package clientapi_test

import (
	"fmt"
	"net/http"
	"net/url"
	"testing"
	"time"

	"github.com/dariuszjaniak/warp/server/internal/httputil"
)

// Simplified Sliding Sync (MSC4186).

const slidingPath = "/_matrix/client/unstable/org.matrix.simplified_msc3575/sync"

type slidingResult struct {
	Pos   string `json:"pos"`
	Lists map[string]struct {
		Count int `json:"count"`
	} `json:"lists"`
	Rooms map[string]struct {
		Name          string           `json:"name"`
		Initial       bool             `json:"initial"`
		RequiredState []syncEvent      `json:"required_state"`
		Timeline      []syncEvent      `json:"timeline"`
		PrevBatch     string           `json:"prev_batch"`
		Limited       bool             `json:"limited"`
		NumLive       *int             `json:"num_live"`
		BumpStamp     int64            `json:"bump_stamp"`
		JoinedCount   *int             `json:"joined_count"`
		InviteState   []map[string]any `json:"invite_state"`
		Heroes        []map[string]any `json:"heroes"`
	} `json:"rooms"`
	Extensions struct {
		ToDevice *struct {
			NextBatch string           `json:"next_batch"`
			Events    []map[string]any `json:"events"`
		} `json:"to_device"`
		E2EE *struct {
			DeviceLists struct {
				Changed []string `json:"changed"`
			} `json:"device_lists"`
			DeviceOneTimeKeysCount map[string]int `json:"device_one_time_keys_count"`
		} `json:"e2ee"`
		AccountData *struct {
			Global []map[string]any            `json:"global"`
			Rooms  map[string][]map[string]any `json:"rooms"`
		} `json:"account_data"`
		Receipts *struct {
			Rooms map[string]map[string]any `json:"rooms"`
		} `json:"receipts"`
		Typing *struct {
			Rooms map[string]map[string]any `json:"rooms"`
		} `json:"typing"`
	} `json:"extensions"`
}

func (ts *testServer) slidingRaw(acc account, pos string, timeout time.Duration, body map[string]any) (int, slidingResult, map[string]any) {
	ts.t.Helper()
	query := url.Values{}
	if pos != "" {
		query.Set("pos", pos)
	}
	query.Set("timeout", fmt.Sprint(timeout.Milliseconds()))
	rec := ts.post(slidingPath+"?"+query.Encode(), acc.AccessToken, body)
	if rec.Code != http.StatusOK {
		return rec.Code, slidingResult{}, jsonBody(ts.t, rec)
	}
	return rec.Code, decode[slidingResult](ts.t, rec), nil
}

func (ts *testServer) sliding(acc account, pos string, body map[string]any) slidingResult {
	ts.t.Helper()
	code, result, errBody := ts.slidingRaw(acc, pos, 0, body)
	if code != http.StatusOK {
		ts.t.Fatalf("sliding sync answered %d: %v", code, errBody)
	}
	if result.Pos == "" {
		ts.t.Fatal("sliding sync returned no pos")
	}
	return result
}

func roomList(ranges [][2]int, timelineLimit int, requiredState [][]string) map[string]any {
	return map[string]any{
		"lists": map[string]any{
			"all": map[string]any{
				"ranges":         ranges,
				"timeline_limit": timelineLimit,
				"required_state": requiredState,
			},
		},
	}
}

func TestSlidingSyncListWindowAndIncrementals(t *testing.T) {
	ts := newTestServer(t, nil)
	alice := ts.register("alice", "correct-horse-battery-staple")

	oldest := ts.createRoom(alice, map[string]any{"name": "Oldest"})
	middle := ts.createRoom(alice, map[string]any{"name": "Middle"})
	newest := ts.createRoom(alice, map[string]any{"name": "Newest"})
	ts.sendMessage(alice, oldest, "o1")
	ts.sendMessage(alice, middle, "m1")
	ts.sendMessage(alice, newest, "n1")
	ts.sendMessage(alice, newest, "n2")

