package etcdserver

import (
	"fmt"
	"math/rand"
	"reflect"
	"testing"
	"time"

	pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
	"github.com/coreos/etcd/raft"
	"github.com/coreos/etcd/raft/raftpb"
	"github.com/coreos/etcd/store"
	"github.com/coreos/etcd/third_party/code.google.com/p/go.net/context"
)

// TestDoLocalAction tests requests which do not need to go through raft to be applied,
// and are served through local data.
func TestDoLocalAction(t *testing.T) {
	tests := []struct {
		req pb.Request

		wresp   Response
		werr    error
		waction []string
	}{
		{
			pb.Request{Method: "GET", Id: 1, Wait: true},
			Response{Watcher: &stubWatcher{}}, nil, []string{"Watch"},
		},
		{
			pb.Request{Method: "GET", Id: 1},
			Response{Event: &store.Event{}}, nil, []string{"Get"},
		},
		{
			pb.Request{Method: "BADMETHOD", Id: 1},
			Response{}, ErrUnknownMethod, nil,
		},
	}
	for i, tt := range tests {
		store := &storeRecorder{}
		srv := &Server{Store: store}
		resp, err := srv.Do(context.TODO(), tt.req)

		if err != tt.werr {
			t.Fatalf("#%d: err = %+v, want %+v", i, err, tt.werr)
		}
		if !reflect.DeepEqual(resp, tt.wresp) {
			t.Errorf("#%d: resp = %+v, want %+v", i, resp, tt.wresp)
		}
		if !reflect.DeepEqual(store.action, tt.waction) {
			t.Errorf("#%d: action = %+v, want %+v", i, store.action, tt.waction)
		}
	}
}

func TestApply(t *testing.T) {
	tests := []struct {
		req pb.Request

		wresp   Response
		waction []string
	}{
		{
			pb.Request{Method: "POST", Id: 1},
			Response{Event: &store.Event{}}, []string{"Create"},
		},
		{
			pb.Request{Method: "PUT", Id: 1, PrevExists: boolp(true), PrevIndex: 1},
			Response{Event: &store.Event{}}, []string{"Update"},
		},
		{
			pb.Request{Method: "PUT", Id: 1, PrevExists: boolp(false), PrevIndex: 1},
			Response{Event: &store.Event{}}, []string{"Create"},
		},
		{
			pb.Request{Method: "PUT", Id: 1, PrevExists: boolp(true)},
			Response{Event: &store.Event{}}, []string{"Update"},
		},
		{
			pb.Request{Method: "PUT", Id: 1, PrevExists: boolp(false)},
			Response{Event: &store.Event{}}, []string{"Create"},
		},
		{
			pb.Request{Method: "PUT", Id: 1, PrevIndex: 1},
			Response{Event: &store.Event{}}, []string{"CompareAndSwap"},
		},
		{
			pb.Request{Method: "PUT", Id: 1, PrevValue: "bar"},
			Response{Event: &store.Event{}}, []string{"CompareAndSwap"},
		},
		{
			pb.Request{Method: "PUT", Id: 1},
			Response{Event: &store.Event{}}, []string{"Set"},
		},
		{
			pb.Request{Method: "DELETE", Id: 1, PrevIndex: 1},
			Response{Event: &store.Event{}}, []string{"CompareAndDelete"},
		},
		{
			pb.Request{Method: "DELETE", Id: 1, PrevValue: "bar"},
			Response{Event: &store.Event{}}, []string{"CompareAndDelete"},
		},
		{
			pb.Request{Method: "DELETE", Id: 1},
			Response{Event: &store.Event{}}, []string{"Delete"},
		},
		{
			pb.Request{Method: "QGET", Id: 1},
			Response{Event: &store.Event{}}, []string{"Get"},
		},
		{
			pb.Request{Method: "BADMETHOD", Id: 1},
			Response{err: ErrUnknownMethod}, nil,
		},
	}

	for i, tt := range tests {
		store := &storeRecorder{}
		srv := &Server{Store: store}
		resp := srv.apply(tt.req)

		if !reflect.DeepEqual(resp, tt.wresp) {
			t.Errorf("#%d: resp = %+v, want %+v", i, resp, tt.wresp)
		}
		if !reflect.DeepEqual(store.action, tt.waction) {
			t.Errorf("#%d: action = %+v, want %+v", i, store.action, tt.waction)
		}
	}
}

