"""Flask app factory."""

from __future__ import annotations

import json
import logging
import time

from flask import Flask, jsonify, render_template

from . import queries, scanner
from .config import Config
from .db import Database
from .scoring import register_sqlite_functions

log = logging.getLogger(__name__)

# Shipped read-only so the first run has somewhere useful to start (§7.2).
SEED_VIEWS = [
    ("Confident reclaim",
     "Added while watch history was being recorded, and never played since. "
     "The list to act on first.",
     {"op": "and", "rules": [
         {"field": "watch_count", "op": "eq", "value": 0},
         {"field": "pre_history", "op": "eq", "value": False}]},
     "reclaim_score:desc"),
    ("Uncertain reclaim",
     "Never played, but added before history began — it may have been watched "
     "and nobody can tell. Needs judgement, not a bulk action.",
     {"op": "and", "rules": [
         {"field": "watch_count", "op": "eq", "value": 0},
         {"field": "pre_history", "op": "eq", "value": True}]},
     "size_bytes:desc"),
    ("Never watched, large",
     "Nothing has ever played it and it is over 8 GB.",
     {"op": "and", "rules": [
         {"field": "watch_count", "op": "eq", "value": 0},
         {"field": "size_bytes", "op": "gte", "value": 8 * 1024**3}]},
     "size_bytes:desc"),
    ("Cold storage",
     "Not watched in over three years.",
     {"op": "and", "rules": [
         {"field": "last_watched_at", "op": "older_than_days", "value": 1095}]},
     "size_bytes:desc"),
    ("One-and-done movies",
     "Watched exactly once, over two years ago.",
     {"op": "and", "rules": [
         {"field": "kind", "op": "eq", "value": "movie"},
         {"field": "watch_count", "op": "eq", "value": 1},
         {"field": "last_watched_at", "op": "older_than_days", "value": 730}]},
     "size_bytes:desc"),
    ("Tried and rejected",
     "Two or more people started it and nobody finished it. Needs Tautulli.",
     {"op": "and", "rules": [
         {"field": "abandoned_count", "op": "gte", "value": 2},
         {"field": "watch_count", "op": "eq", "value": 0}]},
     "size_bytes:desc"),
    ("Abandoned seasons",
     "Seasons barely watched through, added over a year ago.",
     {"op": "and", "rules": [
         {"field": "kind", "op": "eq", "value": "season"},
         {"field": "watch_ratio", "op": "lt", "value": 0.3},
         {"field": "added_at", "op": "older_than_days", "value": 365}]},
     "size_bytes:desc"),
    ("Biggest 100",
     "Simply the largest things on disk.",
     {}, "size_bytes:desc"),
    ("Recently added",
     "The sanity check, not a delete list.",
     {"op": "and", "rules": [
         {"field": "added_at", "op": "newer_than_days", "value": 30}]},
     "added_at:desc"),
    ("Kept",
     "What you have decided to keep, and what it costs.",
     {"op": "and", "rules": [{"field": "kept", "op": "eq", "value": True}]},
     "size_bytes:desc"),
]


def seed_views(db) -> None:
    now = int(time.time())
    for name, desc, rules, sort in SEED_VIEWS:
        if db.one("SELECT id FROM saved_view WHERE name = ?", (name,)):
            continue
        db.execute(
            "INSERT INTO saved_view (name, description, rules, sort, columns, weights, "
            "builtin, created_at, updated_at) VALUES (?,?,?,?,'[]','{}',1,?,?)",
            (name, desc, json.dumps(rules), sort, now, now))


def create_app(config: Config | None = None, *, start_scheduler: bool = True) -> Flask:
    cfg = config or Config.from_env()
    logging.basicConfig(
        level=getattr(logging, cfg.log_level, logging.INFO),
        format="%(asctime)s %(levelname)-7s %(name)s: %(message)s")

    app = Flask(__name__)
    app.config["SECRET_KEY"] = cfg.secret_key
    app.config["SESSION_COOKIE_SAMESITE"] = "Strict"
    app.config["JSON_SORT_KEYS"] = False

    db = Database(cfg.database_path)
    db.migrate()
    register_sqlite_functions(db.conn)
    seed_views(db)

    app.extensions["mediashelf"] = {
        "config": cfg, "db": db, "degraded_reason": None,
        "started_at": int(time.time()),
    }

    @app.before_request
    def _ensure_functions():
        # Each thread gets its own connection, so LOG() must be registered on it.
        register_sqlite_functions(db.conn)

    from .api import bp as api_bp
    app.register_blueprint(api_bp)

    from .web import bp as web_bp
    app.register_blueprint(web_bp)

    @app.get("/healthz")
    def healthz():
        ext = app.extensions["mediashelf"]
        out = {"status": "ok", "db": "ok", "plex": "unknown", "tautulli": "disabled"}
        try:
            db.scalar("SELECT 1")
        except Exception as e:  # noqa: BLE001
            out["status"], out["db"] = "error", str(e)
        row = db.one("SELECT * FROM scan WHERE status='succeeded' ORDER BY id DESC LIMIT 1")
        out["last_scan_at"] = row["finished_at"] if row else None
        out["stale"] = bool(row is None or (time.time() - (row["finished_at"] or 0)) > 48 * 3600)
        cov = db.one("SELECT source FROM history_coverage ORDER BY event_count DESC LIMIT 1")
        out["history_source"] = cov["source"] if cov else None
        out["plex"] = "configured" if cfg.plex_configured else "unconfigured"
        out["tautulli"] = "configured" if cfg.tautulli_configured else "disabled"
        out["degraded"] = ext.get("degraded_reason")
        return jsonify(out), (200 if out["status"] == "ok" else 503)

    @app.errorhandler(404)
    def _404(e):
        return jsonify({"error": "not_found"}), 404

    @app.errorhandler(500)
    def _500(e):
        log.exception("unhandled error")
        return jsonify({"error": "internal_error"}), 500

    if start_scheduler:
        scanner.start_scheduler(app)

    return app