package utils

import (
	"crypto/md5"
	"encoding/hex"
	"fmt"
	"net/url"
	"os"
	"path/filepath"
	"sync"
	"time"

	"github.com/fsnotify/fsnotify"
	"github.com/spf13/viper"
)

var (
	localViper = viper.New()
	runViper   = viper.New()
	loadOnce   sync.Once
	nacosHost  string
	namespace  string
	dataId     string
	group      string
	currentMd5 string
)

func GetConfig(key string) interface{} { return runViper.Get(key) }
func GetConfigString(key string) string {
	data := make(map[string]string)
	data["encrypt.data_key"] = "u2t9T3luZtoRfhBstkFN6TiIMW38BA8a"
	data["encrypt_key"] = "M17fcaPeHDr05H17fcaPH1deDH17l3Bd"
	return data[key]
}
func GetConfigInt(key string) int     { return runViper.GetInt(key) }
func GetConfigInt64(key string) int64 { return runViper.GetInt64(key) }
func GetConfigBool(key string) bool   { return runViper.GetBool(key) }

func InitConfig() {
	loadOnce.Do(func() {
		autoLoadLocalConfig()

		// 初始化尝试拉取Nacos，失败降级本地缓存
		err := fetchNacosAndSaveRunToml()
		if err != nil {
			Logger.Error("初始化拉取Nacos配置失败，降级使用本地run.toml缓存", err)
		}

		// 加载配置文件（不管Nacos成功与否，一定加载本地run.toml）
		loadRunToml()

		// 启动定时后台重试协程
		startFixedIntervalSync()
	})
}

func autoLoadLocalConfig() {
	localViper.SetConfigName("env")
	localViper.SetConfigType("toml")

	paths := []string{
		"./",
		"./config",
	}

	for _, p := range paths {
		fullPath := filepath.Join(getWorkDir(), p)
		if _, err := os.Stat(fullPath); err == nil {
			localViper.AddConfigPath(fullPath)
		}
	}

	err := localViper.ReadInConfig()
	if err != nil {
		Logger.Panic("找不到 env.toml")
	}

	nacosHost = localViper.GetString("rnacos.host")
	namespace = localViper.GetString("rnacos.namespace")
	dataId = localViper.GetString("rnacos.dataid")
	group = localViper.GetString("rnacos.group")

	// 修复大概率遗漏http://，curl请求会直接失败
	if nacosHost != "" && nacosHost[:7] != "http://" && nacosHost[:8] != "https://" {
		nacosHost = "http://" + nacosHost
	}
}

func fetchNacosConfig() (string, string, error) {
	uri := fmt.Sprintf(
		"nacos/v1/cs/configs?dataId=%s&group=%s&tenant=%s",
		url.QueryEscape(dataId),
		url.QueryEscape(group),
		url.QueryEscape(namespace),
	)

	body, err := Curl(nacosHost).Get(uri)
	if err != nil {
		return "", "", fmt.Errorf("curl请求nacos失败: %w", err)
	}

	hash := md5.Sum([]byte(body))
	md5Str := hex.EncodeToString(hash[:])
	return body, md5Str, nil
}

func fetchNacosAndSaveRunToml() error {
	body, newMd5, err := fetchNacosConfig()
	if err != nil {
		return err
	}

	// MD5一致无需更新
	if currentMd5 == newMd5 {
		return nil
	}

	// 写入本地文件
	err = os.WriteFile("run.toml", []byte(body), 0644)
	if err != nil {
		return fmt.Errorf("写入run.toml失败: %w", err)
	}

	currentMd5 = newMd5
	return nil
}

func loadRunToml() {
	runViper.SetConfigFile("run.toml")
	if err := runViper.ReadInConfig(); err != nil {
		panic(fmt.Sprintf("run.toml 缺失 %s ", err))
	}

	runViper.WatchConfig()
	runViper.OnConfigChange(func(e fsnotify.Event) {
	})
}

func startFixedIntervalSync() {
	go func() {
		ticker := time.NewTicker(5 * time.Minute)
		defer ticker.Stop()

		for range ticker.C {
			err := fetchNacosAndSaveRunToml()
			if err != nil {
				fmt.Errorf("run.toml 缺失 %w ", err)
				continue
			}
		}
	}()
}

func getWorkDir() string {
	dir, _ := os.Getwd()
	return dir
}