/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package syncdb

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"github.com/hashicorp/memberlist"
	"io/ioutil"
	"net"
	"os"
	"strconv"
	"sync"

	//"os"
	"strings"
	"time"

	"github.com/hashicorp/serf/cmd/serf/command/agent"
	"github.com/hashicorp/serf/serf"
	//"github.com/apache/servicecomb-service-center/pkg/log"
	"log"
	"runtime/debug"
)

const (
	QueryEventGetDB                 = "GetDatabase"
	QueryEventUpdateDBData          = "UpdateDBData"
	UserEventSyncSql                = "SyncSql"
	UserEventSyncDbTablePersonCache = "SyncCache"
)

// Agent warps the serf agent
type Agent struct {
	*agent.Agent
	conf    *Config
	readyCh chan struct{}
	errorCh chan error
}

type NodeInfo struct {
	ClusterID   string `json:"clusterID"`
	NodeID      string `json:"nodeID"`
	NodeAddress string `json:"nodeAddress"`
	IsAlive     int    `json:"isAlive"`
}

// Create create serf agent with config
func Create(conf *Config, snapshotPath string) (*Agent, error) {
	// config cover to serf config
	serfConf, err := conf.convertToSerf(snapshotPath)
	if err != nil {
		return nil, err
	}

	// create serf agent with serf config
	//fmt.Println("conf.Config.EncryptKey:", conf.EncryptKey)
	serfAgent, err := agent.Create(conf.Config, serfConf, nil)
	if err != nil {
		return nil, err
	}
	// Create the keyring
	keyring, err := memberlist.NewKeyring(nil, []byte(conf.EncryptKey))
	if err != nil {
		//fmt.Printf("Failed to restore keyring: %s", err)
		return nil, err
	}
	serfConf.MemberlistConfig.Keyring = keyring
	//fmt.Printf("[INFO] agent: Restored keyring with %d keys from %s",
	//	len(conf.EncryptKey), conf.EncryptKey)

	return &Agent{
		Agent:   serfAgent,
		conf:    conf,
		readyCh: make(chan struct{}),
		errorCh: make(chan error),
	}, nil
}

// Start agent
func (a *Agent) Start(ctx context.Context) {
	log.Println("aaaaaaaaa")
	log.Println(string(debug.Stack()))
	//debug.PrintStack()
	err := a.Agent.Start()
	if err != nil {
		log.Println(err, "start serf agent failed")
		a.errorCh <- err
		return
	}
	a.RegisterEventHandler(a)

	err = a.retryJoin(ctx)
	if err != nil {
		log.Println(err, "start serf agent failed")
		if err != ctx.Err() && a.errorCh != nil {
			a.errorCh <- err
		}
	}

	go a.BroadcastMemberlist(BroadcastInterval * time.Second)
}

// define call back interface
type ReceiveSqlInterface interface {
	Forward(content string)
}

// callback instance
var receiveSqlInterface ReceiveSqlInterface

// save the callback instance
func RegisterReceiveSqlInterface(c ReceiveSqlInterface) {
	receiveSqlInterface = c
}

type DbHandler interface {
	Execute(sql string) bool
}

type DbDumpHandler interface {
	Dump(tables string) string
}

//数据库execute句柄
var DbHandle DbHandler
//数据库备份句柄,只在syncdb中用到
var dbDumpH DbDumpHandler

func RegisterDbHandler(h DbHandler) {
	DbHandle = h
}

func RegisterDbDumpHandler(h DbDumpHandler) {
	dbDumpH = h
}

// HandleEvent Handles serf.EventMemberJoin events,
// which will wait for members to join until the number of group members is equal to "groupExpect"
// when the startup mode is "ModeCluster",
// used for logical grouping of serf nodes
func (a *Agent) HandleEvent(event serf.Event) {

	switch ev := event.(type) {
	case serf.UserEvent:
		if ev.Name == UserEventSyncSql {
			var sqlUe SqlUserEvent
			//fmt.Println(string(ev.Payload))
			err := json.Unmarshal(ev.Payload, &sqlUe)
			if err != nil {
				//fmt.Println("sqlUe unmarshal err:", err)
				return
			}
			if sqlUe.Owner != a.conf.NodeName {
				//ExecuteWriteSql(sqlUe.Sql, true)
				//flag, _ := ExecuteSqlByGorm(sqlUe.Sql)
				//fmt.Println("userEvent exec 1 ", sqlUe.Sql, ",Result:", results)
				if receiveSqlInterface != nil && sqlUe.Sql !=nil && len(sqlUe.Sql) > 0 {
					receiveSqlInterface.Forward(sqlUe.Sql[0])
				}
			}
		}

	case *serf.Query:

		if ev.Name == QueryEventGetDB {
			//bak file and send resp
			filename, err := BakDbFile()
			if err != nil {
				//fmt.Println("bak db file error!")
				return
			}
			//fmt.Println(filename)

			filebuf, err := ioutil.ReadFile(filename)
			//fmt.Println("filebuf: ", len(filebuf))
			if err != nil {
				//fmt.Printf("file to []bytes error: %s\n", err)
				return
			}

			err = os.Remove(filename)
			if err != nil {
				//fmt.Printf("remove file%s\n failed", filename)
				return
			}

