/*
Copyright 2021 The Matrix.org Foundation C.I.C.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

import React from 'react';
import { IEventRelation, MatrixEvent, Room } from 'matrix-js-sdk/src';
import { Thread, ThreadEvent } from 'matrix-js-sdk/src/models/thread';
import { RelationType } from 'matrix-js-sdk/src/@types/event';

import BaseCard from "../views/right_panel/BaseCard";
import { RightPanelPhases } from "../../stores/RightPanelStorePhases";
import { replaceableComponent } from "../../utils/replaceableComponent";

import ResizeNotifier from '../../utils/ResizeNotifier';
import { TileShape } from '../views/rooms/EventTile';
import MessageComposer from '../views/rooms/MessageComposer';
import { RoomPermalinkCreator } from '../../utils/permalinks/Permalinks';
import { Layout } from '../../settings/enums/Layout';
import TimelinePanel from './TimelinePanel';
import dis from "../../dispatcher/dispatcher";
import { ActionPayload } from '../../dispatcher/payloads';
import { SetRightPanelPhasePayload } from '../../dispatcher/payloads/SetRightPanelPhasePayload';
import { Action } from '../../dispatcher/actions';
import { MatrixClientPeg } from '../../MatrixClientPeg';
import { E2EStatus } from '../../utils/ShieldUtils';
import EditorStateTransfer from '../../utils/EditorStateTransfer';
import RoomContext, { TimelineRenderingType } from '../../contexts/RoomContext';
import ContentMessages from '../../ContentMessages';
import UploadBar from './UploadBar';
import { _t } from '../../languageHandler';
import ThreadListContextMenu from '../views/context_menus/ThreadListContextMenu';
import RightPanelStore from '../../stores/RightPanelStore';
import SettingsStore from '../../settings/SettingsStore';
import { WidgetLayoutStore } from '../../stores/widgets/WidgetLayoutStore';

interface IProps {
    room: Room;
    onClose: () => void;
    resizeNotifier: ResizeNotifier;
    mxEvent: MatrixEvent;
    permalinkCreator?: RoomPermalinkCreator;
    e2eStatus?: E2EStatus;
    initialEvent?: MatrixEvent;
    initialEventHighlighted?: boolean;
}
interface IState {
    thread?: Thread;
    editState?: EditorStateTransfer;
    replyToEvent?: MatrixEvent;
}

@replaceableComponent("structures.ThreadView")
export default class ThreadView extends React.Component<IProps, IState> {
    static contextType = RoomContext;

    private dispatcherRef: string;
    private timelinePanelRef: React.RefObject<TimelinePanel> = React.createRef();

    constructor(props: IProps) {
        super(props);
        this.state = {};
    }

    public componentDidMount(): void {
        this.setupThread(this.props.mxEvent);
        this.dispatcherRef = dis.register(this.onAction);

        const room = MatrixClientPeg.get().getRoom(this.props.mxEvent.getRoomId());
        room.on(ThreadEvent.New, this.onNewThread);
    }

    public componentWillUnmount(): void {
        this.teardownThread();
        dis.unregister(this.dispatcherRef);
        const room = MatrixClientPeg.get().getRoom(this.props.mxEvent.getRoomId());
        room.removeListener(ThreadEvent.New, this.onNewThread);
    }

    public componentDidUpdate(prevProps) {
        if (prevProps.mxEvent !== this.props.mxEvent) {
            this.teardownThread();
            this.setupThread(this.props.mxEvent);
        }

        if (prevProps.room !== this.props.room) {
            dis.dispatch<SetRightPanelPhasePayload>({
                action: Action.SetRightPanelPhase,
                phase: RightPanelPhases.RoomSummary,
            });
        }
    }

    private onAction = (payload: ActionPayload): void => {
        if (payload.phase == RightPanelPhases.ThreadView && payload.event) {
            this.teardownThread();
            this.setupThread(payload.event);
        }
        switch (payload.action) {
            case Action.EditEvent:
                // Quit early if it's not a thread context
                if (payload.timelineRenderingType !== TimelineRenderingType.Thread) return;
                // Quit early if that's not a thread event
                if (payload.event && !payload.event.getThread()) return;
                this.setState({
                    editState: payload.event ? new EditorStateTransfer(payload.event) : null,
                }, () => {
                    if (payload.event) {
                        this.timelinePanelRef.current?.scrollToEventIfNeeded(payload.event.getId());
                    }
                });
                break;
            case 'reply_to_event':
                if (payload.context === TimelineRenderingType.Thread) {
                    this.setState({
                        replyToEvent: payload.event,
                    });
                }
                break;
            default:
                break;
        }
    };

    private setupThread = (mxEv: MatrixEvent) => {
        let thread = this.props.room.threads.get(mxEv.getId());
        if (!thread) {
            const client = MatrixClientPeg.get();
            // Do not attach this thread object to the event for now
            // TODO: When local echo gets reintroduced it will be important
            // to add that back in, and the threads model should go through the
            // same reconciliation algorithm as events
            thread = new Thread(
                [mxEv],
                this.props.room,
                client,
            );
        }
        thread.on(ThreadEvent.Update, this.updateThread);
        thread.once(ThreadEvent.Ready, this.updateThread);
        this.updateThread(thread);
    };

