package syncv3

import (
	"encoding/json"
	"net/http"
	"testing"
	"time"

	"github.com/matrix-org/sliding-sync/sync2"
	"github.com/matrix-org/sliding-sync/sync3"
	"github.com/matrix-org/sliding-sync/sync3/extensions"
	"github.com/matrix-org/sliding-sync/testutils"
	"github.com/matrix-org/sliding-sync/testutils/m"
)

// catch all file for any kind of regression test which doesn't fall into a unique category

// Regression test for https://github.com/matrix-org/sliding-sync/issues/192
//   - Bob on his server invites Alice to a room.
//   - Alice joins the room first over federation. Proxy does the right thing and sets her membership to join. There is no timeline though due to not having backfilled.
//   - Alice's client backfills in the room which pulls in the invite event, but the SS proxy doesn't see it as it's backfill, not /sync.
//   - Charlie joins the same room via SS, which makes the SS proxy see 50 timeline events, which includes the invite.
//     As the proxy has never seen this invite event before, it assumes it is newer than the join event and inserts it, corrupting state.
//
// Manually confirmed this can happen with 3x Element clients. We need to make sure we drop those earlier events.
// The first join over federation presents itself as a single join event in the timeline, with the create event, etc in state.
func TestBackfillInviteDoesntCorruptState(t *testing.T) {
	pqString := testutils.PrepareDBConnectionString()
	// setup code
	v2 := runTestV2Server(t)
	v3 := runTestServer(t, v2, pqString)
	defer v2.close()
	defer v3.close()

	fedBob := "@bob:over_federation"
	charlie := "@charlie:localhost"
	charlieToken := "CHARLIE_TOKEN"
	joinEvent := testutils.NewJoinEvent(t, alice)

	room := roomEvents{
		roomID: "!TestBackfillInviteDoesntCorruptState:localhost",
		events: []json.RawMessage{
			joinEvent,
		},
		state: createRoomState(t, fedBob, time.Now()),
	}
	v2.addAccount(t, alice, aliceToken)
	v2.queueResponse(alice, sync2.SyncResponse{
		Rooms: sync2.SyncRoomsResponse{
			Join: v2JoinTimeline(room),
		},
	})

	// alice syncs and should see the room.
	aliceRes := v3.mustDoV3Request(t, aliceToken, sync3.Request{
		Lists: map[string]sync3.RequestList{
			"a": {
				Ranges: sync3.SliceRanges{{0, 20}},
				RoomSubscription: sync3.RoomSubscription{
					TimelineLimit: 5,
				},
			},
		},
	})
	m.MatchResponse(t, aliceRes, m.MatchList("a", m.MatchV3Count(1), m.MatchV3Ops(m.MatchV3SyncOp(0, 0, []string{room.roomID}))))

	// Alice's client "backfills" new data in, meaning the next user who joins is going to see a different set of timeline events
	dummyMsg := testutils.NewMessageEvent(t, fedBob, "you didn't see this before joining")
	charlieJoinEvent := testutils.NewJoinEvent(t, charlie)
	backfilledTimelineEvents := append(
		room.state, []json.RawMessage{
			dummyMsg,
			testutils.NewStateEvent(t, "m.room.member", alice, fedBob, map[string]interface{}{
				"membership": "invite",
			}),
			joinEvent,
			charlieJoinEvent,
		}...,
	)

	// now charlie also joins the room, causing a different response from /sync v2
	v2.addAccount(t, charlie, charlieToken)
	v2.queueResponse(charlie, sync2.SyncResponse{
		Rooms: sync2.SyncRoomsResponse{
			Join: v2JoinTimeline(roomEvents{
				roomID: room.roomID,
				events: backfilledTimelineEvents,
			}),
		},
	})

	// and now charlie hits SS, which might corrupt membership state for alice.
	charlieRes := v3.mustDoV3Request(t, charlieToken, sync3.Request{
		Lists: map[string]sync3.RequestList{
			"a": {
				Ranges: sync3.SliceRanges{{0, 20}},
			},
		},
	})
	m.MatchResponse(t, charlieRes, m.MatchList("a", m.MatchV3Count(1), m.MatchV3Ops(m.MatchV3SyncOp(0, 0, []string{room.roomID}))))

