/*
Copyright 2022-2024 New Vector Ltd.

SPDX-License-Identifier: AGPL-3.0-only
Please see LICENSE in the repository root for full details.
*/

import { FC, useCallback, useEffect, useMemo, useRef, useState } from "react";
import { useHistory } from "react-router-dom";
import { MatrixClient } from "matrix-js-sdk/src/client";
import {
  Room,
  isE2EESupported as isE2EESupportedBrowser,
} from "livekit-client";
import { logger } from "matrix-js-sdk/src/logger";
import { MatrixRTCSession } from "matrix-js-sdk/src/matrixrtc/MatrixRTCSession";
import { JoinRule } from "matrix-js-sdk/src/matrix";
import { Heading, Text } from "@vector-im/compound-web";
import { useTranslation } from "react-i18next";

import type { IWidgetApiRequest } from "matrix-widget-api";
import { widget, ElementWidgetActions, JoinCallData } from "../widget";
import { FullScreenView } from "../FullScreenView";
import { LobbyView } from "./LobbyView";
import { MatrixInfo } from "./VideoPreview";
import { CallEndedView } from "./CallEndedView";
import { PosthogAnalytics } from "../analytics/PosthogAnalytics";
import { useProfile } from "../profile/useProfile";
import { findDeviceByName } from "../utils/media";
import { ActiveCall } from "./InCallView";
import { MUTE_PARTICIPANT_COUNT, MuteStates } from "./MuteStates";
import { useMediaDevices, MediaDevices } from "../livekit/MediaDevicesContext";
import { useMatrixRTCSessionMemberships } from "../useMatrixRTCSessionMemberships";
import { enterRTCSession, leaveRTCSession } from "../rtcSessionHelpers";
import { useMatrixRTCSessionJoinState } from "../useMatrixRTCSessionJoinState";
import { useRoomEncryptionSystem } from "../e2ee/sharedKeyManagement";
import { useRoomAvatar } from "./useRoomAvatar";
import { useRoomName } from "./useRoomName";
import { useJoinRule } from "./useJoinRule";
import { InviteModal } from "./InviteModal";
import { useUrlParams } from "../UrlParams";
import { E2eeType } from "../e2ee/e2eeType";
import { Link } from "../button/Link";

declare global {
  interface Window {
    rtcSession?: MatrixRTCSession;
  }
}

interface Props {
  client: MatrixClient;
  isPasswordlessUser: boolean;
  confineToRoom: boolean;
  preload: boolean;
  skipLobby: boolean;
  hideHeader: boolean;
  rtcSession: MatrixRTCSession;
  muteStates: MuteStates;
}

export const GroupCallView: FC<Props> = ({
  client,
  isPasswordlessUser,
  confineToRoom,
  preload,
  skipLobby,
  hideHeader,
  rtcSession,
  muteStates,
}) => {
  const memberships = useMatrixRTCSessionMemberships(rtcSession);
  const isJoined = useMatrixRTCSessionJoinState(rtcSession);

  // This should use `useEffectEvent` (only available in experimental versions)
  useEffect(() => {
    if (memberships.length >= MUTE_PARTICIPANT_COUNT)
      muteStates.audio.setEnabled?.(false);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  useEffect(() => {
    window.rtcSession = rtcSession;
    return (): void => {
      delete window.rtcSession;
    };
  }, [rtcSession]);

  useEffect(() => {
    // Sanity check the room object
    if (client.getRoom(rtcSession.room.roomId) !== rtcSession.room)
      logger.warn(
        `We've ended up with multiple rooms for the same ID (${rtcSession.room.roomId}). This indicates a bug in the group call loading code, and may lead to incomplete room state.`,
      );
  }, [client, rtcSession.room]);

  const { displayName, avatarUrl } = useProfile(client);
  const roomName = useRoomName(rtcSession.room);
  const roomAvatar = useRoomAvatar(rtcSession.room);
  const { perParticipantE2EE, returnToLobby } = useUrlParams();
  const e2eeSystem = useRoomEncryptionSystem(rtcSession.room.roomId);

  const matrixInfo = useMemo((): MatrixInfo => {
    return {
      userId: client.getUserId()!,
      displayName: displayName!,
      avatarUrl: avatarUrl!,
      roomId: rtcSession.room.roomId,
      roomName,
      roomAlias: rtcSession.room.getCanonicalAlias(),
      roomAvatar,
      e2eeSystem,
    };
  }, [
    client,
    displayName,
    avatarUrl,
    rtcSession.room,
    roomName,
    roomAvatar,
    e2eeSystem,
  ]);

