package nomad

import (
	"bytes"
	"os"
	"reflect"
	"testing"
	"time"

	"github.com/hashicorp/nomad/nomad/mock"
	"github.com/hashicorp/nomad/nomad/state"
	"github.com/hashicorp/nomad/nomad/structs"
	"github.com/hashicorp/raft"
)

type MockSink struct {
	*bytes.Buffer
	cancel bool
}

func (m *MockSink) ID() string {
	return "Mock"
}

func (m *MockSink) Cancel() error {
	m.cancel = true
	return nil
}

func (m *MockSink) Close() error {
	return nil
}

func testStateStore(t *testing.T) *state.StateStore {
	state, err := state.NewStateStore(os.Stderr)
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	if state == nil {
		t.Fatalf("missing state")
	}
	return state
}

func testFSM(t *testing.T) *nomadFSM {
	fsm, err := NewFSM(testBroker(t, 0), os.Stderr)
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	if fsm == nil {
		t.Fatalf("missing fsm")
	}
	return fsm
}

func makeLog(buf []byte) *raft.Log {
	return &raft.Log{
		Index: 1,
		Term:  1,
		Type:  raft.LogCommand,
		Data:  buf,
	}
}

func TestFSM_RegisterNode(t *testing.T) {
	fsm := testFSM(t)

	req := structs.NodeRegisterRequest{
		Node: mock.Node(),
	}
	buf, err := structs.Encode(structs.NodeRegisterRequestType, req)
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	resp := fsm.Apply(makeLog(buf))
	if resp != nil {
		t.Fatalf("resp: %v", resp)
	}

	// Verify we are registered
	node, err := fsm.State().GetNodeByID(req.Node.ID)
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	if node == nil {
		t.Fatalf("not found!")
	}
	if node.CreateIndex != 1 {
		t.Fatalf("bad index: %d", node.CreateIndex)
	}

	tt := fsm.TimeTable()
	index := tt.NearestIndex(time.Now().UTC())
	if index != 1 {
		t.Fatalf("bad: %d", index)
	}
}

func TestFSM_DeregisterNode(t *testing.T) {
	fsm := testFSM(t)

	node := mock.Node()
	req := structs.NodeRegisterRequest{
		Node: node,
	}
	buf, err := structs.Encode(structs.NodeRegisterRequestType, req)
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	resp := fsm.Apply(makeLog(buf))
	if resp != nil {
		t.Fatalf("resp: %v", resp)
	}

	req2 := structs.NodeDeregisterRequest{
		NodeID: node.ID,
	}
	buf, err = structs.Encode(structs.NodeDeregisterRequestType, req2)
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	resp = fsm.Apply(makeLog(buf))
	if resp != nil {
		t.Fatalf("resp: %v", resp)
	}

	// Verify we are NOT registered
	node, err = fsm.State().GetNodeByID(req.Node.ID)
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	if node != nil {
		t.Fatalf("node found!")
	}
}

func TestFSM_UpdateNodeStatus(t *testing.T) {
	fsm := testFSM(t)

	node := mock.Node()
	req := structs.NodeRegisterRequest{
		Node: node,
	}
	buf, err := structs.Encode(structs.NodeRegisterRequestType, req)
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	resp := fsm.Apply(makeLog(buf))
	if resp != nil {
		t.Fatalf("resp: %v", resp)
	}

	req2 := structs.NodeUpdateStatusRequest{
		NodeID: node.ID,
		Status: structs.NodeStatusReady,
	}
	buf, err = structs.Encode(structs.NodeUpdateStatusRequestType, req2)
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	resp = fsm.Apply(makeLog(buf))
	if resp != nil {
		t.Fatalf("resp: %v", resp)
	}

	// Verify we are NOT registered
	node, err = fsm.State().GetNodeByID(req.Node.ID)
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	if node.Status != structs.NodeStatusReady {
		t.Fatalf("bad node: %#v", node)
	}
}

func TestFSM_RegisterJob(t *testing.T) {
	fsm := testFSM(t)

	req := structs.JobRegisterRequest{
		Job: mock.Job(),
	}
	buf, err := structs.Encode(structs.JobRegisterRequestType, req)
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	resp := fsm.Apply(makeLog(buf))
	if resp != nil {
		t.Fatalf("resp: %v", resp)
	}

