package server

import (
	"bufio"
	"bytes"
	"encoding/json"
	"fmt"
	"net"
	"reflect"
	"regexp"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/nats-io/nats"
)

type serverInfo struct {
	Id           string `json:"server_id"`
	Host         string `json:"host"`
	Port         uint   `json:"port"`
	Version      string `json:"version"`
	AuthRequired bool   `json:"auth_required"`
	TLSRequired  bool   `json:"ssl_required"`
	MaxPayload   int64  `json:"max_payload"`
}

type mockAuth struct{}

func (m *mockAuth) Check(c ClientAuth) bool {
	return true
}

func createClientAsync(ch chan *client, s *Server, cli net.Conn) {
	go func() {
		c := s.createClient(cli)
		// Must be here to suppress +OK
		c.opts.Verbose = false
		ch <- c
	}()
}

var defaultServerOptions = Options{
	Trace:  false,
	Debug:  false,
	NoLog:  true,
	NoSigs: true,
}

func rawSetup(serverOptions Options) (*Server, *client, *bufio.Reader, string) {
	cli, srv := net.Pipe()
	cr := bufio.NewReaderSize(cli, DEFAULT_BUF_SIZE)
	s := New(&serverOptions)
	if serverOptions.Authorization != "" {
		s.SetClientAuthMethod(&mockAuth{})
	}

	ch := make(chan *client)
	createClientAsync(ch, s, srv)

	l, _ := cr.ReadString('\n')

	// Grab client
	c := <-ch
	return s, c, cr, l
}

func setUpClientWithResponse() (*client, string) {
	_, c, _, l := rawSetup(defaultServerOptions)
	return c, l
}

func setupClient() (*Server, *client, *bufio.Reader) {
	s, c, cr, _ := rawSetup(defaultServerOptions)
	return s, c, cr
}

func TestClientCreateAndInfo(t *testing.T) {
	c, l := setUpClientWithResponse()

	if c.cid != 1 {
		t.Fatalf("Expected cid of 1 vs %d\n", c.cid)
	}
	if c.state != OP_START {
		t.Fatal("Expected state to be OP_START")
	}

	if !strings.HasPrefix(l, "INFO ") {
		t.Fatalf("INFO response incorrect: %s\n", l)
	}
	// Make sure payload is proper json
	var info serverInfo
	err := json.Unmarshal([]byte(l[5:]), &info)
	if err != nil {
		t.Fatalf("Could not parse INFO json: %v\n", err)
	}
	// Sanity checks
	if info.MaxPayload != MAX_PAYLOAD_SIZE ||
		info.AuthRequired || info.TLSRequired ||
		info.Port != DEFAULT_PORT {
		t.Fatalf("INFO inconsistent: %+v\n", info)
	}
}

func TestClientConnect(t *testing.T) {
	_, c, _ := setupClient()

	// Basic Connect setting flags
	connectOp := []byte("CONNECT {\"verbose\":true,\"pedantic\":true,\"ssl_required\":false}\r\n")
	err := c.parse(connectOp)
	if err != nil {
		t.Fatalf("Received error: %v\n", err)
	}
	if c.state != OP_START {
		t.Fatalf("Expected state of OP_START vs %d\n", c.state)
	}
	if !reflect.DeepEqual(c.opts, clientOpts{Verbose: true, Pedantic: true}) {
		t.Fatalf("Did not parse connect options correctly: %+v\n", c.opts)
	}

	// Test that we can capture user/pass
	connectOp = []byte("CONNECT {\"user\":\"derek\",\"pass\":\"foo\"}\r\n")
	c.opts = defaultOpts
	err = c.parse(connectOp)
	if err != nil {
		t.Fatalf("Received error: %v\n", err)
	}
	if c.state != OP_START {
		t.Fatalf("Expected state of OP_START vs %d\n", c.state)
	}
	if !reflect.DeepEqual(c.opts, clientOpts{Verbose: true, Pedantic: true, Username: "derek", Password: "foo"}) {
		t.Fatalf("Did not parse connect options correctly: %+v\n", c.opts)
	}

