package config

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

type Config struct {
	HTTPAddr         string
	StaticDir        string
	MySQLDSN         string
	RedisAddr        string
	RedisUsername    string
	RedisPassword    string
	RedisDB          int
	TDengineDriver   string
	TDengineDSN      string
	TDengineDatabase string
	CapacityCheckBin string
	AuthToken        string
	RequestTimeout   time.Duration
}

func Load() Config {
	return Config{
		HTTPAddr:         env("HTTP_ADDR", ":20300"),
		StaticDir:        env("STATIC_DIR", ""),
		MySQLDSN:         os.Getenv("MYSQL_DSN"),
		RedisAddr:        os.Getenv("REDIS_ADDR"),
		RedisUsername:    os.Getenv("REDIS_USERNAME"),
		RedisPassword:    os.Getenv("REDIS_PASSWORD"),
		RedisDB:          envInt("REDIS_DB", 50),
		TDengineDriver:   env("TDENGINE_DRIVER", "taosWS"),
		TDengineDSN:      os.Getenv("TDENGINE_DSN"),
		TDengineDatabase: env("TDENGINE_DATABASE", "lingniu_vehicle_ts"),
		CapacityCheckBin: os.Getenv("CAPACITY_CHECK_BIN"),
		AuthToken:        os.Getenv("AUTH_TOKEN"),
		RequestTimeout:   time.Duration(envInt("REQUEST_TIMEOUT_MS", 5000)) * time.Millisecond,
	}
}

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

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