funstat-mcp-go/internal/app/config.go

package app

import (
	"fmt"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	tgconfig "funstatmcp/internal/telegram"
)

type Config struct {
	Telegram       tgconfig.Config
	Host           string
	Port           int
	RequireSession bool
}

func FromEnv() (Config, error) {
	var cfg Config

	telegramCfg, err := loadTelegramConfig()
	if err != nil {
		return cfg, err
	}

	cfg.Telegram = telegramCfg
	cfg.Host = getEnvDefault("FUNSTAT_HOST", "127.0.0.1")

	portStr := getEnvDefault("FUNSTAT_PORT", "8091")
	port, err := strconv.Atoi(portStr)
	if err != nil {
		return cfg, fmt.Errorf("invalid FUNSTAT_PORT: %w", err)
	}
	cfg.Port = port

	cfg.RequireSession = parseBool(getEnvDefault("FUNSTAT_REQUIRE_SESSION", "false"))

	return cfg, nil
}

func loadTelegramConfig() (tgconfig.Config, error) {
	var cfg tgconfig.Config

	apiIDStr := os.Getenv("TELEGRAM_API_ID")
	if apiIDStr == "" {
		return cfg, fmt.Errorf("TELEGRAM_API_ID is required")
	}
	apiID, err := strconv.Atoi(apiIDStr)
	if err != nil {
		return cfg, fmt.Errorf("invalid TELEGRAM_API_ID: %w", err)
	}
	cfg.APIID = apiID

	cfg.APIHash = strings.TrimSpace(os.Getenv("TELEGRAM_API_HASH"))
	if cfg.APIHash == "" {
		return cfg, fmt.Errorf("TELEGRAM_API_HASH is required")
	}

	cfg.BotUsername = getEnvDefault("FUNSTAT_BOT_USERNAME", "@openaiw_bot")
	cfg.SessionString = strings.TrimSpace(os.Getenv("TELEGRAM_SESSION_STRING"))
	sessionStringFile := strings.TrimSpace(os.Getenv("TELEGRAM_SESSION_STRING_FILE"))
	if cfg.SessionString == "" && sessionStringFile != "" {
		data, err := os.ReadFile(expandPath(sessionStringFile))
		if err != nil {
			return cfg, fmt.Errorf("read TELEGRAM_SESSION_STRING_FILE: %w", err)
		}
		cfg.SessionString = strings.TrimSpace(string(data))
	}

	sessionPath := strings.TrimSpace(os.Getenv("TELEGRAM_SESSION_PATH"))
	if sessionPath != "" {
		if !strings.HasSuffix(sessionPath, ".session") {
			sessionPath = sessionPath + ".session"
		}
		cfg.SessionStorage = expandPath(sessionPath)
	} else {
		cfg.SessionStorage = defaultSessionPath()
	}

	if value := strings.TrimSpace(os.Getenv("FUNSTAT_RATE_LIMIT_PER_SECOND")); value != "" {
		parsed, err := strconv.Atoi(value)
		if err != nil {
			return cfg, fmt.Errorf("invalid FUNSTAT_RATE_LIMIT_PER_SECOND: %w", err)
		}
		cfg.RateLimit = parsed
	}

	if value := strings.TrimSpace(os.Getenv("FUNSTAT_RATE_LIMIT_WINDOW")); value != "" {
		duration, err := time.ParseDuration(value)
		if err != nil {
			return cfg, fmt.Errorf("invalid FUNSTAT_RATE_LIMIT_WINDOW: %w", err)
		}
		cfg.RateLimitWindow = duration
	}

	if value := strings.TrimSpace(os.Getenv("FUNSTAT_CACHE_TTL")); value != "" {
		duration, err := time.ParseDuration(value)
		if err != nil {
			return cfg, fmt.Errorf("invalid FUNSTAT_CACHE_TTL: %w", err)
		}
		cfg.CacheTTL = duration
	}

	proxyHost := strings.TrimSpace(os.Getenv("FUNSTAT_PROXY_HOST"))
	proxyPort := strings.TrimSpace(os.Getenv("FUNSTAT_PROXY_PORT"))
	if proxyHost != "" && proxyPort != "" {
		port, err := strconv.Atoi(proxyPort)
		if err != nil {
			return cfg, fmt.Errorf("invalid FUNSTAT_PROXY_PORT: %w", err)
		}
		cfg.Proxy = &tgconfig.ProxyConfig{
			Type:     getEnvDefault("FUNSTAT_PROXY_TYPE", "socks5"),
			Host:     proxyHost,
			Port:     port,
			Username: strings.TrimSpace(os.Getenv("FUNSTAT_PROXY_USERNAME")),
			Password: strings.TrimSpace(os.Getenv("FUNSTAT_PROXY_PASSWORD")),
		}
	}

	return cfg, nil
}

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

func parseBool(value string) bool {
	switch strings.ToLower(strings.TrimSpace(value)) {
	case "1", "true", "yes", "on":
		return true
	default:
		return false
	}
}

func defaultSessionPath() string {
	home, err := os.UserHomeDir()
	if err != nil {
		return filepath.Join(os.TempDir(), "funstatmcp", "session.json")
	}
	return filepath.Join(home, ".funstatmcp", "session.json")
}

func expandPath(path string) string {
	if strings.HasPrefix(path, "~") {
		home, err := os.UserHomeDir()
		if err == nil {
			return filepath.Join(home, strings.TrimPrefix(path, "~"))
		}
	}
	return path
}