content: import React from 'react';
  import ImmutablePropTypes from 'react-immutable-proptypes';
  import PropTypes from 'prop-types';
  import { is } from 'immutable';
  import IconButton from './icon_button';
  import { defineMessages, injectIntl, FormattedMessage } from 'react-intl';
  import { isIOS } from 'flavours/glitch/util/is_mobile';
  import classNames from 'classnames';
  import { autoPlayGif, displayMedia, useBlurhash } from 'flavours/glitch/util/initial_state';
  import { debounce } from 'lodash';
  import Blurhash from 'flavours/glitch/components/blurhash';
  
  const messages = defineMessages({
    hidden: {
      defaultMessage: 'Media hidden',
      id: 'status.media_hidden',
    },
    sensitive: {
      defaultMessage: 'Sensitive',
      id: 'media_gallery.sensitive',
    },
    toggle: {
      defaultMessage: 'Click to view',
      id: 'status.sensitive_toggle',
    },
    toggle_visible: {
      defaultMessage: '{number, plural, one {Hide image} other {Hide images}}',
      id: 'media_gallery.toggle_visible',
    },
    warning: {
      defaultMessage: 'Sensitive content',
      id: 'status.sensitive_warning',
    },
  });
  
  class Item extends React.PureComponent {
  
    static propTypes = {
      attachment: ImmutablePropTypes.map.isRequired,
      standalone: PropTypes.bool,
      index: PropTypes.number.isRequired,
      size: PropTypes.number.isRequired,
      letterbox: PropTypes.bool,
      onClick: PropTypes.func.isRequired,
      displayWidth: PropTypes.number,
      visible: PropTypes.bool.isRequired,
      autoplay: PropTypes.bool,
    };
  
    static defaultProps = {
      standalone: false,
      index: 0,
      size: 1,
    };
  
    state = {
      loaded: false,
    };
  
    handleMouseEnter = (e) => {
      if (this.hoverToPlay()) {
        e.target.play();
      }
    }
  
    handleMouseLeave = (e) => {
      if (this.hoverToPlay()) {
        e.target.pause();
        e.target.currentTime = 0;
      }
    }
  
    getAutoPlay() {
      return this.props.autoplay || autoPlayGif;
    }
  
    hoverToPlay () {
      const { attachment } = this.props;
      return !this.getAutoPlay() && attachment.get('type') === 'gifv';
    }
  
    handleClick = (e) => {
      const { index, onClick } = this.props;
  
      if (e.button === 0 && !(e.ctrlKey || e.metaKey)) {
        if (this.hoverToPlay()) {
          e.target.pause();
          e.target.currentTime = 0;
        }
        e.preventDefault();
        onClick(index);
      }
  
      e.stopPropagation();
    }
  
    handleImageLoad = () => {
      this.setState({ loaded: true });
    }
  
    render () {
      const { attachment, index, size, standalone, letterbox, displayWidth, visible } = this.props;
  
      let width  = 50;
      let height = 100;
      let top    = 'auto';
      let left   = 'auto';
      let bottom = 'auto';
      let right  = 'auto';
  
      if (size === 1) {
        width = 100;
      }
  
      if (size === 4 || (size === 3 && index > 0)) {
        height = 50;
      }
  
      if (size === 2) {
        if (index === 0) {
          right = '2px';
        } else {
          left = '2px';
        }
      } else if (size === 3) {
        if (index === 0) {
          right = '2px';
        } else if (index > 0) {
          left = '2px';
        }
  
        if (index === 1) {
          bottom = '2px';
        } else if (index > 1) {
          top = '2px';
        }
      } else if (size === 4) {
        if (index === 0 || index === 2) {
          right = '2px';
        }
  
        if (index === 1 || index === 3) {
          left = '2px';
        }
  
        if (index < 2) {
          bottom = '2px';
        } else {
          top = '2px';
        }
      }
  
      let thumbnail = '';
  