			//fmt.Println("query payload: ", len(ev.Payload))
			if query, ok := event.(*serf.Query); ok {
				if err := query.Respond(filebuf); err != nil {
					//fmt.Printf("err: %s\n", err)
					return
				}
			}
		} else if ev.Name == QueryEventUpdateDBData {
			//fmt.Println(string(ev.Payload))
			var tableNames []string
			json.Unmarshal(ev.Payload, &tableNames)

			dumpData := dbDumpH.Dump(strings.Join(tableNames, ","))

			bytesReturn, _ := json.Marshal(dumpData)
			//fmt.Println("results: ", bytesReturn)
			if query, ok := event.(*serf.Query); ok {
				if err := query.Respond(bytesReturn); err != nil {
					//fmt.Printf("err: %s\n", err)
					return
				}
			}
		}
	case serf.MemberEvent:
		if event.EventType() == serf.EventMemberLeave {
			if ev.Members != nil && len(ev.Members) == 1 {
				leaveMember := ev.Members[0]
				leaveSql := "delete from cluster_node where node_id='" + leaveMember.Name + "'"
				//fmt.Println("leaveSql:", leaveSql)
				_, err := ExecuteWriteSql([]string{leaveSql}, false)
				if err != nil {
					//fmt.Printf("err: %s\n", err)
				}

				//fmt.Println("EventMemberLeave,current Members:", ev.Members)
			}
			return
		}

	default:
		//fmt.Printf("Unknown event type: %s\n", ev.EventType().String())
	}
}

func (a *Agent) BroadcastMemberlist(delay time.Duration) {
	//serf := a.serf
	serf := a.Agent.Serf()
	mb := serf.LocalMember()
	mblist := serf.Memberlist()
	//fmt.Println("mb:", mb)

	// copy local node
	localNode := *mblist.LocalNode()
	nodeID := a.conf.NodeName
	nodeAddress := localNode.Address()
	clusterID := mb.Tags[tagKeyClusterID]
	isAlive := int(mb.Status)

	message, _ := json.Marshal(NodeInfo{
		clusterID,
		nodeID,
		nodeAddress,
		isAlive,
	})

	// replace node address
	localNode.Addr = net.ParseIP(BroadcastIP)
	//localNode.Addr = net.IPv4(255,255,255,255)
	localNode.Port = BroadcastPort
	for {
		// //fmt.Printf("localNode: %v %v\n", nodeName, nodeAddress)
		mblist.SendBestEffort(&localNode, []byte(message))
		time.Sleep(delay)
	}
}

// Ready Returns a channel that will be closed when serf is ready
func (a *Agent) Ready() <-chan struct{} {
	return a.readyCh
}

// Error Returns a channel that will be transmit a serf error
func (a *Agent) Error() <-chan error {
	return a.errorCh
}

// Stop serf agent
func (a *Agent) Stop() {
	if a.errorCh != nil {
		a.Leave()
		a.Shutdown()
		close(a.errorCh)
		a.errorCh = nil
	}
}

// LocalMember returns the Member information for the local node
func (a *Agent) LocalMember() *serf.Member {
	serfAgent := a.Agent.Serf()
	if serfAgent != nil {
		member := serfAgent.LocalMember()
		return &member
	}
	return nil
}

// GroupMembers returns a point-in-time snapshot of the members of by clusterID
func (a *Agent) GroupMembers(clusterID string) (members []serf.Member) {
	serfAgent := a.Agent.Serf()
	if serfAgent != nil {
		for _, member := range serfAgent.Members() {
			log.Printf("member = %s, clusterID = %s", member.Name, member.Tags[tagKeyClusterID])
			if member.Tags[tagKeyClusterID] == clusterID {
				members = append(members, member)
			}
		}
	}
	return
}

// Member get member information with node
func (a *Agent) Member(node string) *serf.Member {
	serfAgent := a.Agent.Serf()
	if serfAgent != nil {
		ms := serfAgent.Members()
		for _, m := range ms {
			if m.Name == node {
				return &m
			}
		}
	}
	return nil
}

