/*
Copyright 2015, 2016 OpenMarket Ltd
Copyright 2017 Vector Creations Ltd
Copyright 2018 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 React from 'react';
import classNames from 'classnames';
import sdk from '../../index';
import dis from '../../dispatcher';
import Unread from '../../Unread';
import * as RoomNotifs from '../../RoomNotifs';
import * as FormattingUtils from '../../utils/FormattingUtils';
import IndicatorScrollbar from './IndicatorScrollbar';
import { KeyCode } from '../../Keyboard';
import { Group } from 'matrix-js-sdk';
import PropTypes from 'prop-types';
import RoomTile from "../views/rooms/RoomTile";
import LazyRenderList from "../views/elements/LazyRenderList";
import * as _ from "lodash";

// turn this on for drop & drag console debugging galore
const debug = false;

const RoomSubList = React.createClass({
    displayName: 'RoomSubList',

    debug: debug,

    propTypes: {
        list: PropTypes.arrayOf(PropTypes.object).isRequired,
        label: PropTypes.string.isRequired,
        tagName: PropTypes.string,

        order: PropTypes.string.isRequired,

        // passed through to RoomTile and used to highlight room with `!` regardless of notifications count
        isInvite: PropTypes.bool,

        startAsHidden: PropTypes.bool,
        showSpinner: PropTypes.bool, // true to show a spinner if 0 elements when expanded
        collapsed: PropTypes.bool.isRequired, // is LeftPanel collapsed?
        onHeaderClick: PropTypes.func,
        incomingCall: PropTypes.object,
        isFiltered: PropTypes.bool,
        headerItems: PropTypes.node, // content shown in the sublist header
        extraTiles: PropTypes.arrayOf(PropTypes.node), // extra elements added beneath tiles
    },

    getInitialState: function() {
        // throttle updates to LazyRenderList
        this._onScroll = _.throttle(
            this._onScroll, 100,
            {leading: false, trailing: true},
        );
        this._updateLazyRenderHeight = _.throttle(
            this._updateLazyRenderHeight, 100,
            {leading: false, trailing: true},
        );
        return {
            hidden: this.props.startAsHidden || false,
            // some values to get LazyRenderList starting
            scrollerHeight: 800,
            scrollTop: 0,
        };
    },

    getDefaultProps: function() {
        return {
            onHeaderClick: function() {
            }, // NOP
            extraTiles: [],
            isInvite: false,
        };
    },

    componentWillMount: function() {
        this.dispatcherRef = dis.register(this.onAction);
    },

    componentWillUnmount: function() {
        dis.unregister(this.dispatcherRef);
    },

    // The header is collapsable if it is hidden or not stuck
    // The dataset elements are added in the RoomList _initAndPositionStickyHeaders method
    isCollapsableOnClick: function() {
        const stuck = this.refs.header.dataset.stuck;
        if (!this.props.forceExpand && (this.state.hidden || stuck === undefined || stuck === "none")) {
            return true;
        } else {
            return false;
        }
    },

    onAction: function(payload) {
        // XXX: Previously RoomList would forceUpdate whenever on_room_read is dispatched,
        // but this is no longer true, so we must do it here (and can apply the small
        // optimisation of checking that we care about the room being read).
        //
        // Ultimately we need to transition to a state pushing flow where something
        // explicitly notifies the components concerned that the notif count for a room
        // has change (e.g. a Flux store).
        if (payload.action === 'on_room_read' &&
            this.props.list.some((r) => r.roomId === payload.roomId)
        ) {
            this.forceUpdate();
        }
    },

    onClick: function(ev) {
        if (this.isCollapsableOnClick()) {
            // The header isCollapsable, so the click is to be interpreted as collapse and truncation logic
            const isHidden = !this.state.hidden;
            this.setState({hidden: isHidden}, () => {
                this.props.onHeaderClick(isHidden);
            });
        } else {
            // The header is stuck, so the click is to be interpreted as a scroll to the header
            this.props.onHeaderClick(this.state.hidden, this.refs.header.dataset.originalPosition);
        }
    },

    onRoomTileClick(roomId, ev) {
        dis.dispatch({
            action: 'view_room',
            room_id: roomId,
            clear_search: (ev && (ev.keyCode === KeyCode.ENTER || ev.keyCode === KeyCode.SPACE)),
        });
    },

    _updateSubListCount: function() {
        // Force an update by setting the state to the current state
        // Doing it this way rather than using forceUpdate(), so that the shouldComponentUpdate()
        // method is honoured
        this.setState(this.state);
    },

    makeRoomTile: function(room) {
        return <RoomTile
            room={room}
            roomSubList={this}
            tagName={this.props.tagName}
            key={room.roomId}
            collapsed={this.props.collapsed || false}
            unread={Unread.doesRoomHaveUnreadMessages(room)}
            highlight={room.getUnreadNotificationCount('highlight') > 0 || this.props.isInvite}
            notificationCount={room.getUnreadNotificationCount()}
            isInvite={this.props.isInvite}
            refreshSubList={this._updateSubListCount}
            incomingCall={null}
            onClick={this.onRoomTileClick}
        />;
    },

    _onNotifBadgeClick: function(e) {
        // prevent the roomsublist collapsing
        e.preventDefault();
        e.stopPropagation();
        const room = this.props.list.find(room => RoomNotifs.getRoomHasBadge(room));
        if (room) {
            dis.dispatch({
                action: 'view_room',
                room_id: room.roomId,
            });
        }
    },

