package config

import (
	"errors"
	"fmt"
	"os"
	"strings"

	"github.com/joho/godotenv"
)

type Config struct {
	RunMode   RunMode
	DebugMode bool
	BotToken  string

	DBConnectionString string

	OCRTokenPath string

	TelegramApi string

	APIPort         string
	APIHost         string
	APISecret       string
	OpenAPIEnabled  bool
	OpenAPIEndpoint string
}

func Load() (Config, error) {
	_ = godotenv.Load()
	var warnings []string

	mode := os.Getenv("RUN_MODE")
	debugMode := os.Getenv("DEBUG_MODE") == "true"
	botToken := os.Getenv("BOT_TOKEN")
	ocrTokenPath := os.Getenv("GOOGLE_APPLICATION_CREDENTIALS")
	apiPort := os.Getenv("API_PORT")
	apiHost := os.Getenv("API_HOST")
	apiSecret := os.Getenv("API_SECRET")
	openAPIEnabled := os.Getenv("OPEN_API_ENABLED") == "true"
	openAPIEndpoint := os.Getenv("OPEN_API_ENDPOINT")

	runMode, err := ParseRunMode(mode)
	dbConnectionString := buildConnectionString()
	if err != nil {
		warnings = append(warnings, err.Error())
	}

	if runMode == Bot || runMode == Standalone {
		if ocrTokenPath == "" {
			warnings = append(warnings, "Missing required environment variable: GOOGLE_APPLICATION_CREDENTIALS")
		}
		if botToken == "" {
			warnings = append(warnings, "Missing required environment variable: BOT_TOKEN")
		}
	}
	if runMode == API || runMode == Standalone {
		if ocrTokenPath == "" {
			warnings = append(warnings, "Missing required environment variable: GOOGLE_APPLICATION_CREDENTIALS")
		}
		if apiSecret == "" {
			warnings = append(warnings, "Missing required environment variable: API_SECRET")
		}
		if apiHost == "" {
			apiHost = "localhost"
		}
		if apiPort == "" {
			apiPort = "8000"
		}
		if openAPIEndpoint == "" {
			openAPIEndpoint = "/openapi"
		}
	}

	if len(warnings) > 0 {
		return Config{}, errors.New(strings.Join(warnings, "\n"))
	}
	return Config{
		BotToken:           botToken,
		DBConnectionString: dbConnectionString,
		OCRTokenPath:       ocrTokenPath,
		DebugMode:          debugMode,
		RunMode:            runMode,
		APIPort:            apiPort,
		APIHost:            apiHost,
		APISecret:          apiSecret,
		OpenAPIEnabled:     openAPIEnabled,
		OpenAPIEndpoint:    openAPIEndpoint,
		TelegramApi:        "https://api.telegram.org",
	}, nil
}

func buildConnectionString() string {
	// если задана готовая строка — используем её (удобно для локальной разработки через .env)
	if dsn := os.Getenv("DB_PATH"); dsn != "" {
		return dsn
	}

	// собираем из отдельных переменных (для Kubernetes)
	host := os.Getenv("DB_HOST")
	port := os.Getenv("DB_PORT")
	user := os.Getenv("DB_USER")
	password := os.Getenv("DB_PASSWORD")
	dbName := os.Getenv("DB_NAME")

	if host == "" || user == "" || password == "" || dbName == "" {
		return ""
	}

	if port == "" {
		port = "5432"
	}

	return fmt.Sprintf(
		"postgres://%s:%s@%s:%s/%s?sslmode=disable",
		user, password, host, port, dbName,
	)
}