// Copyright 2020 The OPA Authors.  All rights reserved.
// Use of this source code is governed by an Apache2
// license that can be found in the LICENSE file.

package plugins

import (
	"context"
	"fmt"
	"net/http"
	"reflect"
	"testing"

	prom "github.com/prometheus/client_golang/prometheus"

	"github.com/open-policy-agent/opa/internal/storage/mock"
	"github.com/open-policy-agent/opa/logging"
	"github.com/open-policy-agent/opa/logging/test"
	"github.com/open-policy-agent/opa/plugins/rest"
	"github.com/open-policy-agent/opa/storage/inmem"
	"github.com/open-policy-agent/opa/topdown/cache"
)

func TestManagerCacheTriggers(t *testing.T) {
	m, err := New([]byte{}, "test", inmem.New())
	if err != nil {
		t.Fatalf("Unexpected error: %s", err)
	}

	l1Called := false
	m.RegisterCacheTrigger(func(*cache.Config) {
		l1Called = true
	})

	if m.registeredCacheTriggers[0] == nil {
		t.Fatal("First listener failed to register")
	}

	l2Called := false
	m.RegisterCacheTrigger(func(*cache.Config) {
		l2Called = true
	})

	if m.registeredCacheTriggers[0] == nil || m.registeredCacheTriggers[1] == nil {
		t.Fatal("Second listener failed to register")
	}

	if l1Called == true || l2Called == true {
		t.Fatal("Listeners should not be called yet")
	}

	err = m.Reconfigure(m.Config)
	if err != nil {
		t.Fatalf("Unexpected error: %s", err)
	}

	if l1Called == false || l2Called == false {
		t.Fatal("Listeners should hav been called")
	}
}

func TestManagerPluginStatusListener(t *testing.T) {
	m, err := New([]byte{}, "test", inmem.New())
	if err != nil {
		t.Fatalf("Unexpected error: %s", err)
	}

	// Start by registering a single listener and validate that it was registered correctly
	var l1Status map[string]*Status
	m.RegisterPluginStatusListener("l1", func(status map[string]*Status) {
		l1Status = status
	})
	if len(m.pluginStatusListeners) != 1 || m.pluginStatusListeners["l1"] == nil {
		t.Fatalf("Expected a single listener named 'l1' got: %+v", m.pluginStatusListeners)
	}

	// Register a second one, validate both are there
	var l2Status map[string]*Status
	m.RegisterPluginStatusListener("l2", func(status map[string]*Status) {
		l2Status = status
	})
	if len(m.pluginStatusListeners) != 2 || m.pluginStatusListeners["l2"] == nil {
		t.Fatalf("Expected a two listeners named 'l1' and 'l2' got: %+v", m.pluginStatusListeners)
	}

	// Ensure starting statuses are empty by default
	currentStatus := m.PluginStatus()
	if len(currentStatus) != 0 {
		t.Fatalf("Expected 0 statuses in current plugin status map, got: %+v", currentStatus)
	}

	// Push an update to a plugin, ensure current status is reflected and listeners were called
	const message = "foo"
	m.UpdatePluginStatus("p1", &Status{State: StateOK, Message: message})
	currentStatus = m.PluginStatus()
	if len(currentStatus) != 1 || currentStatus["p1"].State != StateOK || currentStatus["p1"].Message != message {
		t.Fatalf("Expected 1 statuses in current plugin status map with state OK and message 'foo', got: %+v", currentStatus)
	}
	if !reflect.DeepEqual(currentStatus, l1Status) || !reflect.DeepEqual(l1Status, l2Status) {
		t.Fatalf("Unexpected status in updates:\n\n\texpecting: %+v\n\n\tgot: l1: %+v  l2: %+v\n", currentStatus, l1Status, l2Status)
	}

	// Unregister the first listener, ensure it is removed
	m.UnregisterPluginStatusListener("l1")
	if len(m.pluginStatusListeners) != 1 || m.pluginStatusListeners["l2"] == nil {
		t.Fatalf("Expected a single listeners named 'l2' got: %+v", m.pluginStatusListeners)
	}

	// Send another update, ensure the status is ok and the remaining listener is still called
	m.UpdatePluginStatus("p2", &Status{State: StateErr})
	currentStatus = m.PluginStatus()
	if len(currentStatus) != 2 || currentStatus["p1"].State != StateOK || currentStatus["p1"].Message != message || currentStatus["p2"].State != StateErr {
		t.Fatalf("Unexpected current plugin status, got: %+v", currentStatus)
	}
	if !reflect.DeepEqual(currentStatus, l2Status) {
		t.Fatalf("Unexpected status in updates:\n\n\texpecting: %+v\n\n\tgot: %+v\n", currentStatus, l2Status)
	}

