import React, { PureComponent } from 'react';
import copy from 'copy-to-clipboard';
import { ColorPicker } from './color_picker';
import {
  split_text,
  NICKNAME_RE,
  PID_RE,
  URL_RE,
  URL_PID_RE,
} from './text_splitter';
import {
  format_time,
  build_highlight_re,
  Time,
  TitleLine,
  ClickHandler,
  ColoredSpan,
  HighlightedMarkdown,
} from './Common';
import './Flows.css';
import LazyLoad, { forceCheck } from './react-lazyload/src';
import { TokenCtx, ReplyForm } from './UserAction';

import { API } from './flows_api';

const IMAGE_BASE = 'https://thimg.yecdn.com/';
const IMAGE_BAK_BASE = 'https://img2.thuhole.com/';

const CLICKABLE_TAGS = { a: true, audio: true };
const PREVIEW_REPLY_COUNT = 10;
// const QUOTE_BLACKLIST=['23333','233333','66666','666666','10086','10000','100000','99999','999999','55555','555555'];
const QUOTE_BLACKLIST = [];

window.LATEST_POST_ID = parseInt(localStorage['_LATEST_POST_ID'], 10) || 0;

const DZ_NAME = '洞主';

function load_single_meta(show_sidebar, token) {
  return async (pid, replace = false) => {
    let color_picker = new ColorPicker();
    let title_elem = '树洞 #' + pid;
    show_sidebar(
      title_elem,
      <div className="box box-tip">正在加载 #{pid}</div>,
      replace ? 'replace' : 'push',
    );
    try {
      let single = await API.get_single(pid, token);
      single.data.variant = {};
      let { data: replies } = await API.load_replies_with_cache(
        pid,
        token,
        color_picker,
        parseInt(single.data.reply),
      );
      show_sidebar(
        title_elem,
        <FlowSidebar
          key={+new Date()}
          info={single.data}
          replies={replies.data}
          attention={replies.attention}
          token={token}
          show_sidebar={show_sidebar}
          color_picker={color_picker}
          deletion_detect={localStorage['DELETION_DETECT'] === 'on'}
        />,
        'replace',
      );
    } catch (e) {
      console.error(e);
      show_sidebar(
        title_elem,
        <div className="box box-tip">
          <p>
            <a onClick={() => load_single_meta(show_sidebar, token)(pid, true)}>
              重新加载
            </a>
          </p>
          <p>{'' + e}</p>
        </div>,
        'replace',
      );
    }
  };
}

class Reply extends PureComponent {
  constructor(props) {
    super(props);
  }

  render() {
    const author = this.props.info.name,
      replyText = this.props.info.text;
    return (
      <div
        className={'flow-reply box'}
        style={
          this.props.info._display_color
            ? {
                '--box-bgcolor-light': this.props.info._display_color[0],
                '--box-bgcolor-dark': this.props.info._display_color[1],
              }
            : null
        }
      >
        <div className="box-header">
          {!!this.props.do_filter_name && (
            <span
              className="reply-header-badge clickable"
              onClick={() => {
                this.props.do_filter_name(this.props.info.name);
              }}
            >
              <span className="icon icon-locate" />
            </span>
          )}
          &nbsp;
          {(
            <span className="box-header-name">{this.props.info.name}</span>
          )}
          <Time stamp={this.props.info.timestamp} short={false} />
          &nbsp;
          <code className="box-id">{'$' + this.props.info.cid}</code>
        </div>
        <div className="box-content">
          <HighlightedMarkdown
            author={author}
            text={replyText}
            color_picker={this.props.color_picker}
            show_pid={this.props.show_pid}
          />
        </div>
      </div>
    );
  }
}

class FlowItem extends PureComponent {
  constructor(props) {
    super(props);
  }

