package config

import (
	"bufio"
	"fmt"
	"os"
	"strings"
)

type Config struct {
	HTTPAddr    string
	DatabaseURL string
	SessionKey  string
	AppEnv      string
	AdminEmail  string
	AdminPass   string
}

func Load() Config {
	if err := loadDotEnv(".env"); err != nil {
		fmt.Fprintf(os.Stderr, "warning: load .env: %v\n", err)
	}

	return Config{
		HTTPAddr:    getenv("HTTP_ADDR", ":8080"),
		DatabaseURL: getenv("DATABASE_URL", "postgres://postgres:postgres@localhost:5433/superbanka?sslmode=disable"),
		SessionKey:  getenv("SESSION_KEY", "dev-session-key-change-me"),
		AppEnv:      getenv("APP_ENV", "development"),
		AdminEmail:  getenv("ADMIN_EMAIL", "admin@superbanka.local"),
		AdminPass:   getenv("ADMIN_PASSWORD", "admin123456"),
	}
}

func getenv(key, fallback string) string {
	if value := os.Getenv(key); value != "" {
		return value
	}

	return fallback
}

func loadDotEnv(path string) error {
	file, err := os.Open(path)
	if err != nil {
		if os.IsNotExist(err) {
			return nil
		}
		return err
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	lineNumber := 0
	for scanner.Scan() {
		lineNumber++
		line := strings.TrimSpace(scanner.Text())
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}

		key, value, ok := strings.Cut(line, "=")
		if !ok {
			return fmt.Errorf("line %d: missing '='", lineNumber)
		}

		key = strings.TrimSpace(key)
		value = strings.TrimSpace(value)
		value = strings.Trim(value, `"'`)
		if key == "" {
			return fmt.Errorf("line %d: empty key", lineNumber)
		}

		if _, exists := os.LookupEnv(key); exists {
			continue
		}

		if err := os.Setenv(key, value); err != nil {
			return fmt.Errorf("line %d: set %s: %w", lineNumber, key, err)
		}
	}

	return scanner.Err()
}