	// alice should not see dummyMsg or the invite
	aliceRes = v3.mustDoV3RequestWithPos(t, aliceToken, aliceRes.Pos, sync3.Request{})
	m.MatchResponse(t, aliceRes, m.MatchNoV3Ops(), m.LogResponse(t), m.MatchRoomSubscriptionsStrict(
		map[string][]m.RoomMatcher{
			room.roomID: {
				m.MatchJoinCount(3), // alice, bob, charlie,
				m.MatchNoInviteCount(),
				m.MatchNumLive(1),
				m.MatchRoomTimeline([]json.RawMessage{charlieJoinEvent}),
			},
		},
	))
}

func TestMalformedEventsTimeline(t *testing.T) {
	pqString := testutils.PrepareDBConnectionString()
	// setup code
	v2 := runTestV2Server(t)
	v3 := runTestServer(t, v2, pqString)
	defer v2.close()
	defer v3.close()

	// unusual events ARE VALID EVENTS and should be sent to the client, but are unusual for some reason.
	unusualEvents := []json.RawMessage{
		testutils.NewStateEvent(t, "", "", alice, map[string]interface{}{
			"empty string": "for event type",
		}),
	}
	// malformed events are INVALID and should be ignored by the proxy.
	malformedEvents := []json.RawMessage{
		json.RawMessage(`{}`),                                        // empty object
		json.RawMessage(`{"type":5}`),                                // type is an integer
		json.RawMessage(`{"type":"foo","content":{},"event_id":""}`), // 0-length string as event ID
		json.RawMessage(`{"type":"foo","content":{}}`),               // missing event ID
	}

	room := roomEvents{
		roomID: "!TestMalformedEventsTimeline:localhost",
		// append malformed after unusual. All malformed events should be dropped,
		// leaving only unusualEvents.
		events: append(unusualEvents, malformedEvents...),
		state:  createRoomState(t, alice, time.Now()),
	}
	v2.addAccount(t, alice, aliceToken)
	v2.queueResponse(alice, sync2.SyncResponse{
		Rooms: sync2.SyncRoomsResponse{
			Join: v2JoinTimeline(room),
		},
	})

	// alice syncs and should see the room.
	aliceRes := v3.mustDoV3Request(t, aliceToken, sync3.Request{
		Lists: map[string]sync3.RequestList{
			"a": {
				Ranges: sync3.SliceRanges{{0, 20}},
				RoomSubscription: sync3.RoomSubscription{
					TimelineLimit: int64(len(unusualEvents)),
				},
			},
		},
	})
	m.MatchResponse(t, aliceRes, m.MatchList("a", m.MatchV3Count(1), m.MatchV3Ops(m.MatchV3SyncOp(0, 0, []string{room.roomID}))),
		m.MatchRoomSubscriptionsStrict(map[string][]m.RoomMatcher{
			room.roomID: {
				m.MatchJoinCount(1),
				m.MatchRoomTimeline(unusualEvents),
			},
		}))
}

func TestMalformedEventsState(t *testing.T) {
	pqString := testutils.PrepareDBConnectionString()
	// setup code
	v2 := runTestV2Server(t)
	v3 := runTestServer(t, v2, pqString)
	defer v2.close()
	defer v3.close()

	// unusual events ARE VALID EVENTS and should be sent to the client, but are unusual for some reason.
	unusualEvents := []json.RawMessage{
		testutils.NewStateEvent(t, "", "", alice, map[string]interface{}{
			"empty string": "for event type",
		}),
	}
	// malformed events are INVALID and should be ignored by the proxy.
	malformedEvents := []json.RawMessage{
		json.RawMessage(`{}`), // empty object
		json.RawMessage(`{"type":5,"content":{},"event_id":"f","state_key":""}`),    // type is an integer
		json.RawMessage(`{"type":"foo","content":{},"event_id":"","state_key":""}`), // 0-length string as event ID
		json.RawMessage(`{"type":"foo","content":{},"state_key":""}`),               // missing event ID
	}

	latestEvent := testutils.NewEvent(t, "m.room.message", alice, map[string]interface{}{"body": "hi"})

	room := roomEvents{
		roomID: "!TestMalformedEventsState:localhost",
		events: []json.RawMessage{latestEvent},
		// append malformed after unusual. All malformed events should be dropped,
		// leaving only unusualEvents.
		state: append(createRoomState(t, alice, time.Now()), append(unusualEvents, malformedEvents...)...),
	}
	v2.addAccount(t, alice, aliceToken)
	v2.queueResponse(alice, sync2.SyncResponse{
		Rooms: sync2.SyncRoomsResponse{
			Join: v2JoinTimeline(room),
		},
	})

