package db

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

	"ResendIt/internal/logger"

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

func Connect() (*gorm.DB, error) {
	dbType := os.Getenv("DB_TYPE")
	if dbType == "" {
		dbType = "sqlite"
	}
	dsn := os.Getenv("DATABASE_URL")
	if dbType == "sqlite" && dsn == "" {
		dsn = "./data/database.db"
	}

	logger.Log.Info().
		Str("type", "db_connect").
		Str("db_type", dbType).
		Msg("Connecting to database")

	var db *gorm.DB
	var err error

	switch dbType {
	case "sqlite":
		db, err = connectSQLite(dsn)

	case "postgres":
		db, err = connectPostgres(dsn)

	case "mysql":
		db, err = connectMySQL(dsn)

	default:
		return nil, fmt.Errorf("unsupported DB_TYPE: %s", dbType)
	}

	if err != nil {
		logger.Log.Error().
			Str("type", "db_connect").
			Str("db_type", dbType).
			Err(err).
			Msg("Failed to connect to database")
		return nil, err
	}

	logger.Log.Info().
		Str("type", "db_connect").
		Str("db_type", dbType).
		Msg("Database connected successfully")

	return db, nil
}

func connectSQLite(filePath string) (*gorm.DB, error) {
	if filePath == "" {
		filePath = "./data.db"
	}

	dir := filepath.Dir(filePath)
	if err := os.MkdirAll(dir, 0755); err != nil {
		return nil, fmt.Errorf("failed to create directory %s: %w", dir, err)
	}

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

	sqlDB, err := db.DB()
	if err == nil {
		sqlDB.SetMaxIdleConns(10)
		sqlDB.SetMaxOpenConns(100)
	}

	return db, nil
}

func connectPostgres(dsn string) (*gorm.DB, error) {
	if dsn == "" {
		return nil, fmt.Errorf("DATABASE_URL is required for postgres")
	}

	db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{})
	if err != nil {
		return nil, fmt.Errorf("failed to connect to Postgres: %w", err)
	}

	sqlDB, err := db.DB()
	if err == nil {
		sqlDB.SetMaxIdleConns(10)
		sqlDB.SetMaxOpenConns(100)
	}

	return db, nil
}

func connectMySQL(dsn string) (*gorm.DB, error) {
	if dsn == "" {
		return nil, fmt.Errorf("DATABASE_URL is required for mysql")
	}

	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{})
	if err != nil {
		return nil, fmt.Errorf("failed to connect to MySQL: %w", err)
	}

	sqlDB, err := db.DB()
	if err == nil {
		sqlDB.SetMaxIdleConns(10)
		sqlDB.SetMaxOpenConns(100)
	}

	return db, nil
}