/*
Copyright 2015, 2016 OpenMarket Ltd
Copyright 2017 Vector Creations Ltd
Copyright 2017, 2018, 2020 New Vector Ltd

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 * as React from 'react';
import * as PropTypes from 'prop-types';
import { MatrixClient } from 'matrix-js-sdk/src/client';
import { MatrixEvent } from 'matrix-js-sdk/src/models/event';
import { DragDropContext } from 'react-beautiful-dnd';

import {Key, isOnlyCtrlOrCmdKeyEvent, isOnlyCtrlOrCmdIgnoreShiftKeyEvent} from '../../Keyboard';
import PageTypes from '../../PageTypes';
import CallMediaHandler from '../../CallMediaHandler';
import { fixupColorFonts } from '../../utils/FontManager';
import * as sdk from '../../index';
import dis from '../../dispatcher/dispatcher';
import sessionStore from '../../stores/SessionStore';
import {MatrixClientPeg, IMatrixClientCreds} from '../../MatrixClientPeg';
import SettingsStore from "../../settings/SettingsStore";

import TagOrderActions from '../../actions/TagOrderActions';
import RoomListActions from '../../actions/RoomListActions';
import ResizeHandle from '../views/elements/ResizeHandle';
import {Resizer, CollapseDistributor} from '../../resizer';
import MatrixClientContext from "../../contexts/MatrixClientContext";
import * as KeyboardShortcuts from "../../accessibility/KeyboardShortcuts";
import HomePage from "./HomePage";
import ResizeNotifier from "../../utils/ResizeNotifier";
import PlatformPeg from "../../PlatformPeg";
import { RoomListStoreTempProxy } from "../../stores/room-list/RoomListStoreTempProxy";
import { DefaultTagID } from "../../stores/room-list/models";
import {
    showToast as showSetPasswordToast,
    hideToast as hideSetPasswordToast
} from "../../toasts/SetPasswordToast";
import {
    showToast as showServerLimitToast,
    hideToast as hideServerLimitToast
} from "../../toasts/ServerLimitToast";

// We need to fetch each pinned message individually (if we don't already have it)
// so each pinned message may trigger a request. Limit the number per room for sanity.
// NB. this is just for server notices rather than pinned messages in general.
const MAX_PINNED_NOTICES_PER_ROOM = 2;

function canElementReceiveInput(el) {
    return el.tagName === "INPUT" ||
        el.tagName === "TEXTAREA" ||
        el.tagName === "SELECT" ||
        !!el.getAttribute("contenteditable");
}

interface IProps {
    matrixClient: MatrixClient;
    onRegistered: (credentials: IMatrixClientCreds) => Promise<MatrixClient>;
    viaServers?: string[];
    hideToSRUsers: boolean;
    resizeNotifier: ResizeNotifier;
    middleDisabled: boolean;
    initialEventPixelOffset: number;
    leftDisabled: boolean;
    rightDisabled: boolean;
    page_type: string;
    autoJoin: boolean;
    thirdPartyInvite?: object;
    roomOobData?: object;
    currentRoomId: string;
    ConferenceHandler?: object;
    collapseLhs: boolean;
    config: {
        piwik: {
            policyUrl: string;
        },
        [key: string]: any,
    };
    currentUserId?: string;
    currentGroupId?: string;
    currentGroupIsNew?: boolean;
}

interface IState {
    mouseDown?: {
        x: number;
        y: number;
    };
    syncErrorData: any;
    useCompactLayout: boolean;
}

/**
 * This is what our MatrixChat shows when we are logged in. The precise view is
 * determined by the page_type property.
 *
 * Currently it's very tightly coupled with MatrixChat. We should try to do
 * something about that.
 *
 * Components mounted below us can access the matrix client via the react context.
 */
class LoggedInView extends React.PureComponent<IProps, IState> {
    static displayName = 'LoggedInView';

    static propTypes = {
        matrixClient: PropTypes.instanceOf(MatrixClient).isRequired,
        page_type: PropTypes.string.isRequired,
        onRoomCreated: PropTypes.func,

        // Called with the credentials of a registered user (if they were a ROU that
        // transitioned to PWLU)
        onRegistered: PropTypes.func,

        // Used by the RoomView to handle joining rooms
        viaServers: PropTypes.arrayOf(PropTypes.string),

        // and lots and lots of other stuff.
    };

    protected readonly _matrixClient: MatrixClient;
    protected readonly _roomView: React.RefObject<any>;
    protected readonly _resizeContainer: React.RefObject<ResizeHandle>;
    protected readonly _sessionStore: sessionStore;
    protected readonly _sessionStoreToken: { remove: () => void };
    protected resizer: Resizer;

    constructor(props, context) {
        super(props, context);

        this.state = {
            mouseDown: undefined,
            syncErrorData: undefined,
            // use compact timeline view
            useCompactLayout: SettingsStore.getValue('useCompactLayout'),
        };