  copy_link(event) {
    event.preventDefault();
    copy(
      `${event.target.href}${
        this.props.info.cw ? ' 【' + this.props.info.cw + '】' : ''
      }\n` +
        `${this.props.info.text}${
          this.props.info.type === 'image'
            ? ' [图片]'
            : this.props.info.type === 'audio'
            ? ' [语音]'
            : ''
        }\n` +
        `（${format_time(new Date(this.props.info.timestamp * 1000))} ${
          this.props.info.likenum
        }关注 ${this.props.info.reply}回复）\n` +
        this.props.replies
          .map((r) => (r.cw ? '【' + r.cw + '】' : '') + r.text)
          .join('\n'),
    );
  }

  render() {
    let props = this.props;
    return (
      <div className={'flow-item' + (props.is_quote ? ' flow-item-quote' : '')}>
        {!!props.is_quote && (
          <div className="quote-tip black-outline">
            <div>
              <span className="icon icon-quote" />
            </div>
            {/*<div>*/}
            {/*  <small>提到</small>*/}
            {/*</div>*/}
          </div>
        )}
        <div className="box">
          {!!window.LATEST_POST_ID &&
            parseInt(props.info.pid, 10) > window.LATEST_POST_ID && (
              <div className="flow-item-dot" />
            )}
          {!!this.props.attention && !this.props.cached && (
            <div className="flow-item-dot" />
          )}
          <div className="box-header">
            {!!this.props.do_filter_name && (
              <span
                className="reply-header-badge clickable"
                onClick={() => {
                  this.props.do_filter_name(DZ_NAME);
                }}
              >
                <span className="icon icon-locate" />
              </span>
            )}
            {!!parseInt(props.info.likenum, 10) && (
              <span className="box-header-badge">
                {props.info.likenum}&nbsp;
                <span
                  className={
                    'icon icon-' + (props.attention ? 'star-ok' : 'star')
                  }
                />
              </span>
            )}
            {!!parseInt(props.info.reply, 10) && (
              <span className="box-header-badge">
                {props.info.reply}&nbsp;
                <span className="icon icon-reply" />
              </span>
            )}
            <code className="box-id">
              <a
                href={'##' + props.info.pid}
                onClick={this.copy_link.bind(this)}
              >
                #{props.info.pid}
              </a>
            </code>
            &nbsp;
            {props.info.cw !== null && (
              <span className="box-header-cw">{props.info.cw}</span>
            )}
            <Time stamp={props.info.timestamp} short={!props.img_clickable} />
          </div>
          <div className="box-content">
            <HighlightedMarkdown
              text={props.info.text}
              color_picker={props.color_picker}
              show_pid={props.show_pid}
            />
            {props.info.type === 'image' && (
              <p className="img">
                {props.img_clickable ? (
                  <a
                    className="no-underline"
                    href={IMAGE_BASE + props.info.url}
                    target="_blank"
                  >
                    <img
                      src={IMAGE_BASE + props.info.url}
                      onError={(e) => {
                        if (e.target.src === IMAGE_BASE + props.info.url) {
                          e.target.src = IMAGE_BAK_BASE + props.info.url;
                        }
                      }}
                      alt={IMAGE_BASE + props.info.url}
                    />
                  </a>
                ) : (
                  <img
                    src={IMAGE_BASE + props.info.url}
                    onError={(e) => {
                      if (e.target.src === IMAGE_BASE + props.info.url) {
                        e.target.src = IMAGE_BAK_BASE + props.info.url;
                      }
                    }}
                    alt={IMAGE_BASE + props.info.url}
                  />
                )}
              </p>
            )}
            {/*{props.info.type==='audio' && <AudioWidget src={AUDIO_BASE+props.info.url} />}*/}
          </div>
          {!!(props.attention && props.info.variant.latest_reply) && (
            <p className="box-footer">
              最新回复{' '}
              <Time stamp={props.info.variant.latest_reply} short={false} />
            </p>
          )}
        </div>
      </div>
    );
  }
}

class FlowSidebar extends PureComponent {
  constructor(props) {
    super(props);
    this.state = {
      attention: props.attention,
      info: props.info,
      replies: props.replies,
      loading_status: 'done',
      error_msg: null,
      filter_name: null,
      rev: false,
    };
    this.color_picker = props.color_picker;
    this.syncState = props.sync_state || (() => {});
    this.reply_ref = React.createRef();
  }