    private teardownThread = () => {
        if (this.state.thread) {
            this.state.thread.removeListener(ThreadEvent.Update, this.updateThread);
            this.state.thread.removeListener(ThreadEvent.Ready, this.updateThread);
        }
    };

    private onNewThread = (thread: Thread) => {
        if (thread.id === this.props.mxEvent.getId()) {
            this.teardownThread();
            this.setupThread(this.props.mxEvent);
        }
    };

    private updateThread = (thread?: Thread) => {
        if (thread && this.state.thread !== thread) {
            this.setState({
                thread,
            });
            thread.emit(ThreadEvent.ViewThread);
        }

        this.timelinePanelRef.current?.refreshTimeline();
    };

    private onScroll = (): void => {
        if (this.props.initialEvent && this.props.initialEventHighlighted) {
            dis.dispatch({
                action: Action.ViewRoom,
                room_id: this.props.room.roomId,
                event_id: this.props.initialEvent?.getId(),
                highlighted: false,
                replyingToEvent: this.state.replyToEvent,
            });
        }
    };

    private renderThreadViewHeader = (): JSX.Element => {
        return <div className="mx_ThreadPanel__header">
            <span>{ _t("Thread") }</span>
            <ThreadListContextMenu
                mxEvent={this.props.mxEvent}
                permalinkCreator={this.props.permalinkCreator} />
        </div>;
    };

    public render(): JSX.Element {
        const highlightedEventId = this.props.initialEventHighlighted
            ? this.props.initialEvent?.getId()
            : null;

        const threadRelation: IEventRelation = {
            rel_type: RelationType.Thread,
            event_id: this.state.thread?.id,
        };

        let previousPhase = RightPanelStore.getSharedInstance().previousPhase;
        if (!SettingsStore.getValue("feature_maximised_widgets")) {
            previousPhase = RightPanelPhases.ThreadPanel;
        }

        // change the previous phase to the threadPanel in case there is no maximised widget anymore
        if (!WidgetLayoutStore.instance.hasMaximisedWidget(this.props.room)) {
            previousPhase = RightPanelPhases.ThreadPanel;
        }

        // Make sure the previous Phase is always one of the two: Timeline or ThreadPanel
        if (![RightPanelPhases.ThreadPanel, RightPanelPhases.Timeline].includes(previousPhase)) {
            previousPhase = RightPanelPhases.ThreadPanel;
        }
        const previousPhaseLabels = {};
        previousPhaseLabels[RightPanelPhases.ThreadPanel] = _t("All threads");
        previousPhaseLabels[RightPanelPhases.Timeline] = _t("Chat");

        return (
            <RoomContext.Provider value={{
                ...this.context,
                timelineRenderingType: TimelineRenderingType.Thread,
                liveTimeline: this.state?.thread?.timelineSet?.getLiveTimeline(),
            }}>

                <BaseCard
                    className="mx_ThreadView mx_ThreadPanel"
                    onClose={this.props.onClose}
                    previousPhase={previousPhase}
                    previousPhaseLabel={previousPhaseLabels[previousPhase]}
                    withoutScrollContainer={true}
                    header={this.renderThreadViewHeader()}
                >
                    { this.state.thread && (
                        <TimelinePanel
                            ref={this.timelinePanelRef}
                            showReadReceipts={false} // Hide the read receipts
                            // until homeservers speak threads language
                            manageReadReceipts={true}
                            manageReadMarkers={true}
                            sendReadReceiptOnLoad={true}
                            timelineSet={this.state?.thread?.timelineSet}
                            showUrlPreview={true}
                            tileShape={TileShape.Thread}
                            layout={Layout.Group}
                            hideThreadedMessages={false}
                            hidden={false}
                            showReactions={true}
                            className="mx_RoomView_messagePanel mx_GroupLayout"
                            permalinkCreator={this.props.permalinkCreator}
                            membersLoaded={true}
                            editState={this.state.editState}
                            eventId={this.props.initialEvent?.getId()}
                            highlightedEventId={highlightedEventId}
                            onUserScroll={this.onScroll}
                        />
                    ) }

                    { ContentMessages.sharedInstance().getCurrentUploads(threadRelation).length > 0 && (
                        <UploadBar room={this.props.room} relation={threadRelation} />
                    ) }

                    { this.state?.thread?.timelineSet && (<MessageComposer
                        room={this.props.room}
                        resizeNotifier={this.props.resizeNotifier}
                        relation={threadRelation}
                        replyToEvent={this.state.replyToEvent}
                        permalinkCreator={this.props.permalinkCreator}
                        e2eStatus={this.props.e2eStatus}
                        compact={true}
                    />) }
                </BaseCard>
            </RoomContext.Provider>
        );
    }
}