        // stash the MatrixClient in case we log out before we are unmounted
        this._matrixClient = this.props.matrixClient;

        CallMediaHandler.loadDevices();

        document.addEventListener('keydown', this._onNativeKeyDown, false);

        this._sessionStore = sessionStore;
        this._sessionStoreToken = this._sessionStore.addListener(
            this._setStateFromSessionStore,
        );
        this._setStateFromSessionStore();

        this._updateServerNoticeEvents();

        this._matrixClient.on("accountData", this.onAccountData);
        this._matrixClient.on("sync", this.onSync);
        this._matrixClient.on("RoomState.events", this.onRoomStateEvents);

        fixupColorFonts();

        this._roomView = React.createRef();
        this._resizeContainer = React.createRef();
    }

    componentDidMount() {
        this.resizer = this._createResizer();
        this.resizer.attach();
        this._loadResizerPreferences();
    }

    componentWillUnmount() {
        document.removeEventListener('keydown', this._onNativeKeyDown, false);
        this._matrixClient.removeListener("accountData", this.onAccountData);
        this._matrixClient.removeListener("sync", this.onSync);
        this._matrixClient.removeListener("RoomState.events", this.onRoomStateEvents);
        if (this._sessionStoreToken) {
            this._sessionStoreToken.remove();
        }
        this.resizer.detach();
    }

    // Child components assume that the client peg will not be null, so give them some
    // sort of assurance here by only allowing a re-render if the client is truthy.
    //
    // This is required because `LoggedInView` maintains its own state and if this state
    // updates after the client peg has been made null (during logout), then it will
    // attempt to re-render and the children will throw errors.
    shouldComponentUpdate() {
        return Boolean(MatrixClientPeg.get());
    }

    canResetTimelineInRoom = (roomId) => {
        if (!this._roomView.current) {
            return true;
        }
        return this._roomView.current.canResetTimeline();
    };

    _setStateFromSessionStore = () => {
        if (this._sessionStore.getCachedPassword()) {
            showSetPasswordToast();
        } else {
            hideSetPasswordToast();
        }
    };

    _createResizer() {
        const classNames = {
            handle: "mx_ResizeHandle",
            vertical: "mx_ResizeHandle_vertical",
            reverse: "mx_ResizeHandle_reverse",
        };
        const collapseConfig = {
            toggleSize: 260 - 50,
            onCollapsed: (collapsed) => {
                if (collapsed) {
                    dis.dispatch({action: "hide_left_panel"}, true);
                    window.localStorage.setItem("mx_lhs_size", '0');
                } else {
                    dis.dispatch({action: "show_left_panel"}, true);
                }
            },
            onResized: (size) => {
                window.localStorage.setItem("mx_lhs_size", '' + size);
                this.props.resizeNotifier.notifyLeftHandleResized();
            },
        };
        const resizer = new Resizer(
            this._resizeContainer.current,
            CollapseDistributor,
            collapseConfig);
        resizer.setClassNames(classNames);
        return resizer;
    }

    _loadResizerPreferences() {
        let lhsSize = parseInt(window.localStorage.getItem("mx_lhs_size"), 10);
        if (isNaN(lhsSize)) {
            lhsSize = 350;
        }
        this.resizer.forHandleAt(0).resize(lhsSize);
    }

    onAccountData = (event) => {
        if (event.getType() === "im.vector.web.settings") {
            this.setState({
                useCompactLayout: event.getContent().useCompactLayout,
            });
        }
        if (event.getType() === "m.ignored_user_list") {
            dis.dispatch({action: "ignore_state_changed"});
        }
    };

    onSync = (syncState, oldSyncState, data) => {
        const oldErrCode = (
            this.state.syncErrorData &&
            this.state.syncErrorData.error &&
            this.state.syncErrorData.error.errcode
        );
        const newErrCode = data && data.error && data.error.errcode;
        if (syncState === oldSyncState && oldErrCode === newErrCode) return;

        if (syncState === 'ERROR') {
            this.setState({
                syncErrorData: data,
            });
        } else {
            this.setState({
                syncErrorData: null,
            });
        }

        if (oldSyncState === 'PREPARED' && syncState === 'SYNCING') {
            this._updateServerNoticeEvents();
        } else {
            this._calculateServerLimitToast(data);
        }
    };

    onRoomStateEvents = (ev, state) => {
        const roomLists = RoomListStoreTempProxy.getRoomLists();
        if (roomLists[DefaultTagID.ServerNotice] && roomLists[DefaultTagID.ServerNotice].some(r => r.roomId === ev.getRoomId())) {
            this._updateServerNoticeEvents();
        }
    };