  set_variant(cid, variant) {
    this.setState(
      (prev) => {
        if (cid)
          return {
            replies: prev.replies.map((reply) => {
              if (reply.cid === cid)
                return Object.assign({}, reply, {
                  variant: Object.assign({}, reply.variant, variant),
                });
              else return reply;
            }),
          };
        else
          return {
            info: Object.assign({}, prev.info, {
              variant: Object.assign({}, prev.info.variant, variant),
            }),
          };
      },
      function () {
        this.syncState({
          info: this.state.info,
          replies: this.state.replies,
        });
      },
    );
  }

  load_replies(update_count = true) {
    this.setState({
      loading_status: 'loading',
      error_msg: null,
    });
    API.load_replies(
      this.state.info.pid,
      this.props.token,
      this.color_picker,
      null,
    )
      .then((json) => {
        this.setState(
          (prev, props) => ({
            replies: json.data,
            info: update_count
              ? Object.assign({}, prev.info, {
                  reply: '' + json.data.length,
                })
              : prev.info,
            attention: !!json.attention,
            loading_status: 'done',
            error_msg: null,
          }),
          () => {
            this.syncState({
              replies: this.state.replies,
              attention: this.state.attention,
              info: this.state.info,
            });
            if (this.state.replies.length)
              this.set_variant(null, {
                latest_reply: Math.max.apply(
                  null,
                  this.state.replies.map((r) => parseInt(r.timestamp)),
                ),
              });
          },
        );
      })
      .catch((e) => {
        console.error(e);
        this.setState({
          replies: [],
          loading_status: 'done',
          error_msg: '' + e,
        });
      });
  }

  toggle_attention() {
    this.setState({
      loading_status: 'loading',
    });
    const next_attention = !this.state.attention;
    API.set_attention(this.state.info.pid, next_attention, this.props.token)
      .then((json) => {
        this.setState({
          loading_status: 'done',
          attention: next_attention,
        });
        this.syncState({
          attention: next_attention,
        });
      })
      .catch((e) => {
        this.setState({
          loading_status: 'done',
        });
        alert('设置关注失败');
        console.error(e);
      });
  }

  report() {
    let reason = prompt(`举报 #${this.state.info.pid} 的理由：`);
    if (reason !== null) {
      API.report(this.state.info.pid, reason, this.props.token)
        .then((json) => {
          alert('举报成功');
        })
        .catch((e) => {
          alert('举报失败');
          console.error(e);
        });
    }
  }

  set_filter_name(name) {
    this.setState((prevState) => ({
      filter_name: name === prevState.filter_name ? null : name,
    }));
  }

  toggle_rev() {
    this.setState((prevState) => ({ rev: !prevState.rev }), forceCheck);
  }

  show_reply_bar(name, event) {
    if (this.reply_ref.current && !event.target.closest('a, .clickable')) {
      let text = this.reply_ref.current.get();
      if (
        /^\s*(?:Re (?:|洞主|(?:[A-Z][a-z]+ )?(?:[A-Z][a-z]+)|You Win(?: \d+)?):)?\s*$/.test(
          text,
        )
      ) {
        // text is nearly empty so we can replace it
        let should_text = 'Re ' + name + ': ';
        if (should_text === this.reply_ref.current.get())
          this.reply_ref.current.set('');
        else this.reply_ref.current.set(should_text);
      }
    }
  }

  render() {
    if (this.state.loading_status === 'loading')
      return <p className="box box-tip">加载中……</p>;

    let show_pid = load_single_meta(this.props.show_sidebar, this.props.token);

    let replies_to_show = this.state.filter_name
      ? this.state.replies.filter((r) => r.name === this.state.filter_name)
      : this.state.replies.slice();
    if (this.state.rev) replies_to_show.reverse();