// SerfConfig get serf config
func (a *Agent) SerfConfig() *serf.Config {
	return a.Agent.SerfConfig()
}

// Join serf clusters through one or more members
func (a *Agent) Join(addrs []string, replay bool) (n int, err error) {
	return a.Agent.Join(addrs, replay)
}

// UserEvent sends a UserEvent on Serf
func (a *Agent) UserEvent(name string, payload []byte, coalesce bool) error {
	return a.Agent.UserEvent(name, payload, coalesce)
}

// Query sends a Query on Serf
func (a *Agent) Query(name string, payload []byte, params *serf.QueryParam) (*serf.QueryResponse, error) {
	return a.Agent.Query(name, payload, params)
}

func (a *Agent) retryJoin(ctx context.Context) (err error) {
	if len(a.conf.RetryJoin) == 0 {
		log.Printf("retry join mumber %d", len(a.conf.RetryJoin))
		return nil
	}

	// Count of attempts
	attempt := 0
	ticker := time.NewTicker(a.conf.RetryInterval)
	for {
		log.Printf("serf: Joining cluster...(replay: %v)", a.conf.ReplayOnJoin)
		var n int

		// Try to join the specified serf nodes
		n, err = a.Join(a.conf.RetryJoin, a.conf.ReplayOnJoin)
		if err == nil {
			log.Printf("serf: Join completed. Synced with %d initial agents", n)
			break
		}
		attempt++

		// If RetryMaxAttempts is greater than 0, agent will exit
		// and throw an error when the number of attempts exceeds RetryMaxAttempts,
		// else agent will try to join other nodes until successful always
		if a.conf.RetryMaxAttempts > 0 && attempt > a.conf.RetryMaxAttempts {
			err = errors.New("serf: maximum retry join attempts made, exiting")
			log.Println(err, err.Error())
			break
		}
		select {
		case <-ctx.Done():
			err = ctx.Err()
			goto done
		// Waiting for ticker to trigger
		case <-ticker.C:
		}
	}
done:
	ticker.Stop()
	return
}

//GetDbFromCluster get the newest database after join cluster
//dbPathWrite the path where to write after got a database,
func (a *Agent) GetDbFromCluster(dbPathWrite string) {
	//members: get name of first member
	mbs := a.GroupMembers(a.conf.ClusterID)
	var specmembername string
	for _, m := range mbs {
		if m.Addr.String() != a.conf.BindAddr {
			specmembername = m.Name
			break
		}
	}
	//fmt.Println(specmembername)

	//query: get db file.
	params := serf.QueryParam{
		FilterNodes: strings.Fields(specmembername),
	}

	resp, err := a.Query(QueryEventGetDB, []byte(""), &params)
	if err == nil || !strings.Contains(err.Error(), "cannot contain") {
		//fmt.Println("err: ", err)
	}

	go func() {
		respCh := resp.ResponseCh()
		for {
			select {
			case r := <-respCh:
				//fmt.Println("x length is: ", len(r.Payload))

				// // byte to file.
				SerfDbConn.Close()
				SerfDbConn = nil
				err = ioutil.WriteFile(dbPathWrite, r.Payload, 0644)
				if err != nil {
					//fmt.Println("query byte to file error!", err)
				}
				err := InitDbConn("")
				if err != nil {
					//fmt.Println("create db conn of test.db error: ", err)
				}
				return
			}
		}
	}()
}

//GetDbFromCluster get the newest database after join cluster
//dbPathWrite the path where to write after got a database,
func (a *Agent) GetTableDataFromCluster(tableNames []string) (*[]string, error) {
	//members: get name of first member
	mbs := a.GroupMembers(a.conf.ClusterID)
	var specmembername string
	for _, m := range mbs {
		//fmt.Println("m", m)
		if m.Name != a.conf.NodeName { //前缀：DSVAD:分析服务器 DSPAD:进出入pad
			if strings.HasPrefix(a.conf.NodeName, "PSPAD"){
				if strings.HasPrefix(m.Name, "PSPAD") {
					specmembername = m.Name
					break
				}
			}else{
				specmembername = m.Name
				break
			}
		}
	}
	//fmt.Println("mbs:", mbs, "a.conf.BindAddr:", a.conf.BindAddr, "specmembername:", specmembername)

	//query: get db file.
	params := serf.QueryParam{
		FilterNodes: strings.Fields(specmembername),
	}