  // Count each member only once, regardless of how many devices they use
  const participantCount = useMemo(
    () => new Set<string>(memberships.map((m) => m.sender!)).size,
    [memberships],
  );

  const deviceContext = useMediaDevices();
  const latestDevices = useRef<MediaDevices>();
  latestDevices.current = deviceContext;

  const latestMuteStates = useRef<MuteStates>();
  latestMuteStates.current = muteStates;

  useEffect(() => {
    const defaultDeviceSetup = async (
      requestedDeviceData: JoinCallData,
    ): Promise<void> => {
      // XXX: I think this is broken currently - LiveKit *won't* request
      // permissions and give you device names unless you specify a kind, but
      // here we want all kinds of devices. This needs a fix in livekit-client
      // for the following name-matching logic to do anything useful.
      const devices = await Room.getLocalDevices(undefined, true);
      const { audioInput, videoInput } = requestedDeviceData;
      if (audioInput === null) {
        latestMuteStates.current!.audio.setEnabled?.(false);
      } else {
        const deviceId = findDeviceByName(audioInput, "audioinput", devices);
        if (!deviceId) {
          logger.warn("Unknown audio input: " + audioInput);
          latestMuteStates.current!.audio.setEnabled?.(false);
        } else {
          logger.debug(
            `Found audio input ID ${deviceId} for name ${audioInput}`,
          );
          latestDevices.current!.audioInput.select(deviceId);
          latestMuteStates.current!.audio.setEnabled?.(true);
        }
      }

      if (videoInput === null) {
        latestMuteStates.current!.video.setEnabled?.(false);
      } else {
        const deviceId = findDeviceByName(videoInput, "videoinput", devices);
        if (!deviceId) {
          logger.warn("Unknown video input: " + videoInput);
          latestMuteStates.current!.video.setEnabled?.(false);
        } else {
          logger.debug(
            `Found video input ID ${deviceId} for name ${videoInput}`,
          );
          latestDevices.current!.videoInput.select(deviceId);
          latestMuteStates.current!.video.setEnabled?.(true);
        }
      }
    };

    if (widget && preload && skipLobby) {
      // In preload mode without lobby we wait for a join action before entering
      const onJoin = (ev: CustomEvent<IWidgetApiRequest>): void => {
        (async (): Promise<void> => {
          await defaultDeviceSetup(ev.detail.data as unknown as JoinCallData);
          await enterRTCSession(rtcSession, perParticipantE2EE);
          widget!.api.transport.reply(ev.detail, {});
        })().catch((e) => {
          logger.error("Error joining RTC session", e);
        });
      };
      widget.lazyActions.on(ElementWidgetActions.JoinCall, onJoin);
      return (): void => {
        widget!.lazyActions.off(ElementWidgetActions.JoinCall, onJoin);
      };
    } else if (widget && !preload && skipLobby) {
      // No lobby and no preload: we enter the rtc session right away
      (async (): Promise<void> => {
        await defaultDeviceSetup({ audioInput: null, videoInput: null });
        await enterRTCSession(rtcSession, perParticipantE2EE);
      })().catch((e) => {
        logger.error("Error joining RTC session", e);
      });
    }
  }, [rtcSession, preload, skipLobby, perParticipantE2EE]);

  const [left, setLeft] = useState(false);
  const [leaveError, setLeaveError] = useState<Error | undefined>(undefined);
  const history = useHistory();

  const onLeave = useCallback(
    (leaveError?: Error): void => {
      setLeaveError(leaveError);
      setLeft(true);

      // In embedded/widget mode the iFrame will be killed right after the call ended prohibiting the posthog event from getting sent,
      // therefore we want the event to be sent instantly without getting queued/batched.
      const sendInstantly = !!widget;
      PosthogAnalytics.instance.eventCallEnded.track(
        rtcSession.room.roomId,
        rtcSession.memberships.length,
        sendInstantly,
        rtcSession,
      );