    _calculateServerLimitToast(syncErrorData, usageLimitEventContent?) {
        const error = syncErrorData && syncErrorData.error && syncErrorData.error.errcode === "M_RESOURCE_LIMIT_EXCEEDED";
        if (error) {
            usageLimitEventContent = syncErrorData.error.data;
        }

        if (usageLimitEventContent) {
            showServerLimitToast(usageLimitEventContent.limit_type, usageLimitEventContent.admin_contact, error);
        } else {
            hideServerLimitToast();
        }
    }

    _updateServerNoticeEvents = async () => {
        const roomLists = RoomListStoreTempProxy.getRoomLists();
        if (!roomLists[DefaultTagID.ServerNotice]) return [];

        const events = [];
        for (const room of roomLists[DefaultTagID.ServerNotice]) {
            const pinStateEvent = room.currentState.getStateEvents("m.room.pinned_events", "");

            if (!pinStateEvent || !pinStateEvent.getContent().pinned) continue;

            const pinnedEventIds = pinStateEvent.getContent().pinned.slice(0, MAX_PINNED_NOTICES_PER_ROOM);
            for (const eventId of pinnedEventIds) {
                const timeline = await this._matrixClient.getEventTimeline(room.getUnfilteredTimelineSet(), eventId, 0);
                const event = timeline.getEvents().find(ev => ev.getId() === eventId);
                if (event) events.push(event);
            }
        }

        const usageLimitEvent = events.find((e) => {
            return (
                e && e.getType() === 'm.room.message' &&
                e.getContent()['server_notice_type'] === 'm.server_notice.usage_limit_reached'
            );
        });

        this._calculateServerLimitToast(this.state.syncErrorData, usageLimitEvent && usageLimitEvent.getContent());
    };

    _onPaste = (ev) => {
        let canReceiveInput = false;
        let element = ev.target;
        // test for all parents because the target can be a child of a contenteditable element
        while (!canReceiveInput && element) {
            canReceiveInput = canElementReceiveInput(element);
            element = element.parentElement;
        }
        if (!canReceiveInput) {
            // refocusing during a paste event will make the
            // paste end up in the newly focused element,
            // so dispatch synchronously before paste happens
            dis.dispatch({action: 'focus_composer'}, true);
        }
    };

    /*
    SOME HACKERY BELOW:
    React optimizes event handlers, by always attaching only 1 handler to the document for a given type.
    It then internally determines the order in which React event handlers should be called,
    emulating the capture and bubbling phases the DOM also has.

    But, as the native handler for React is always attached on the document,
    it will always run last for bubbling (first for capturing) handlers,
    and thus React basically has its own event phases, and will always run
    after (before for capturing) any native other event handlers (as they tend to be attached last).

    So ideally one wouldn't mix React and native event handlers to have bubbling working as expected,
    but we do need a native event handler here on the document,
    to get keydown events when there is no focused element (target=body).

    We also do need bubbling here to give child components a chance to call `stopPropagation()`,
    for keydown events it can handle itself, and shouldn't be redirected to the composer.

    So we listen with React on this component to get any events on focused elements, and get bubbling working as expected.
    We also listen with a native listener on the document to get keydown events when no element is focused.
    Bubbling is irrelevant here as the target is the body element.
    */
    _onReactKeyDown = (ev) => {
        // events caught while bubbling up on the root element
        // of this component, so something must be focused.
        this._onKeyDown(ev);
    };

    _onNativeKeyDown = (ev) => {
        // only pass this if there is no focused element.
        // if there is, _onKeyDown will be called by the
        // react keydown handler that respects the react bubbling order.
        if (ev.target === document.body) {
            this._onKeyDown(ev);
        }
    };