	//SQL
	tBytes, _ := json.Marshal(tableNames)

	resp, err := a.Query(QueryEventUpdateDBData, tBytes, &params)
	if err == nil || !strings.Contains(err.Error(), "cannot contain") {
		//fmt.Println("err: ", err)
	}
	//fmt.Println("Query.resp.err:", err, "resp:", resp)

	var wg sync.WaitGroup
	wg.Add(1)
	var dumpSqls []string
	go func() {
		defer wg.Done()
		respCh := resp.ResponseCh()
		for {
			select {
			case r := <-respCh:
				//fmt.Println("Query response's len:", len(r.Payload))
				err := json.Unmarshal(r.Payload, &dumpSqls)
				if err == nil {
					//fmt.Println("dumpSql:", dumpSqls)
					//fmt.Println("data dump success")
				}
				return
			}
		}
	}()
	wg.Wait()
	return &dumpSqls, nil
}

type SqlUserEvent struct {
	Owner string   `json:"owner"`
	Sql   []string `json:"sql"`
}

//SyncSql boardcast sql to cluster
func (a *Agent) SyncSql(sqlOp []string) {
	// event : use to send command to operate db.
	var sqlUe = SqlUserEvent{
		Owner: a.conf.NodeName,
		Sql:   sqlOp,
	}
	ueB, err := json.Marshal(sqlUe)
	if err != nil {
		//fmt.Println("sqlUE marshal err:", err)
		return
	}
	err = a.UserEvent(UserEventSyncSql, ueB, false)
	if err == nil || !strings.Contains(err.Error(), "cannot contain") {
		//fmt.Println("err: ", err)
	}
}

//Init serf Init
func Init(clusterID string, password string, nodeID string, addrs []string, snapshotPath string) (*Agent, error) {
	agent, err := InitNode(clusterID, password, nodeID, snapshotPath)
	if err != nil {
		//fmt.Printf("InitNode failed, error: %s", err)
		return agent, err
	}

	err = agent.JoinByNodeAddrs(addrs)
	if err != nil {
		//fmt.Printf("JoinByNodeIP failed, error: %s", err)
		return agent, err
	}

	return agent, err
}

//InitNode web后台收到创建集群的请求，
func InitNode(clusterID string, password string, nodeID string, snapshotPath string) (*Agent, error) {
	conf := DefaultConfig()
	//fmt.Println("clusterID:", clusterID, "password:", password, "nodeID:", nodeID)
	conf.ClusterID = clusterID
	conf.NodeName = nodeID
	if password == "" {
		conf.EncryptKey = DefaultEncryptKey
	} else {
		if len(password) >= 16 {
			password = password[:16]
		} else {
			password = fmt.Sprintf("%016s", password)[:16]
			//return nil, fmt.Errorf("error password")
		}
		conf.EncryptKey = password
	}
	agent, err := Create(conf, snapshotPath)
	if err != nil {
		//fmt.Printf("create agent failed, error: %s", err)
		return agent, err
	}

	agent.Start(context.Background())
	//<- agent.readyCh
	go func() {
		agent.ShutdownCh()
	}()
	time.Sleep(time.Second)
	//fmt.Println("Stats:", agent.Agent.Serf().Stats())
	//fmt.Println("EncryptionEnabled:", agent.Agent.Serf().EncryptionEnabled())
	//fmt.Println("create agent sucess!!")

	return agent, nil
}

func (a *Agent) JoinByNodeAddrs(addrs []string) error {
	var nodes []string

	if len(addrs) == 0 {
		return fmt.Errorf("No Nodes To Join!")
	}
	for _, addr := range addrs {
		nodes = append(nodes, addr)
	}

	a.Agent.Join(nodes, true)

	return nil
}

//func (a *Agent) JoinByNodeIP(ips []string) error {
//	var nodes []string
//
//	if len(ips) == 0 {
//		return fmt.Errorf("No Nodes To Join!")
//	}
//	for _, ip := range ips {
//		node := fmt.Sprintf("%s:%d", ip, DefaultBindPort)
//		nodes = append(nodes, node)
//	}
//
//	n, err := a.Agent.Join(nodes, true)
//	if err != nil || n == 0 {
//		return fmt.Errorf("Error Encrypt Key!")
//	}
//
//	return err
//}

func (a *Agent) GetNodes() (nodes []NodeInfo) {
	var node NodeInfo
	//fmt.Println("a.conf.ClusterID:", a.conf.ClusterID)
	mbs := a.GroupMembers(a.conf.ClusterID)
	for _, mb := range mbs {
		node.NodeID = mb.Name
		node.NodeAddress = mb.Addr.String() + ":" + strconv.Itoa(int(mb.Port))
		node.IsAlive = int(mb.Status)
		node.ClusterID = mb.Tags[tagKeyClusterID]

		nodes = append(nodes, node)
	}

	return nodes
}