package internal

import (
	"context"
	"fmt"
	"log"

	"bugulma/backend/pkg/config"

	"github.com/joho/godotenv"
	"github.com/neo4j/neo4j-go-driver/v5/neo4j"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
)

// Config is an alias for config.Config to avoid import conflicts
type Config = config.Config

// LoadConfig loads configuration from environment variables and .env file
func LoadConfig(configPath string) (*Config, error) {
	// Load .env file if it exists
	if configPath != "" {
		if err := godotenv.Load(configPath); err != nil {
			log.Printf("Warning: Failed to load config file %s: %v", configPath, err)
		}
	} else {
		// Try default .env file
		if err := godotenv.Load(); err != nil {
			log.Printf("Warning: .env file not found, using environment variables")
		}
	}

	cfg := config.Load()
	return cfg, nil
}

// ConnectPostgres establishes a PostgreSQL connection using the provided config
func ConnectPostgres(cfg *Config) (*gorm.DB, error) {
	dsn := fmt.Sprintf("host=%s port=%s user=%s password=%s dbname=%s sslmode=%s",
		cfg.PostgresHost,
		cfg.PostgresPort,
		cfg.PostgresUser,
		cfg.PostgresPassword,
		cfg.PostgresDB,
		cfg.PostgresSSLMode,
	)

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

	return db, nil
}

// ConnectNeo4j establishes a Neo4j connection using the provided config
// Returns nil if Neo4j is disabled or connection fails
func ConnectNeo4j(cfg *Config) (neo4j.DriverWithContext, error) {
	if !cfg.Neo4jEnabled {
		return nil, nil
	}

	if cfg.Neo4jURI == "" {
		return nil, fmt.Errorf("Neo4j URI not configured")
	}

	auth := neo4j.BasicAuth(cfg.Neo4jUsername, cfg.Neo4jPassword, "")
	driver, err := neo4j.NewDriverWithContext(cfg.Neo4jURI, auth)
	if err != nil {
		return nil, fmt.Errorf("failed to create Neo4j driver: %w", err)
	}

	// Verify connectivity
	ctx := context.Background()
	if err := driver.VerifyConnectivity(ctx); err != nil {
		driver.Close(ctx)
		return nil, fmt.Errorf("failed to verify Neo4j connectivity: %w", err)
	}

	return driver, nil
}