func TestClusterOf1(t *testing.T) { testServer(t, 1) }
func TestClusterOf3(t *testing.T) { testServer(t, 3) }

func testServer(t *testing.T, ns int64) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	ss := make([]*Server, ns)

	send := func(msgs []raftpb.Message) {
		for _, m := range msgs {
			t.Logf("m = %+v\n", m)
			ss[m.To-1].Node.Step(ctx, m)
		}
	}

	peers := make([]int64, ns)
	for i := int64(0); i < ns; i++ {
		peers[i] = i + 1
	}

	for i := int64(0); i < ns; i++ {
		id := i + 1
		n := raft.Start(id, peers, 10, 1)
		tk := time.NewTicker(10 * time.Millisecond)
		defer tk.Stop()
		srv := &Server{
			Node:   n,
			Store:  store.New(),
			Send:   send,
			Save:   func(_ raftpb.State, _ []raftpb.Entry) {},
			Ticker: tk.C,
		}
		Start(srv)
		// TODO(xiangli): randomize election timeout
		// then remove this sleep.
		time.Sleep(1 * time.Millisecond)
		ss[i] = srv
	}

	for i := 1; i <= 10; i++ {
		r := pb.Request{
			Method: "PUT",
			Id:     int64(i),
			Path:   "/foo",
			Val:    "bar",
		}
		j := rand.Intn(len(ss))
		t.Logf("ss = %d", j)
		resp, err := ss[j].Do(ctx, r)
		if err != nil {
			t.Fatal(err)
		}

		g, w := resp.Event.Node, &store.NodeExtern{
			Key:           "/foo",
			ModifiedIndex: uint64(i),
			CreatedIndex:  uint64(i),
			Value:         stringp("bar"),
		}

		if !reflect.DeepEqual(g, w) {
			t.Error("value:", *g.Value)
			t.Errorf("g = %+v, w %+v", g, w)
		}
	}

	time.Sleep(10 * time.Millisecond)

	var last interface{}
	for i, sv := range ss {
		sv.Stop()
		g, _ := sv.Store.Get("/", true, true)
		if last != nil && !reflect.DeepEqual(last, g) {
			t.Errorf("server %d: Root = %#v, want %#v", i, g, last)
		}
		last = g
	}
}

func TestDoProposal(t *testing.T) {
	tests := []pb.Request{
		pb.Request{Method: "POST", Id: 1},
		pb.Request{Method: "PUT", Id: 1},
		pb.Request{Method: "DELETE", Id: 1},
		pb.Request{Method: "GET", Id: 1, Quorum: true},
	}

	for i, tt := range tests {
		ctx, _ := context.WithCancel(context.Background())
		n := raft.Start(0xBAD0, []int64{0xBAD0}, 10, 1)
		st := &storeRecorder{}
		tk := make(chan time.Time)
		// this makes <-tk always successful, which accelerates internal clock
		close(tk)
		srv := &Server{
			Node:   n,
			Store:  st,
			Send:   func(_ []raftpb.Message) {},
			Save:   func(_ raftpb.State, _ []raftpb.Entry) {},
			Ticker: tk,
		}
		Start(srv)
		resp, err := srv.Do(ctx, tt)
		srv.Stop()

		if len(st.action) != 1 {
			t.Errorf("#%d: len(action) = %d, want 1", i, len(st.action))
		}
		if err != nil {
			t.Fatalf("#%d: err = %v, want nil", i, err)
		}
		wresp := Response{Event: &store.Event{}}
		if !reflect.DeepEqual(resp, wresp) {
			t.Errorf("#%d: resp = %v, want %v", i, resp, wresp)
		}
	}
}

func TestDoProposalCancelled(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	// node cannot make any progress because there are two nodes
	n := raft.Start(0xBAD0, []int64{0xBAD0, 0xBAD1}, 10, 1)
	st := &storeRecorder{}
	wait := &waitRecorder{}
	srv := &Server{
		// TODO: use fake node for better testability
		Node:  n,
		Store: st,
		w:     wait,
	}

	done := make(chan struct{})
	var err error
	go func() {
		_, err = srv.Do(ctx, pb.Request{Method: "PUT", Id: 1})
		close(done)
	}()
	cancel()
	<-done

	if len(st.action) != 0 {
		t.Errorf("len(action) = %v, want 0", len(st.action))
	}
	if err != context.Canceled {
		t.Fatalf("err = %v, want %v", err, context.Canceled)
	}
	w := []string{"Register1", "Trigger1"}
	if !reflect.DeepEqual(wait.action, w) {
		t.Errorf("wait.action = %+v, want %+v", wait.action, w)
	}
}