	// Test that we can capture client name
	connectOp = []byte("CONNECT {\"user\":\"derek\",\"pass\":\"foo\",\"name\":\"router\"}\r\n")
	c.opts = defaultOpts
	err = c.parse(connectOp)
	if err != nil {
		t.Fatalf("Received error: %v\n", err)
	}
	if c.state != OP_START {
		t.Fatalf("Expected state of OP_START vs %d\n", c.state)
	}

	if !reflect.DeepEqual(c.opts, clientOpts{Verbose: true, Pedantic: true, Username: "derek", Password: "foo", Name: "router"}) {
		t.Fatalf("Did not parse connect options correctly: %+v\n", c.opts)
	}

	// Test that we correctly capture auth tokens
	connectOp = []byte("CONNECT {\"auth_token\":\"YZZ222\",\"name\":\"router\"}\r\n")
	c.opts = defaultOpts
	err = c.parse(connectOp)
	if err != nil {
		t.Fatalf("Received error: %v\n", err)
	}
	if c.state != OP_START {
		t.Fatalf("Expected state of OP_START vs %d\n", c.state)
	}

	if !reflect.DeepEqual(c.opts, clientOpts{Verbose: true, Pedantic: true, Authorization: "YZZ222", Name: "router"}) {
		t.Fatalf("Did not parse connect options correctly: %+v\n", c.opts)
	}
}

func TestClientPing(t *testing.T) {
	_, c, cr := setupClient()

	// PING
	pingOp := []byte("PING\r\n")
	go c.parse(pingOp)
	l, err := cr.ReadString('\n')
	if err != nil {
		t.Fatalf("Error receiving info from server: %v\n", err)
	}
	if !strings.HasPrefix(l, "PONG\r\n") {
		t.Fatalf("PONG response incorrect: %s\n", l)
	}
}

var msgPat = regexp.MustCompile(`\AMSG\s+([^\s]+)\s+([^\s]+)\s+(([^\s]+)[^\S\r\n]+)?(\d+)\r\n`)

const (
	SUB_INDEX   = 1
	SID_INDEX   = 2
	REPLY_INDEX = 4
	LEN_INDEX   = 5
)

func checkPayload(cr *bufio.Reader, expected []byte, t *testing.T) {
	// Read in payload
	d := make([]byte, len(expected))
	n, err := cr.Read(d)
	if err != nil {
		t.Fatalf("Error receiving msg payload from server: %v\n", err)
	}
	if n != len(expected) {
		t.Fatalf("Did not read correct amount of bytes: %d vs %d\n", n, len(expected))
	}
	if !bytes.Equal(d, expected) {
		t.Fatalf("Did not read correct payload:: <%s>\n", d)
	}
}

func TestClientSimplePubSub(t *testing.T) {
	_, c, cr := setupClient()
	// SUB/PUB
	go c.parse([]byte("SUB foo 1\r\nPUB foo 5\r\nhello\r\nPING\r\n"))
	l, err := cr.ReadString('\n')
	if err != nil {
		t.Fatalf("Error receiving msg from server: %v\n", err)
	}
	matches := msgPat.FindAllStringSubmatch(l, -1)[0]
	if len(matches) != 6 {
		t.Fatalf("Did not get correct # matches: %d vs %d\n", len(matches), 6)
	}
	if matches[SUB_INDEX] != "foo" {
		t.Fatalf("Did not get correct subject: '%s'\n", matches[SUB_INDEX])
	}
	if matches[SID_INDEX] != "1" {
		t.Fatalf("Did not get correct sid: '%s'\n", matches[SID_INDEX])
	}
	if matches[LEN_INDEX] != "5" {
		t.Fatalf("Did not get correct msg length: '%s'\n", matches[LEN_INDEX])
	}
	checkPayload(cr, []byte("hello\r\n"), t)
}

func TestClientSimplePubSubWithReply(t *testing.T) {
	_, c, cr := setupClient()

