package db

import (
	"database/sql"
	"fmt"
	"log/slog"
	"os"
	"path/filepath"
	"sync"

	_ "modernc.org/sqlite"
)

var (
	mu       sync.Mutex
	globalDB *sql.DB
)

// Init opens (or creates) the SQLite database and runs migrations.
func Init(dataDir string) error {
	mu.Lock()
	defer mu.Unlock()

	if globalDB != nil {
		return nil
	}

	if err := os.MkdirAll(dataDir, 0o755); err != nil {
		return fmt.Errorf("create data dir: %w", err)
	}

	dbPath := filepath.Join(dataDir, "gogobee.db")
	d, err := sql.Open("sqlite", dbPath+"?_pragma=journal_mode(WAL)&_pragma=busy_timeout(5000)&_pragma=foreign_keys(ON)")
	if err != nil {
		return fmt.Errorf("open database: %w", err)
	}

	d.SetMaxOpenConns(1) // SQLite is single-writer

	if err := runMigrations(d); err != nil {
		return fmt.Errorf("run migrations: %w", err)
	}

	globalDB = d
	slog.Info("database initialized", "path", dbPath)
	return nil
}

// Get returns the global database handle. Panics if Init was not called.
func Get() *sql.DB {
	if globalDB == nil {
		panic("db.Get() called before db.Init()")
	}
	return globalDB
}

func runMigrations(d *sql.DB) error {
	_, err := d.Exec(schema)
	return err
}

// JobCompleted checks if a scheduled job has already completed for the given date key.
// Use date "2006-01-02" for daily jobs, or "2006-W01" style for weekly jobs.
func JobCompleted(jobName, dateKey string) bool {
	var completed int
	err := Get().QueryRow(
		`SELECT completed FROM daily_prefetch WHERE job_name = ? AND date = ?`,
		jobName, dateKey,
	).Scan(&completed)
	return err == nil && completed == 1
}

// MarkJobCompleted marks a scheduled job as completed for the given date key.
func MarkJobCompleted(jobName, dateKey string) {
	_, err := Get().Exec(
		`INSERT INTO daily_prefetch (job_name, date, completed) VALUES (?, ?, 1)
		 ON CONFLICT(job_name, date) DO UPDATE SET completed = 1`,
		jobName, dateKey,
	)
	if err != nil {
		slog.Error("mark job completed", "job", jobName, "date", dateKey, "err", err)
	}
}

const schema = `
-- Users & XP
CREATE TABLE IF NOT EXISTS users (
	user_id TEXT PRIMARY KEY,
	display_name TEXT DEFAULT '',
	xp INTEGER DEFAULT 0,
	level INTEGER DEFAULT 0,
	last_xp_at INTEGER DEFAULT 0,
	created_at INTEGER DEFAULT (unixepoch())
);

CREATE TABLE IF NOT EXISTS user_stats (
	user_id TEXT PRIMARY KEY,
	total_messages INTEGER DEFAULT 0,
	total_words INTEGER DEFAULT 0,
	total_chars INTEGER DEFAULT 0,
	total_links INTEGER DEFAULT 0,
	total_images INTEGER DEFAULT 0,
	total_questions INTEGER DEFAULT 0,
	total_exclamations INTEGER DEFAULT 0,
	total_emojis INTEGER DEFAULT 0,
	night_messages INTEGER DEFAULT 0,
	morning_messages INTEGER DEFAULT 0,
	updated_at INTEGER DEFAULT (unixepoch())
);

CREATE TABLE IF NOT EXISTS xp_log (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	user_id TEXT NOT NULL,
	amount INTEGER NOT NULL,
	reason TEXT DEFAULT '',
	created_at INTEGER DEFAULT (unixepoch())
);

-- Reputation
CREATE TABLE IF NOT EXISTS rep_cooldowns (
	giver TEXT NOT NULL,
	receiver TEXT NOT NULL,
	last_given INTEGER DEFAULT (unixepoch()),
	PRIMARY KEY (giver, receiver)
);

-- Reminders
CREATE TABLE IF NOT EXISTS reminders (
	id TEXT PRIMARY KEY,
	user_id TEXT NOT NULL,
	room_id TEXT NOT NULL,
	message TEXT NOT NULL,
	fire_at INTEGER NOT NULL,
	fired INTEGER DEFAULT 0,
	created_at INTEGER DEFAULT (unixepoch())
);
CREATE INDEX IF NOT EXISTS idx_reminders_fire ON reminders(fired, fire_at);

-- Daily activity / streaks
CREATE TABLE IF NOT EXISTS daily_activity (
	user_id TEXT NOT NULL,
	date TEXT NOT NULL,
	message_count INTEGER DEFAULT 0,
	PRIMARY KEY (user_id, date)
);

