package server

import (
	"bytes"
	"encoding/json"
	"io"
	"mime/multipart"
	"net/http"
	"net/http/httptest"
	"net/textproto"
	"testing"
	"time"
)

// TestFriendRequestFlow проверяет заявки в друзья и поиск пользователей.
func TestFriendRequestFlow(t *testing.T) {
	srv, _ := newTestServer(t)
	aliceCookie := registerAndLogin(t, srv, "alice_friend", "alice-friend@example.com")
	bobCookie := registerAndLogin(t, srv, "bob_friend", "bob-friend@example.com")
	bob, err := srv.auth.UserByEmail(t.Context(), "bob-friend@example.com")
	if err != nil {
		t.Fatalf("UserByEmail: %v", err)
	}

	// Поиск по логину находит Боба и показывает состояние связи.
	search := doJSON(t, srv, http.MethodGet, "/api/v1/users/search?q=bob_fr", "", aliceCookie)
	if search.Code != http.StatusOK {
		t.Fatalf("search = %d, body = %s", search.Code, search.Body.String())
	}
	found := decodeResponse[struct {
		Users []struct {
			Username     string `json:"username"`
			Relationship string `json:"relationship"`
		} `json:"users"`
	}](t, search)
	if len(found.Users) != 1 || found.Users[0].Username != "bob_friend" || found.Users[0].Relationship != "none" {
		t.Fatalf("search results = %+v", found.Users)
	}

	// Алиса отправляет заявку: у неё outgoing, у Боба incoming.
	sent := doJSON(t, srv, http.MethodPost, "/api/v1/users/@me/relationships", `{"username":"bob_friend"}`, aliceCookie)
	if sent.Code != http.StatusOK {
		t.Fatalf("send request = %d, body = %s", sent.Code, sent.Body.String())
	}
	bobList := doJSON(t, srv, http.MethodGet, "/api/v1/users/@me/relationships", "", bobCookie)
	bobPayload := decodeResponse[struct {
		Incoming []struct {
			Username     string `json:"username"`
			Relationship string `json:"relationship"`
		} `json:"incoming"`
		Friends []struct {
			Username string `json:"username"`
		} `json:"friends"`
	}](t, bobList)
	if len(bobPayload.Incoming) != 1 || bobPayload.Incoming[0].Username != "alice_friend" {
		t.Fatalf("incoming = %+v", bobPayload.Incoming)
	}
	if len(bobPayload.Friends) != 0 {
		t.Fatalf("friends must be empty before accept: %+v", bobPayload.Friends)
	}

	// Боб принимает: оба видят друг друга в друзьях.
	accept := doJSON(t, srv, http.MethodPost,
		"/api/v1/users/@me/relationships/"+formatSnowflake(mustUserID(t, srv, "alice-friend@example.com"))+"/accept",
		"", bobCookie)
	if accept.Code != http.StatusOK {
		t.Fatalf("accept = %d, body = %s", accept.Code, accept.Body.String())
	}
	aliceFriends := doJSON(t, srv, http.MethodGet, "/api/v1/users/@me/relationships", "", aliceCookie)
	payload := decodeResponse[struct {
		Friends []struct {
			Username      string `json:"username"`
			VisibleStatus string `json:"visible_status"`
			Timezone      string `json:"timezone"`
		} `json:"friends"`
	}](t, aliceFriends)
	if len(payload.Friends) != 1 || payload.Friends[0].Username != "bob_friend" {
		t.Fatalf("friends = %+v", payload.Friends)
	}
	if payload.Friends[0].Timezone != "Europe/Moscow" {
		t.Fatalf("default timezone = %q, want Europe/Moscow", payload.Friends[0].Timezone)
	}

	// Повторная заявка ничего не ломает.
	repeat := doJSON(t, srv, http.MethodPost, "/api/v1/users/@me/relationships", `{"user_id":"`+formatSnowflake(bob.ID)+`"}`, aliceCookie)
	if repeat.Code != http.StatusOK {
		t.Fatalf("repeat request = %d, body = %s", repeat.Code, repeat.Body.String())
	}
}

// TestDirectChannelMessaging проверяет личные беседы: доступ только участникам.
func TestDirectChannelMessaging(t *testing.T) {
	srv, _ := newTestServer(t)
	aliceCookie := registerAndLogin(t, srv, "alice_dm", "alice-dm@example.com")
	bobCookie := registerAndLogin(t, srv, "bob_dm", "bob-dm@example.com")
	strangerCookie := registerAndLogin(t, srv, "eve_dm", "eve-dm@example.com")
	bobID := formatSnowflake(mustUserID(t, srv, "bob-dm@example.com"))