	// SUB/PUB
	go c.parse([]byte("SUB foo 1\r\nPUB foo bar 5\r\nhello\r\nPING\r\n"))
	l, err := cr.ReadString('\n')
	if err != nil {
		t.Fatalf("Error receiving msg from server: %v\n", err)
	}
	matches := msgPat.FindAllStringSubmatch(l, -1)[0]
	if len(matches) != 6 {
		t.Fatalf("Did not get correct # matches: %d vs %d\n", len(matches), 6)
	}
	if matches[SUB_INDEX] != "foo" {
		t.Fatalf("Did not get correct subject: '%s'\n", matches[SUB_INDEX])
	}
	if matches[SID_INDEX] != "1" {
		t.Fatalf("Did not get correct sid: '%s'\n", matches[SID_INDEX])
	}
	if matches[REPLY_INDEX] != "bar" {
		t.Fatalf("Did not get correct reply subject: '%s'\n", matches[REPLY_INDEX])
	}
	if matches[LEN_INDEX] != "5" {
		t.Fatalf("Did not get correct msg length: '%s'\n", matches[LEN_INDEX])
	}
}

func TestClientNoBodyPubSubWithReply(t *testing.T) {
	_, c, cr := setupClient()

	// SUB/PUB
	go c.parse([]byte("SUB foo 1\r\nPUB foo bar 0\r\n\r\nPING\r\n"))
	l, err := cr.ReadString('\n')
	if err != nil {
		t.Fatalf("Error receiving msg from server: %v\n", err)
	}
	matches := msgPat.FindAllStringSubmatch(l, -1)[0]
	if len(matches) != 6 {
		t.Fatalf("Did not get correct # matches: %d vs %d\n", len(matches), 6)
	}
	if matches[SUB_INDEX] != "foo" {
		t.Fatalf("Did not get correct subject: '%s'\n", matches[SUB_INDEX])
	}
	if matches[SID_INDEX] != "1" {
		t.Fatalf("Did not get correct sid: '%s'\n", matches[SID_INDEX])
	}
	if matches[REPLY_INDEX] != "bar" {
		t.Fatalf("Did not get correct reply subject: '%s'\n", matches[REPLY_INDEX])
	}
	if matches[LEN_INDEX] != "0" {
		t.Fatalf("Did not get correct msg length: '%s'\n", matches[LEN_INDEX])
	}
}

func TestClientPubWithQueueSub(t *testing.T) {
	_, c, cr := setupClient()

	num := 100

	// Queue SUB/PUB
	subs := []byte("SUB foo g1 1\r\nSUB foo g1 2\r\n")
	pubs := []byte("PUB foo bar 5\r\nhello\r\n")
	op := []byte{}
	op = append(op, subs...)
	for i := 0; i < num; i++ {
		op = append(op, pubs...)
	}

	go func() {
		c.parse(op)
		for cp := range c.pcd {
			cp.bw.Flush()
		}
		c.nc.Close()
	}()

	var n1, n2, received int
	for ; ; received++ {
		l, err := cr.ReadString('\n')
		if err != nil {
			break
		}
		matches := msgPat.FindAllStringSubmatch(l, -1)[0]

		// Count which sub
		switch matches[SID_INDEX] {
		case "1":
			n1++
		case "2":
			n2++
		}
		checkPayload(cr, []byte("hello\r\n"), t)
	}
	if received != num {
		t.Fatalf("Received wrong # of msgs: %d vs %d\n", received, num)
	}
	// Threshold for randomness for now
	if n1 < 20 || n2 < 20 {
		t.Fatalf("Received wrong # of msgs per subscriber: %d - %d\n", n1, n2)
	}
}

func TestClientUnSub(t *testing.T) {
	_, c, cr := setupClient()

	num := 1

	// SUB/PUB
	subs := []byte("SUB foo 1\r\nSUB foo 2\r\n")
	unsub := []byte("UNSUB 1\r\n")
	pub := []byte("PUB foo bar 5\r\nhello\r\n")

	op := []byte{}
	op = append(op, subs...)
	op = append(op, unsub...)
	op = append(op, pub...)