	// Verify we are registered
	job, err := fsm.State().GetJobByID(req.Job.ID)
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	if job == nil {
		t.Fatalf("not found!")
	}
	if job.CreateIndex != 1 {
		t.Fatalf("bad index: %d", job.CreateIndex)
	}
}

func TestFSM_DeregisterJob(t *testing.T) {
	fsm := testFSM(t)

	job := mock.Job()
	req := structs.JobRegisterRequest{
		Job: job,
	}
	buf, err := structs.Encode(structs.JobRegisterRequestType, req)
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	resp := fsm.Apply(makeLog(buf))
	if resp != nil {
		t.Fatalf("resp: %v", resp)
	}

	req2 := structs.JobDeregisterRequest{
		JobID: job.ID,
	}
	buf, err = structs.Encode(structs.JobDeregisterRequestType, req2)
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	resp = fsm.Apply(makeLog(buf))
	if resp != nil {
		t.Fatalf("resp: %v", resp)
	}

	// Verify we are NOT registered
	job, err = fsm.State().GetJobByID(req.Job.ID)
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	if job != nil {
		t.Fatalf("job found!")
	}
}

func TestFSM_UpdateEval(t *testing.T) {
	fsm := testFSM(t)
	fsm.evalBroker.SetEnabled(true)

	req := structs.EvalUpdateRequest{
		Evals: []*structs.Evaluation{mock.Eval()},
	}
	buf, err := structs.Encode(structs.EvalUpdateRequestType, req)
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	resp := fsm.Apply(makeLog(buf))
	if resp != nil {
		t.Fatalf("resp: %v", resp)
	}

	// Verify we are registered
	eval, err := fsm.State().GetEvalByID(req.Evals[0].ID)
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	if eval == nil {
		t.Fatalf("not found!")
	}
	if eval.CreateIndex != 1 {
		t.Fatalf("bad index: %d", eval.CreateIndex)
	}

	// Verify enqueued
	stats := fsm.evalBroker.Stats()
	if stats.TotalReady != 1 {
		t.Fatalf("bad: %#v %#v", stats, eval)
	}
}

func TestFSM_DeleteEval(t *testing.T) {
	fsm := testFSM(t)

	eval := mock.Eval()
	req := structs.EvalUpdateRequest{
		Evals: []*structs.Evaluation{eval},
	}
	buf, err := structs.Encode(structs.EvalUpdateRequestType, req)
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	resp := fsm.Apply(makeLog(buf))
	if resp != nil {
		t.Fatalf("resp: %v", resp)
	}

	req2 := structs.EvalDeleteRequest{
		Evals: []string{eval.ID},
	}
	buf, err = structs.Encode(structs.EvalDeleteRequestType, req2)
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	resp = fsm.Apply(makeLog(buf))
	if resp != nil {
		t.Fatalf("resp: %v", resp)
	}

	// Verify we are NOT registered
	eval, err = fsm.State().GetEvalByID(req.Evals[0].ID)
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	if eval != nil {
		t.Fatalf("eval found!")
	}
}

func TestFSM_UpdateAllocations(t *testing.T) {
	fsm := testFSM(t)

	alloc := mock.Alloc()
	req := structs.AllocUpdateRequest{
		Evict: nil,
		Alloc: []*structs.Allocation{alloc},
	}
	buf, err := structs.Encode(structs.AllocUpdateRequestType, req)
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	resp := fsm.Apply(makeLog(buf))
	if resp != nil {
		t.Fatalf("resp: %v", resp)
	}

	// Verify we are registered
	out, err := fsm.State().GetAllocByID(alloc.ID)
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	alloc.CreateIndex = out.CreateIndex
	alloc.ModifyIndex = out.ModifyIndex
	if !reflect.DeepEqual(alloc, out) {
		t.Fatalf("bad: %#v %#v", alloc, out)
	}

	req2 := structs.AllocUpdateRequest{
		Evict: []string{alloc.ID},
	}
	buf, err = structs.Encode(structs.AllocUpdateRequestType, req2)
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	resp = fsm.Apply(makeLog(buf))
	if resp != nil {
		t.Fatalf("resp: %v", resp)
	}

	// Verify we are evicted
	out, err = fsm.State().GetAllocByID(alloc.ID)
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	if out.Status != structs.AllocStatusEvict {
		t.Fatalf("alloc found!")
	}
}

func testSnapshotRestore(t *testing.T, fsm *nomadFSM) *nomadFSM {
	// Snapshot
	snap, err := fsm.Snapshot()
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	defer snap.Release()

	// Persist
	buf := bytes.NewBuffer(nil)
	sink := &MockSink{buf, false}
	if err := snap.Persist(sink); err != nil {
		t.Fatalf("err: %v", err)
	}

	// Try to restore on a new FSM
	fsm2 := testFSM(t)