    // may not need key, for performance
    // key for lazyload elem
    // let view_mode_key =
    //   (this.state.rev ? 'y-' : 'n-') + (this.state.filter_name || 'null');

    let replies_cnt = { [DZ_NAME]: 1 };
    replies_to_show.forEach((r) => {
      if (replies_cnt[r.name] === undefined) replies_cnt[r.name] = 0;
      replies_cnt[r.name]++;
    });

    // hide main thread when filtered
    let main_thread_elem =
      this.state.filter_name && this.state.filter_name !== DZ_NAME ? null : (
        <ClickHandler
          callback={(e) => {
            this.show_reply_bar('', e);
          }}
        >
          <FlowItem
            info={this.state.info}
            attention={this.state.attention}
            img_clickable={true}
            color_picker={this.color_picker}
            show_pid={show_pid}
            replies={this.state.replies}
            set_variant={(variant) => {
              this.set_variant(null, variant);
            }}
            do_filter_name={
              replies_cnt[DZ_NAME] > 1 ? this.set_filter_name.bind(this) : null
            }
          />
        </ClickHandler>
      );

    return (
      <div className="flow-item-row sidebar-flow-item">
        <div className="box box-tip">
          {!!this.props.token && (
            <span>
              <a onClick={this.report.bind(this)}>
                <span className="icon icon-flag" />
                <label>举报</label>
              </a>
              &nbsp;&nbsp;
            </span>
          )}
          <a onClick={this.load_replies.bind(this)}>
            <span className="icon icon-refresh" />
            <label>刷新</label>
          </a>
          {(this.state.replies.length >= 1 || this.state.rev) && (
            <span>
              &nbsp;&nbsp;
              <a onClick={this.toggle_rev.bind(this)}>
                <span className="icon icon-order-rev" />
                <label>{this.state.rev ? '还原' : '逆序'}</label>
              </a>
            </span>
          )}
          {!!this.props.token && (
            <span>
              &nbsp;&nbsp;
              <a
                onClick={() => {
                  this.toggle_attention();
                }}
              >
                {this.state.attention ? (
                  <span>
                    <span className="icon icon-star-ok" />
                    <label>已关注</label>
                  </span>
                ) : (
                  <span>
                    <span className="icon icon-star" />
                    <label>未关注</label>
                  </span>
                )}
              </a>
            </span>
          )}
        </div>
        {!!this.state.filter_name && (
          <div className="box box-tip flow-item filter-name-bar">
            <p>
              <span style={{ float: 'left' }}>
                <a
                  onClick={() => {
                    this.set_filter_name(null);
                  }}
                >
                  还原
                </a>
              </span>
              <span className="icon icon-locate" />
              &nbsp;当前只看&nbsp;
              <ColoredSpan
                colors={this.color_picker.get(this.state.filter_name)}
              >
                {this.state.filter_name}
              </ColoredSpan>
            </p>
          </div>
        )}
        {!this.state.rev && main_thread_elem}
        {!!this.state.error_msg && (
          <div className="box box-tip flow-item">
            <p>回复加载失败</p>
            <p>{this.state.error_msg}</p>
          </div>
        )}
        {this.props.deletion_detect &&
          parseInt(this.state.info.reply) > this.state.replies.length &&
          !!this.state.replies.length && (
            <div className="box box-tip flow-item box-danger">
              {parseInt(this.state.info.reply) - this.state.replies.length}{' '}
              条回复被删除
            </div>
          )}
        {replies_to_show.map((reply, i) => (
          <LazyLoad
            key={i}
            offset={1500}
            height="5em"
            overflow={true}
            once={true}
          >
            <ClickHandler
              callback={(e) => {
                this.show_reply_bar(reply.name, e);
              }}
            >
              <Reply
                info={reply}
                color_picker={this.color_picker}
                show_pid={show_pid}
                set_variant={(variant) => {
                  this.set_variant(reply.cid, variant);
                }}
                do_filter_name={
                  replies_cnt[reply.name] > 1
                    ? this.set_filter_name.bind(this)
                    : null
                }
              />
            </ClickHandler>
          </LazyLoad>
        ))}
        {this.state.rev && main_thread_elem}
        {this.props.token ? (
          <ReplyForm
            pid={this.state.info.pid}
            token={this.props.token}
            area_ref={this.reply_ref}
            on_complete={this.load_replies.bind(this)}
          />
        ) : (
          <div className="box box-tip flow-item">登录后可以回复树洞</div>
        )}
      </div>
    );
  }
}