CREATE TABLE IF NOT EXISTS daily_first (
	room_id TEXT NOT NULL,
	date TEXT NOT NULL,
	user_id TEXT NOT NULL,
	timestamp INTEGER NOT NULL,
	PRIMARY KEY (room_id, date)
);

-- Word of the Day
CREATE TABLE IF NOT EXISTS wotd_log (
	date TEXT PRIMARY KEY,
	word TEXT NOT NULL,
	definition TEXT NOT NULL,
	part_of_speech TEXT DEFAULT '',
	example TEXT DEFAULT '',
	posted INTEGER DEFAULT 0
);

CREATE TABLE IF NOT EXISTS wotd_usage (
	user_id TEXT NOT NULL,
	date TEXT NOT NULL,
	count INTEGER DEFAULT 0,
	rewarded INTEGER DEFAULT 0,
	PRIMARY KEY (user_id, date)
);

-- Holidays
CREATE TABLE IF NOT EXISTS holidays_log (
	date TEXT PRIMARY KEY,
	data TEXT NOT NULL,
	posted INTEGER DEFAULT 0
);

-- Game releases
CREATE TABLE IF NOT EXISTS releases_cache (
	cache_key TEXT PRIMARY KEY,
	data TEXT NOT NULL,
	cached_at INTEGER DEFAULT (unixepoch())
);

CREATE TABLE IF NOT EXISTS release_watchlist (
	user_id TEXT NOT NULL,
	game_name TEXT NOT NULL,
	room_id TEXT NOT NULL,
	PRIMARY KEY (user_id, game_name)
);

-- HLTB cache
CREATE TABLE IF NOT EXISTS hltb_cache (
	game_name TEXT PRIMARY KEY,
	data TEXT NOT NULL,
	cached_at INTEGER DEFAULT (unixepoch())
);

-- Achievements
CREATE TABLE IF NOT EXISTS achievements (
	user_id TEXT NOT NULL,
	achievement_id TEXT NOT NULL,
	unlocked_at INTEGER DEFAULT (unixepoch()),
	PRIMARY KEY (user_id, achievement_id)
);

-- Quotes
CREATE TABLE IF NOT EXISTS quotes (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	room_id TEXT NOT NULL,
	user_id TEXT NOT NULL,
	quote_text TEXT NOT NULL,
	saved_by TEXT NOT NULL,
	created_at INTEGER DEFAULT (unixepoch())
);

-- Now Playing
CREATE TABLE IF NOT EXISTS now_playing (
	user_id TEXT PRIMARY KEY,
	track TEXT NOT NULL,
	updated_at INTEGER DEFAULT (unixepoch())
);

-- Backlog
CREATE TABLE IF NOT EXISTS backlog (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	user_id TEXT NOT NULL,
	item TEXT NOT NULL,
	done INTEGER DEFAULT 0,
	created_at INTEGER DEFAULT (unixepoch())
);

-- Predictions (stub/future)
CREATE TABLE IF NOT EXISTS predictions (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	user_id TEXT NOT NULL,
	room_id TEXT NOT NULL,
	prediction TEXT NOT NULL,
	outcome TEXT DEFAULT '',
	resolved INTEGER DEFAULT 0,
	created_at INTEGER DEFAULT (unixepoch())
);

-- Keyword watches
CREATE TABLE IF NOT EXISTS keyword_watches (
	user_id TEXT NOT NULL,
	keyword TEXT NOT NULL,
	room_id TEXT NOT NULL,
	PRIMARY KEY (user_id, keyword)
);

-- Scheduler config
CREATE TABLE IF NOT EXISTS scheduler_config (
	job_name TEXT PRIMARY KEY,
	enabled INTEGER DEFAULT 1,
	cron_expr TEXT NOT NULL,
	last_run TEXT DEFAULT ''
);

-- Shade (stub)
CREATE TABLE IF NOT EXISTS shade_log (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	user_id TEXT NOT NULL,
	target_user TEXT NOT NULL,
	message TEXT NOT NULL,
	room_id TEXT NOT NULL,
	created_at INTEGER DEFAULT (unixepoch())
);

CREATE TABLE IF NOT EXISTS shade_optout (
	user_id TEXT PRIMARY KEY
);

-- Birthdays
CREATE TABLE IF NOT EXISTS birthdays (
	user_id TEXT PRIMARY KEY,
	month INTEGER NOT NULL,
	day INTEGER NOT NULL,
	year INTEGER DEFAULT 0,
	timezone TEXT DEFAULT 'UTC'
);

