package apollo

import (
	"bufio"
	"fmt"
	"io/ioutil"
	"os"
	"os/signal"
	"reflect"
	"sync"
	"time"

	agollo2 "git.shuncheng.lu/bigthing/gocommon/pkg/conf/remote/apollo/agollo"

	"git.shuncheng.lu/bigthing/gocommon/pkg/internal/util"

	"github.com/tidwall/gjson"
)

var (
	readLock               sync.Mutex
	rootPath               string
	lastConfig             map[string]interface{}
	watchChannel           = make(chan struct{})
	nameSpaceConfig        gjson.Result
	regularMonitorInterval = 30 * time.Second
)

func Start() {
	rootPath = util.GetRootPath() + "/config"
	err := loadNameSpacesConfig(getNameSpacesConfigPath())
	if err != nil {
		panic(fmt.Sprintf("apollo:load err: %s", err.Error()))
	}
	err = agollo2.InitWithConfigFile(
		getApolloConfigPath(),
		agollo2.WithLogger(agollo2.NewLogger(agollo2.LoggerWriter(os.Stdout))), // 打印日志信息
		agollo2.PreloadNamespaces(getNameSpaces()...),                          // 预先加载的namespace列表，如果是通过配置启动，会在app.properties配置的基础上追加
		agollo2.AutoFetchOnCacheMiss(),                                         // 在配置未找到时，去apollo的带缓存的获取配置接口，获取配置
		agollo2.FailTolerantOnBackupExists(),
		agollo2.BackupFile(getBackFilePath()), // 在连接apollo失败时，如果在配置的目录下存在.agollo备份配置，会读取备份在服务器无法连接的情况下
	)
	if err != nil {
		panic(fmt.Sprintf("apollo:init err: %s", err.Error()))
	}
	err = writeMapToFile()
	if err != nil {
		panic(fmt.Sprintf("apollo:write file err: %s", err.Error()))
	}
	go listen()
}

func GetConfigPath() string {
	return rootPath + "/apollo/env.ini"
}

func SetRefreshInterval(second int) {
	regularMonitorInterval = time.Duration(second) * time.Second
}

func Watch() <-chan struct{} {
	return watchChannel
}

func listen() {
	signals := make(chan os.Signal)
	signal.Notify(signals, os.Interrupt)
	lastConfig = deepCopy(agollo2.GetAll())
	for {
		timer := time.NewTimer(regularMonitorInterval)
		select {
		case <-timer.C:
			err := agollo2.Reload()
			if err != nil {
				fmt.Printf("[apollo] reload err: %s\n", err)
				continue
			}
			newConfig := deepCopy(agollo2.GetAll())
			if reflect.DeepEqual(lastConfig, newConfig) {
				continue
			}
			lastConfig = newConfig
			err = writeMapToFile()
			if err != nil {
				fmt.Printf("[apollo] write env err: %s\n", err)
				continue
			}
			watchChannel <- struct{}{}
		case <-signals:
			fmt.Println("[apollo] receive signal, exited")
			return
		}
	}
	select {}
}

func getBackFilePath() string {
	return rootPath + "/apollo/.agollo"
}

func getApolloConfigPath() string {
	return rootPath + "/apollo/apollo.json"
}

func getNameSpacesConfigPath() string {
	return rootPath + "/apollo/namespaces.json"
}

func getNameSpaces() []string {
	nameSpaceList := make([]string, 0)
	nameSpaceConfig.ForEach(func(key gjson.Result, value gjson.Result) bool {
		nameSpaceList = append(nameSpaceList, getNameSpace(value))
		return true
	})
	return nameSpaceList
}

func getNameSpace(nameSpace gjson.Result) string {
	return nameSpace.Get("namespace").String()
}

func getSections(sections gjson.Result) gjson.Result {
	return sections.Get("sections")
}

func getSectionName(section gjson.Result) string {
	return section.Get("name").String()
}

func getKeys(section gjson.Result) gjson.Result {
	return section.Get("keys")
}

func getKeyName(key gjson.Result) string {
	return key.Get("name").String()
}

func getKeyMapTo(key gjson.Result) string {
	return key.Get("mapTo").String()
}

func getKeysMap() map[string]map[string]map[string]string {
	maps := map[string]map[string]map[string]string{}
	nameSpaceConfig.ForEach(func(nameSpaceKey gjson.Result, value gjson.Result) bool {
		nameSpace := getNameSpace(value)
		_, ok := maps[nameSpace]
		if !ok {
			maps[nameSpace] = map[string]map[string]string{}
		}
		sections := getSections(value)
		sections.ForEach(func(sectionKey gjson.Result, section gjson.Result) bool {
			sectionName := getSectionName(section)
			keys := getKeys(section)
			keys.ForEach(func(keys gjson.Result, key gjson.Result) bool {
				keyName := getKeyName(key)
				keyMapTo := getKeyMapTo(key)
				_, ok := maps[nameSpace][keyName]
				if ok {
					return true
				}
				maps[nameSpace][keyName] = map[string]string{}
				maps[nameSpace][keyName]["section"] = sectionName
				keyRealName := keyMapTo
				if keyMapTo == "" {
					keyRealName = keyName
				}
				maps[nameSpace][keyName]["mapTo"] = keyRealName
				return true
			})
			return true
		})
		return true
	})
	return maps
}

func loadNameSpacesConfig(configPath string) error {
	file, err := os.Open(configPath)
	if err != nil {
		return err
	}
	defer file.Close()
	contents, err := ioutil.ReadAll(file)
	if err != nil {
		return err
	}
	nameSpaceConfig = gjson.Get(string(contents), "namespaces")
	return nil
}

//将所有的配置信息写入标准的配置文件里面
func writeMapToFile() error {
	readLock.Lock()
	defer readLock.Unlock()
	f, err := os.Create(GetConfigPath())
	if err != nil {
		fmt.Printf("apollo:create config file err, err: %s", err.Error())
		return err
	}
	defer f.Close()
	w := bufio.NewWriter(f)
	keysMap := getKeysMap()
	for _, nameSpace := range getNameSpaces() {
		sections := map[string][]string{}
		_, ok := keysMap[nameSpace]
		if !ok {
			continue
		}
		ConfigInfo := agollo2.GetNameSpace(nameSpace)
		for key, val := range ConfigInfo {
			_, ok = keysMap[nameSpace][key]
			if !ok {
				continue
			}
			_, ok = sections[keysMap[nameSpace][key]["section"]]
			if !ok {
				sections[keysMap[nameSpace][key]["section"]] = make([]string, 0)
			}
			lineStr := fmt.Sprintf("%s=%s", keysMap[nameSpace][key]["mapTo"], val)
			sections[keysMap[nameSpace][key]["section"]] = append(sections[keysMap[nameSpace][key]["section"]], lineStr)
		}
		if len(sections) == 0 {
			continue
		}
		for section, lineStrs := range sections {
			lineSection := fmt.Sprintf("[%s]", section)
			fmt.Fprintln(w, lineSection)
			for _, lineStr := range lineStrs {
				fmt.Fprintln(w, lineStr)
			}
		}
	}
	err = w.Flush()
	if err == nil {
		return nil
	}
	return err
}

func deepCopy(value map[string]interface{}) map[string]interface{} {
	newMap := make(map[string]interface{})
	for k, v := range value {
		newMap[k] = v
	}
	return newMap

}