	go func() {
		c.parse(op)
		for cp := range c.pcd {
			cp.bw.Flush()
		}
		c.nc.Close()
	}()

	var received int
	for ; ; received++ {
		l, err := cr.ReadString('\n')
		if err != nil {
			break
		}
		matches := msgPat.FindAllStringSubmatch(l, -1)[0]
		if matches[SID_INDEX] != "2" {
			t.Fatalf("Received msg on unsubscribed subscription!\n")
		}
		checkPayload(cr, []byte("hello\r\n"), t)
	}
	if received != num {
		t.Fatalf("Received wrong # of msgs: %d vs %d\n", received, num)
	}
}

func TestClientUnSubMax(t *testing.T) {
	_, c, cr := setupClient()

	num := 10
	exp := 5

	// SUB/PUB
	subs := []byte("SUB foo 1\r\n")
	unsub := []byte("UNSUB 1 5\r\n")
	pub := []byte("PUB foo bar 5\r\nhello\r\n")

	op := []byte{}
	op = append(op, subs...)
	op = append(op, unsub...)
	for i := 0; i < num; i++ {
		op = append(op, pub...)
	}

	go func() {
		c.parse(op)
		for cp := range c.pcd {
			cp.bw.Flush()
		}
		c.nc.Close()
	}()

	var received int
	for ; ; received++ {
		l, err := cr.ReadString('\n')
		if err != nil {
			break
		}
		matches := msgPat.FindAllStringSubmatch(l, -1)[0]
		if matches[SID_INDEX] != "1" {
			t.Fatalf("Received msg on unsubscribed subscription!\n")
		}
		checkPayload(cr, []byte("hello\r\n"), t)
	}
	if received != exp {
		t.Fatalf("Received wrong # of msgs: %d vs %d\n", received, exp)
	}
}

func TestClientAutoUnsubExactReceived(t *testing.T) {
	_, c, _ := setupClient()
	defer c.nc.Close()

	// SUB/PUB
	subs := []byte("SUB foo 1\r\n")
	unsub := []byte("UNSUB 1 1\r\n")
	pub := []byte("PUB foo bar 2\r\nok\r\n")

	op := []byte{}
	op = append(op, subs...)
	op = append(op, unsub...)
	op = append(op, pub...)

	ch := make(chan bool)
	go func() {
		c.parse(op)
		ch <- true
	}()

	// Wait for processing
	<-ch

	// We should not have any subscriptions in place here.
	if c.subs.Count() != 0 {
		t.Fatalf("Wrong number of subscriptions: expected 0, got %d\n",
			c.subs.Count())
	}
}

func TestClientUnsubAfterAutoUnsub(t *testing.T) {
	_, c, _ := setupClient()
	defer c.nc.Close()

	// SUB/UNSUB/UNSUB
	subs := []byte("SUB foo 1\r\n")
	asub := []byte("UNSUB 1 1\r\n")
	unsub := []byte("UNSUB 1\r\n")

	op := []byte{}
	op = append(op, subs...)
	op = append(op, asub...)
	op = append(op, unsub...)

	ch := make(chan bool)
	go func() {
		c.parse(op)
		ch <- true
	}()