    _onKeyDown = (ev) => {
            /*
            // Remove this for now as ctrl+alt = alt-gr so this breaks keyboards which rely on alt-gr for numbers
            // Will need to find a better meta key if anyone actually cares about using this.
            if (ev.altKey && ev.ctrlKey && ev.keyCode > 48 && ev.keyCode < 58) {
                dis.dispatch({
                    action: 'view_indexed_room',
                    roomIndex: ev.keyCode - 49,
                });
                ev.stopPropagation();
                ev.preventDefault();
                return;
            }
            */

        let handled = false;
        const ctrlCmdOnly = isOnlyCtrlOrCmdKeyEvent(ev);
        const hasModifier = ev.altKey || ev.ctrlKey || ev.metaKey || ev.shiftKey;
        const isModifier = ev.key === Key.ALT || ev.key === Key.CONTROL || ev.key === Key.META || ev.key === Key.SHIFT;

        switch (ev.key) {
            case Key.PAGE_UP:
            case Key.PAGE_DOWN:
                if (!hasModifier && !isModifier) {
                    this._onScrollKeyPressed(ev);
                    handled = true;
                }
                break;

            case Key.HOME:
            case Key.END:
                if (ev.ctrlKey && !ev.shiftKey && !ev.altKey && !ev.metaKey) {
                    this._onScrollKeyPressed(ev);
                    handled = true;
                }
                break;
            case Key.K:
                if (ctrlCmdOnly) {
                    dis.dispatch({
                        action: 'focus_room_filter',
                    });
                    handled = true;
                }
                break;
            case Key.BACKTICK:
                // Ideally this would be CTRL+P for "Profile", but that's
                // taken by the print dialog. CTRL+I for "Information"
                // was previously chosen but conflicted with italics in
                // composer, so CTRL+` it is

                if (ctrlCmdOnly) {
                    dis.dispatch({
                        action: 'toggle_top_left_menu',
                    });
                    handled = true;
                }
                break;

            case Key.SLASH:
                if (isOnlyCtrlOrCmdIgnoreShiftKeyEvent(ev)) {
                    KeyboardShortcuts.toggleDialog();
                    handled = true;
                }
                break;

            case Key.ARROW_UP:
            case Key.ARROW_DOWN:
                if (ev.altKey && !ev.ctrlKey && !ev.metaKey) {
                    dis.dispatch({
                        action: 'view_room_delta',
                        delta: ev.key === Key.ARROW_UP ? -1 : 1,
                        unread: ev.shiftKey,
                    });
                    handled = true;
                }
                break;

            case Key.PERIOD:
                if (ctrlCmdOnly && (this.props.page_type === "room_view" || this.props.page_type === "group_view")) {
                    dis.dispatch({
                        action: 'toggle_right_panel',
                        type: this.props.page_type === "room_view" ? "room" : "group",
                    });
                    handled = true;
                }
                break;

            default:
                // if we do not have a handler for it, pass it to the platform which might
                handled = PlatformPeg.get().onKeyDown(ev);
        }

        if (handled) {
            ev.stopPropagation();
            ev.preventDefault();
        } else if (!isModifier && !ev.altKey && !ev.ctrlKey && !ev.metaKey) {
            // The above condition is crafted to _allow_ characters with Shift
            // already pressed (but not the Shift key down itself).

            const isClickShortcut = ev.target !== document.body &&
                (ev.key === Key.SPACE || ev.key === Key.ENTER);

            // Do not capture the context menu key to improve keyboard accessibility
            if (ev.key === Key.CONTEXT_MENU) {
                return;
            }

            if (!isClickShortcut && ev.key !== Key.TAB && !canElementReceiveInput(ev.target)) {
                // synchronous dispatch so we focus before key generates input
                dis.dispatch({action: 'focus_composer'}, true);
                ev.stopPropagation();
                // we should *not* preventDefault() here as
                // that would prevent typing in the now-focussed composer
            }
        }
    };

    /**
     * dispatch a page-up/page-down/etc to the appropriate component
     * @param {Object} ev The key event
     */
    _onScrollKeyPressed = (ev) => {
        if (this._roomView.current) {
            this._roomView.current.handleScrollKey(ev);
        }
    };

    _onDragEnd = (result) => {
        // Dragged to an invalid destination, not onto a droppable
        if (!result.destination) {
            return;
        }

        const dest = result.destination.droppableId;

        if (dest === 'tag-panel-droppable') {
            // Could be "GroupTile +groupId:domain"
            const draggableId = result.draggableId.split(' ').pop();

            // Dispatch synchronously so that the TagPanel receives an
            // optimistic update from TagOrderStore before the previous
            // state is shown.
            dis.dispatch(TagOrderActions.moveTag(
                this._matrixClient,
                draggableId,
                result.destination.index,
            ), true);
        } else if (dest.startsWith('room-sub-list-droppable_')) {
            this._onRoomTileEndDrag(result);
        }
    };