      if (attachment.get('type') === 'unknown') {
        return (
          <div className={classNames('media-gallery__item', { standalone })} key={attachment.get('id')} style={{ left: left, top: top, right: right, bottom: bottom, width: `${width}%`, height: `${height}%` }}>
            <a className='media-gallery__item-thumbnail' href={attachment.get('remote_url') || attachment.get('url')} style={{ cursor: 'pointer' }} title={attachment.get('description')} target='_blank' rel='noopener noreferrer'>
              <Blurhash
                hash={attachment.get('blurhash')}
                className='media-gallery__preview'
                dummy={!useBlurhash}
              />
            </a>
          </div>
        );
      } else if (attachment.get('type') === 'image') {
        const previewUrl   = attachment.get('preview_url');
        const previewWidth = attachment.getIn(['meta', 'small', 'width']);
  
        const originalUrl   = attachment.get('url');
        const originalWidth = attachment.getIn(['meta', 'original', 'width']);
  
        const hasSize = typeof originalWidth === 'number' && typeof previewWidth === 'number';
  
        const srcSet = hasSize ? `${originalUrl} ${originalWidth}w, ${previewUrl} ${previewWidth}w` : null;
        const sizes  = hasSize && (displayWidth > 0) ? `${displayWidth * (width / 100)}px` : null;
  
        const focusX = attachment.getIn(['meta', 'focus', 'x']) || 0;
        const focusY = attachment.getIn(['meta', 'focus', 'y']) || 0;
        const x      = ((focusX /  2) + .5) * 100;
        const y      = ((focusY / -2) + .5) * 100;
  
        thumbnail = (
          <a
            className='media-gallery__item-thumbnail'
            href={attachment.get('remote_url') || originalUrl}
            onClick={this.handleClick}
            target='_blank'
            rel='noopener noreferrer'
          >
            <img
              className={letterbox ? 'letterbox' : null}
              src={previewUrl}
              srcSet={srcSet}
              sizes={sizes}
              alt={attachment.get('description')}
              title={attachment.get('description')}
              style={{ objectPosition: letterbox ? null : `${x}% ${y}%` }}
              onLoad={this.handleImageLoad}
            />
          </a>
        );
      } else if (attachment.get('type') === 'gifv') {
        const autoPlay = !isIOS() && this.getAutoPlay();
  
        thumbnail = (
          <div className={classNames('media-gallery__gifv', { autoplay: autoPlay })}>
            <video
              className={`media-gallery__item-gifv-thumbnail${letterbox ? ' letterbox' : ''}`}
              aria-label={attachment.get('description')}
              title={attachment.get('description')}
              role='application'
              src={attachment.get('url')}
              onClick={this.handleClick}
              onMouseEnter={this.handleMouseEnter}
              onMouseLeave={this.handleMouseLeave}
              autoPlay={autoPlay}
              loop
              muted
            />
  
            <span className='media-gallery__gifv__label'>GIF</span>
          </div>
        );
      }
  
      return (
        <div className={classNames('media-gallery__item', { standalone, letterbox })} key={attachment.get('id')} style={{ left: left, top: top, right: right, bottom: bottom, width: `${width}%`, height: `${height}%` }}>
          <Blurhash
            hash={attachment.get('blurhash')}
            dummy={!useBlurhash}
            className={classNames('media-gallery__preview', {
              'media-gallery__preview--hidden': visible && this.state.loaded,
            })}
          />
          {visible && thumbnail}
        </div>
      );
    }
  
  }
  
  export default @injectIntl
  class MediaGallery extends React.PureComponent {
  
    static propTypes = {
      sensitive: PropTypes.bool,
      standalone: PropTypes.bool,
      letterbox: PropTypes.bool,
      fullwidth: PropTypes.bool,
      hidden: PropTypes.bool,
      media: ImmutablePropTypes.list.isRequired,
      size: PropTypes.object,
      onOpenMedia: PropTypes.func.isRequired,
      intl: PropTypes.object.isRequired,
      defaultWidth: PropTypes.number,
      cacheWidth: PropTypes.func,
      visible: PropTypes.bool,
      autoplay: PropTypes.bool,
      onToggleVisibility: PropTypes.func,
    };
  
    static defaultProps = {
      standalone: false,
    };
  
    state = {
      visible: this.props.visible !== undefined ? this.props.visible : (displayMedia !== 'hide_all' && !this.props.sensitive || displayMedia === 'show_all'),
      width: this.props.defaultWidth,
    };
  
    componentDidMount () {
      window.addEventListener('resize', this.handleResize, { passive: true });
    }
  