CREATE TABLE IF NOT EXISTS birthday_fired (
	user_id TEXT NOT NULL,
	year INTEGER NOT NULL,
	PRIMARY KEY (user_id, year)
);

-- Trivia
CREATE TABLE IF NOT EXISTS trivia_sessions (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	room_id TEXT NOT NULL,
	category INTEGER DEFAULT 0,
	difficulty TEXT DEFAULT 'medium',
	question TEXT NOT NULL,
	correct_answer TEXT NOT NULL,
	incorrect_answers TEXT NOT NULL,
	question_type TEXT DEFAULT 'multiple',
	thread_id TEXT DEFAULT '',
	started_at INTEGER DEFAULT (unixepoch()),
	ended INTEGER DEFAULT 0,
	winner_id TEXT DEFAULT '',
	winner_time_ms INTEGER DEFAULT 0
);

CREATE TABLE IF NOT EXISTS trivia_scores (
	user_id TEXT NOT NULL,
	room_id TEXT NOT NULL,
	correct INTEGER DEFAULT 0,
	wrong INTEGER DEFAULT 0,
	total_score INTEGER DEFAULT 0,
	fastest_ms INTEGER DEFAULT 0,
	PRIMARY KEY (user_id, room_id)
);

-- LLM classifications
CREATE TABLE IF NOT EXISTS llm_classifications (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	user_id TEXT NOT NULL,
	room_id TEXT NOT NULL,
	message_text TEXT NOT NULL,
	sentiment TEXT DEFAULT '',
	sentiment_score REAL DEFAULT 0,
	topics TEXT DEFAULT '[]',
	profanity INTEGER DEFAULT 0,
	profanity_severity INTEGER DEFAULT 0,
	insult_target TEXT DEFAULT '',
	wotd_used INTEGER DEFAULT 0,
	gratitude_target TEXT DEFAULT '',
	created_at INTEGER DEFAULT (unixepoch())
);

CREATE TABLE IF NOT EXISTS potty_mouth (
	user_id TEXT PRIMARY KEY,
	count INTEGER DEFAULT 0,
	mild INTEGER DEFAULT 0,
	moderate INTEGER DEFAULT 0,
	scorching INTEGER DEFAULT 0
);

CREATE TABLE IF NOT EXISTS insult_log (
	user_id TEXT PRIMARY KEY,
	times_insulted INTEGER DEFAULT 0,
	times_insulting INTEGER DEFAULT 0
);

-- Stocks
CREATE TABLE IF NOT EXISTS stocks_cache (
	ticker TEXT PRIMARY KEY,
	data TEXT NOT NULL,
	cached_at INTEGER DEFAULT (unixepoch())
);

CREATE TABLE IF NOT EXISTS stock_watchlist (
	user_id TEXT NOT NULL,
	ticker TEXT NOT NULL,
	room_id TEXT NOT NULL,
	PRIMARY KEY (user_id, ticker)
);

-- Command usage
CREATE TABLE IF NOT EXISTS command_usage (
	command TEXT NOT NULL,
	user_id TEXT NOT NULL,
	count INTEGER DEFAULT 0,
	PRIMARY KEY (command, user_id)
);

-- Concerts
CREATE TABLE IF NOT EXISTS concerts_cache (
	artist TEXT PRIMARY KEY,
	data TEXT NOT NULL,
	cached_at INTEGER DEFAULT (unixepoch())
);

CREATE TABLE IF NOT EXISTS concert_watchlist (
	user_id TEXT NOT NULL,
	artist TEXT NOT NULL,
	room_id TEXT NOT NULL,
	PRIMARY KEY (user_id, artist)
);

-- Anime
CREATE TABLE IF NOT EXISTS anime_watchlist (
	user_id TEXT NOT NULL,
	mal_id INTEGER NOT NULL,
	title TEXT NOT NULL,
	room_id TEXT NOT NULL,
	PRIMARY KEY (user_id, mal_id)
);

CREATE TABLE IF NOT EXISTS anime_cache (
	mal_id INTEGER PRIMARY KEY,
	data TEXT NOT NULL,
	cached_at INTEGER DEFAULT (unixepoch())
);

-- Movies
CREATE TABLE IF NOT EXISTS movie_watchlist (
	user_id TEXT NOT NULL,
	tmdb_id INTEGER NOT NULL,
	title TEXT NOT NULL,
	media_type TEXT DEFAULT 'movie',
	room_id TEXT NOT NULL,
	PRIMARY KEY (user_id, tmdb_id)
);