	// alice syncs and should see the room.
	aliceRes := v3.mustDoV3Request(t, aliceToken, sync3.Request{
		Lists: map[string]sync3.RequestList{
			"a": {
				Ranges: sync3.SliceRanges{{0, 20}},
				RoomSubscription: sync3.RoomSubscription{
					TimelineLimit: int64(len(unusualEvents)),
					RequiredState: [][2]string{{"", ""}},
				},
			},
		},
	})
	m.MatchResponse(t, aliceRes, m.MatchList("a", m.MatchV3Count(1), m.MatchV3Ops(m.MatchV3SyncOp(0, 0, []string{room.roomID}))),
		m.MatchRoomSubscriptionsStrict(map[string][]m.RoomMatcher{
			room.roomID: {
				m.MatchJoinCount(1),
				m.MatchRoomTimeline([]json.RawMessage{latestEvent}),
				m.MatchRoomRequiredState([]json.RawMessage{
					unusualEvents[0],
				}),
			},
		}))
}

// Regression test for https://github.com/matrix-org/sliding-sync/issues/295
// This test:
// - injects a good room and a bad room in the v2 response
// - then injects a good room update if the since token advanced
// - checks we see all updates
// In the past, the bad room in the first v2 response caused the proxy to retry and never advance,
// wedging the poller.
func TestBadCreateInitialiseDoesntWedgePolling(t *testing.T) {
	pqString := testutils.PrepareDBConnectionString()
	// setup code
	v2 := runTestV2Server(t)
	v3 := runTestServer(t, v2, pqString)
	defer v2.close()
	defer v3.close()

	goodRoom := "!good:localhost"
	badRoom := "!bad:localhost"

	v2.addAccount(t, alice, aliceToken)
	// we should see the since token increment, if we see repeats it means
	// we aren't returning DataErrors when we should be.
	wantSinces := []string{"", "1", "2"}
	ch := make(chan bool)
	v2.checkRequest = func(token string, req *http.Request) {
		if len(wantSinces) == 0 {
			return
		}
		gotSince := req.URL.Query().Get("since")
		t.Logf("checkRequest got since=%v", gotSince)
		want := wantSinces[0]
		wantSinces = wantSinces[1:]
		if gotSince != want {
			t.Errorf("v2.checkRequest since got '%v' want '%v'", gotSince, want)
		}
		if len(wantSinces) == 0 {
			close(ch)
		}
	}

	// initial sync, everything fine
	v2.queueResponse(alice, sync2.SyncResponse{
		NextBatch: "1",
		Rooms: sync2.SyncRoomsResponse{
			Join: map[string]sync2.SyncV2JoinResponse{
				goodRoom: {
					Timeline: sync2.TimelineResponse{
						Events: createRoomState(t, alice, time.Now()),
					},
				},
			},
		},
	})
	aliceRes := v3.mustDoV3Request(t, aliceToken, sync3.Request{
		Lists: map[string]sync3.RequestList{
			"a": {
				Ranges: sync3.SliceRanges{{0, 20}},
				RoomSubscription: sync3.RoomSubscription{
					TimelineLimit: 1,
				},
			},
		},
	})
	// we should only see 1 room
	m.MatchResponse(t, aliceRes, m.MatchRoomSubscriptionsStrict(map[string][]m.RoomMatcher{
		goodRoom: {
			m.MatchJoinCount(1),
		},
	},
	))

	// now inject a bad room and some extra good event
	extraGoodEvent := testutils.NewMessageEvent(t, alice, "Extra!", testutils.WithTimestamp(time.Now().Add(time.Second)))
	v2.queueResponse(alice, sync2.SyncResponse{
		NextBatch: "2",
		Rooms: sync2.SyncRoomsResponse{
			Join: map[string]sync2.SyncV2JoinResponse{
				goodRoom: {
					Timeline: sync2.TimelineResponse{
						Events: []json.RawMessage{extraGoodEvent},
					},
				},
				badRoom: {
					State: sync2.EventsResponse{
						// BAD: missing create event
						Events: createRoomState(t, alice, time.Now())[1:],
					},
					Timeline: sync2.TimelineResponse{
						Events: []json.RawMessage{
							testutils.NewMessageEvent(t, alice, "Hello World"),
						},
					},
				},
			},
		},
	})
	v2.waitUntilEmpty(t, alice)

	// we should see the extra good event and not the bad room
	aliceRes = v3.mustDoV3RequestWithPos(t, aliceToken, aliceRes.Pos, sync3.Request{})
	// we should only see 1 room
	m.MatchResponse(t, aliceRes, m.MatchRoomSubscriptionsStrict(map[string][]m.RoomMatcher{
		goodRoom: {
			m.MatchRoomTimelineMostRecent(1, []json.RawMessage{extraGoodEvent}),
		},
	},
	))

