package config

import (
	"fmt"
	"os"
	"strconv"
	"strings"
	"time"

	"github.com/joho/godotenv"
)

// Config centralizes runtime configuration loaded from the environment.
type Config struct {
	AppName               string
	Port                  string
	DatabaseURL           string
	MercadoPagoBaseURL    string
	MarketplaceCommission float64
	BuyerFeeRate          float64 // Fee rate applied to buyer prices (e.g., 0.12 = 12%)
	JWTSecret             string
	JWTExpiresIn          time.Duration
	PasswordPepper        string
	CORSOrigins           []string
	BackendHost           string
	SwaggerSchemes        []string
	AdminName             string
	AdminUsername         string
	AdminEmail            string
	AdminPassword         string
}

// Load reads configuration from environment variables and applies sane defaults
// for local development.
func Load() Config {
	_ = godotenv.Load() // Load from .env if present

	cfg := Config{
		AppName:               getEnv("APP_NAME", "saveinmed-performance-core"),
		Port:                  getEnv("BACKEND_PORT", "8214"),
		DatabaseURL:           getEnv("DATABASE_URL", "postgres://postgres:postgres@localhost:5432/saveinmed?sslmode=disable"),
		MercadoPagoBaseURL:    getEnv("MERCADOPAGO_BASE_URL", "https://api.mercadopago.com"),
		MarketplaceCommission: getEnvFloat("MARKETPLACE_COMMISSION", 2.5),
		BuyerFeeRate:          getEnvFloat("BUYER_FEE_RATE", 0.12), // 12% invisible fee
		JWTSecret:             getEnv("JWT_SECRET", "dev-secret"),
		JWTExpiresIn:          getEnvDuration("JWT_EXPIRES_IN", 24*time.Hour),
		PasswordPepper:        getEnv("PASSWORD_PEPPER", ""),
		CORSOrigins:           getEnvStringSlice("CORS_ORIGINS", []string{"*"}),
		BackendHost:           getEnv("BACKEND_HOST", ""),
		SwaggerSchemes:        getEnvStringSlice("SWAGGER_SCHEMES", []string{"http"}),
		AdminName:             getEnv("ADMIN_NAME", "Administrator"),
		AdminUsername:         getEnv("ADMIN_USERNAME", "admin"),
		AdminEmail:            getEnv("ADMIN_EMAIL", "admin@saveinmed.com"),
		AdminPassword:         getEnv("ADMIN_PASSWORD", "admin123"),
	}

	return cfg
}

// Addr returns the address binding for the HTTP server.
func (c Config) Addr() string {
	return fmt.Sprintf(":%s", c.Port)
}

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

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

func getEnvDuration(key string, fallback time.Duration) time.Duration {
	if value := os.Getenv(key); value != "" {
		if parsed, err := time.ParseDuration(value); err == nil {
			return parsed
		}
	}
	return fallback
}

func getEnvFloat(key string, fallback float64) float64 {
	if value := os.Getenv(key); value != "" {
		if parsed, err := strconv.ParseFloat(value, 64); err == nil {
			return parsed
		}
	}
	return fallback
}

func getEnvStringSlice(key string, fallback []string) []string {
	if value := os.Getenv(key); value != "" {
		parts := strings.Split(value, ",")
		result := make([]string, 0, len(parts))
		for _, p := range parts {
			if trimmed := strings.TrimSpace(p); trimmed != "" {
				result = append(result, trimmed)
			}
		}
		if len(result) > 0 {
			return result
		}
	}
	return fallback
}