	// Алиса открывает беседу с Бобом.
	opened := doJSON(t, srv, http.MethodPost, "/api/v1/users/@me/channels",
		`{"recipient_id":"`+bobID+`"}`, aliceCookie)
	if opened.Code != http.StatusOK {
		t.Fatalf("open dm = %d, body = %s", opened.Code, opened.Body.String())
	}
	channel := decodeResponse[struct {
		Channel struct {
			ID        string `json:"id"`
			Type      string `json:"type"`
			CanSend   bool   `json:"can_send"`
			Recipient struct {
				UserID        string `json:"user_id"`
				DisplayName   string `json:"display_name"`
				VisibleStatus string `json:"visible_status"`
			} `json:"recipient"`
		} `json:"channel"`
	}](t, opened)
	if channel.Channel.Type != "dm" || !channel.Channel.CanSend {
		t.Fatalf("unexpected dm channel: %+v", channel.Channel)
	}
	if channel.Channel.Recipient.UserID != bobID {
		t.Fatalf("recipient = %q, want %q", channel.Channel.Recipient.UserID, bobID)
	}

	// Повторное открытие возвращает ту же беседу.
	again := doJSON(t, srv, http.MethodPost, "/api/v1/users/@me/channels",
		`{"recipient_id":"`+bobID+`"}`, aliceCookie)
	reopened := decodeResponse[struct {
		Channel struct {
			ID string `json:"id"`
		} `json:"channel"`
	}](t, again)
	if reopened.Channel.ID != channel.Channel.ID {
		t.Fatalf("dm channel changed: %s → %s", channel.Channel.ID, reopened.Channel.ID)
	}

	// Сообщение из беседы и список бесед у обоих участников.
	sent := doJSON(t, srv, http.MethodPost, "/api/v1/channels/"+channel.Channel.ID+"/messages",
		`{"content":"привет в личке"}`, aliceCookie)
	if sent.Code != http.StatusOK {
		t.Fatalf("dm message = %d, body = %s", sent.Code, sent.Body.String())
	}
	list := doJSON(t, srv, http.MethodGet, "/api/v1/users/@me/channels", "", bobCookie)
	channels := decodeResponse[struct {
		Channels []struct {
			ID            string `json:"id"`
			LastMessageID string `json:"last_message_id"`
		} `json:"channels"`
	}](t, list)
	if len(channels.Channels) != 1 || channels.Channels[0].ID != channel.Channel.ID || channels.Channels[0].LastMessageID == "" {
		t.Fatalf("dm list = %+v", channels.Channels)
	}

	// Посторонний не видит беседу и не может писать.
	forbidden := doJSON(t, srv, http.MethodGet, "/api/v1/channels/"+channel.Channel.ID+"/messages", "", strangerCookie)
	if forbidden.Code != http.StatusNotFound {
		t.Fatalf("stranger dm read = %d, want 404", forbidden.Code)
	}
	forbiddenSend := doJSON(t, srv, http.MethodPost, "/api/v1/channels/"+channel.Channel.ID+"/messages",
		`{"content":"я тут лишний"}`, strangerCookie)
	if forbiddenSend.Code != http.StatusNotFound {
		t.Fatalf("stranger dm write = %d, want 404", forbiddenSend.Code)
	}
}

// TestInvisibleStatusHiddenFromFriends проверяет, что «невидимка» виден как офлайн.
func TestInvisibleStatusHiddenFromFriends(t *testing.T) {
	srv, _ := newTestServer(t)
	aliceCookie := registerAndLogin(t, srv, "alice_inv", "alice-inv@example.com")
	bobCookie := registerAndLogin(t, srv, "bob_inv", "bob-inv@example.com")

	doJSON(t, srv, http.MethodPost, "/api/v1/users/@me/relationships", `{"username":"bob_inv"}`, aliceCookie)
	accept := doJSON(t, srv, http.MethodPost,
		"/api/v1/users/@me/relationships/"+formatSnowflake(mustUserID(t, srv, "alice-inv@example.com"))+"/accept", "", bobCookie)
	if accept.Code != http.StatusOK {
		t.Fatalf("accept = %d", accept.Code)
	}

	// Боб уходит в невидимку.
	hidden := doJSON(t, srv, http.MethodPatch, "/api/v1/users/@me", `{"status":"invisible"}`, bobCookie)
	if hidden.Code != http.StatusOK {
		t.Fatalf("set invisible = %d, body = %s", hidden.Code, hidden.Body.String())
	}
	friends := doJSON(t, srv, http.MethodGet, "/api/v1/users/@me/relationships", "", aliceCookie)
	payload := decodeResponse[struct {
		Friends []struct {
			Username      string `json:"username"`
			Status        string `json:"status"`
			VisibleStatus string `json:"visible_status"`
		} `json:"friends"`
	}](t, friends)
	if len(payload.Friends) != 1 {
		t.Fatalf("friends = %+v", payload.Friends)
	}
	if payload.Friends[0].VisibleStatus != "offline" {
		t.Fatalf("invisible user must look offline, got %q", payload.Friends[0].VisibleStatus)
	}

