package clientapi_test

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

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

const delayedEventsPath = "/_matrix/client/unstable/org.matrix.msc4140/delayed_events"

// callMemberPath is where a member of a room's group call puts its state.
func callMemberPath(roomID, stateKey string) string {
	return "/_matrix/client/v3/rooms/" + url.PathEscape(roomID) +
		"/state/org.matrix.msc3401.call.member/" + url.PathEscape(stateKey)
}

// scheduleDelayed PUTs a delayed state event and returns its delay ID.
func (ts *testServer) scheduleDelayed(path string, delayMS int, acc account, content map[string]any) string {
	ts.t.Helper()
	rec := ts.put(path+"?org.matrix.msc4140.delay="+strconv.Itoa(delayMS), acc.AccessToken, content)
	expectStatus(ts.t, rec, http.StatusOK)
	delayID, _ := jsonBody(ts.t, rec)["delay_id"].(string)
	if delayID == "" {
		ts.t.Fatalf("a delayed send returned no delay_id: %s", rec.Body.String())
	}
	return delayID
}

// tick moves the clock and sends whatever has come due.
func (ts *testServer) tick(d time.Duration) {
	ts.t.Helper()
	ts.clock.advance(d)
	ts.delayed.SendDue(ts.t.Context())
}

type delayedList struct {
	Scheduled []struct {
		DelayID      string         `json:"delay_id"`
		RoomID       string         `json:"room_id"`
		Type         string         `json:"type"`
		StateKey     *string        `json:"state_key"`
		Content      map[string]any `json:"content"`
		Delay        int64          `json:"delay"`
		RunningSince int64          `json:"running_since"`
	} `json:"scheduled"`
	Finalised []struct {
		DelayedEvent struct {
			DelayID string `json:"delay_id"`
		} `json:"delayed_event"`
		Outcome string         `json:"outcome"`
		Reason  string         `json:"reason"`
		EventID string         `json:"event_id"`
		Error   map[string]any `json:"error"`
	} `json:"finalised"`
}

func (ts *testServer) delayedList(acc account) delayedList {
	ts.t.Helper()
	rec := ts.get(delayedEventsPath, acc.AccessToken)
	expectStatus(ts.t, rec, http.StatusOK)
	return decode[delayedList](ts.t, rec)
}

// TestDelayedStateEventIsSentWhenDue is the MatrixRTC case: a member's
// "left the call" is scheduled when it joins, and arrives on its own once
// the delay runs out.
func TestDelayedStateEventIsSentWhenDue(t *testing.T) {
	ts := newTestServer(t, nil)
	alice := ts.register("alice", "correct-horse-battery-staple")
	roomID := ts.createRoom(alice, map[string]any{"preset": "public_chat"})
	stateKey := "_" + alice.UserID + "_" + alice.DeviceID + "_m.call"
	path := callMemberPath(roomID, stateKey)

	delayID := ts.scheduleDelayed(path, 5000, alice, map[string]any{})

	// Nothing is in the room yet.
	expectError(t, ts.get(path, alice.AccessToken), http.StatusNotFound, httputil.ErrCodeNotFound)

	list := ts.delayedList(alice)
	if len(list.Scheduled) != 1 || list.Scheduled[0].DelayID != delayID {
		t.Fatalf("scheduled = %+v", list.Scheduled)
	}
	got := list.Scheduled[0]
	if got.RoomID != roomID || got.Type != "org.matrix.msc3401.call.member" ||
		got.StateKey == nil || *got.StateKey != stateKey || got.Delay != 5000 {
		t.Errorf("the scheduled event is %+v", got)
	}

	ts.tick(4 * time.Second)
	expectError(t, ts.get(path, alice.AccessToken), http.StatusNotFound, httputil.ErrCodeNotFound)

	ts.tick(2 * time.Second)
	expectStatus(t, ts.get(path, alice.AccessToken), http.StatusOK)

	list = ts.delayedList(alice)
	if len(list.Scheduled) != 0 {
		t.Errorf("still scheduled after sending: %+v", list.Scheduled)
	}
	if len(list.Finalised) != 1 || list.Finalised[0].Outcome != "send" ||
		list.Finalised[0].Reason != "delay" || list.Finalised[0].EventID == "" {
		t.Errorf("finalised = %+v", list.Finalised)
	}

	// Looked up on its own, it is the same.
	rec := ts.get(delayedEventsPath+"/"+delayID, alice.AccessToken)
	expectStatus(t, rec, http.StatusOK)
	if jsonBody(t, rec)["outcome"] != "send" {
		t.Errorf("GET by ID = %s", rec.Body.String())
	}
}