    _onRoomTileEndDrag = (result) => {
        let newTag = result.destination.droppableId.split('_')[1];
        let prevTag = result.source.droppableId.split('_')[1];
        if (newTag === 'undefined') newTag = undefined;
        if (prevTag === 'undefined') prevTag = undefined;

        const roomId = result.draggableId.split('_')[1];

        const oldIndex = result.source.index;
        const newIndex = result.destination.index;

        dis.dispatch(RoomListActions.tagRoom(
            this._matrixClient,
            this._matrixClient.getRoom(roomId),
            prevTag, newTag,
            oldIndex, newIndex,
        ), true);
    };

    _onMouseDown = (ev) => {
        // When the panels are disabled, clicking on them results in a mouse event
        // which bubbles to certain elements in the tree. When this happens, close
        // any settings page that is currently open (user/room/group).
        if (this.props.leftDisabled && this.props.rightDisabled) {
            const targetClasses = new Set(ev.target.className.split(' '));
            if (
                targetClasses.has('mx_MatrixChat') ||
                targetClasses.has('mx_MatrixChat_middlePanel') ||
                targetClasses.has('mx_RoomView')
            ) {
                this.setState({
                    mouseDown: {
                        x: ev.pageX,
                        y: ev.pageY,
                    },
                });
            }
        }
    };

    _onMouseUp = (ev) => {
        if (!this.state.mouseDown) return;

        const deltaX = ev.pageX - this.state.mouseDown.x;
        const deltaY = ev.pageY - this.state.mouseDown.y;
        const distance = Math.sqrt((deltaX * deltaX) + (deltaY + deltaY));
        const maxRadius = 5; // People shouldn't be straying too far, hopefully

        // Note: we track how far the user moved their mouse to help
        // combat against https://github.com/vector-im/riot-web/issues/7158

        if (distance < maxRadius) {
            // This is probably a real click, and not a drag
            dis.dispatch({ action: 'close_settings' });
        }

        // Always clear the mouseDown state to ensure we don't accidentally
        // use stale values due to the mouseDown checks.
        this.setState({mouseDown: null});
    };

    render() {
        const LeftPanel = sdk.getComponent('structures.LeftPanel');
        const RoomView = sdk.getComponent('structures.RoomView');
        const UserView = sdk.getComponent('structures.UserView');
        const GroupView = sdk.getComponent('structures.GroupView');
        const MyGroups = sdk.getComponent('structures.MyGroups');
        const ToastContainer = sdk.getComponent('structures.ToastContainer');

        let pageElement;

        switch (this.props.page_type) {
            case PageTypes.RoomView:
                pageElement = <RoomView
                        ref={this._roomView}
                        autoJoin={this.props.autoJoin}
                        onRegistered={this.props.onRegistered}
                        thirdPartyInvite={this.props.thirdPartyInvite}
                        oobData={this.props.roomOobData}
                        viaServers={this.props.viaServers}
                        eventPixelOffset={this.props.initialEventPixelOffset}
                        key={this.props.currentRoomId || 'roomview'}
                        disabled={this.props.middleDisabled}
                        ConferenceHandler={this.props.ConferenceHandler}
                        resizeNotifier={this.props.resizeNotifier}
                    />;
                break;

            case PageTypes.MyGroups:
                pageElement = <MyGroups />;
                break;

            case PageTypes.RoomDirectory:
                // handled by MatrixChat for now
                break;

            case PageTypes.HomePage:
                pageElement = <HomePage />;
                break;

            case PageTypes.UserView:
                pageElement = <UserView userId={this.props.currentUserId} />;
                break;
            case PageTypes.GroupView:
                pageElement = <GroupView
                    groupId={this.props.currentGroupId}
                    isNew={this.props.currentGroupIsNew}
                />;
                break;
        }

        let bodyClasses = 'mx_MatrixChat';
        if (this.state.useCompactLayout) {
            bodyClasses += ' mx_MatrixChat_useCompactLayout';
        }

        return (
            <MatrixClientContext.Provider value={this._matrixClient}>
                <div
                    onPaste={this._onPaste}
                    onKeyDown={this._onReactKeyDown}
                    className='mx_MatrixChat_wrapper'
                    aria-hidden={this.props.hideToSRUsers}
                    onMouseDown={this._onMouseDown}
                    onMouseUp={this._onMouseUp}
                >
                    <ToastContainer />
                    <DragDropContext onDragEnd={this._onDragEnd}>
                        <div ref={this._resizeContainer} className={bodyClasses}>
                            <LeftPanel
                                resizeNotifier={this.props.resizeNotifier}
                                collapsed={this.props.collapseLhs || false}
                                disabled={this.props.leftDisabled}
                            />
                            <ResizeHandle />
                            { pageElement }
                        </div>
                    </DragDropContext>
                </div>
            </MatrixClientContext.Provider>
        );
    }
}

export default LoggedInView;