class FlowItemRow extends PureComponent {
  constructor(props) {
    super(props);
    this.needFold = props.info.cw &&
      (props.search_param === '热榜' || !props.search_param) &&
      window.config.fold &&
      props.mode !== 'attention' && props.mode !== 'attention_finished';
    this.state = {
      replies: [],
      reply_status: 'done',
      reply_error: null,
      info: Object.assign({}, props.info, { variant: {} }),
      hidden: window.config.block_words.some((word) =>
        props.info.text.includes(word),
      ) || this.needFold,
      attention:
        props.attention_override === null ? false : props.attention_override,
      cached: true, // default no display anything
    };
    this.color_picker = new ColorPicker();
  }

  componentDidMount() {
    if (parseInt(this.state.info.reply, 10)) {
      this.load_replies(null, /*update_count=*/ false);
    }
  }

  // reveal() {
  //   this.setState({ hidden: false });
  // }

  load_replies(callback, update_count = true) {
    console.log('fetching reply', this.state.info.pid);
    this.setState({
      reply_status: 'loading',
      reply_error: null,
    });
    API.load_replies_with_cache(
      this.state.info.pid,
      this.props.token,
      this.color_picker,
      parseInt(this.state.info.reply),
    )
      .then(({ data: json, cached }) => {
        this.setState(
          (prev, props) => ({
            replies: json.data,
            info: Object.assign({}, prev.info, {
              reply: update_count ? '' + json.data.length : prev.info.reply,
              variant: json.data.length
                ? {
                    latest_reply: Math.max.apply(
                      null,
                      json.data.map((r) => parseInt(r.timestamp)),
                    ),
                  }
                : {},
            }),
            attention: !!json.attention,
            reply_status: 'done',
            reply_error: null,
            cached,
          }),
          callback,
        );
      })
      .catch((e) => {
        console.error(e);
        this.setState(
          {
            replies: [],
            reply_status: 'failed',
            reply_error: '' + e,
          },
          callback,
        );
      });
  }

  show_sidebar() {
    this.props.show_sidebar(
      '树洞 #' + this.state.info.pid,
      <FlowSidebar
        key={+new Date()}
        info={this.state.info}
        replies={this.state.replies}
        attention={this.state.attention}
        sync_state={this.setState.bind(this)}
        token={this.props.token}
        show_sidebar={this.props.show_sidebar}
        color_picker={this.color_picker}
        deletion_detect={this.props.deletion_detect}
      />,
    );
  }

  render() {
    let show_pid = load_single_meta(this.props.show_sidebar, this.props.token, [
      this.state.info.pid,
    ]);

    let hl_rules = [
      ['url_pid', URL_PID_RE],
      ['url', URL_RE],
      ['pid', PID_RE],
      ['nickname', NICKNAME_RE],
    ];
    if (this.props.search_param) {
      hl_rules.push([
        'search',
        !!this.props.search_param.match(/\/.+\//)
          ? build_highlight_re(this.props.search_param, ' ', 'gi', true) // Use regex
          : build_highlight_re(this.props.search_param, ' ', 'gi'), // Don't use regex
      ]);
    }
    let parts = split_text(this.state.info.text, hl_rules);

    let quote_id = null;
    if (!this.props.is_quote)
      for (let [mode, content] of parts) {
        content = content.length > 0 ? content.substring(1) : content;
        if (
          mode === 'pid' &&
          QUOTE_BLACKLIST.indexOf(content) === -1 &&
          parseInt(content) < parseInt(this.state.info.pid)
        )
          if (quote_id === null) quote_id = parseInt(content);
          else {
            quote_id = null;
            break;
          }
      }

