package database

import (
	"fmt"
	"log"

	"github.com/ydn/yourdreamnamehere/internal/models"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"
)

type Database struct {
	DB *gorm.DB
}

func NewDatabase(dsn string, logLevel logger.LogLevel) (*Database, error) {
	db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{
		Logger: logger.Default.LogMode(logLevel),
	})
	if err != nil {
		return nil, fmt.Errorf("failed to connect to database: %w", err)
	}

	return &Database{DB: db}, nil
}

func (d *Database) Migrate() error {
	log.Println("Running database migrations...")

	err := d.DB.AutoMigrate(
		&models.User{},
		&models.Customer{},
		&models.Subscription{},
		&models.Domain{},
		&models.VPS{},
		&models.DeploymentLog{},
		&models.Invitation{},
	)

	if err != nil {
		return fmt.Errorf("failed to run migrations: %w", err)
	}

	// Add additional constraints that GORM doesn't handle
	if err := d.addConstraints(); err != nil {
		return fmt.Errorf("failed to add constraints: %w", err)
	}

	// Create indexes for performance
	if err := d.createIndexes(); err != nil {
		return fmt.Errorf("failed to create indexes: %w", err)
	}

	log.Println("Database migrations completed successfully")
	return nil
}

func (d *Database) addConstraints() error {
	// Add check constraints
	constraints := []string{
		"ALTER TABLE users ADD CONSTRAINT check_users_role CHECK (role IN ('user', 'admin'))",
		"ALTER TABLE customers ADD CONSTRAINT check_customers_status CHECK (status IN ('pending', 'active', 'canceled', 'past_due'))",
		"ALTER TABLE subscriptions ADD CONSTRAINT check_subscriptions_status CHECK (status IN ('active', 'trialing', 'past_due', 'canceled', 'unpaid'))",
		"ALTER TABLE subscriptions ADD CONSTRAINT check_subscriptions_interval CHECK (interval IN ('month', 'year'))",
		"ALTER TABLE domains ADD CONSTRAINT check_domains_status CHECK (status IN ('pending', 'registered', 'active', 'error', 'expired'))",
		"ALTER TABLE vps ADD CONSTRAINT check_vps_status CHECK (status IN ('pending', 'provisioning', 'active', 'error', 'terminated'))",
		"ALTER TABLE deployment_logs ADD CONSTRAINT check_deployment_logs_status CHECK (status IN ('started', 'completed', 'failed', 'in_progress'))",
		"ALTER TABLE invitations ADD CONSTRAINT check_invitations_status CHECK (status IN ('pending', 'accepted', 'expired'))",
	}

	for _, constraint := range constraints {
		if err := d.DB.Exec(constraint).Error; err != nil {
			// Log but don't fail if constraint already exists
			log.Printf("Warning: Failed to add constraint (may already exist): %v", err)
		}
	}

	return nil
}

func (d *Database) createIndexes() error {
	indexes := []string{
		"CREATE INDEX IF NOT EXISTS idx_users_email ON users(email)",
		"CREATE INDEX IF NOT EXISTS idx_customers_user_id ON customers(user_id)",
		"CREATE INDEX IF NOT EXISTS idx_customers_stripe_id ON customers(stripe_id)",
		"CREATE INDEX IF NOT EXISTS idx_customers_status ON customers(status)",
		"CREATE INDEX IF NOT EXISTS idx_subscriptions_customer_id ON subscriptions(customer_id)",
		"CREATE INDEX IF NOT EXISTS idx_subscriptions_stripe_id ON subscriptions(stripe_id)",
		"CREATE INDEX IF NOT EXISTS idx_subscriptions_status ON subscriptions(status)",
		"CREATE INDEX IF NOT EXISTS idx_domains_customer_id ON domains(customer_id)",
		"CREATE INDEX IF NOT EXISTS idx_domains_name ON domains(name)",
		"CREATE INDEX IF NOT EXISTS idx_domains_status ON domains(status)",
		"CREATE INDEX IF NOT EXISTS idx_vps_domain_id ON vps(domain_id)",
		"CREATE INDEX IF NOT EXISTS idx_vps_ovh_instance_id ON vps(ovh_instance_id)",
		"CREATE INDEX IF NOT EXISTS idx_vps_status ON vps(status)",
		"CREATE INDEX IF NOT EXISTS idx_deployment_logs_vps_id ON deployment_logs(vps_id)",
		"CREATE INDEX IF NOT EXISTS idx_deployment_logs_created_at ON deployment_logs(created_at)",
		"CREATE INDEX IF NOT EXISTS idx_invitations_token ON invitations(token)",
		"CREATE INDEX IF NOT EXISTS idx_invitations_vps_id ON invitations(vps_id)",
		"CREATE INDEX IF NOT EXISTS idx_invitations_expires_at ON invitations(expires_at)",
	}

	for _, index := range indexes {
		if err := d.DB.Exec(index).Error; err != nil {
			log.Printf("Warning: Failed to create index (may already exist): %v", err)
		}
	}

	return nil
}

func (d *Database) Close() error {
	sqlDB, err := d.DB.DB()
	if err != nil {
		return fmt.Errorf("failed to get underlying sql.DB: %w", err)
	}

	return sqlDB.Close()
}

func (d *Database) Health() error {
	sqlDB, err := d.DB.DB()
	if err != nil {
		return fmt.Errorf("failed to get underlying sql.DB: %w", err)
	}

	if err := sqlDB.Ping(); err != nil {
		return fmt.Errorf("failed to ping database: %w", err)
	}

	return nil
}