package config

import (
	"fmt"
	"os"
	"strconv"

	"github.com/joho/godotenv"
)

// Config holds all configuration for the application.
type Config struct {
	// Server
	Env  string // "development" | "production"
	Port int

	// MongoDB (content database)
	MongoURI string
	MongoDB  string

	// PostgreSQL (users, relations, URL shortener)
	PostgresURI string

	// Meilisearch
	MeilisearchHost   string
	MeilisearchAPIKey string

	// DragonflyDB / Redis
	RedisURI string

	// AWS S3
	S3Region    string
	S3Bucket    string
	S3AccessKey string
	S3SecretKey string
	S3Endpoint  string // optional — for S3-compatible services (MinIO, etc.)

	// Push Notifications
	FCMCredentialsFile string // path to Firebase service account JSON
	APNsKeyFile        string // path to APNs auth key
	APNsKeyID          string
	APNsTeamID         string
	APNsBundleID       string

	// JWT Auth
	JWTSecret     string
	JWTExpiration string // e.g., "24h"

	// Frontend
	FrontendURL string // for CORS
}

// Load reads configuration from environment variables (with .env fallback).
func Load() (*Config, error) {
	// Load .env file if present (ignored in production)
	_ = godotenv.Load()

	cfg := &Config{
		Env:  getEnv("APP_ENV", "development"),
		Port: getEnvInt("PORT", 8080),

		MongoURI: getEnv("MONGO_URI", ""),
		MongoDB:  getEnv("MONGO_DB", "spsays"),

		PostgresURI: getEnv("POSTGRES_URI", ""),

		MeilisearchHost:   getEnv("MEILISEARCH_HOST", "http://localhost:7700"),
		MeilisearchAPIKey: getEnv("MEILISEARCH_API_KEY", ""),

		RedisURI: getEnv("REDIS_URI", "redis://localhost:6379"),

		S3Region:    getEnv("S3_REGION", ""),
		S3Bucket:    getEnv("S3_BUCKET", ""),
		S3AccessKey: getEnv("S3_ACCESS_KEY", ""),
		S3SecretKey: getEnv("S3_SECRET_KEY", ""),
		S3Endpoint:  getEnv("S3_ENDPOINT", ""),

		FCMCredentialsFile: getEnv("FCM_CREDENTIALS_FILE", ""),
		APNsKeyFile:        getEnv("APNS_KEY_FILE", ""),
		APNsKeyID:          getEnv("APNS_KEY_ID", ""),
		APNsTeamID:         getEnv("APNS_TEAM_ID", ""),
		APNsBundleID:       getEnv("APNS_BUNDLE_ID", ""),

		JWTSecret:     getEnv("JWT_SECRET", ""),
		JWTExpiration: getEnv("JWT_EXPIRATION", "24h"),

		FrontendURL: getEnv("FRONTEND_URL", "http://localhost:3000"),
	}

	// Validate required fields
	if cfg.MongoURI == "" {
		return nil, fmt.Errorf("MONGO_URI is required")
	}

	return cfg, nil
}

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

func getEnvInt(key string, fallback int) int {
	if v := os.Getenv(key); v != "" {
		if i, err := strconv.Atoi(v); err == nil {
			return i
		}
	}
	return fallback
}