	body := roomList([][2]int{{0, 1}}, 2, [][]string{{"m.room.name", ""}})
	first := ts.sliding(alice, "", body)
	if first.Lists["all"].Count != 3 {
		t.Fatalf("list count = %d, want 3", first.Lists["all"].Count)
	}
	if len(first.Rooms) != 2 {
		t.Fatalf("rooms = %v, want the two most recently active", keysOf(first.Rooms))
	}
	room, ok := first.Rooms[newest]
	if !ok || !room.Initial || room.Name != "Newest" {
		t.Fatalf("newest room = %+v", room)
	}
	if got := bodiesOf(room.Timeline); len(got) != 2 || got[1] != "n2" || !room.Limited || room.PrevBatch == "" {
		t.Errorf("newest timeline = %v (limited %v, prev_batch %q)", got, room.Limited, room.PrevBatch)
	}
	if len(room.RequiredState) != 1 || room.RequiredState[0].Type != "m.room.name" {
		t.Errorf("required_state = %+v", room.RequiredState)
	}
	if room.JoinedCount == nil || *room.JoinedCount != 1 || room.BumpStamp == 0 {
		t.Errorf("counts and bump stamp = %v %d", room.JoinedCount, room.BumpStamp)
	}
	if _, ok := first.Rooms[middle]; !ok {
		t.Errorf("middle room missing from the window: %v", keysOf(first.Rooms))
	}

	// Nothing has happened: nothing is sent.
	idle := ts.sliding(alice, first.Pos, body)
	if len(idle.Rooms) != 0 {
		t.Errorf("an idle incremental sent %v", keysOf(idle.Rooms))
	}

	// A message in a room already sent comes as an increment.
	ts.sendMessage(alice, middle, "m2")
	inc := ts.sliding(alice, idle.Pos, body)
	got, ok := inc.Rooms[middle]
	if !ok || got.Initial || len(got.Timeline) != 1 || got.Timeline[0].Content["body"] != "m2" {
		t.Fatalf("increment for middle = %+v (rooms %v)", got, keysOf(inc.Rooms))
	}
	if got.NumLive == nil || *got.NumLive != 1 {
		t.Errorf("num_live = %v, want 1", got.NumLive)
	}

	// The oldest room becomes active, moves into the window, and is sent
	// in full because this connection has never seen it.
	ts.sendMessage(alice, oldest, "o2")
	bumped := ts.sliding(alice, inc.Pos, body)
	if o, ok := bumped.Rooms[oldest]; !ok || !o.Initial {
		t.Errorf("the bumped room = %+v (rooms %v)", o, keysOf(bumped.Rooms))
	}

	// A retry of an earlier pos still works; a made-up one does not.
	if retry := ts.sliding(alice, inc.Pos, body); retry.Pos == "" {
		t.Error("retrying the previous pos failed")
	}
	code, _, errBody := ts.slidingRaw(alice, "nonsense.5", 0, body)
	if code != http.StatusBadRequest || errBody["errcode"] != httputil.ErrCodeUnknownPos {
		t.Errorf("an unknown pos answered %d %v, want M_UNKNOWN_POS", code, errBody)
	}
}

func TestSlidingSyncInvitesSubscriptionsAndLeaves(t *testing.T) {
	ts := newTestServer(t, nil)
	alice := ts.register("alice", "correct-horse-battery-staple")
	bob := ts.register("bob", "correct-horse-battery-staple")

	joined := ts.createRoom(bob, nil)
	ts.sendMessage(bob, joined, "hello")
	invited := ts.createRoom(alice, map[string]any{"name": "Party", "invite": []string{bob.UserID}})

