package database

import (
	"fmt"
	"os"

	"gorm.io/driver/mysql"
	"gorm.io/gorm"
	"gorm.io/gorm/clause"
)

var DB *gorm.DB

func Connect() error {
	var err error
	var db *gorm.DB
	dbUser := os.Getenv("DB_USER")
	dbPassword := os.Getenv("DB_PASSWORD")
	dbHost := os.Getenv("DB_HOST")
	dbPort := os.Getenv("DB_PORT")
	dbName := os.Getenv("DB_NAME")

	dsn := fmt.Sprintf(
		"%s:%s@tcp(%s:%s)/%s?parseTime=true",
		dbUser, dbPassword, dbHost, dbPort, dbName,
	)

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

	DB = db
	return nil
}

var allModels []any

func RegisterModel(model any) {
	allModels = append(allModels, model)
}

type JoinTable struct {
	model     any
	field     string
	joinTable any
}

var allJoinTables []JoinTable

func RegisterJoinTable(model any, field string, joinTable any) {
	newJoin := JoinTable{
		model:     model,
		field:     field,
		joinTable: joinTable,
	}
	allJoinTables = append(allJoinTables, newJoin)
}

func Migrate() error {
	// Run migrations
	if err := DB.AutoMigrate(allModels...); err != nil {
		return fmt.Errorf("auto migration failed: %w", err)
	}

	for _, table := range allJoinTables {
		if err := DB.SetupJoinTable(table.model, table.field, table.joinTable); err != nil {
			return fmt.Errorf("creating custom join tables failed: %w", err)
		}
	}

	return nil
}

func Preload() *gorm.DB {
	return DB.Preload(clause.Associations)
}