import React from 'react';
import {
    Animated,
    Keyboard,
    SafeAreaView,
    TextInput,
    TouchableHighlight,
    TouchableOpacity,
    View
} from 'react-native';
import Permissions from 'react-native-permissions';
import { connect } from 'react-redux';

import { translate } from '../../base/i18n';
import { Icon } from '../../base/font-icons';
import { MEDIA_TYPE } from '../../base/media';
import { Header, LoadingIndicator, Text } from '../../base/react';
import { ColorPalette } from '../../base/styles';
import {
    createDesiredLocalTracks,
    destroyLocalTracks
} from '../../base/tracks';
import { SettingsView } from '../../settings';

import { AbstractWelcomePage, _mapStateToProps } from './AbstractWelcomePage';
import { setSideBarVisible } from '../actions';
import LocalVideoTrackUnderlay from './LocalVideoTrackUnderlay';
import styles, { PLACEHOLDER_TEXT_COLOR } from './styles';
import VideoSwitch from './VideoSwitch';
import WelcomePageLists from './WelcomePageLists';
import WelcomePageSideBar from './WelcomePageSideBar';

/**
 * The native container rendering the welcome page.
 *
 * @extends AbstractWelcomePage
 */
class WelcomePage extends AbstractWelcomePage {
    /**
     * Constructor of the Component.
     *
     * @inheritdoc
     */
    constructor(props) {
        super(props);

        this.state._fieldFocused = false;
        this.state.hintBoxAnimation = new Animated.Value(0);

        // Bind event handlers so they are only bound once per instance.
        this._onFieldFocusChange = this._onFieldFocusChange.bind(this);
        this._onShowSideBar = this._onShowSideBar.bind(this);
        this._renderHintBox = this._renderHintBox.bind(this);

        // Specially bind functions to avoid function definition on render.
        this._onFieldBlur = this._onFieldFocusChange.bind(this, false);
        this._onFieldFocus = this._onFieldFocusChange.bind(this, true);
    }

    /**
     * Implements React's {@link Component#componentWillMount()}. Invoked
     * immediately before mounting occurs. Creates a local video track if none
     * is available and the camera permission was already granted.
     *
     * @inheritdoc
     * @returns {void}
     */
    componentWillMount() {
        super.componentWillMount();

        const { dispatch } = this.props;

        if (this.props._settings.startAudioOnly) {
            dispatch(destroyLocalTracks());
        } else {
            // Make sure we don't request the permission for the camera from
            // the start. We will, however, create a video track iff the user
            // already granted the permission.
            Permissions.check('camera').then(response => {
                response === 'authorized'
                    && dispatch(createDesiredLocalTracks(MEDIA_TYPE.VIDEO));
            });
        }
    }

    /**
     * Implements React's {@link Component#render()}. Renders a prompt for
     * entering a room name.
     *
     * @inheritdoc
     * @returns {ReactElement}
     */
    render() {
        const { buttonStyle, pageStyle } = Header;
        const roomnameAccLabel = 'welcomepage.accessibilityLabel.roomname';
        const { t } = this.props;

        return (
            <LocalVideoTrackUnderlay style = { styles.welcomePage }>
                <View style = { pageStyle }>
                    <Header style = { styles.header }>
                        <TouchableOpacity onPress = { this._onShowSideBar } >
                            <Icon
                                name = 'menu'
                                style = { buttonStyle } />
                        </TouchableOpacity>
                        <VideoSwitch />
                    </Header>
                    <SafeAreaView style = { styles.roomContainer } >
                        <View style = { styles.joinControls } >
                            <TextInput
                                accessibilityLabel = { t(roomnameAccLabel) }
                                autoCapitalize = 'none'
                                autoComplete = { false }
                                autoCorrect = { false }
                                autoFocus = { false }
                                onBlur = { this._onFieldBlur }
                                onChangeText = { this._onRoomChange }
                                onFocus = { this._onFieldFocus }
                                onSubmitEditing = { this._onJoin }
                                placeholder = { t('welcomepage.roomname') }
                                placeholderTextColor = {
                                    PLACEHOLDER_TEXT_COLOR
                                }
                                returnKeyType = { 'go' }
                                style = { styles.textInput }
                                underlineColorAndroid = 'transparent'
                                value = { this.state.room } />
                            {
                                this._renderHintBox()
                            }
                        </View>
                    </SafeAreaView>
                    <WelcomePageLists disabled = { this.state._fieldFocused } />
                    <SettingsView />
                </View>
                <WelcomePageSideBar />
            </LocalVideoTrackUnderlay>
        );
    }

    /**
     * Constructs a style array to handle the hint box animation.
     *
     * @private
     * @returns {Array<Object>}
     */
    _getHintBoxStyle() {
        return [
            styles.hintContainer,
            {
                opacity: this.state.hintBoxAnimation
            }
        ];
    }

    /**
     * Callback for when the room field's focus changes so the hint box
     * must be rendered or removed.
     *
     * @private
     * @param {boolean} focused - The focused state of the field.
     * @returns {void}
     */
    _onFieldFocusChange(focused) {
        focused
            && this.setState({
                _fieldFocused: true
            });

        Animated.timing(
            this.state.hintBoxAnimation,
            {
                duration: 300,
                toValue: focused ? 1 : 0
            })
            .start(animationState =>
                animationState.finished
                    && !focused
                    && this.setState({
                        _fieldFocused: false
                    }));
    }

    /**
     * Toggles the side bar.
     *
     * @private
     * @returns {void}
     */
    _onShowSideBar() {
        Keyboard.dismiss();
        this.props.dispatch(setSideBarVisible(true));
    }

    /**
     * Renders the hint box if necessary.
     *
     * @private
     * @returns {React$Node}
     */
    _renderHintBox() {
        if (this.state._fieldFocused) {
            const { t } = this.props;

            return (
                <Animated.View style = { this._getHintBoxStyle() }>
                    <View style = { styles.hintTextContainer } >
                        <Text style = { styles.hintText }>
                            { t('welcomepage.roomnameHint') }
                        </Text>
                    </View>
                    <View style = { styles.hintButtonContainer } >
                        { this._renderJoinButton() }
                    </View>
                </Animated.View>
            );
        }

        return null;
    }

    /**
     * Renders the join button.
     *
     * @private
     * @returns {ReactElement}
     */
    _renderJoinButton() {
        const { t } = this.props;
        let children;


        if (this.state.joining) {
            // TouchableHighlight is picky about what its children can be, so
            // wrap it in a native component, i.e. View to avoid having to
            // modify non-native children.
            children = (
                <View>
                    <LoadingIndicator
                        color = { styles.buttonText.color }
                        size = 'small' />
                </View>
            );
        } else {
            children = (
                <Text style = { styles.buttonText }>
                    { this.props.t('welcomepage.join') }
                </Text>
            );
        }


        const buttonDisabled = this._isJoinDisabled();

        return (
            <TouchableHighlight
                accessibilityLabel =
                    { t('welcomepage.accessibilityLabel.join') }
                disabled = { buttonDisabled }
                onPress = { this._onJoin }
                style = { [
                    styles.button,
                    buttonDisabled ? styles.buttonDisabled : null
                ] }
                underlayColor = { ColorPalette.white }>
                { children }
            </TouchableHighlight>
        );
    }
}

export default translate(connect(_mapStateToProps)(WelcomePage));