package db

import (
	"database/sql"
	"fmt"
	"log"

	_ "github.com/mattn/go-sqlite3"
)

// New opens a SQLite database at the given path and runs schema migrations.
func New(path string) (*sql.DB, error) {
	db, err := sql.Open("sqlite3", path+"?_journal_mode=WAL&_foreign_keys=on")
	if err != nil {
		return nil, fmt.Errorf("open db: %w", err)
	}

	if err := db.Ping(); err != nil {
		return nil, fmt.Errorf("ping db: %w", err)
	}

	if err := migrate(db); err != nil {
		return nil, fmt.Errorf("migrate db: %w", err)
	}

	log.Println("database ready:", path)
	return db, nil
}

func migrate(db *sql.DB) error {
	schema := `
	CREATE TABLE IF NOT EXISTS players (
		id              INTEGER PRIMARY KEY AUTOINCREMENT,
		client_id       TEXT    NOT NULL UNIQUE,
		first_seen      TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now')),
		last_seen       TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now')),
		total_sessions  INTEGER NOT NULL DEFAULT 0
	);
	CREATE INDEX IF NOT EXISTS idx_players_client_id ON players(client_id);

	CREATE TABLE IF NOT EXISTS player_ips (
		id         INTEGER PRIMARY KEY AUTOINCREMENT,
		player_id  INTEGER NOT NULL REFERENCES players(id) ON DELETE CASCADE,
		ip_address TEXT    NOT NULL,
		first_seen TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now')),
		last_seen  TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now')),
		UNIQUE(player_id, ip_address)
	);
	CREATE INDEX IF NOT EXISTS idx_player_ips_ip ON player_ips(ip_address);

	CREATE TABLE IF NOT EXISTS game_sessions (
		id               TEXT    PRIMARY KEY,
		player_id        INTEGER NOT NULL REFERENCES players(id) ON DELETE CASCADE,
		score            INTEGER NOT NULL DEFAULT 0,
		level_reached    INTEGER NOT NULL DEFAULT 1,
		lives_used       INTEGER NOT NULL DEFAULT 0,
		duration_seconds INTEGER NOT NULL DEFAULT 0,
		end_reason       TEXT    NOT NULL DEFAULT 'death',
		started_at       TEXT    NOT NULL,
		ended_at         TEXT    NOT NULL
	);
	CREATE INDEX IF NOT EXISTS idx_game_sessions_score ON game_sessions(score DESC);
	CREATE INDEX IF NOT EXISTS idx_game_sessions_player_ended ON game_sessions(player_id, ended_at DESC);

	CREATE TABLE IF NOT EXISTS device_infos (
		id                 INTEGER PRIMARY KEY AUTOINCREMENT,
		session_id         TEXT    NOT NULL UNIQUE REFERENCES game_sessions(id) ON DELETE CASCADE,
		ip_address         TEXT    NOT NULL DEFAULT '',
		user_agent         TEXT    NOT NULL DEFAULT '',
		platform           TEXT    NOT NULL DEFAULT '',
		language           TEXT    NOT NULL DEFAULT '',
		screen_width       INTEGER,
		screen_height      INTEGER,
		device_pixel_ratio REAL,
		timezone           TEXT    NOT NULL DEFAULT '',
		webgl_renderer     TEXT    NOT NULL DEFAULT '',
		touch_support      INTEGER NOT NULL DEFAULT 0
	);

	CREATE TABLE IF NOT EXISTS high_scores (
		id          INTEGER PRIMARY KEY AUTOINCREMENT,
		player_id   INTEGER NOT NULL UNIQUE REFERENCES players(id) ON DELETE CASCADE,
		score       INTEGER NOT NULL,
		session_id  TEXT    REFERENCES game_sessions(id) ON DELETE SET NULL,
		achieved_at TEXT    NOT NULL
	);
	CREATE INDEX IF NOT EXISTS idx_high_scores_score ON high_scores(score DESC);
	`

	_, err := db.Exec(schema)
	return err
}