from flask import Flask, render_template, jsonify
from datetime import datetime, timezone, timedelta
import os
from dotenv import load_dotenv

load_dotenv()

import db
from clients import jellyfin

app = Flask(__name__)

PHT = timezone(timedelta(hours=8))


def _sunday_midnight_pht_for(now_pht=None):
    """Return the Sunday midnight (start of day) in PHT used for week-start logic.

    This function treats Sunday as belonging to the previous week (used for producing
    week ranges like "Feb 15-21" when today is Sunday Feb 22).
    """
    now_pht = now_pht or datetime.now(PHT)
    wd = now_pht.weekday()
    days_since_sunday = (wd + 1) % 7
    if wd == 6:
        days_since_sunday = 7
    sunday_midnight_pht = (now_pht - timedelta(days=days_since_sunday)).replace(
        hour=0, minute=0, second=0, microsecond=0
    )
    return sunday_midnight_pht


def _latest_sunday_midnight_pht(now_pht=None):
    """Return the latest Sunday midnight (start of day) in PHT including today if it's Sunday.

    This is for computing the exact UTC cutoff timestamps for a given latest Sunday.
    """
    now_pht = now_pht or datetime.now(PHT)
    wd = now_pht.weekday()
    days_since_sunday = (wd + 1) % 7  # Sunday -> 0
    sunday_midnight_pht = (now_pht - timedelta(days=days_since_sunday)).replace(
        hour=0, minute=0, second=0, microsecond=0
    )
    return sunday_midnight_pht


def current_week():
    """Return (week_start, week_end, cutoff_utc) for the current week in PHT.

    week_start = most recent Sunday (PHT date)
    week_end   = that Sunday + 6 days (Saturday)
    cutoff_utc = Sunday 00:00 PHT expressed in UTC (= Saturday 16:00 UTC)
    """
    sunday_midnight_pht = _sunday_midnight_pht_for()
    week_start = sunday_midnight_pht.date()
    week_end = week_start + timedelta(days=6)
    cutoff_utc = sunday_midnight_pht.astimezone(timezone.utc)
    return week_start, week_end, cutoff_utc


def _iso_z(dt):
    """Format timezone-aware datetime to 'YYYY-MM-DDTHH:MM:SS.mmmZ' in UTC."""
    s = dt.astimezone(timezone.utc).strftime("%Y-%m-%dT%H:%M:%S.%f")
    return s[:-3] + "Z"


def get_latest_sunday():
    """Return latest Sunday start-of-day PHT expressed in UTC ISO Z format (inclusive)."""
    sunday_midnight_pht = _latest_sunday_midnight_pht()
    cutoff_utc = sunday_midnight_pht.astimezone(timezone.utc)
    return _iso_z(cutoff_utc)


def get_previous_sunday():
    """Return the Sunday prior to the latest Sunday (UTC ISO Z)."""
    sunday_midnight_pht = _latest_sunday_midnight_pht()
    prev_midnight = sunday_midnight_pht - timedelta(weeks=1)
    prev_cutoff_utc = prev_midnight.astimezone(timezone.utc)
    return _iso_z(prev_cutoff_utc)


def format_date_range(week_start, week_end) -> str:
    """Format date range: 'Feb 8-14' (same month) or 'Mar 29 - Apr 4' (different)."""
    if week_start.month == week_end.month:
        return f"{week_start.strftime('%b %-d')}-{week_end.strftime('%-d')}"
    return f"{week_start.strftime('%b %-d')} - {week_end.strftime('%b %-d')}"


@app.route("/")
def index():
    week_start, week_end, _ = current_week()
    config = {
        "JELLYFIN_HOST": os.environ.get("JELLYFIN_HOST", ""),
        "JELLYFIN_API_KEY": os.environ.get("JELLYFIN_API_KEY", ""),
        "JELLYFIN_USER_ID": os.environ.get("JELLYFIN_USER_ID", ""),
        "TOTAL_EPISODES": os.environ.get("TOTAL_EPISODES", "1155"),
        "DB_PATH": os.environ.get("DB_PATH", "/app/data/episodes.db"),
    }
    latest = get_latest_sunday()
    previous = get_previous_sunday()
    return render_template(
        "index.html",
        week_start=week_start.isoformat(),
        week_end=week_end.isoformat(),
        date_range=format_date_range(week_start, week_end),
        config=config,
        latest_sunday=latest,
        previous_sunday=previous,
    )


@app.route("/api/report")
def report():
    week_start, week_end, cutoff_utc = current_week()
    total_episodes = int(os.environ.get("TOTAL_EPISODES", 1155))
    latest = get_latest_sunday()
    previous = get_previous_sunday()

    jellyfin.clear_debug_logs()

    try:
        ep_info = jellyfin.find_last_one_piece_before(cutoff_utc)
    except Exception as e:
        debug_output = jellyfin.get_debug_logs()
        return jsonify({"error": str(e), "debug": debug_output}), 502

    db.save_episode(
        episode_number=ep_info["episode_number"],
        week_start=week_start.isoformat(),
        week_end=week_end.isoformat(),
        item_id=ep_info.get("item_id"),
        media_name=ep_info.get("media_name"),
        watched_at=ep_info.get("watched_at"),
    )

    prev = db.get_previous_episode(week_start.isoformat())
    previous_episode = prev["episode_number"] if prev else ep_info["episode_number"]
    watched_this_week = ep_info["episode_number"] - previous_episode

    date_range = format_date_range(week_start, week_end)
    report_text = (
        f"ONE PIECE PROGRESS!!! ({date_range})\n"
        f"Episode {ep_info['episode_number']}/{total_episodes}\n"
        f"Around {watched_this_week} episodes watched this week!"
    )

    debug_output = jellyfin.get_debug_logs()
    
    return jsonify({
        "week_start": week_start.isoformat(),
        "week_end": week_end.isoformat(),
        "date_range": date_range,
        "latest_episode": ep_info["episode_number"],
        "previous_episode": previous_episode,
        "watched_this_week": watched_this_week,
        "total_episodes": total_episodes,
        "media_name": ep_info.get("media_name"),
        "watched_at": ep_info.get("watched_at"),
        "report": report_text,
        "latest_sunday": latest,
        "previous_sunday": previous,
        "debug": debug_output,
    })


@app.route("/api/history")
def history():
    return jsonify(db.get_all_history())


if __name__ == "__main__":
    db.init_db()
    port = int(os.environ.get("PORT", 5000))
    app.run(host="0.0.0.0", port=port, debug=False)