	body := map[string]any{
		"lists": map[string]any{
			"invites": map[string]any{"ranges": [][2]int{{0, 10}}, "filters": map[string]any{"is_invite": true}},
			"rooms": map[string]any{
				"ranges": [][2]int{{0, 10}}, "filters": map[string]any{"is_invite": false},
				"timeline_limit": 5, "required_state": [][]string{{"m.room.member", "$LAZY"}},
			},
		},
	}
	first := ts.sliding(bob, "", body)
	if first.Lists["invites"].Count != 1 || first.Lists["rooms"].Count != 1 {
		t.Fatalf("list counts = %+v", first.Lists)
	}
	if inv := first.Rooms[invited]; len(inv.InviteState) == 0 || inv.Timeline != nil {
		t.Errorf("the invite = %+v, want stripped state and no timeline", inv)
	}
	lazy := first.Rooms[joined].RequiredState
	if len(lazy) != 1 || lazy[0].Type != "m.room.member" || *lazy[0].StateKey != bob.UserID {
		t.Errorf("lazy-loaded members = %+v, want only bob, who sent the timeline", lazy)
	}

	// A subscription to a room outside every list.
	public := ts.createRoom(alice, map[string]any{"name": "Public", "preset": "public_chat"})
	expectStatus(t, ts.post("/_matrix/client/v3/join/"+url.PathEscape(public), bob.AccessToken, map[string]any{}), http.StatusOK)
	sub := ts.sliding(bob, first.Pos, map[string]any{
		"room_subscriptions": map[string]any{public: map[string]any{"timeline_limit": 1, "required_state": [][]string{{"*", "*"}}}},
	})
	if r, ok := sub.Rooms[public]; !ok || !r.Initial || len(r.RequiredState) < 5 {
		t.Fatalf("subscribed room = %+v", r)
	}

	// Joining the invited room turns it into a room sent in full.
	expectStatus(t, ts.post("/_matrix/client/v3/join/"+url.PathEscape(invited), bob.AccessToken, map[string]any{}), http.StatusOK)
	afterJoin := ts.sliding(bob, sub.Pos, body)
	if r, ok := afterJoin.Rooms[invited]; !ok || !r.Initial || len(r.Timeline) == 0 {
		t.Errorf("the room just joined = %+v", r)
	}

	// Leaving is reported, with the leave in the timeline.
	expectStatus(t, ts.post("/_matrix/client/v3/rooms/"+url.PathEscape(invited)+"/leave", bob.AccessToken, map[string]any{}), http.StatusOK)
	afterLeave := ts.sliding(bob, afterJoin.Pos, body)
	r, ok := afterLeave.Rooms[invited]
	if !ok || len(r.Timeline) == 0 || r.Timeline[len(r.Timeline)-1].Type != "m.room.member" {
		t.Errorf("the room just left = %+v (rooms %v)", r, keysOf(afterLeave.Rooms))
	}
}

func TestSlidingSyncExtensions(t *testing.T) {
	ts := newTestServer(t, nil)
	alice := ts.register("alice", "correct-horse-battery-staple")
	roomID := ts.createRoom(alice, nil)
	eventID := ts.sendMessage(alice, roomID, "read me")

	body := roomList([][2]int{{0, 0}}, 1, nil)
	body["extensions"] = map[string]any{
		"to_device":    map[string]any{"enabled": true},
		"e2ee":         map[string]any{"enabled": true},
		"account_data": map[string]any{"enabled": true},
		"receipts":     map[string]any{"enabled": true},
		"typing":       map[string]any{"enabled": true},
	}

	expectStatus(t, ts.put("/_matrix/client/v3/user/"+url.PathEscape(alice.UserID)+"/account_data/com.example.setting",
		alice.AccessToken, map[string]any{"on": true}), http.StatusOK)
	expectStatus(t, ts.post(fmt.Sprintf("/_matrix/client/v3/rooms/%s/receipt/m.read/%s",
		url.PathEscape(roomID), url.PathEscape(eventID)), alice.AccessToken, map[string]any{}), http.StatusOK)
	expectStatus(t, ts.put("/_matrix/client/v3/sendToDevice/m.test/t1", alice.AccessToken, map[string]any{
		"messages": map[string]any{alice.UserID: map[string]any{alice.DeviceID: map[string]any{"hello": "device"}}},
	}), http.StatusOK)

