package db

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

	_ "modernc.org/sqlite"
)

// DB wraps a SQLite database connection.
type DB struct {
	*sql.DB
}

// Open opens (or creates) a SQLite database at the given path with the
// standard Metacircular pragmas: WAL mode, foreign keys, busy timeout.
func Open(path string) (*DB, error) {
	dir := filepath.Dir(path)
	if err := os.MkdirAll(dir, 0700); err != nil {
		return nil, fmt.Errorf("db: create directory %s: %w", dir, err)
	}

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

	pragmas := []string{
		"PRAGMA journal_mode = WAL",
		"PRAGMA foreign_keys = ON",
		"PRAGMA busy_timeout = 5000",
	}
	for _, p := range pragmas {
		if _, err := sqlDB.Exec(p); err != nil {
			_ = sqlDB.Close()
			return nil, fmt.Errorf("db: %s: %w", p, err)
		}
	}

	// Set file permissions to 0600 (owner read/write only).
	if err := os.Chmod(path, 0600); err != nil {
		_ = sqlDB.Close()
		return nil, fmt.Errorf("db: chmod %s: %w", path, err)
	}

	return &DB{sqlDB}, nil
}