// TestDelayedEventRestart: a client still in the call keeps pushing its
// leave back, and it never arrives.
func TestDelayedEventRestart(t *testing.T) {
	ts := newTestServer(t, nil)
	alice := ts.register("alice", "correct-horse-battery-staple")
	roomID := ts.createRoom(alice, map[string]any{"preset": "public_chat"})
	path := callMemberPath(roomID, "_"+alice.UserID+"_D_m.call")

	delayID := ts.scheduleDelayed(path, 5000, alice, map[string]any{})

	for range 3 {
		ts.tick(4 * time.Second)
		// The action endpoints need no token: the delay ID is the
		// capability.
		expectStatus(t, ts.post(delayedEventsPath+"/"+delayID+"/restart", "", nil), http.StatusOK)
	}
	ts.tick(4 * time.Second)
	expectError(t, ts.get(path, alice.AccessToken), http.StatusNotFound, httputil.ErrCodeNotFound)

	ts.tick(2 * time.Second)
	expectStatus(t, ts.get(path, alice.AccessToken), http.StatusOK)

	// Once it has been sent it cannot be restarted.
	rec := ts.post(delayedEventsPath+"/"+delayID+"/restart", "", nil)
	expectError(t, rec, http.StatusNotFound, httputil.ErrCodeNotFound)
}

// TestDelayedEventActions covers cancel and send, in both the path and the
// body spelling.
func TestDelayedEventActions(t *testing.T) {
	ts := newTestServer(t, nil)
	alice := ts.register("alice", "correct-horse-battery-staple")
	roomID := ts.createRoom(alice, map[string]any{"preset": "public_chat"})
	escaped := url.PathEscape(roomID)

	// Cancelled with the action in the body: never sent.
	topic := "/_matrix/client/v3/rooms/" + escaped + "/state/m.room.topic"
	cancelled := ts.scheduleDelayed(topic, 1000, alice, map[string]any{"topic": "never"})
	expectStatus(t, ts.post(delayedEventsPath+"/"+cancelled, alice.AccessToken,
		map[string]any{"action": "cancel"}), http.StatusOK)
	ts.tick(2 * time.Second)
	expectError(t, ts.get(topic, alice.AccessToken), http.StatusNotFound, httputil.ErrCodeNotFound)

	// Sent at once with the action in the path: a timeline event, which
	// is how a client sends a message it held back.
	send := "/_matrix/client/v3/rooms/" + escaped + "/send/m.room.message/txn1"
	sent := ts.scheduleDelayed(send, 60000, alice, map[string]any{"msgtype": "m.text", "body": "later"})
	expectStatus(t, ts.post(delayedEventsPath+"/"+sent+"/send", "", nil), http.StatusOK)

	list := ts.delayedList(alice)
	if len(list.Scheduled) != 0 || len(list.Finalised) != 2 {
		t.Fatalf("list = %+v", list)
	}
	outcomes := map[string]string{}
	for _, f := range list.Finalised {
		outcomes[f.DelayedEvent.DelayID] = f.Outcome + "/" + f.Reason
	}
	if outcomes[cancelled] != "cancel/action" || outcomes[sent] != "send/action" {
		t.Errorf("outcomes = %v", outcomes)
	}

	// status narrows the list.
	rec := ts.get(delayedEventsPath+"?status=scheduled", alice.AccessToken)
	expectStatus(t, rec, http.StatusOK)
	if l := decode[delayedList](t, rec); len(l.Finalised) != 0 {
		t.Errorf("status=scheduled listed finalised events: %s", rec.Body.String())
	}

	expectError(t, ts.post(delayedEventsPath+"/nope/cancel", "", nil), http.StatusNotFound, httputil.ErrCodeNotFound)
	expectError(t, ts.post(delayedEventsPath+"/"+sent+"/explode", "", nil),
		http.StatusBadRequest, httputil.ErrCodeInvalidParam)
}

// TestDelayedEventFailureIsRecorded: an event that can no longer be sent
// is finalised with the error the client would have got.
func TestDelayedEventFailureIsRecorded(t *testing.T) {
	ts := newTestServer(t, nil)
	alice := ts.register("alice", "correct-horse-battery-staple")
	roomID := ts.createRoom(alice, map[string]any{"preset": "public_chat"})
	path := callMemberPath(roomID, "_"+alice.UserID+"_D_m.call")

	ts.scheduleDelayed(path, 1000, alice, map[string]any{})
	expectStatus(t, ts.post("/_matrix/client/v3/rooms/"+url.PathEscape(roomID)+"/leave",
		alice.AccessToken, map[string]any{}), http.StatusOK)
	ts.tick(2 * time.Second)

	list := ts.delayedList(alice)
	if len(list.Finalised) != 1 || list.Finalised[0].Reason != "error" ||
		list.Finalised[0].Error["errcode"] != httputil.ErrCodeForbidden {
		t.Errorf("finalised = %+v", list.Finalised)
	}
}

// TestDelayedStateIsCancelledByOthers: someone else setting the same state
// cancels a delayed event that would have overwritten it, and the owner's
// own updates do not. It also proves an ordinary member may join a call.
func TestDelayedStateIsCancelledByOthers(t *testing.T) {
	ts := newTestServer(t, nil)
	alice := ts.register("alice", "correct-horse-battery-staple")
	bob := ts.register("bob", "correct-horse-battery-staple")
	roomID := ts.createRoom(alice, map[string]any{"preset": "public_chat"})
	expectStatus(t, ts.post("/_matrix/client/v3/rooms/"+url.PathEscape(roomID)+"/join",
		bob.AccessToken, map[string]any{}), http.StatusOK)

	aliceKey := callMemberPath(roomID, "_"+alice.UserID+"_A_m.call")
	ts.scheduleDelayed(aliceKey, 5000, alice, map[string]any{})

