package repository

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

	"gorm.io/driver/postgres"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"

	"github.com/dhao2001/mygo/internal/config"
	"github.com/dhao2001/mygo/internal/model"
)

// Open creates a GORM database connection based on the config driver.
func Open(cfg config.DatabaseConfig) (*gorm.DB, error) {
	var dialector gorm.Dialector

	switch cfg.Driver {
	case "sqlite3":
		dir := filepath.Dir(cfg.SQLite.Path)
		if err := os.MkdirAll(dir, 0755); err != nil {
			return nil, fmt.Errorf("create db directory: %w", err)
		}
		dialector = sqlite.Open(cfg.SQLite.Path)
	case "postgres":
		dsn := fmt.Sprintf(
			"host=%s user=%s password=%s dbname=%s port=%d sslmode=%s",
			cfg.Postgres.Host,
			cfg.Postgres.User,
			cfg.Postgres.Password,
			cfg.Postgres.DBName,
			cfg.Postgres.Port,
			cfg.Postgres.SSLMode,
		)
		dialector = postgres.Open(dsn)
	default:
		return nil, fmt.Errorf("unsupported database driver: %s", cfg.Driver)
	}

	db, err := gorm.Open(dialector, &gorm.Config{})
	if err != nil {
		return nil, fmt.Errorf("open database: %w", err)
	}

	return db, nil
}

// AutoMigrate runs schema migration for all domain models.
func AutoMigrate(db *gorm.DB) error {
	return db.AutoMigrate(
		&model.User{},
		&model.Session{},
		&model.File{},
	)
}