package fsm

import (
	"bytes"
	"encoding/gob"
	"flag"
	"fmt"
	"fusenapi/initalize"
	"fusenapi/utils/autoconfig"
	"log"
	"net"
	"os"
	"os/signal"
	"path/filepath"
	"runtime"
	"syscall"
	"time"

	"github.com/hashicorp/raft"
	"github.com/lni/dragonboat"
	"github.com/lni/dragonboat/config"
	"github.com/lni/dragonboat/logger"
	"gorm.io/gorm"
)

func test1() {
	log.SetFlags(log.Llongfile)

	fsm := StartNode("fs1", "localhost:5500", nil, initalize.InitMysql("fusentest:XErSYmLELKMnf3Dh@tcp(110.41.19.98:3306)/fusentest"))

	time.Sleep(time.Second * 5)

	for i := 0; i < 30; i++ {
		go log.Println(fsm.GetUserState(39))
	}

	log.Println(fsm.GetUserState(39))

	select {}
}

var addresses []string = []string{
	"localhost:5500",
	"localhost:5501",
	"localhost:5502",
}

func StartNode(replicaID uint64, exampleShardID uint64, addr string, gdb *gorm.DB) *dragonboat.NodeHost {

	// addr := "localhost"

	// addr = fmt.Sprintf("%s:%d", addr, port)

	flag.Parse()
	if len(addr) == 0 && replicaID != 1 && replicaID != 2 && replicaID != 3 {
		fmt.Fprintf(os.Stderr, "node id must be 1, 2 or 3 when address is not specified\n")
		os.Exit(1)
	}
	// https://github.com/golang/go/issues/17393
	if runtime.GOOS == "darwin" {
		signal.Ignore(syscall.Signal(0xd))
	}
	initialMembers := make(map[uint64]string)

	// when joining a new node which is not an initial members, the initialMembers
	// map should be empty.
	// when restarting a node that is not a member of the initial nodes, you can
	// leave the initialMembers to be empty. we still populate the initialMembers
	// here for simplicity.

	for idx, v := range addresses {
		// key is the ReplicaID, ReplicaID is not allowed to be 0
		// value is the raft address
		initialMembers[uint64(idx+1)] = v
	}

	// for simplicity, in this example program, addresses of all those 3 initial
	// raft members are hard coded. when address is not specified on the command
	// line, we assume the node being launched is an initial raft member.

	var nodeAddr = initialMembers[uint64(replicaID)]

	fmt.Fprintf(os.Stdout, "node address: %s\n", nodeAddr)
	// change the log verbosity
	logger.GetLogger("raft").SetLevel(logger.ERROR)
	logger.GetLogger("rsm").SetLevel(logger.WARNING)
	logger.GetLogger("transport").SetLevel(logger.WARNING)
	logger.GetLogger("grpc").SetLevel(logger.WARNING)
	// config for raft node
	// See GoDoc for all available options
	rc := config.Config{
		// ShardID and ReplicaID of the raft node
		ReplicaID: uint64(replicaID),
		ShardID:   exampleShardID,

		ElectionRTT: 10,

		HeartbeatRTT: 1,
		CheckQuorum:  true,

		SnapshotEntries: 10,

		CompactionOverhead: 5,
	}
	datadir := filepath.Join(
		"example-data",
		"queue-data",
		fmt.Sprintf("node%d", replicaID))

	nhc := config.NodeHostConfig{

		WALDir: datadir,
		// NodeHostDir is where everything else is stored.
		NodeHostDir: datadir,
		// RTTMillisecond is the average round trip time between NodeHosts (usually
		// on two machines/vms), it is in millisecond. Such RTT includes the
		// processing delays caused by NodeHosts, not just the network delay between
		// two NodeHost instances.
		RTTMillisecond: 200,
		// RaftAddress is used to identify the NodeHost instance
		RaftAddress: nodeAddr,
	}
	nh, err := dragonboat.NewNodeHost(nhc)
	if err != nil {
		panic(err)
	}

	if err := nh.StartReplica(initialMembers, false, NewSMQueue, rc); err != nil {
		fmt.Fprintf(os.Stderr, "failed to add cluster, %v\n", err)
		os.Exit(1)
	}

	return nh

}

// StartNode 启动节点
func StartNode1(ServerID string, RaftBind string, serverconfigs []*autoconfig.ConfigServer, gdb *gorm.DB) *StateCluster {

	fsm := &StateCluster{
		store: make(map[int64]*UserState),

		gdb: gdb,
	}

	var retainSnapshotCount = 2
	// var ServerID string = "fs1"
	// var RaftBind string = "localhost:5500"
	var RaftDir string = fmt.Sprintf("/tmp/raftdir/%s", ServerID)

	// Setup Raft configuration.
	config := raft.DefaultConfig()
	config.LocalID = raft.ServerID(ServerID)