	// Alice refreshing her own membership leaves the delayed leave alone.
	expectStatus(t, ts.put(aliceKey, alice.AccessToken, map[string]any{"application": "m.call"}), http.StatusOK)
	// Bob, an ordinary member, may put call state of his own.
	expectStatus(t, ts.put(callMemberPath(roomID, "_"+bob.UserID+"_B_m.call"), bob.AccessToken,
		map[string]any{"application": "m.call"}), http.StatusOK)
	// The cancellation runs off the emit stage, so give it a moment.
	time.Sleep(100 * time.Millisecond)
	if l := ts.delayedList(alice); len(l.Scheduled) != 1 {
		t.Fatalf("alice's own update cancelled her delayed event: %+v", l)
	}

	// Bob writing the same piece of state cancels it.
	expectStatus(t, ts.put(aliceKey, bob.AccessToken, map[string]any{}), http.StatusOK)
	deadline := time.Now().Add(5 * time.Second)
	for {
		l := ts.delayedList(alice)
		if len(l.Scheduled) == 0 {
			if len(l.Finalised) != 1 || l.Finalised[0].Outcome != "cancel" {
				t.Errorf("finalised = %+v", l.Finalised)
			}
			break
		}
		if time.Now().After(deadline) {
			t.Fatal("the overwritten delayed event was never cancelled")
		}
		time.Sleep(10 * time.Millisecond)
	}
}

func TestDelayedEventLimits(t *testing.T) {
	ts := newTestServer(t, nil)
	alice := ts.register("alice", "correct-horse-battery-staple")
	roomID := ts.createRoom(alice, map[string]any{"preset": "public_chat"})
	topic := "/_matrix/client/v3/rooms/" + url.PathEscape(roomID) + "/state/m.room.topic"

	// Longer than the server allows: the MSC's own code and the maximum
	// come with the error.
	rec := ts.put(topic+"?org.matrix.msc4140.delay=7200000", alice.AccessToken, map[string]any{"topic": "x"})
	expectError(t, rec, http.StatusBadRequest, httputil.ErrCodeUnknown)
	body := jsonBody(t, rec)
	if body["org.matrix.msc4140.errcode"] != "M_MAX_DELAY_EXCEEDED" || body["org.matrix.msc4140.max_delay"] != float64(3600000) {
		t.Errorf("error = %s", rec.Body.String())
	}

	expectError(t, ts.put(topic+"?org.matrix.msc4140.delay=soon", alice.AccessToken, map[string]any{"topic": "x"}),
		http.StatusBadRequest, httputil.ErrCodeInvalidParam)
	expectError(t, ts.put(topic+"?org.matrix.msc4140.parent_delay_id=x", alice.AccessToken, map[string]any{"topic": "x"}),
		http.StatusBadRequest, httputil.ErrCodeInvalidParam)

	// Five at once is the test server's limit.
	for range 5 {
		ts.scheduleDelayed(topic, 1000, alice, map[string]any{"topic": "x"})
	}
	rec = ts.put(topic+"?org.matrix.msc4140.delay=1000", alice.AccessToken, map[string]any{"topic": "x"})
	expectError(t, rec, http.StatusBadRequest, "M_LIMIT_EXCEEDED")

	// Nobody else can read them.
	bob := ts.register("bob", "correct-horse-battery-staple")
	if l := ts.delayedList(bob); len(l.Scheduled) != 0 {
		t.Errorf("bob sees alice's delayed events: %+v", l)
	}
	expectError(t, ts.get(delayedEventsPath, ""), http.StatusUnauthorized, "M_MISSING_TOKEN")
}

// TestDelayedEventsDisabled: without the service the parameter is refused,
// rather than the event being sent at once, and the endpoints are absent.
func TestDelayedEventsDisabled(t *testing.T) {
	ts := newTestServer(t, func(o *clientapi.Options) { o.DelayedEvents = nil })
	alice := ts.register("alice", "correct-horse-battery-staple")
	roomID := ts.createRoom(alice, map[string]any{"preset": "public_chat"})
	path := callMemberPath(roomID, "_"+alice.UserID+"_A_m.call")

	expectError(t, ts.put(path+"?org.matrix.msc4140.delay=1000", alice.AccessToken, map[string]any{}),
		http.StatusBadRequest, httputil.ErrCodeInvalidParam)
	expectError(t, ts.get(path, alice.AccessToken), http.StatusNotFound, httputil.ErrCodeNotFound)
	expectError(t, ts.get(delayedEventsPath, alice.AccessToken), http.StatusNotFound, httputil.ErrCodeUnrecognized)
}