    let res = (
      <div
        className={
          'flow-item-row flow-item-row-with-prompt' +
          (this.props.is_quote ? ' flow-item-row-quote' : '')
        }
        onClick={(event) => {
          if (!CLICKABLE_TAGS[event.target.tagName.toLowerCase()])
            this.show_sidebar();
        }}
      >
        <FlowItem
          parts={parts}
          info={this.state.info}
          attention={this.state.attention}
          img_clickable={false}
          is_quote={this.props.is_quote}
          color_picker={this.color_picker}
          show_pid={show_pid}
          replies={this.state.replies}
          cached={this.state.cached}
        />
        <div className="flow-reply-row">
          {this.state.reply_status === 'loading' && (
            <div className="box box-tip">加载中</div>
          )}
          {this.state.reply_status === 'failed' && (
            <div className="box box-tip">
              <p>
                <a
                  onClick={() => {
                    this.load_replies();
                  }}
                >
                  重新加载评论
                </a>
              </p>
              <p>{this.state.reply_error}</p>
            </div>
          )}
          {this.state.replies.slice(0, PREVIEW_REPLY_COUNT).map((reply) => (
            <Reply
              key={reply.cid}
              info={reply}
              color_picker={this.color_picker}
              show_pid={show_pid}
            />
          ))}
          {this.state.replies.length > PREVIEW_REPLY_COUNT && (
            <div className="box box-tip">
              还有 {this.state.replies.length - PREVIEW_REPLY_COUNT} 条
            </div>
          )}
        </div>
      </div>
    );

    if (this.state.hidden) {
      return (
        <div
          className="flow-item-row flow-item-row-with-prompt"
          onClick={(event) => {
            if (!CLICKABLE_TAGS[event.target.tagName.toLowerCase()])
              this.show_sidebar();
          }}
        >
          <div
            className={
              'flow-item' + (this.props.is_quote ? ' flow-item-quote' : '')
            }
          >
            {!!this.props.is_quote && (
              <div className="quote-tip black-outline">
                <div>
                  <span className="icon icon-quote" />
                </div>
                {/*<div>*/}
                {/*  <small>提到</small>*/}
                {/*</div>*/}
              </div>
            )}
            <div className="box">
              <div className="box-header">
                {!!this.props.do_filter_name && (
                  <span
                    className="reply-header-badge clickable"
                    onClick={() => {
                      this.props.do_filter_name(DZ_NAME);
                    }}
                  >
                    <span className="icon icon-locate" />
                  </span>
                )}
                <code className="box-id">#{this.props.info.pid}</code>
                &nbsp;
                {this.props.info.cw !== null && (
                  <span className="box-header-cw">{this.props.info.cw}</span>
                )}
                <Time stamp={this.props.info.timestamp} short={true} />
                <span className="box-header-badge">
                  {this.needFold ? '已隐藏' : '已屏蔽'}
                </span>
                <div style={{ clear: 'both' }} />
              </div>
            </div>
          </div>
        </div>
      );
    }

    return quote_id ? (
      <div>
        {res}
        <FlowItemQuote
          pid={quote_id}
          show_sidebar={this.props.show_sidebar}
          token={this.props.token}
          deletion_detect={this.props.deletion_detect}
        />
      </div>
    ) : (
      res
    );
  }
}

class FlowItemQuote extends PureComponent {
  constructor(props) {
    super(props);
    this.state = {
      loading_status: 'empty',
      error_msg: null,
      info: null,
    };
  }

  componentDidMount() {
    this.load();
  }

  load() {
    this.setState(
      {
        loading_status: 'loading',
      },
      () => {
        API.get_single(this.props.pid, this.props.token)
          .then((json) => {
            this.setState({
              loading_status: 'done',
              info: json.data,
            });
          })
          .catch((err) => {
            if (('' + err).indexOf('没有这条树洞') !== -1)
              this.setState({
                loading_status: 'empty',
              });
            else
              this.setState({
                loading_status: 'error',
                error_msg: '' + err,
              });
          });
      },
    );
  }