	// Do a restore
	if err := fsm2.Restore(sink); err != nil {
		t.Fatalf("err: %v", err)
	}
	return fsm2
}

func TestFSM_SnapshotRestore_Nodes(t *testing.T) {
	// Add some state
	fsm := testFSM(t)
	state := fsm.State()
	node1 := mock.Node()
	state.RegisterNode(1000, node1)
	node2 := mock.Node()
	state.RegisterNode(1001, node2)

	// Verify the contents
	fsm2 := testSnapshotRestore(t, fsm)
	state2 := fsm2.State()
	out1, _ := state2.GetNodeByID(node1.ID)
	out2, _ := state2.GetNodeByID(node2.ID)
	if !reflect.DeepEqual(node1, out1) {
		t.Fatalf("bad: \n%#v\n%#v", out1, node1)
	}
	if !reflect.DeepEqual(node2, out2) {
		t.Fatalf("bad: \n%#v\n%#v", out2, node2)
	}
}

func TestFSM_SnapshotRestore_Jobs(t *testing.T) {
	// Add some state
	fsm := testFSM(t)
	state := fsm.State()
	job1 := mock.Job()
	state.RegisterJob(1000, job1)
	job2 := mock.Job()
	state.RegisterJob(1001, job2)

	// Verify the contents
	fsm2 := testSnapshotRestore(t, fsm)
	state2 := fsm2.State()
	out1, _ := state2.GetJobByID(job1.ID)
	out2, _ := state2.GetJobByID(job2.ID)
	if !reflect.DeepEqual(job1, out1) {
		t.Fatalf("bad: \n%#v\n%#v", out1, job1)
	}
	if !reflect.DeepEqual(job2, out2) {
		t.Fatalf("bad: \n%#v\n%#v", out2, job2)
	}
}

func TestFSM_SnapshotRestore_Evals(t *testing.T) {
	// Add some state
	fsm := testFSM(t)
	state := fsm.State()
	eval1 := mock.Eval()
	state.UpsertEvals(1000, []*structs.Evaluation{eval1})
	eval2 := mock.Eval()
	state.UpsertEvals(1001, []*structs.Evaluation{eval2})

	// Verify the contents
	fsm2 := testSnapshotRestore(t, fsm)
	state2 := fsm2.State()
	out1, _ := state2.GetEvalByID(eval1.ID)
	out2, _ := state2.GetEvalByID(eval2.ID)
	if !reflect.DeepEqual(eval1, out1) {
		t.Fatalf("bad: \n%#v\n%#v", out1, eval1)
	}
	if !reflect.DeepEqual(eval2, out2) {
		t.Fatalf("bad: \n%#v\n%#v", out2, eval2)
	}
}

func TestFSM_SnapshotRestore_Allocs(t *testing.T) {
	// Add some state
	fsm := testFSM(t)
	state := fsm.State()
	alloc1 := mock.Alloc()
	state.UpdateAllocations(1000, nil, []*structs.Allocation{alloc1})
	alloc2 := mock.Alloc()
	state.UpdateAllocations(1001, nil, []*structs.Allocation{alloc2})

	// Verify the contents
	fsm2 := testSnapshotRestore(t, fsm)
	state2 := fsm2.State()
	out1, _ := state2.GetAllocByID(alloc1.ID)
	out2, _ := state2.GetAllocByID(alloc2.ID)
	if !reflect.DeepEqual(alloc1, out1) {
		t.Fatalf("bad: \n%#v\n%#v", out1, alloc1)
	}
	if !reflect.DeepEqual(alloc2, out2) {
		t.Fatalf("bad: \n%#v\n%#v", out2, alloc2)
	}
}

func TestFSM_SnapshotRestore_Indexes(t *testing.T) {
	// Add some state
	fsm := testFSM(t)
	state := fsm.State()
	node1 := mock.Node()
	state.RegisterNode(1000, node1)

	// Verify the contents
	fsm2 := testSnapshotRestore(t, fsm)
	state2 := fsm2.State()

	index, err := state2.GetIndex("nodes")
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	if index != 1000 {
		t.Fatalf("bad: %d", index)
	}
}

func TestFSM_SnapshotRestore_TimeTable(t *testing.T) {
	// Add some state
	fsm := testFSM(t)

	tt := fsm.TimeTable()
	start := time.Now().UTC()
	tt.Witness(1000, start)
	tt.Witness(2000, start.Add(10*time.Minute))

	// Verify the contents
	fsm2 := testSnapshotRestore(t, fsm)

	tt2 := fsm2.TimeTable()
	if tt2.NearestTime(1500) != start {
		t.Fatalf("bad")
	}
	if tt2.NearestIndex(start.Add(15*time.Minute)) != 2000 {
		t.Fatalf("bad")
	}
}