    componentWillUnmount () {
      window.removeEventListener('resize', this.handleResize);
    }
  
    componentWillReceiveProps (nextProps) {
      if (!is(nextProps.media, this.props.media) && nextProps.visible === undefined) {
        this.setState({ visible: displayMedia !== 'hide_all' && !nextProps.sensitive || displayMedia === 'show_all' });
      } else if (!is(nextProps.visible, this.props.visible) && nextProps.visible !== undefined) {
        this.setState({ visible: nextProps.visible });
      }
    }
  
    componentDidUpdate (prevProps) {
      if (this.node) {
        this.handleResize();
      }
    }
  
    handleResize = debounce(() => {
      if (this.node) {
        this._setDimensions();
      }
    }, 250, {
      leading: true,
      trailing: true,
    });
  
    handleOpen = () => {
      if (this.props.onToggleVisibility) {
        this.props.onToggleVisibility();
      } else {
        this.setState({ visible: !this.state.visible });
      }
    }
  
    handleClick = (index) => {
      this.props.onOpenMedia(this.props.media, index);
    }
  
    handleRef = (node) => {
      this.node = node;
  
      if (this.node) {
        this._setDimensions();
      }
    }
  
    _setDimensions () {
      const width = this.node.offsetWidth;
   
      if (width && width != this.state.width) {
        // offsetWidth triggers a layout, so only calculate when we need to
        if (this.props.cacheWidth) {
          this.props.cacheWidth(width);
        }
  
        this.setState({
          width: width,
        });
      }
    }
  
    isStandaloneEligible() {
      const { media, standalone } = this.props;
      return standalone && media.size === 1 && media.getIn([0, 'meta', 'small', 'aspect']);
    }
  
    render () {
      const { media, intl, sensitive, letterbox, fullwidth, defaultWidth, autoplay } = this.props;
      const { visible } = this.state;
      const size     = media.take(4).size;
      const uncached = media.every(attachment => attachment.get('type') === 'unknown');
  
      const width = this.state.width || defaultWidth;
  
      let children, spoilerButton;
  
      const style = {};
  
      const computedClass = classNames('media-gallery', { 'full-width': fullwidth });
  
      if (this.isStandaloneEligible() && width) {
        style.height = width / this.props.media.getIn([0, 'meta', 'small', 'aspect']);
      } else if (width) {
        style.height = width / (16/9);
      } else {
        return (<div className={computedClass} ref={this.handleRef}></div>);
      }
  
      if (this.isStandaloneEligible()) {
        children = <Item standalone autoplay={autoplay} onClick={this.handleClick} attachment={media.get(0)} displayWidth={width} visible={visible} />;
      } else {
        children = media.take(4).map((attachment, i) => <Item key={attachment.get('id')} autoplay={autoplay} onClick={this.handleClick} attachment={attachment} index={i} size={size} letterbox={letterbox} displayWidth={width} visible={visible || uncached} />);
      }
  
      if (uncached) {
        spoilerButton = (
          <button type='button' disabled className='spoiler-button__overlay'>
            <span className='spoiler-button__overlay__label'><FormattedMessage id='status.uncached_media_warning' defaultMessage='Not available' /></span>
          </button>
        );
      } else if (visible) {
        spoilerButton = <IconButton title={intl.formatMessage(messages.toggle_visible, { number: size })} icon='eye-slash' overlay onClick={this.handleOpen} />;
      } else {
        spoilerButton = (
          <button type='button' onClick={this.handleOpen} className='spoiler-button__overlay'>
            <span className='spoiler-button__overlay__label'>{sensitive ? <FormattedMessage id='status.sensitive_warning' defaultMessage='Sensitive content' /> : <FormattedMessage id='status.media_hidden' defaultMessage='Media hidden' />}</span>
          </button>
        );
      }
  
      return (
        <div className={computedClass} style={style} ref={this.handleRef}>
          <div className={classNames('spoiler-button', { 'spoiler-button--minified': visible && !uncached, 'spoiler-button--click-thru': uncached })}>
            {spoilerButton}
            {visible && sensitive && (
              <span className='sensitive-marker'>
                <FormattedMessage {...messages.sensitive} />
              </span>
            )}
          </div>
  
          {children}
        </div>
      );
    }
  
  }
  