package main

import (
	"encoding/json"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"regexp"
	"sparrow/pkg/redispool"
	"sparrow/pkg/rpcs"
	"sparrow/pkg/server"
	"sparrow/pkg/utils"
	"sync"
	"time"

	"github.com/garyburd/redigo/redis"
	"github.com/opentracing/opentracing-go"
	"github.com/opentracing/opentracing-go/ext"
)

const checkTimeOut = 30 * time.Minute
const tempFilesKey = "tempfilelist"

// FileAccess RPC服务
type FileAccess struct {
	mu sync.RWMutex
	// store tmp file list
	tempFiles map[string]*tempFile
	redisHost string
}

// 临时文件
type tempFile struct {
	//文件路径
	FileName string
	//创建时间
	CreateTime time.Time
}

// NewFileAccess create a FileAccessor instance
func NewFileAccess(redis string) *FileAccess {
	return &FileAccess{
		tempFiles: make(map[string]*tempFile),
		redisHost: redis,
	}
}

// 增加一个tempfile
func (f *FileAccess) addTempFile(fileName string) {
	obj := &tempFile{
		FileName:   fileName,
		CreateTime: time.Now(),
	}
	f.mu.Lock()
	f.tempFiles[fileName] = obj
	f.mu.Unlock()
	// store redis
	err := f.saveToRedis(obj)
	if err != nil {
		server.Log.Error(err)
	}
}

func (f *FileAccess) delTempFile(fileName string) {
	f.mu.Lock()
	if obj, ok := f.tempFiles[fileName]; ok {
		conn, err := redispool.GetClient(f.redisHost)
		if err != nil {
			server.Log.Errorf("conn redis error :%v", err)
			f.mu.Unlock()
			return
		}
		bytes, err := json.Marshal(obj)
		if err != nil {
			server.Log.Errorf("json marshal error :%v", err)
		}
		conn.Do("SREM", tempFilesKey, string(bytes))
	}
	f.mu.Unlock()
}

//
func (f *FileAccess) saveToRedis(obj *tempFile) error {
	conn, err := redispool.GetClient(f.redisHost)
	if err != nil {
		server.Log.Errorf("saveToRedis error :%v", err)
		return err
	}
	bytes, err := json.Marshal(obj)
	if err != nil {
		server.Log.Errorf("json marshal error :%v", err)
		return err
	}
	_, err = conn.Do("SADD", tempFilesKey, string(bytes))
	if err != nil {
		server.Log.Errorf("store to redis error :%v", err)
		return err
	}
	return nil
}

func (f *FileAccess) getTempFileFromRedis() error {
	conn, err := redispool.GetClient(f.redisHost)
	if err != nil {
		server.Log.Errorf("conn to redis error :%v", err)
	} else {
		// fill tempFile
		lists, err := redis.Strings(conn.Do("SMEMBERS", tempFilesKey))
		if err != nil {
			server.Log.Error(err)
			return err
		}
		for _, str := range lists {
			var obj tempFile
			json.Unmarshal([]byte(str), &obj)
			server.Log.Debugf("%v", obj)
			f.mu.Lock()
			f.tempFiles[obj.FileName] = &obj
			f.mu.Unlock()
		}
	}
	return nil

}

// TODO:  临时解决文案，下个版本把文件信息写到redis中，利用redis的pub/sub机制，自动清理文件
func (f *FileAccess) checker() {
	server.Log.Info("start temp file checker")
	f.getTempFileFromRedis()
	for {
		for k, v := range f.tempFiles {
			if time.Now().Sub(v.CreateTime) > checkTimeOut {
				//delete file
				f.delTempFile(v.FileName)
				f.mu.Lock()
				delete(f.tempFiles, k)
				f.mu.Unlock()
				err := os.Remove(v.FileName)
				if err != nil {
					server.Log.Errorf("error while delete file:%v", err)
				}
			}
		}
		time.Sleep(15 * time.Minute)
	}
}

// DeleteFile 删除文件
func (f *FileAccess) DeleteFile(args *rpcs.ArgsDeleteFile, reply *rpcs.ReplyEmptyResult) error {
	reg := regexp.MustCompile(`upload/\$*.*`)
	src := reg.FindString(args.FileName)
	err := os.Remove(src)
	return err
}

// MoveFile move a file to new path
// source:http://192.168.175.60:9000/upload/tmp/2c9d7d85-2266-450a-9d47-28e67703d818.jpeg
func (f *FileAccess) MoveFile(args *rpcs.ArgsMoveFile, reply *rpcs.ReplyMoveFile) error {
	spanCtx, _ := opentracing.GlobalTracer().Extract(opentracing.TextMap, opentracing.TextMapCarrier(args.SpanCarrier))
	span := opentracing.StartSpan("movefile", ext.RPCServerOption(spanCtx))
	defer span.Finish()
	span.LogKV("tmpfile", args.Source)
	// check source file
	reg := regexp.MustCompile(`tmp/\$*.*`)
	src := reg.FindString(args.Source)
	fileName := filepath.Base(src)
	src = *conStaticPath + "/" + src
	b, err := utils.Exists(src)
	if err != nil {
		server.Log.Error(err)
		return err
	}
	if b {
		// copy file
		sourceFileStat, err := os.Stat(src)
		if err != nil {
			return err
		}

		if !sourceFileStat.Mode().IsRegular() {
			return fmt.Errorf("%s is not a regular file", src)
		}

		source, err := os.Open(src)
		if err != nil {
			return err
		}
		defer source.Close()

		dst := *conStaticPath + "/" + args.Target + "/" + fileName
		utils.CreateIfNotExist(dst)
		destination, err := os.Create(dst)
		if err != nil {
			return err
		}
		defer destination.Close()
		io.Copy(destination, source)
		fpath := fmt.Sprintf("http://%s/%s/%s/%s", server.GetHTTPHost(), *conStaticPath, args.Target, fileName)
		if *conDomain != "" {
			fpath = fmt.Sprintf("%s/%s/%s/%s", *conDomain, *conStaticPath, args.Target, fileName)
		}
		reply.FilePath = fpath
		span.LogKV("tartgetfile", fpath)
		//delete src
		os.Remove(src)
		return nil
	}
	return nil
}