    _onInviteBadgeClick: function(e) {
        // prevent the roomsublist collapsing
        e.preventDefault();
        e.stopPropagation();
        // switch to first room in sortedList as that'll be the top of the list for the user
        if (this.props.list && this.props.list.length > 0) {
            dis.dispatch({
                action: 'view_room',
                room_id: this.props.list[0].roomId,
            });
        } else if (this.props.extraTiles && this.props.extraTiles.length > 0) {
            // Group Invites are different in that they are all extra tiles and not rooms
            // XXX: this is a horrible special case because Group Invite sublist is a hack
            if (this.props.extraTiles[0].props && this.props.extraTiles[0].props.group instanceof Group) {
                dis.dispatch({
                    action: 'view_group',
                    group_id: this.props.extraTiles[0].props.group.groupId,
                });
            }
        }
    },

    _getHeaderJsx: function(isCollapsed) {
        const AccessibleButton = sdk.getComponent('elements.AccessibleButton');
        const subListNotifications = !this.props.isInvite ?
            RoomNotifs.aggregateNotificationCount(this.props.list) :
            {count: 0, highlight: true};
        const subListNotifCount = subListNotifications.count;
        const subListNotifHighlight = subListNotifications.highlight;

        let badge;
        if (!this.props.collapsed) {
            const badgeClasses = classNames({
                'mx_RoomSubList_badge': true,
                'mx_RoomSubList_badgeHighlight': subListNotifHighlight,
            });
            if (subListNotifCount > 0) {
                badge = <div className={badgeClasses} onClick={this._onNotifBadgeClick}>
                    { FormattingUtils.formatCount(subListNotifCount) }
                </div>;
            } else if (this.props.isInvite && this.props.list.length) {
                // no notifications but highlight anyway because this is an invite badge
                badge = <div className={badgeClasses} onClick={this._onInviteBadgeClick}>{this.props.list.length}</div>;
            }
        }

        // When collapsed, allow a long hover on the header to show user
        // the full tag name and room count
        let title;
        if (this.props.collapsed) {
            title = this.props.label;
        }

        let incomingCall;
        if (this.props.incomingCall) {
            // We can assume that if we have an incoming call then it is for this list
            const IncomingCallBox = sdk.getComponent("voip.IncomingCallBox");
            incomingCall =
                <IncomingCallBox className="mx_RoomSubList_incomingCall" incomingCall={this.props.incomingCall} />;
        }

        let addRoomButton;
        if (this.props.onAddRoom) {
            addRoomButton = (
                <AccessibleButton onClick={ this.props.onAddRoom } className="mx_RoomSubList_addRoom" />
            );
        }

        const len = this.props.list.length + this.props.extraTiles.length;
        let chevron;
        if (len) {
            const chevronClasses = classNames({
                'mx_RoomSubList_chevron': true,
                'mx_RoomSubList_chevronRight': isCollapsed,
                'mx_RoomSubList_chevronDown': !isCollapsed,
            });
            chevron = (<div className={chevronClasses}></div>);
        }

        const tabindex = this.props.isFiltered ? "0" : "-1";
        return (
            <div className="mx_RoomSubList_labelContainer" title={ title } ref="header">
                <AccessibleButton onClick={ this.onClick } className="mx_RoomSubList_label" tabIndex={tabindex}>
                    { chevron }
                    <span>{this.props.label}</span>
                    { incomingCall }
                </AccessibleButton>
                { badge }
                { addRoomButton }
            </div>
        );
    },

    checkOverflow: function() {
        if (this.refs.scroller) {
            this.refs.scroller.checkOverflow();
        }
    },

    setHeight: function(height) {
        if (this.refs.subList) {
            this.refs.subList.style.height = `${height}px`;
        }
        this._updateLazyRenderHeight(height);
    },

    _updateLazyRenderHeight: function(height) {
        this.setState({scrollerHeight: height});
    },

    _onScroll: function() {
        this.setState({scrollTop: this.refs.scroller.getScrollTop()});
    },

    render: function() {
        const len = this.props.list.length + this.props.extraTiles.length;
        const isCollapsed = this.state.hidden && !this.props.forceExpand;
        if (len) {
            const subListClasses = classNames({
                "mx_RoomSubList": true,
                "mx_RoomSubList_hidden": isCollapsed,
                "mx_RoomSubList_nonEmpty": len && !isCollapsed,
            });

            if (isCollapsed) {
                return <div ref="subList" className={subListClasses}>
                    {this._getHeaderJsx(isCollapsed)}
                </div>;
            } else {
                const items = this.props.list.concat(this.props.extraTiles);
                return <div ref="subList" className={subListClasses}>
                    {this._getHeaderJsx(isCollapsed)}
                    <IndicatorScrollbar ref="scroller" className="mx_RoomSubList_scroll" onScroll={ this._onScroll }>
                        <LazyRenderList
                            scrollTop={this.state.scrollTop }
                            height={ this.state.scrollerHeight }
                            renderItem={ this.makeRoomTile }
                            itemHeight={34}
                            items={items} />
                    </IndicatorScrollbar>
                </div>;
            }
        } else {
            const Loader = sdk.getComponent("elements.Spinner");
            let content;
            if (this.props.showSpinner && !isCollapsed) {
                content = <Loader />;
            }

            return (
                <div ref="subList" className="mx_RoomSubList">
                    { this._getHeaderJsx(isCollapsed) }
                    { content }
                </div>
            );
        }
    },
});

module.exports = RoomSubList;