package db

import (
	"database/sql"
	"fmt"
	"os"
	"path/filepath"

	_ "modernc.org/sqlite"
)

func Open(path string) (*sql.DB, error) {
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		return nil, fmt.Errorf("create database directory: %w", err)
	}

	database, err := sql.Open("sqlite", path)
	if err != nil {
		return nil, fmt.Errorf("open sqlite: %w", err)
	}

	if _, err := database.Exec("PRAGMA foreign_keys = ON"); err != nil {
		database.Close()
		return nil, fmt.Errorf("enable foreign keys: %w", err)
	}

	if _, err := database.Exec("PRAGMA journal_mode = WAL"); err != nil {
		database.Close()
		return nil, fmt.Errorf("enable wal mode: %w", err)
	}

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

	if err := migrate(database); err != nil {
		database.Close()
		return nil, err
	}

	return database, nil
}

func migrate(database *sql.DB) error {
	statements := []string{
		`CREATE TABLE IF NOT EXISTS users (
			id INTEGER PRIMARY KEY AUTOINCREMENT,
			username TEXT NOT NULL UNIQUE,
			password_hash TEXT NOT NULL,
			is_admin INTEGER NOT NULL DEFAULT 0,
			created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
		)`,
		`CREATE TABLE IF NOT EXISTS sessions (
			token TEXT PRIMARY KEY,
			user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
			expires_at DATETIME NOT NULL
		)`,
	}

	for _, statement := range statements {
		if _, err := database.Exec(statement); err != nil {
			return fmt.Errorf("run migration: %w", err)
		}
	}

	return nil
}