  render() {
    if (this.state.loading_status === 'empty') return null;
    else if (this.state.loading_status === 'loading')
      return (
        <div className="aux-margin">
          <div className="box box-tip">
            <span className="icon icon-loading" />
            提到了 #{this.props.pid}
          </div>
        </div>
      );
    else if (this.state.loading_status === 'error')
      return (
        <div className="aux-margin">
          <div className="box box-tip">
            <p>
              <a onClick={this.load.bind(this)}>重新加载</a>
            </p>
            <p>{this.state.error_msg}</p>
          </div>
        </div>
      );
    // 'done'
    else
      return (
        <FlowItemRow
          info={this.state.info}
          mode={this.props.mode}
          show_sidebar={this.props.show_sidebar}
          token={this.props.token}
          is_quote={true}
          deletion_detect={this.props.deletion_detect}
        />
      );
  }
}

function FlowChunk(props) {
  return (
    <TokenCtx.Consumer>
      {({ value: token }) => (
        <div className="flow-chunk">
          {!!props.title && <TitleLine text={props.title} />}
          {props.list.map((info, ind) => (
            <LazyLoad
              key={info.pid}
              offset={500}
              height="15em"
              hiddenIfInvisible={false}
            >
              <div>
                {!!(
                  props.deletion_detect &&
                  props.mode === 'list' &&
                  ind &&
                  props.list[ind - 1].pid - info.pid > 1
                ) && (
                  <div className="flow-item-row">
                    <div className="box box-tip flow-item box-danger">
                      {props.list[ind - 1].pid - info.pid - 1} 条被删除
                    </div>
                  </div>
                )}
                <FlowItemRow
                  info={info}
                  mode={props.mode}
                  show_sidebar={props.show_sidebar}
                  token={token}
                  attention_override={
                    props.mode === 'attention_finished' ? true : null
                  }
                  deletion_detect={props.deletion_detect}
                  search_param={props.search_param}
                />
              </div>
            </LazyLoad>
          ))}
        </div>
      )}
    </TokenCtx.Consumer>
  );
}

export class Flow extends PureComponent {
  constructor(props) {
    super(props);
    this.state = {
      mode: props.mode,
      search_param: props.search_text,
      loaded_pages: 0,
      chunks: {
        title: '',
        data: [],
      },
      loading_status: 'done',
      error_msg: null,
    };
    this.on_scroll_bound = this.on_scroll.bind(this);
    window.LATEST_POST_ID = parseInt(localStorage['_LATEST_POST_ID'], 10) || 0;
  }

  load_page(page) {
    const failed = (err) => {
      console.error(err);
      console.log(err.to_string);
      this.setState((prev, props) => ({
        loaded_pages: prev.loaded_pages - 1,
        loading_status: 'failed',
        error_msg: prev.loaded_pages>1 ? '找不到更多了' : '' + err,
      }));
    };