func TestDoProposalStopped(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	// node cannot make any progress because there are two nodes
	n := raft.Start(0xBAD0, []int64{0xBAD0, 0xBAD1}, 10, 1)
	st := &storeRecorder{}
	tk := make(chan time.Time)
	// this makes <-tk always successful, which accelarates internal clock
	close(tk)
	srv := &Server{
		// TODO: use fake node for better testability
		Node:   n,
		Store:  st,
		Send:   func(_ []raftpb.Message) {},
		Save:   func(_ raftpb.State, _ []raftpb.Entry) {},
		Ticker: tk,
	}
	Start(srv)

	done := make(chan struct{})
	var err error
	go func() {
		_, err = srv.Do(ctx, pb.Request{Method: "PUT", Id: 1})
		close(done)
	}()
	srv.Stop()
	<-done

	if len(st.action) != 0 {
		t.Errorf("len(action) = %v, want 0", len(st.action))
	}
	if err != ErrStopped {
		t.Errorf("err = %v, want %v", err, ErrStopped)
	}
}

// TODO: test wait trigger correctness in multi-server case

func TestGetBool(t *testing.T) {
	tests := []struct {
		b    *bool
		wb   bool
		wset bool
	}{
		{nil, false, false},
		{boolp(true), true, true},
		{boolp(false), false, true},
	}
	for i, tt := range tests {
		b, set := getBool(tt.b)
		if b != tt.wb {
			t.Errorf("#%d: value = %v, want %v", i, b, tt.wb)
		}
		if set != tt.wset {
			t.Errorf("#%d: set = %v, want %v", i, set, tt.wset)
		}
	}
}

type storeRecorder struct {
	action []string
}

func (s *storeRecorder) Version() int  { return 0 }
func (s *storeRecorder) Index() uint64 { return 0 }
func (s *storeRecorder) Get(_ string, _, _ bool) (*store.Event, error) {
	s.action = append(s.action, "Get")
	return &store.Event{}, nil
}
func (s *storeRecorder) Set(_ string, _ bool, _ string, _ time.Time) (*store.Event, error) {
	s.action = append(s.action, "Set")
	return &store.Event{}, nil
}
func (s *storeRecorder) Update(_, _ string, _ time.Time) (*store.Event, error) {
	s.action = append(s.action, "Update")
	return &store.Event{}, nil
}
func (s *storeRecorder) Create(_ string, _ bool, _ string, _ bool, _ time.Time) (*store.Event, error) {
	s.action = append(s.action, "Create")
	return &store.Event{}, nil
}
func (s *storeRecorder) CompareAndSwap(_, _ string, _ uint64, _ string, _ time.Time) (*store.Event, error) {
	s.action = append(s.action, "CompareAndSwap")
	return &store.Event{}, nil
}
func (s *storeRecorder) Delete(_ string, _, _ bool) (*store.Event, error) {
	s.action = append(s.action, "Delete")
	return &store.Event{}, nil
}
func (s *storeRecorder) CompareAndDelete(_, _ string, _ uint64) (*store.Event, error) {
	s.action = append(s.action, "CompareAndDelete")
	return &store.Event{}, nil
}
func (s *storeRecorder) Watch(_ string, _, _ bool, _ uint64) (store.Watcher, error) {
	s.action = append(s.action, "Watch")
	return &stubWatcher{}, nil
}
func (s *storeRecorder) Save() ([]byte, error)              { return nil, nil }
func (s *storeRecorder) Recovery(b []byte) error            { return nil }
func (s *storeRecorder) TotalTransactions() uint64          { return 0 }
func (s *storeRecorder) JsonStats() []byte                  { return nil }
func (s *storeRecorder) DeleteExpiredKeys(cutoff time.Time) {}

type stubWatcher struct{}

func (w *stubWatcher) EventChan() chan *store.Event { return nil }
func (w *stubWatcher) Remove()                      {}

type waitRecorder struct {
	action []string
}

func (w *waitRecorder) Register(id int64) <-chan interface{} {
	w.action = append(w.action, fmt.Sprint("Register", id))
	return nil
}
func (w *waitRecorder) Trigger(id int64, x interface{}) {
	w.action = append(w.action, fmt.Sprint("Trigger", id))
}

func boolp(b bool) *bool { return &b }

func stringp(s string) *string { return &s }