      // Only sends matrix leave event. The Livekit session will disconnect once the ActiveCall-view unmounts.
      leaveRTCSession(rtcSession)
        .then(() => {
          if (
            !isPasswordlessUser &&
            !confineToRoom &&
            !PosthogAnalytics.instance.isEnabled()
          ) {
            history.push("/");
          }
        })
        .catch((e) => {
          logger.error("Error leaving RTC session", e);
        });
    },
    [rtcSession, isPasswordlessUser, confineToRoom, history],
  );

  useEffect(() => {
    if (widget && isJoined) {
      // set widget to sticky once joined.
      widget!.api.setAlwaysOnScreen(true).catch((e) => {
        logger.error("Error calling setAlwaysOnScreen(true)", e);
      });

      const onHangup = (ev: CustomEvent<IWidgetApiRequest>): void => {
        widget!.api.transport.reply(ev.detail, {});
        // Only sends matrix leave event. The Livekit session will disconnect once the ActiveCall-view unmounts.
        leaveRTCSession(rtcSession).catch((e) => {
          logger.error("Failed to leave RTC session", e);
        });
      };
      widget.lazyActions.once(ElementWidgetActions.HangupCall, onHangup);
      return (): void => {
        widget!.lazyActions.off(ElementWidgetActions.HangupCall, onHangup);
      };
    }
  }, [isJoined, rtcSession]);

  const onReconnect = useCallback(() => {
    setLeft(false);
    setLeaveError(undefined);
    enterRTCSession(rtcSession, perParticipantE2EE).catch((e) => {
      logger.error("Error re-entering RTC session on reconnect", e);
    });
  }, [rtcSession, perParticipantE2EE]);

  const joinRule = useJoinRule(rtcSession.room);

  const [shareModalOpen, setInviteModalOpen] = useState(false);
  const onDismissInviteModal = useCallback(
    () => setInviteModalOpen(false),
    [setInviteModalOpen],
  );

  const onShareClickFn = useCallback(
    () => setInviteModalOpen(true),
    [setInviteModalOpen],
  );
  const onShareClick = joinRule === JoinRule.Public ? onShareClickFn : null;

  const { t } = useTranslation();

  if (!isE2EESupportedBrowser() && e2eeSystem.kind !== E2eeType.NONE) {
    // If we have a encryption system but the browser does not support it.
    return (
      <FullScreenView>
        <Heading>{t("browser_media_e2ee_unsupported_heading")}</Heading>
        <Text>{t("browser_media_e2ee_unsupported")}</Text>
        <Link to="/">{t("common.home")}</Link>
      </FullScreenView>
    );
  }

  const shareModal = (
    <InviteModal
      room={rtcSession.room}
      open={shareModalOpen}
      onDismiss={onDismissInviteModal}
    />
  );
  const lobbyView = (
    <>
      {shareModal}
      <LobbyView
        client={client}
        matrixInfo={matrixInfo}
        muteStates={muteStates}
        onEnter={() => void enterRTCSession(rtcSession, perParticipantE2EE)}
        confineToRoom={confineToRoom}
        hideHeader={hideHeader}
        participantCount={participantCount}
        onShareClick={onShareClick}
      />
    </>
  );

  if (isJoined) {
    return (
      <>
        {shareModal}
        <ActiveCall
          client={client}
          matrixInfo={matrixInfo}
          rtcSession={rtcSession}
          participantCount={participantCount}
          onLeave={onLeave}
          hideHeader={hideHeader}
          muteStates={muteStates}
          e2eeSystem={e2eeSystem}
          //otelGroupCallMembership={otelGroupCallMembership}
          onShareClick={onShareClick}
        />
      </>
    );
  } else if (left && widget === null) {
    // Left in SPA mode:

    // The call ended view is shown for two reasons: prompting guests to create
    // an account, and prompting users that have opted into analytics to provide
    // feedback. We don't show a feedback prompt to widget users however (at
    // least for now), because we don't yet have designs that would allow widget
    // users to dismiss the feedback prompt and close the call window without
    // submitting anything.
    if (
      isPasswordlessUser ||
      (PosthogAnalytics.instance.isEnabled() && widget === null) ||
      leaveError
    ) {
      return (
        <CallEndedView
          endedCallId={rtcSession.room.roomId}
          client={client}
          isPasswordlessUser={isPasswordlessUser}
          confineToRoom={confineToRoom}
          leaveError={leaveError}
          reconnect={onReconnect}
        />
      );
    } else {
      // If the user is a regular user, we'll have sent them back to the homepage,
      // so just sit here & do nothing: otherwise we would (briefly) mount the
      // LobbyView again which would open capture devices again.
      return null;
    }
  } else if (left && widget !== null) {
    // Left in widget mode:
    if (!returnToLobby) {
      return null;
    }
  } else if (preload || skipLobby) {
    return null;
  }

  return lobbyView;
};