    if (page > this.state.loaded_pages + 1) throw new Error('bad page');
    if (page === this.state.loaded_pages + 1) {
      console.log('fetching page', page);
      if (this.state.mode === 'list') {
        API.get_list(page, this.props.token)
          .then((json) => {
            if (page === 1 && json.data.length) {
              // update latest_post_id
              let max_id = -1;
              json.data.forEach((x) => {
                if (parseInt(x.pid, 10) > max_id) max_id = parseInt(x.pid, 10);
              });
              localStorage['_LATEST_POST_ID'] = '' + max_id;
            }
            this.setState((prev, props) => ({
              chunks: {
                title: 'News Feed',
                data: prev.chunks.data.concat(
                  json.data.filter(
                    (x) =>
                      prev.chunks.data.length === 0 ||
                      !prev.chunks.data
                        .slice(-100)
                        .some((p) => p.pid === x.pid),
                  ),
                ),
              },
              loading_status: 'done',
            }));
          })
          .catch(failed);
      } else if (this.state.mode === 'search') {
        API.get_search(page, this.state.search_param, this.props.token)
          .then((json) => {
            const finished = json.data.length === 0;
            this.setState((prev, props) => ({
              chunks: {
                title: 'Result for "' + this.state.search_param + '"',
                data: prev.chunks.data.concat(
                  json.data.filter(
                    (x) =>
                      prev.chunks.data.length === 0 ||
                      !prev.chunks.data
                        .slice(-100)
                        .some((p) => p.pid === x.pid),
                  ),
                ),
              },
              mode: finished ? 'search_finished' : 'search',
              loading_status: 'done',
            }));
          })
          .catch(failed);
      } else if (this.state.mode === 'single') {
        const pid = parseInt(this.state.search_param.substr(1), 10);
        API.get_single(pid, this.props.token)
          .then((json) => {
            this.setState({
              chunks: {
                title: 'PID = ' + pid,
                data: [json.data],
              },
              mode: 'single_finished',
              loading_status: 'done',
            });
          })
          .catch(failed);
      } else if (this.state.mode === 'attention') {
        let use_search = !!this.state.search_param;
        let use_regex = use_search && !!this.state.search_param.match(/\/.+\//);
        let regex_search = /.+/;
        if (use_regex) {
          try {
            regex_search = new RegExp(this.state.search_param.slice(1, -1));
          } catch (e) {
            alert(`请检查正则表达式合法性！\n${e}`);
            regex_search = /.+/;
          }
        }
        console.log(use_search, use_regex);
        API.get_attention(this.props.token)
          .then((json) => {
            this.setState({
              chunks: {
                title: `${
                  use_search
                    ? use_regex
                      ? `Result for RegEx ${regex_search.toString()} in `
                      : `Result for "${this.state.search_param}" in `
                    : ''
                }Attention List`,
                data: !use_search
                  ? json.data
                  : !use_regex
                  ? json.data.filter((post) => {
                      return this.state.search_param
                        .split(' ')
                        .every((keyword) => post.text.includes(keyword));
                    }) // Not using regex
                  : json.data.filter((post) => !!post.text.match(regex_search)), // Using regex
              },
              mode: 'attention_finished',
              loading_status: 'done',
            });
          })
          .catch(failed);
      } else {
        console.log('nothing to load');
        return;
      }

      this.setState((prev, props) => ({
        loaded_pages: prev.loaded_pages + 1,
        loading_status: 'loading',
        error_msg: null,
      }));
    }
  }

  on_scroll(event) {
    if (event.target === document) {
      const avail =
        document.body.scrollHeight - window.scrollY - window.innerHeight;
      if (avail < window.innerHeight && this.state.loading_status === 'done')
        this.load_page(this.state.loaded_pages + 1);
    }
  }

  componentDidMount() {
    this.load_page(1);
    window.addEventListener('scroll', this.on_scroll_bound);
    window.addEventListener('resize', this.on_scroll_bound);
  }
  componentWillUnmount() {
    window.removeEventListener('scroll', this.on_scroll_bound);
    window.removeEventListener('resize', this.on_scroll_bound);
  }

  render() {
    const should_deletion_detect = localStorage['DELETION_DETECT'] === 'on';
    return (
      <div className="flow-container">
        <FlowChunk
          title={this.state.chunks.title}
          list={this.state.chunks.data}
          mode={this.state.mode}
          search_param={this.state.search_param || null}
          show_sidebar={this.props.show_sidebar}
          deletion_detect={should_deletion_detect}
        />
        {this.state.loading_status === 'failed' && (
          <div className="aux-margin">
            <div className="box box-tip">
              <p>
                <a
                  onClick={() => {
                    this.load_page(this.state.loaded_pages + 1);
                  }}
                >
                  重新加载
                </a>
              </p>
              <p>{this.state.error_msg}</p>
            </div>
          </div>
        )}
        <TitleLine
          text={
            this.state.loading_status === 'loading' ? (
              <span>
                <span className="icon icon-loading" />
                &nbsp;Loading...
              </span>
            ) : (
              '🄯 2020 copyleft: hole_thu'
            )
          }
        />
      </div>
    );
  }
}