	// Wait for processing
	<-ch

	// We should not have any subscriptions in place here.
	if c.subs.Count() != 0 {
		t.Fatalf("Wrong number of subscriptions: expected 0, got %d\n",
			c.subs.Count())
	}
}

func TestClientRemoveSubsOnDisconnect(t *testing.T) {
	s, c, _ := setupClient()
	subs := []byte("SUB foo 1\r\nSUB bar 2\r\n")

	ch := make(chan bool)
	go func() {
		c.parse(subs)
		ch <- true
	}()
	<-ch

	if s.sl.Count() != 2 {
		t.Fatalf("Should have 2 subscriptions, got %d\n", s.sl.Count())
	}
	c.closeConnection()
	if s.sl.Count() != 0 {
		t.Fatalf("Should have no subscriptions after close, got %d\n", s.sl.Count())
	}
}

func TestClientDoesNotAddSubscriptionsWhenConnectionClosed(t *testing.T) {
	s, c, _ := setupClient()
	c.closeConnection()
	subs := []byte("SUB foo 1\r\nSUB bar 2\r\n")

	ch := make(chan bool)
	go func() {
		c.parse(subs)
		ch <- true
	}()
	<-ch

	if s.sl.Count() != 0 {
		t.Fatalf("Should have no subscriptions after close, got %d\n", s.sl.Count())
	}
}

func TestClientMapRemoval(t *testing.T) {
	s, c, _ := setupClient()
	c.nc.Close()
	end := time.Now().Add(1 * time.Second)

	for time.Now().Before(end) {
		s.mu.Lock()
		lsc := len(s.clients)
		s.mu.Unlock()
		if lsc > 0 {
			time.Sleep(5 * time.Millisecond)
		}
	}
	s.mu.Lock()
	lsc := len(s.clients)
	s.mu.Unlock()
	if lsc > 0 {
		t.Fatal("Client still in server map")
	}
}

func TestAuthorizationTimeout(t *testing.T) {
	serverOptions := defaultServerOptions
	serverOptions.Authorization = "my_token"
	serverOptions.AuthTimeout = 1
	s, _, cr, _ := rawSetup(serverOptions)
	s.SetClientAuthMethod(&mockAuth{})

	time.Sleep(secondsToDuration(serverOptions.AuthTimeout))
	l, err := cr.ReadString('\n')
	if err != nil {
		t.Fatalf("Error receiving info from server: %v\n", err)
	}
	if !strings.Contains(l, "Authorization Timeout") {
		t.Fatalf("Authorization Timeout response incorrect: %q\n", l)
	}
}

// This is from bug report #18
func TestTwoTokenPubMatchSingleTokenSub(t *testing.T) {
	_, c, cr := setupClient()
	test := []byte("PUB foo.bar 5\r\nhello\r\nSUB foo 1\r\nPING\r\nPUB foo.bar 5\r\nhello\r\nPING\r\n")
	go c.parse(test)
	l, err := cr.ReadString('\n')
	if err != nil {
		t.Fatalf("Error receiving info from server: %v\n", err)
	}
	if !strings.HasPrefix(l, "PONG\r\n") {
		t.Fatalf("PONG response incorrect: %q\n", l)
	}
	// Expect just a pong, no match should exist here..
	l, err = cr.ReadString('\n')
	if !strings.HasPrefix(l, "PONG\r\n") {
		t.Fatalf("PONG response was expected, got: %q\n", l)
	}
}

func TestUnsubRace(t *testing.T) {
	s := RunServer(nil)
	defer s.Shutdown()

	nc, err := nats.Connect(fmt.Sprintf("nats://%s:%d",
		DefaultOptions.Host,
		DefaultOptions.Port))
	if err != nil {
		t.Fatalf("Error creating client: %v\n", err)
	}
	defer nc.Close()

	ncp, err := nats.Connect(fmt.Sprintf("nats://%s:%d",
		DefaultOptions.Host,
		DefaultOptions.Port))
	if err != nil {
		t.Fatalf("Error creating client: %v\n", err)
	}
	defer ncp.Close()

	sub, _ := nc.Subscribe("foo", func(m *nats.Msg) {
		// Just eat it..
	})

	nc.Flush()

	var wg sync.WaitGroup

	wg.Add(1)

	go func() {
		for i := 0; i < 10000; i++ {
			ncp.Publish("foo", []byte("hello"))
		}
		wg.Done()
	}()

	time.Sleep(5 * time.Millisecond)

	sub.Unsubscribe()

	wg.Wait()
}