CREATE TABLE IF NOT EXISTS movie_cache (
	tmdb_id INTEGER PRIMARY KEY,
	data TEXT NOT NULL,
	cached_at INTEGER DEFAULT (unixepoch())
);

-- Countdowns
CREATE TABLE IF NOT EXISTS countdowns (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	user_id TEXT NOT NULL,
	room_id TEXT NOT NULL,
	label TEXT NOT NULL,
	target_date TEXT NOT NULL,
	public INTEGER DEFAULT 1,
	completed INTEGER DEFAULT 0,
	created_at INTEGER DEFAULT (unixepoch())
);

-- Presence
CREATE TABLE IF NOT EXISTS presence (
	user_id TEXT PRIMARY KEY,
	status TEXT DEFAULT 'online',
	message TEXT DEFAULT '',
	updated_at INTEGER DEFAULT (unixepoch())
);

-- Markov
CREATE TABLE IF NOT EXISTS markov_corpus (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	user_id TEXT NOT NULL,
	text TEXT NOT NULL,
	created_at INTEGER DEFAULT (unixepoch())
);
CREATE INDEX IF NOT EXISTS idx_markov_user ON markov_corpus(user_id);

-- Retro/game lookup cache
CREATE TABLE IF NOT EXISTS retro_cache (
	search_term TEXT PRIMARY KEY,
	data TEXT NOT NULL,
	cached_at INTEGER DEFAULT (unixepoch())
);

-- Urban Dictionary cache
CREATE TABLE IF NOT EXISTS urban_cache (
	term TEXT PRIMARY KEY,
	data TEXT NOT NULL,
	cached_at INTEGER DEFAULT (unixepoch())
);

-- Room milestones
CREATE TABLE IF NOT EXISTS room_milestones (
	room_id TEXT PRIMARY KEY,
	total_messages INTEGER DEFAULT 0,
	last_milestone INTEGER DEFAULT 0
);

-- Reaction log
CREATE TABLE IF NOT EXISTS reaction_log (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	room_id TEXT NOT NULL,
	event_id TEXT NOT NULL,
	sender TEXT NOT NULL,
	target_user TEXT NOT NULL,
	emoji TEXT NOT NULL,
	created_at INTEGER DEFAULT (unixepoch())
);

-- Sentiment stats (aggregated)
CREATE TABLE IF NOT EXISTS sentiment_stats (
	user_id TEXT PRIMARY KEY,
	positive INTEGER DEFAULT 0,
	negative INTEGER DEFAULT 0,
	neutral INTEGER DEFAULT 0,
	total_score REAL DEFAULT 0
);

-- Daily prefetch tracking
CREATE TABLE IF NOT EXISTS daily_prefetch (
	job_name TEXT NOT NULL,
	date TEXT NOT NULL,
	completed INTEGER DEFAULT 0,
	PRIMARY KEY (job_name, date)
);

-- URL preview cache
CREATE TABLE IF NOT EXISTS url_cache (
	url TEXT PRIMARY KEY,
	title TEXT DEFAULT '',
	description TEXT DEFAULT '',
	cached_at INTEGER DEFAULT (unixepoch())
);

-- Rate limits
CREATE TABLE IF NOT EXISTS rate_limits (
	user_id TEXT NOT NULL,
	action TEXT NOT NULL,
	date TEXT NOT NULL,
	count INTEGER DEFAULT 0,
	PRIMARY KEY (user_id, action, date)
);
`

// SeedSchedulerDefaults inserts default scheduler jobs if they don't exist.
func SeedSchedulerDefaults(d *sql.DB) error {
	defaults := []struct {
		name string
		cron string
	}{
		{"prefetch", "5 0 * * *"},       // 00:05 daily
		{"maintenance", "0 3 * * *"},    // 03:00 daily
		{"wotd", "0 8 * * *"},           // 08:00 daily
		{"holidays", "0 7 * * *"},       // 07:00 daily
		{"releases", "0 9 * * 1"},       // 09:00 Monday
		{"birthday_check", "0 6 * * *"}, // 06:00 daily
		{"anime_releases", "0 10 * * *"},// 10:00 daily
		{"movie_releases", "0 11 * * *"},// 11:00 daily
		{"concert_digest", "0 12 * * 0"},// 12:00 Sunday
	}

	stmt, err := d.Prepare(`INSERT OR IGNORE INTO scheduler_config (job_name, cron_expr) VALUES (?, ?)`)
	if err != nil {
		return err
	}
	defer stmt.Close()

	for _, def := range defaults {
		if _, err := stmt.Exec(def.name, def.cron); err != nil {
			return fmt.Errorf("seed scheduler %s: %w", def.name, err)
		}
	}
	return nil
}