	// Unregister the last listener
	m.UnregisterPluginStatusListener("l2")
	if len(m.pluginStatusListeners) != 0 {
		t.Fatalf("Expected zero listeners got: %+v", m.pluginStatusListeners)
	}

	// Ensure updates can still be sent with no listeners
	m.UpdatePluginStatus("p2", &Status{State: StateOK})
	currentStatus = m.PluginStatus()
	if len(currentStatus) != 2 || currentStatus["p1"].State != StateOK || currentStatus["p1"].Message != message || currentStatus["p2"].State != StateOK {
		t.Fatalf("Unexpected current plugin status, got: %+v", currentStatus)
	}
}

func TestPluginStatusUpdateOnStartAndStop(t *testing.T) {
	m, err := New([]byte{}, "test", inmem.New())
	if err != nil {
		t.Fatalf("Unexpected error: %s", err)
	}

	m.Register("p1", &testPlugin{m})

	err = m.Start(context.Background())
	if err != nil {
		t.Fatalf("Unexpected error: %s", err)
	}

	m.Stop(context.Background())
}

type testPlugin struct {
	m *Manager
}

func (p *testPlugin) Start(context.Context) error {
	p.m.UpdatePluginStatus("p1", &Status{State: StateOK})
	return nil
}

func (p *testPlugin) Stop(context.Context) {
	p.m.UpdatePluginStatus("p1", &Status{State: StateNotReady})
}

func (p *testPlugin) Reconfigure(context.Context, interface{}) {
	p.m.UpdatePluginStatus("p1", &Status{State: StateNotReady})
}

func TestPluginManagerLazyInitBeforePluginStart(t *testing.T) {

	m, err := New([]byte(`{"plugins": {"someplugin": {"enabled": true}}}`), "test", inmem.New())
	if err != nil {
		t.Fatal(err)
	}

	mock := &mockForInitStartOrdering{Manager: m}

	m.Register("someplugin", mock)

	if err := m.Start(context.Background()); err != nil {
		t.Fatal(err)
	}

	if !mock.Started {
		t.Fatal("expected plugin to be started")
	}

}

func TestPluginManagerInitBeforePluginStart(t *testing.T) {

	m, err := New([]byte(`{"plugins": {"someplugin": {}}}`), "test", inmem.New())
	if err != nil {
		t.Fatal(err)
	}

	if err := m.Init(context.Background()); err != nil {
		t.Fatal(err)
	}

	mock := &mockForInitStartOrdering{Manager: m}

	m.Register("someplugin", mock)

	if err := m.Start(context.Background()); err != nil {
		t.Fatal(err)
	}

	if !mock.Started {
		t.Fatal("expected plugin to be started")
	}

}

func TestPluginManagerInitIdempotence(t *testing.T) {

	mockStore := mock.New()

	m, err := New([]byte(`{"plugins": {"someplugin": {}}}`), "test", mockStore)
	if err != nil {
		t.Fatal(err)
	}

	ctx := context.Background()

	if err := m.Init(ctx); err != nil {
		t.Fatal(err)
	}

	exp := len(mockStore.Transactions)

	if err := m.Init(ctx); err != nil {
		t.Fatal(err)
	}

	if len(mockStore.Transactions) != exp {
		t.Fatal("expected num txns to be:", exp, "but got:", len(mockStore.Transactions))
	}

}

func TestManagerWithCachingConfig(t *testing.T) {
	m, err := New([]byte(`{"caching": {"inter_query_builtin_cache": {"max_size_bytes": 100}}}`), "test", inmem.New())
	if err != nil {
		t.Fatal(err)
	}

	expected, _ := cache.ParseCachingConfig(nil)
	limit := int64(100)
	expected.InterQueryBuiltinCache.MaxSizeBytes = &limit

	if !reflect.DeepEqual(m.InterQueryBuiltinCacheConfig(), expected) {
		t.Fatalf("want %+v got %+v", expected, m.interQueryBuiltinCacheConfig)
	}

