package database

import (
	"fmt"
	"log"
	"net/url"
	"strings"

	"gorm.io/driver/postgres"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"

	"onixbyte.com/pipely/internal/model"
)

// Connect opens a PostgreSQL connection via GORM. If the target database does
// not exist it is created automatically. Tables are then migrated.
func Connect(databaseURL string) (*gorm.DB, error) {
	dbName, err := ensureDatabase(databaseURL)
	if err != nil {
		return nil, err
	}

	db, err := gorm.Open(postgres.Open(databaseURL), &gorm.Config{
		Logger: logger.Default.LogMode(logger.Warn),
	})
	if err != nil {
		return nil, fmt.Errorf("failed to open database: %w", err)
	}

	sqlDB, err := db.DB()
	if err != nil {
		return nil, fmt.Errorf("failed to get underlying sql.DB: %w", err)
	}
	sqlDB.SetMaxOpenConns(50)
	sqlDB.SetMaxIdleConns(10)

	log.Printf("[database] Connected to PostgreSQL database: %s", dbName)
	return db, nil
}

// AutoMigrate creates or updates tables to match the model definitions.
func AutoMigrate(db *gorm.DB) error {
	return db.AutoMigrate(
		&model.AdminUser{},
		&model.Device{},
		&model.Artefact{},
		&model.Deployment{},
		&model.DeploymentDevice{},
	)
}

// ensureDatabase creates the target database if it does not exist.
func ensureDatabase(databaseURL string) (string, error) {
	u, err := url.Parse(databaseURL)
	if err != nil {
		return "", fmt.Errorf("invalid database URL: %w", err)
	}
	dbName := strings.TrimPrefix(u.Path, "/")

	adminURL := *u
	adminURL.Path = "/postgres"

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

	var exists bool
	db.Raw("SELECT EXISTS(SELECT 1 FROM pg_database WHERE datname = ?)", dbName).Scan(&exists)
	if !exists {
		if err := db.Exec(fmt.Sprintf(`CREATE DATABASE "%s"`, dbName)).Error; err != nil {
			return "", fmt.Errorf("failed to create database %s: %w", dbName, err)
		}
		log.Printf("[database] Created database: %s", dbName)
	}

	sqlDB, _ := db.DB()
	if sqlDB != nil {
		sqlDB.Close()
	}
	return dbName, nil
}