	// Setup Raft communication.
	addr, err := net.ResolveTCPAddr("tcp", RaftBind)
	if err != nil {
		panic(err)
	}
	transport, err := raft.NewTCPTransport(RaftBind, addr, 3, 30*time.Second, os.Stderr)
	if err != nil {
		panic(err)
	}

	// Create the snapshot store. This allows the Raft to truncate the log.
	snapshots, err := raft.NewFileSnapshotStore(RaftDir, retainSnapshotCount, os.Stderr)
	if err != nil {
		panic(fmt.Errorf("file snapshot store: %s", err))
	}

	// Create the log store and stable store.
	logStore := raft.NewInmemStore()
	stableStore := raft.NewInmemStore()

	// Create the Raft system.
	fsm.ra, err = raft.NewRaft(config, fsm, logStore, stableStore, snapshots, transport)
	if err != nil {
		panic(err)
	}

	var dup map[string]bool = make(map[string]bool)
	var rserver []raft.Server = []raft.Server{
		{
			Suffrage: raft.Voter,
			ID:       config.LocalID,
			Address:  transport.LocalAddr(),
		},
	}
	dup[string(config.LocalID)] = true
	dup[string("backend")] = true
	dup[string("product-model")] = true
	dup[string("product-template")] = true

	for _, cfg := range serverconfigs {
		if _, ok := dup[cfg.Name]; !ok {
			dup[cfg.Name] = true
			rserver = append(rserver, raft.Server{
				Suffrage: raft.Voter,
				ID:       raft.ServerID(cfg.Name),
				Address:  raft.ServerAddress(fmt.Sprintf("%s:%d", cfg.Host, cfg.Port-2000)),
			})
		}
	}

	configuration := raft.Configuration{
		Servers: rserver,
	}

	fu := fsm.ra.BootstrapCluster(configuration)
	if err := fu.Error(); err != nil {
		log.Println(err)
	}

	waitForCluster(fsm.ra)

	return fsm
}

// func JoinCluster(ServerID string, LeaderAddress string, RaftBind string, gdb *gorm.DB) *StateCluster {

// 	fsm := StartNode(ServerID, RaftBind, gdb)

// 	configFuture := fsm.ra.GetConfiguration()
// 	if err := configFuture.Error(); err != nil {
// 		log.Fatalf("failed to get raft configuration: %v", err)
// 	}

// 	for _, srv := range configFuture.Configuration().Servers {
// 		if srv.ID == raft.ServerID(ServerID) && srv.Address == raft.ServerAddress(LeaderAddress) {
// 			if future := fsm.ra.RemoveServer(srv.ID, 0, 0); future.Error() != nil {
// 				log.Fatalf("Error removing existing server [%s]: %v", ServerID, future.Error())
// 			}
// 		}
// 	}

// 	f := fsm.ra.AddVoter(raft.ServerID(ServerID), raft.ServerAddress(RaftBind), 0, 0)
// 	if f.Error() != nil {
// 		log.Fatalf("Error adding voter: %v", f.Error())
// 	}

// 	return fsm
// }

func waitForCluster(ra *raft.Raft) {
	ticker := time.NewTicker(500 * time.Millisecond)
	defer ticker.Stop()

	for range ticker.C {
		state := ra.State()
		if state == raft.Leader || state == raft.Follower {
			log.Println("Raft cluster is running")
			return
		} else {
			log.Println("Still waiting for the cluster to start...")
		}
	}
}

// var gdb *gorm.DB = initalize.InitMysql("fusentest:XErSYmLELKMnf3Dh@tcp(110.41.19.98:3306)/fusentest")

type UserState struct {
	UpdateAt time.Time
	UserId   int64
	PwdHash  uint64
}

func (us *UserState) Encode(do func([]byte) error) error {

	var buf bytes.Buffer
	err := gob.NewEncoder(&buf).Encode(us)
	if err != nil {
		return err
	}

	if do != nil {
		err := do(buf.Bytes())
		if err != nil {
			return err
		}
	}

	return nil
}

func (us *UserState) Decode(data []byte) error {
	buf := bytes.NewBuffer(data)
	err := gob.NewDecoder(buf).Decode(us)
	if err != nil {
		return err
	}
	return nil
}

type OperateType string

const (
	OP_Update OperateType = "update"
)

// Command is used for internal Command representation.
type Command struct {
	Op    OperateType
	Key   int64
	Value *UserState
}

func (cmd *Command) Encode(do func(buf []byte) error) error {
	var buf bytes.Buffer

	err := gob.NewEncoder(&buf).Encode(cmd)
	if err != nil {
		return err
	}

	if do != nil {
		err := do(buf.Bytes())
		if err != nil {
			return err
		}
	}

	return nil
}

func (cmd *Command) Decode(sbuf []byte) error {
	var buf = bytes.NewBuffer(sbuf)
	err := gob.NewDecoder(buf).Decode(cmd)
	if err != nil {
		// log.Panic(err)
		return err
	}
	return nil
}