package database

import (
	"api_yal/internal/config"
	"api_yal/migrations"
	"database/sql"
	"fmt"
	"time"

	"github.com/golang-migrate/migrate/v4"
	"github.com/golang-migrate/migrate/v4/database/postgres"
	"github.com/golang-migrate/migrate/v4/source/iofs"
	"go.uber.org/zap"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"

	"api_yal/internal/logger"
)

func NewPostgresConnection(cfg *config.Config) (*gorm.DB, error) {
	zapLogger := logger.Get()
	zapLogger.Info("Start connect to Postgres DB")
	dsn := fmt.Sprintf("host=%s user=%s password=%s dbname=%s port=%s sslmode=disable TimeZone=UTC",
		cfg.DBHost, cfg.DBUser, cfg.DBPassword, cfg.DBName, cfg.DBPort)
	zapLogger.Info("dsn = %s", zap.String("dsn", dsn))

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

	zapLogger.Info("Configure connection pool")
	sqlDB, err := db.DB()
	if err != nil {
		return nil, fmt.Errorf("failed to get underlying sql.DB: %w", err)
	}
	sqlDB.SetMaxOpenConns(25)
	sqlDB.SetMaxIdleConns(10)
	sqlDB.SetConnMaxLifetime(30 * time.Minute)

	zapLogger.Info("Run database migrations")
	if err := runMigrations(sqlDB); err != nil {
		return nil, fmt.Errorf("failed to run migrations: %w", err)
	}
	zapLogger.Info("Migrations completed successfully")

	zapLogger.Info("Successfully connected to database")
	return db, nil
}

func runMigrations(sqlDB *sql.DB) error {
	zapLogger := logger.Get()

	source, err := iofs.New(migrations.FS, ".")
	if err != nil {
		return fmt.Errorf("failed to create migration source: %w", err)
	}

	driver, err := postgres.WithInstance(sqlDB, &postgres.Config{})
	if err != nil {
		return fmt.Errorf("failed to create postgres driver: %w", err)
	}

	m, err := migrate.NewWithInstance("iofs", source, "postgres", driver)
	if err != nil {
		return fmt.Errorf("failed to create migrate instance: %w", err)
	}

	if err := m.Up(); err != nil && err != migrate.ErrNoChange {
		zapLogger.Error("Migration error", zap.Error(err))
		return fmt.Errorf("failed to apply migrations: %w", err)
	}

	return nil
}