package db

import (
	"database/sql"
	"embed"
	"fmt"
	"io/fs"
	"sort"
	"strings"

	_ "modernc.org/sqlite"
)

//go:embed migrations/*.sql
var migrationsFS embed.FS

type DB struct {
	conn *sql.DB
}

func Open(path string) (*DB, error) {
	conn, err := sql.Open("sqlite", path)
	if err != nil {
		return nil, fmt.Errorf("open sqlite: %w", err)
	}
	if _, err := conn.Exec(`PRAGMA foreign_keys = ON`); err != nil {
		_ = conn.Close()
		return nil, fmt.Errorf("enable foreign keys: %w", err)
	}
	return &DB{conn: conn}, nil
}

func (d *DB) Close() error {
	return d.conn.Close()
}

func (d *DB) Conn() *sql.DB {
	return d.conn
}

func (d *DB) Migrate() error {
	entries, err := fs.ReadDir(migrationsFS, "migrations")
	if err != nil {
		return fmt.Errorf("read migrations: %w", err)
	}
	sort.Slice(entries, func(i, j int) bool {
		return entries[i].Name() < entries[j].Name()
	})
	for _, entry := range entries {
		if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".sql") {
			continue
		}
		content, err := migrationsFS.ReadFile("migrations/" + entry.Name())
		if err != nil {
			return fmt.Errorf("read migration %s: %w", entry.Name(), err)
		}
		if _, err := d.conn.Exec(string(content)); err != nil {
			return fmt.Errorf("apply migration %s: %w", entry.Name(), err)
		}
	}
	return nil
}