	// Обычный статус виден как есть.
	doJSON(t, srv, http.MethodPatch, "/api/v1/users/@me", `{"status":"idle"}`, bobCookie)
	friends = doJSON(t, srv, http.MethodGet, "/api/v1/users/@me/relationships", "", aliceCookie)
	payload = decodeResponse[struct {
		Friends []struct {
			Username      string `json:"username"`
			Status        string `json:"status"`
			VisibleStatus string `json:"visible_status"`
		} `json:"friends"`
	}](t, friends)
	if payload.Friends[0].VisibleStatus != "idle" {
		t.Fatalf("idle status must be visible, got %q", payload.Friends[0].VisibleStatus)
	}
}

// TestTimezoneAndAvatarUpdate проверяет часовой пояс и загрузку аватара.
func TestTimezoneAndAvatarUpdate(t *testing.T) {
	srv, _ := newTestServer(t)
	httpServer := httptest.NewServer(srv.Handler())
	t.Cleanup(httpServer.Close)
	cookie := registerAndLogin(t, srv, "tz_user", "tz-user@example.com")

	// Часовой пояс по умолчанию — МСК, можно сменить.
	type mePayload struct {
		User struct {
			Timezone     string `json:"timezone"`
			AvatarFileID string `json:"avatar_file_id"`
		} `json:"user"`
	}
	me := doJSON(t, srv, http.MethodGet, "/api/v1/users/@me", "", cookie)
	profile := decodeResponse[mePayload](t, me)
	if profile.User.Timezone != "Europe/Moscow" {
		t.Fatalf("default timezone = %q", profile.User.Timezone)
	}
	updated := doJSON(t, srv, http.MethodPatch, "/api/v1/users/@me", `{"timezone":"Europe/Berlin"}`, cookie)
	if updated.Code != http.StatusOK {
		t.Fatalf("set timezone = %d, body = %s", updated.Code, updated.Body.String())
	}
	after := decodeResponse[mePayload](t, updated)
	if after.User.Timezone != "Europe/Berlin" {
		t.Fatalf("timezone = %q, want Europe/Berlin", after.User.Timezone)
	}
	bad := doJSON(t, srv, http.MethodPatch, "/api/v1/users/@me", `{"timezone":"Марс/Олимп"}`, cookie)
	if bad.Code != http.StatusUnprocessableEntity {
		t.Fatalf("invalid timezone = %d, want 422", bad.Code)
	}

	// Аватар: загрузка картинки и удаление.
	fileID := uploadAvatar(t, httpServer, cookie, "me.png",
		append([]byte("\x89PNG\r\n\x1a\n"), []byte("аватар-данные")...))
	if fileID == "" {
		t.Fatal("avatar upload must return a file id")
	}
	me = doJSON(t, srv, http.MethodGet, "/api/v1/users/@me", "", cookie)
	profile = decodeResponse[mePayload](t, me)
	if profile.User.AvatarFileID != fileID {
		t.Fatalf("avatar_file_id = %q, want %q", profile.User.AvatarFileID, fileID)
	}

	// Аватар виден другому авторизованному пользователю (он показывается в
	// списках друзей и участников), но не анонимному.
	otherCookie := registerAndLogin(t, srv, "tz_other", "tz-other@example.com")
	_ = otherCookie
	downloadReq, err := http.NewRequestWithContext(t.Context(), http.MethodGet,
		httpServer.URL+"/files/"+fileID, nil)
	if err != nil {
		t.Fatalf("new request: %v", err)
	}
	downloadReq.AddCookie(otherCookie)
	downloadResp, err := httpServer.Client().Do(downloadReq)
	if err != nil {
		t.Fatalf("avatar download: %v", err)
	}
	_ = downloadResp.Body.Close()
	if downloadResp.StatusCode != http.StatusOK {
		t.Fatalf("другой пользователь не видит аватар: %d", downloadResp.StatusCode)
	}

	removed := doJSON(t, srv, http.MethodDelete, "/api/v1/users/@me/avatar", "", cookie)
	if removed.Code != http.StatusOK {
		t.Fatalf("delete avatar = %d, body = %s", removed.Code, removed.Body.String())
	}
	me = doJSON(t, srv, http.MethodGet, "/api/v1/users/@me", "", cookie)
	profile = decodeResponse[mePayload](t, me)
	if profile.User.AvatarFileID != "" {
		t.Fatalf("avatar must be cleared, got %q", profile.User.AvatarFileID)
	}
}

// mustUserID находит пользователя по email и возвращает его идентификатор.
func mustUserID(t *testing.T, srv *Server, email string) uint64 {
	t.Helper()
	user, err := srv.auth.UserByEmail(t.Context(), email)
	if err != nil {
		t.Fatalf("UserByEmail(%s): %v", email, err)
	}
	return user.ID
}