	// make sure we've seen all the v2 requests
	select {
	case <-ch:
	case <-time.After(time.Second):
		t.Fatalf("timed out waiting for all v2 requests")
	}
}

// Regression test for https://github.com/matrix-org/sliding-sync/issues/295
// This test:
// - injects to-device msgs and a bad room in the v2 response
// - checks we see the to-device msgs
// It's possible for the poller to bail early and skip over processing the remaining response
// which this test is trying to safeguard against.
func TestBadPollDataDoesntDropToDeviceMsgs(t *testing.T) {
	pqString := testutils.PrepareDBConnectionString()
	// setup code
	v2 := runTestV2Server(t)
	v3 := runTestServer(t, v2, pqString)
	defer v2.close()
	defer v3.close()

	goodRoom := "!good:localhost"
	badRoom := "!bad:localhost"

	v2.addAccount(t, alice, aliceToken)
	// we should see the since token increment, if we see repeats it means
	// we aren't returning DataErrors when we should be.
	wantSinces := []string{"", "1", "2"}
	ch := make(chan bool)
	v2.checkRequest = func(token string, req *http.Request) {
		if len(wantSinces) == 0 {
			return
		}
		gotSince := req.URL.Query().Get("since")
		t.Logf("checkRequest got since=%v", gotSince)
		want := wantSinces[0]
		wantSinces = wantSinces[1:]
		if gotSince != want {
			t.Errorf("v2.checkRequest since got '%v' want '%v'", gotSince, want)
		}
		if len(wantSinces) == 0 {
			close(ch)
		}
	}

	// initial sync, everything fine
	v2.queueResponse(alice, sync2.SyncResponse{
		NextBatch: "1",
		Rooms: sync2.SyncRoomsResponse{
			Join: map[string]sync2.SyncV2JoinResponse{
				goodRoom: {
					Timeline: sync2.TimelineResponse{
						Events: createRoomState(t, alice, time.Now()),
					},
				},
			},
		},
	})
	aliceRes := v3.mustDoV3Request(t, aliceToken, sync3.Request{
		Extensions: extensions.Request{
			ToDevice: &extensions.ToDeviceRequest{
				Core: extensions.Core{
					Enabled: &boolTrue,
				},
			},
		},
		Lists: map[string]sync3.RequestList{
			"a": {
				Ranges: sync3.SliceRanges{{0, 20}},
				RoomSubscription: sync3.RoomSubscription{
					TimelineLimit: 1,
				},
			},
		},
	})
	// we should only see 1 room
	m.MatchResponse(t, aliceRes, m.MatchRoomSubscriptionsStrict(map[string][]m.RoomMatcher{
		goodRoom: {
			m.MatchJoinCount(1),
		},
	},
	))

	// now inject a bad room and some to-device events
	toDeviceEvent := testutils.NewEvent(t, "m.todevice", alice, map[string]interface{}{"body": "testio"})
	v2.queueResponse(alice, sync2.SyncResponse{
		NextBatch: "2",
		ToDevice: sync2.EventsResponse{
			Events: []json.RawMessage{toDeviceEvent},
		},
		Rooms: sync2.SyncRoomsResponse{
			Join: map[string]sync2.SyncV2JoinResponse{
				badRoom: {
					State: sync2.EventsResponse{
						// BAD: missing create event
						Events: createRoomState(t, alice, time.Now())[1:],
					},
					Timeline: sync2.TimelineResponse{
						Events: []json.RawMessage{
							testutils.NewMessageEvent(t, alice, "Hello World"),
						},
					},
				},
			},
		},
	})
	v2.waitUntilEmpty(t, alice)

	// we should see the to-device event and not the bad room
	aliceRes = v3.mustDoV3RequestWithPos(t, aliceToken, aliceRes.Pos, sync3.Request{})
	// we should only see the to-device event
	m.MatchResponse(t, aliceRes,
		m.LogResponse(t),
		m.MatchRoomSubscriptionsStrict(map[string][]m.RoomMatcher{}),
		m.MatchToDeviceMessages([]json.RawMessage{toDeviceEvent}),
	)

	// make sure we've seen all the v2 requests
	select {
	case <-ch:
	case <-time.After(time.Second):
		t.Fatalf("timed out waiting for all v2 requests")
	}
}