// Copyright (c) 2016-present Mattermost, Inc. All Rights Reserved.
// See License.txt for license information.

import LoadingScreen from './loading_screen.jsx';

import * as UserAgent from 'utils/user_agent.jsx';

import $ from 'jquery';
import React from 'react';
import ReactDOM from 'react-dom';
import {localizeMessage} from 'utils/utils.jsx';
import {FormattedMessage} from 'react-intl';

import loadingGif from 'images/load.gif';

const NEXT_BUTTON_TIMEOUT_MILLISECONDS = 500;

export default class SearchableChannelList extends React.Component {
    constructor(props) {
        super(props);

        this.createChannelRow = this.createChannelRow.bind(this);
        this.nextPage = this.nextPage.bind(this);
        this.previousPage = this.previousPage.bind(this);
        this.doSearch = this.doSearch.bind(this);

        this.nextTimeoutId = 0;

        this.state = {
            joiningChannel: '',
            page: 0,
            nextDisabled: false
        };
    }

    componentDidMount() {
        // only focus the search box on desktop so that we don't cause the keyboard to open on mobile
        if (!UserAgent.isMobile()) {
            this.refs.filter.focus();
        }
    }

    componentDidUpdate(prevProps, prevState) {
        if (prevState.page !== this.state.page) {
            $(this.refs.channelList).scrollTop(0);
        }
    }

    handleJoin(channel) {
        this.setState({joiningChannel: channel.id});
        this.props.handleJoin(
            channel,
            () => {
                this.setState({joiningChannel: ''});
            }
        );
    }

    createChannelRow(channel) {
        let joinButton;
        if (this.state.joiningChannel === channel.id) {
            joinButton = (
                <img
                    className='join-channel-loading-gif'
                    src={loadingGif}
                />
            );
        } else {
            joinButton = (
                <button
                    onClick={this.handleJoin.bind(this, channel)}
                    className='btn btn-primary'
                >
                    <FormattedMessage
                        id='more_channels.join'
                        defaultMessage='Join'
                    />
                </button>
            );
        }

        return (
            <div
                className='more-modal__row'
                key={channel.id}
            >
                <div className='more-modal__details'>
                    <p className='more-modal__name'>{channel.display_name}</p>
                    <p className='more-modal__description'>{channel.purpose}</p>
                </div>
                <div className='more-modal__actions'>
                    {joinButton}
                </div>
            </div>
        );
    }

    nextPage(e) {
        e.preventDefault();
        this.setState({page: this.state.page + 1, nextDisabled: true});
        this.nextTimeoutId = setTimeout(() => this.setState({nextDisabled: false}), NEXT_BUTTON_TIMEOUT_MILLISECONDS);
        this.props.nextPage(this.state.page + 1);
        $(ReactDOM.findDOMNode(this.refs.channelListScroll)).scrollTop(0);
    }

    previousPage(e) {
        e.preventDefault();
        this.setState({page: this.state.page - 1});
        $(ReactDOM.findDOMNode(this.refs.channelListScroll)).scrollTop(0);
    }

    doSearch() {
        const term = this.refs.filter.value;
        this.props.search(term);
        if (term === '') {
            this.setState({page: 0});
        }
    }

    render() {
        const channels = this.props.channels;
        let listContent;
        let nextButton;
        let previousButton;

        if (channels == null) {
            listContent = <LoadingScreen/>;
        } else if (channels.length === 0) {
            listContent = (
                <div className='no-channel-message'>
                    <p className='primary-message'>
                        <FormattedMessage
                            id='more_channels.noMore'
                            defaultMessage='No more channels to join'
                        />
                    </p>
                    {this.props.noResultsText}
                </div>
            );
        } else {
            const pageStart = this.state.page * this.props.channelsPerPage;
            const pageEnd = pageStart + this.props.channelsPerPage;
            const channelsToDisplay = this.props.channels.slice(pageStart, pageEnd);
            listContent = channelsToDisplay.map(this.createChannelRow);

            if (channelsToDisplay.length >= this.props.channelsPerPage) {
                nextButton = (
                    <button
                        className='btn btn-default filter-control filter-control__next'
                        onClick={this.nextPage}
                        disabled={this.state.nextDisabled}
                    >
                        <FormattedMessage
                            id='more_channels.next'
                            defaultMessage='Next'
                        />
                    </button>
                );
            }

            if (this.state.page > 0) {
                previousButton = (
                    <button
                        className='btn btn-default filter-control filter-control__prev'
                        onClick={this.previousPage}
                    >
                        <FormattedMessage
                            id='more_channels.prev'
                            defaultMessage='Previous'
                        />
                    </button>
                );
            }
        }

        return (
            <div className='filtered-user-list'>
                <div className='filter-row'>
                    <div className='col-sm-12'>
                        <input
                            ref='filter'
                            className='form-control filter-textbox'
                            placeholder={localizeMessage('filtered_channels_list.search', 'Search channels')}
                            onInput={this.doSearch}
                        />
                    </div>
                </div>
                <div
                    ref='channelList'
                    className='more-modal__list'
                >
                    <div ref='channelListScroll'>
                        {listContent}
                    </div>
                </div>
                <div className='filter-controls'>
                    {previousButton}
                    {nextButton}
                </div>
            </div>
        );
    }
}

SearchableChannelList.defaultProps = {
    channels: []
};

SearchableChannelList.propTypes = {
    channels: React.PropTypes.arrayOf(React.PropTypes.object),
    channelsPerPage: React.PropTypes.number,
    nextPage: React.PropTypes.func.isRequired,
    search: React.PropTypes.func.isRequired,
    handleJoin: React.PropTypes.func.isRequired,
    noResultsText: React.PropTypes.object
};