	first := ts.sliding(alice, "", body)
	ext := first.Extensions
	if ext.ToDevice == nil || len(ext.ToDevice.Events) != 1 || ext.ToDevice.NextBatch == "" {
		t.Fatalf("to_device = %+v", ext.ToDevice)
	}
	if ext.E2EE == nil || ext.E2EE.DeviceOneTimeKeysCount == nil {
		t.Errorf("e2ee = %+v", ext.E2EE)
	}
	foundSetting := false
	if ext.AccountData != nil {
		for _, e := range ext.AccountData.Global {
			if e["type"] == "com.example.setting" {
				foundSetting = true
			}
		}
	}
	if !foundSetting {
		t.Errorf("account_data = %+v", ext.AccountData)
	}
	if ext.Receipts == nil || ext.Receipts.Rooms[roomID] == nil {
		t.Errorf("receipts = %+v", ext.Receipts)
	}

	// Coming back with the to-device token acknowledges the batch.
	body["extensions"].(map[string]any)["to_device"] = map[string]any{"enabled": true, "since": ext.ToDevice.NextBatch}
	second := ts.sliding(alice, first.Pos, body)
	if second.Extensions.ToDevice == nil || len(second.Extensions.ToDevice.Events) != 0 {
		t.Errorf("an acknowledged batch came again: %+v", second.Extensions.ToDevice)
	}

	// Typing is sent when it starts and again when it stops.
	expectStatus(t, ts.put(fmt.Sprintf("/_matrix/client/v3/rooms/%s/typing/%s", url.PathEscape(roomID), url.PathEscape(alice.UserID)),
		alice.AccessToken, map[string]any{"typing": true, "timeout": 30000}), http.StatusOK)
	typing := ts.sliding(alice, second.Pos, body)
	if typing.Extensions.Typing == nil || typing.Extensions.Typing.Rooms[roomID] == nil {
		t.Fatalf("typing = %+v", typing.Extensions.Typing)
	}
	again := ts.sliding(alice, typing.Pos, body)
	if len(again.Extensions.Typing.Rooms) != 0 {
		t.Errorf("unchanged typing was sent again: %+v", again.Extensions.Typing.Rooms)
	}
	expectStatus(t, ts.put(fmt.Sprintf("/_matrix/client/v3/rooms/%s/typing/%s", url.PathEscape(roomID), url.PathEscape(alice.UserID)),
		alice.AccessToken, map[string]any{"typing": false}), http.StatusOK)
	stopped := ts.sliding(alice, again.Pos, body)
	if stopped.Extensions.Typing.Rooms[roomID] == nil {
		t.Errorf("stopping typing was not sent: %+v", stopped.Extensions.Typing.Rooms)
	}
}

func TestSlidingSyncLongPoll(t *testing.T) {
	ts := newTestServer(t, nil)
	alice := ts.register("alice", "correct-horse-battery-staple")
	roomID := ts.createRoom(alice, nil)
	body := roomList([][2]int{{0, 0}}, 5, nil)
	first := ts.sliding(alice, "", body)

	done := make(chan slidingResult, 1)
	start := time.Now()
	go func() {
		_, result, _ := ts.slidingRaw(alice, first.Pos, 10*time.Second, body)
		done <- result
	}()
	time.Sleep(200 * time.Millisecond)
	ts.sendMessage(alice, roomID, "wake up")

	select {
	case result := <-done:
		if r, ok := result.Rooms[roomID]; !ok || len(r.Timeline) != 1 {
			t.Errorf("the woken response = %+v", result.Rooms)
		}
		if time.Since(start) > 5*time.Second {
			t.Errorf("the long poll took %s to wake", time.Since(start))
		}
	case <-time.After(15 * time.Second):
		t.Fatal("the long poll never returned")
	}
}

func keysOf[V any](m map[string]V) []string {
	out := make([]string, 0, len(m))
	for k := range m {
		out = append(out, k)
	}
	return out
}