	// config error
	_, err = New([]byte(`{"caching": {"inter_query_builtin_cache": {"max_size_bytes": "100"}}}`), "test", inmem.New())
	if err == nil {
		t.Fatal("expected error but got nil")
	}
}

type mockForInitStartOrdering struct {
	Manager *Manager
	Started bool
}

func (m *mockForInitStartOrdering) Start(ctx context.Context) error {
	m.Started = true
	if m.Manager.initialized {
		return nil
	}
	return fmt.Errorf("expected manager to be initialized")
}

func (*mockForInitStartOrdering) Stop(context.Context)                     {}
func (*mockForInitStartOrdering) Reconfigure(context.Context, interface{}) {}

func TestPluginManagerAuthPlugin(t *testing.T) {
	m, err := New([]byte(`{"plugins": {"someplugin": {}}}`), "test", inmem.New())
	if err != nil {
		t.Fatal(err)
	}

	if err := m.Init(context.Background()); err != nil {
		t.Fatal(err)
	}

	mock := &myAuthPluginMock{}

	m.Register("someplugin", mock)

	authPlugin := m.AuthPlugin("someplugin")

	if authPlugin == nil {
		t.Fatal("expected to receive HTTPAuthPlugin")
	}

	switch authPlugin.(type) {
	case *myAuthPluginMock:
		return
	default:
		t.Fatal("expected HTTPAuthPlugin to be myAuthPluginMock")
	}
}

func TestPluginManagerLogger(t *testing.T) {

	logger := logging.Get().WithFields(map[string]interface{}{"context": "myloggincontext"})

	m, err := New([]byte(`{}`), "test", inmem.New(), Logger(logger))
	if err != nil {
		t.Fatal(err)
	}

	if m.Logger() != logger {
		t.Fatal("Logger was not configured on plugin manager")
	}
}

func TestPluginManagerConsoleLogger(t *testing.T) {
	consoleLogger := test.New()

	mgr, err := New([]byte(`{}`), "", inmem.New(), ConsoleLogger(consoleLogger))
	if err != nil {
		t.Fatal(err)
	}

	const fieldKey = "foo"
	const fieldValue = "bar"
	mgr.ConsoleLogger().WithFields(map[string]interface{}{fieldKey: fieldValue}).Info("Some message")

	entries := consoleLogger.Entries()

	exp := []test.LogEntry{
		{
			Level:   logging.Info,
			Fields:  map[string]interface{}{fieldKey: fieldValue},
			Message: "Some message",
		},
	}

	if !reflect.DeepEqual(exp, entries) {
		t.Fatalf("want %v but got %v", exp, entries)
	}
}

func TestPluginManagerPrometheusRegister(t *testing.T) {
	register := prometheusRegisterMock{Collectors: map[prom.Collector]bool{}}
	mgr, err := New([]byte(`{}`), "", inmem.New(), WithPrometheusRegister(register))
	if err != nil {
		t.Fatal(err)
	}

	counter := prom.NewCounter(prom.CounterOpts{})
	if err := mgr.PrometheusRegister().Register(counter); err != nil {
		t.Fatal(err)
	}
	if register.Collectors[counter] != true {
		t.Fatalf("Counter metric was not registered on prometheus")
	}
}

func TestPluginManagerServerInitialized(t *testing.T) {
	// Verify that ServerInitializedChannel is closed when
	// ServerInitialized is called.
	m1, err := New([]byte{}, "test1", inmem.New())
	if err != nil {
		t.Fatal(err)
	}
	initChannel1 := m1.ServerInitializedChannel()
	m1.ServerInitialized()
	// Verify that ServerInitialized is idempotent and will not panic
	m1.ServerInitialized()
	select {
	case <-initChannel1:
		break
	default:
		t.Fatal("expected ServerInitializedChannel to be closed")
	}

	// Verify that ServerInitializedChannel is open when
	// ServerInitialized is not called.
	m2, err := New([]byte{}, "test2", inmem.New())
	if err != nil {
		t.Fatal(err)
	}
	initChannel2 := m2.ServerInitializedChannel()
	select {
	case <-initChannel2:
		t.Fatal("expected ServerInitializedChannel to be open and have no messages")
	default:
		break
	}
}

type myAuthPluginMock struct{}

func (m *myAuthPluginMock) NewClient(c rest.Config) (*http.Client, error) {
	tlsConfig, err := rest.DefaultTLSConfig(c)
	if err != nil {
		return nil, err
	}
	return rest.DefaultRoundTripperClient(
		tlsConfig,
		10,
	), nil
}
func (*myAuthPluginMock) Prepare(*http.Request) error {
	return nil
}
func (*myAuthPluginMock) Start(context.Context) error {
	return nil
}
func (*myAuthPluginMock) Stop(context.Context) {
}
func (*myAuthPluginMock) Reconfigure(context.Context, interface{}) {
}

type prometheusRegisterMock struct {
	Collectors map[prom.Collector]bool
}

func (p prometheusRegisterMock) Register(collector prom.Collector) error {
	p.Collectors[collector] = true
	return nil
}

func (p prometheusRegisterMock) MustRegister(collector ...prom.Collector) {
	for _, c := range collector {
		p.Collectors[c] = true
	}
}

func (p prometheusRegisterMock) Unregister(collector prom.Collector) bool {
	delete(p.Collectors, collector)
	return true
}
