today()
            # Optional ?start=YYYY-MM-DD for week navigation; default = today.
            start = today
            start_s = request.args.get("start")
            if start_s:
                try:
                    start = datetime.strptime(start_s, "%Y-%m-%d").date()
                except ValueError:
                    start = today
            if abs((start - today).days) > 400:     # sane bound around today
                start = today
            end = start + timedelta(days=days - 1)
            db = get_video_db()

            # One-time backfill: existing shows matched TVDB before air time was
            # captured, so re-queue them once (background, only those missing it).
            try:
                if (db.get_setting("airs_time_backfill") or "") != "1":
                    n = db.requeue_shows_for_airtime()
                    db.set_setting("airs_time_backfill", "1")
                    if n:
                        logger.info("calendar: queued %d shows for TVDB air-time backfill", n)
            except Exception:
                logger.exception("airs_time backfill queue failed")

            from core.video.sources import resolve_video_server
            # scope: 'watchlist' (default — shows you follow/track) or 'all' (every
            # airing show in the library). The toggle on the page sends ?scope=.
            scope = (request.args.get("scope") or "watchlist").lower()
            eps = db.calendar_upcoming(start.isoformat(), end.isoformat(),
                                       server_source=resolve_video_server(),
                                       watchlist_only=(scope != "all"))

            # Per-date counts drive the day-strip dots without a second query.
            counts: dict[str, int] = {}
            owned = 0
            for e in eps:
                counts[e["air_date"]] = counts.get(e["air_date"], 0) + 1
                if e.get("has_file"):
                    owned += 1
            return jsonify({
                "today": today.isoformat(),       # real today (for the highlight)
                "start": start.isoformat(),       # window start (may be a future week)
                "end": end.isoformat(),
                "days": days,
                "scope": "all" if scope == "all" else "watchlist",
                "counts_by_date": counts,
                "total": len(eps),
                "owned": owned,
                "episodes": eps,
            })
        except Exception:
            logger.exception("video calendar failed")
            return jsonify({"error": "calendar failed"}), 500