package config

import (
	"log"
	"os"
	"strconv"
	"strings"
	"time"
)

type Config struct {
	Addr            string
	SessionTTL      time.Duration
	MaxUploadSize   int64
	CookieSecure    bool
	LogLevel        string
	GitAllowedHosts []string
}

func Load() Config {
	cfg := Config{
		Addr:          envOrDefault("ADDR", ":8080"),
		SessionTTL:    durationEnvOrDefault("SESSION_TTL", 30*time.Minute),
		MaxUploadSize: int64(intEnvOrDefault("MAX_UPLOAD_SIZE", 5*1024*1024)),
		CookieSecure:  boolEnvOrDefault("COOKIE_SECURE", true),
		LogLevel:      envOrDefault("LOG_LEVEL", "info"),
		GitAllowedHosts: csvEnvOrDefault("GIT_ALLOWED_HOSTS", []string{
			"github.com",
			"gitlab.com",
			"bitbucket.org",
		}),
	}
	return cfg
}

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

func intEnvOrDefault(key string, fallback int) int {
	if value := os.Getenv(key); value != "" {
		parsed, err := strconv.Atoi(value)
		if err != nil {
			log.Printf("invalid integer for %s: %v", key, err)
			return fallback
		}
		return parsed
	}
	return fallback
}

func boolEnvOrDefault(key string, fallback bool) bool {
	if value := os.Getenv(key); value != "" {
		parsed, err := strconv.ParseBool(value)
		if err != nil {
			log.Printf("invalid boolean for %s: %v", key, err)
			return fallback
		}
		return parsed
	}
	return fallback
}

func durationEnvOrDefault(key string, fallback time.Duration) time.Duration {
	if value := os.Getenv(key); value != "" {
		parsed, err := time.ParseDuration(value)
		if err != nil {
			log.Printf("invalid duration for %s: %v", key, err)
			return fallback
		}
		return parsed
	}
	return fallback
}

func csvEnvOrDefault(key string, fallback []string) []string {
	raw := strings.TrimSpace(os.Getenv(key))
	if raw == "" {
		return fallback
	}
	var out []string
	for _, part := range strings.Split(raw, ",") {
		host := strings.ToLower(strings.TrimSpace(part))
		if host == "" {
			continue
		}
		out = append(out, host)
	}
	if len(out) == 0 {
		return fallback
	}
	return out
}