package config

import (
	"os"
	"strconv"
	"time"
)

type Config struct {
	Server   ServerConfig
	Postgres PostgresConfig
	Redis    RedisConfig
	Log      LogConfig
	Auth     AuthConfig
}

type ServerConfig struct {
	Port string
}

type AuthConfig struct {
	JWTSecret string
}

type PostgresConfig struct {
	DSN string
}

type RedisConfig struct {
	Addr     string
	Password string
	DB       int
}

type LogConfig struct {
	BatchSize     int
	FlushInterval time.Duration
	QueueCapacity int
}

func Load() (*Config, error) {
	return &Config{
		Server: ServerConfig{
			Port: getEnv("EZ_API_PORT", "8080"),
		},
		Postgres: PostgresConfig{
			DSN: getEnv("EZ_PG_DSN", "host=localhost user=postgres password=postgres dbname=ezapi port=5432 sslmode=disable"),
		},
		Redis: RedisConfig{
			Addr:     getEnv("EZ_REDIS_ADDR", "localhost:6379"),
			Password: getEnv("EZ_REDIS_PASSWORD", ""),
			DB:       getEnvInt("EZ_REDIS_DB", 0),
		},
		Log: LogConfig{
			BatchSize:     getEnvInt("EZ_LOG_BATCH_SIZE", 10),
			FlushInterval: getEnvDuration("EZ_LOG_FLUSH_MS", 1000),
			QueueCapacity: getEnvInt("EZ_LOG_QUEUE", 10000),
		},
		Auth: AuthConfig{
			JWTSecret: getEnv("EZ_JWT_SECRET", "change_me_in_production"),
		},
	}, nil
}

func getEnv(key, fallback string) string {
	if value, ok := os.LookupEnv(key); ok {
		return value
	}
	return fallback
}

func getEnvInt(key string, fallback int) int {
	if value, ok := os.LookupEnv(key); ok {
		if i, err := strconv.Atoi(value); err == nil {
			return i
		}
	}
	return fallback
}

func getEnvDuration(key string, fallbackMs int) time.Duration {
	if value, ok := os.LookupEnv(key); ok {
		if i, err := strconv.Atoi(value); err == nil {
			return time.Duration(i) * time.Millisecond
		}
	}
	return time.Duration(fallbackMs) * time.Millisecond
}