// TestPresenceUpdateReachesFriends проверяет, что смена статуса видна другу
// через Gateway без перезагрузки (AGENT.md 7.16).
func TestPresenceUpdateReachesFriends(t *testing.T) {
	srv, _ := newTestServer(t)
	httpServer := httptest.NewServer(srv.Handler())
	t.Cleanup(httpServer.Close)

	aliceCookie := registerAndLogin(t, srv, "alice_pres", "alice-pres@example.com")
	bobCookie := registerAndLogin(t, srv, "bob_pres", "bob-pres@example.com")
	doJSON(t, srv, http.MethodPost, "/api/v1/users/@me/relationships", `{"username":"bob_pres"}`, aliceCookie)
	doJSON(t, srv, http.MethodPost,
		"/api/v1/users/@me/relationships/"+formatSnowflake(mustUserID(t, srv, "alice-pres@example.com"))+"/accept", "", bobCookie)

	alice := dialGateway(t, httpServer, aliceCookie)
	doJSON(t, srv, http.MethodPatch, "/api/v1/users/@me", `{"status":"dnd"}`, bobCookie)

	frame := alice.expectEvent("PRESENCE_UPDATE")
	var payload struct {
		Status        string `json:"status"`
		VisibleStatus string `json:"visible_status"`
	}
	if err := json.Unmarshal(frame.D, &payload); err != nil {
		t.Fatalf("decode PRESENCE_UPDATE: %v", err)
	}
	if payload.Status != "dnd" || payload.VisibleStatus != "dnd" {
		t.Fatalf("presence payload = %+v", payload)
	}
}

// TestDirectChannelEventsOnlyForParticipants проверяет фильтрацию событий DM.
func TestDirectChannelEventsOnlyForParticipants(t *testing.T) {
	srv, _ := newTestServer(t)
	httpServer := httptest.NewServer(srv.Handler())
	t.Cleanup(httpServer.Close)

	aliceCookie := registerAndLogin(t, srv, "alice_dmev", "alice-dmev@example.com")
	bobCookie := registerAndLogin(t, srv, "bob_dmev", "bob-dmev@example.com")
	eveCookie := registerAndLogin(t, srv, "eve_dmev", "eve-dmev@example.com")
	bobID := formatSnowflake(mustUserID(t, srv, "bob-dmev@example.com"))

	opened := doJSON(t, srv, http.MethodPost, "/api/v1/users/@me/channels", `{"recipient_id":"`+bobID+`"}`, aliceCookie)
	channel := decodeResponse[struct {
		Channel struct {
			ID string `json:"id"`
		} `json:"channel"`
	}](t, opened)

	bob := dialGateway(t, httpServer, bobCookie)
	eve := dialGateway(t, httpServer, eveCookie)

	doJSON(t, srv, http.MethodPost, "/api/v1/channels/"+channel.Channel.ID+"/messages",
		`{"content":"личное сообщение"}`, aliceCookie)
	bob.expectEvent("MESSAGE_CREATE")
	eve.expectNoEvent("MESSAGE_CREATE", 700*time.Millisecond)
}

// uploadAvatar загружает аватар через multipart и возвращает file_id.
func uploadAvatar(t *testing.T, server *httptest.Server, cookie *http.Cookie, filename string, content []byte) string {
	t.Helper()
	body := &bytes.Buffer{}
	writer := multipart.NewWriter(body)
	partHeader := textproto.MIMEHeader{}
	partHeader.Set("Content-Disposition", `form-data; name="file"; filename="`+filename+`"`)
	partHeader.Set("Content-Type", "image/png")
	part, err := writer.CreatePart(partHeader)
	if err != nil {
		t.Fatalf("CreatePart: %v", err)
	}
	if _, err := part.Write(content); err != nil {
		t.Fatalf("write avatar: %v", err)
	}
	if err := writer.Close(); err != nil {
		t.Fatalf("close writer: %v", err)
	}
	req, err := http.NewRequestWithContext(t.Context(), http.MethodPost,
		server.URL+"/api/v1/users/@me/avatar", bytes.NewReader(body.Bytes()))
	if err != nil {
		t.Fatalf("new request: %v", err)
	}
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.AddCookie(cookie)
	resp, err := server.Client().Do(req)
	if err != nil {
		t.Fatalf("upload avatar: %v", err)
	}
	payload, _ := io.ReadAll(resp.Body)
	_ = resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("upload avatar = %d, body = %s", resp.StatusCode, payload)
	}
	var decoded struct {
		User struct {
			AvatarFileID string `json:"avatar_file_id"`
		} `json:"user"`
	}
	if err := json.Unmarshal(payload, &decoded); err != nil {
		t.Fatalf("decode avatar response: %v", err)
	}
	return decoded.User.AvatarFileID
}