import React from 'react';
import PropTypes from 'prop-types';
import { Link } from 'react-router-dom';
import * as qs from 'query-string';
import moment from 'moment';

import Message from './Message';
import Spinner from './Spinner';

import  { getMessages } from '../api';

export function Discover(props) {
  const query = {
    baseUrl: "/messages",
    pageParam: 'before_mid'
  };
  return (<Feed query={query} {...props} />)
}

export function Discussions(props) {
  const query = {
    baseUrl: "/messages/discussions",
    pageParam: 'to'
  };
  return (<Feed authRequired="true" query={query} {...props} />)
}

export function Blog(props) {
  const { user } = props.match.params;
  const query = {
    baseUrl: `/messages`,
    search: {
      uname: user
    },
    pageParam: 'before_mid'
  };
  return (<Feed query={query} {...props} />)
}

export function Tag(props) {
  const { tag } = props.match.params;
  const query = {
    baseUrl: '/messages',
    search: {
      tag: tag
    },
    pageParam: 'before_mid'
  };
  return (<Feed query={query} {...props} />)
}

export function Home(props) {
  const query = {
    baseUrl: '/home',
    pageParam: 'before_mid'
  };
  return (<Feed authRequired="true" query={query} {...props} />)
}

class Feed extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      msgs: []
    };
  }
  componentDidMount() {
    this.loadMessages(this.props.visitor.hash, this.props.location.search);
  }
  componentWillReceiveProps(nextProps) {
    if (this.props.location.search != nextProps.location.search
      || this.props.visitor != nextProps.visitor) {
      this.loadMessages(nextProps.visitor.hash, nextProps.location.search)
    }
  }
  loadMessages = (hash = '', filter = '') => {
    document.body.scrollTop = 0;
    document.documentElement.scrollTop = 0;
    this.setState({ msgs: [] })
    const filterParams = qs.parse(filter);
    let params = Object.assign({}, filterParams || {}, this.props.query.search || {});
    let url = this.props.query.baseUrl;
    if (hash) {
      params.hash = hash;
    }
    if (!params.hash && this.props.authRequired) {
      this.props.history.push('/')
    }
    getMessages(url, params)
      .then(response => {
        const { data } = response;
        const { pageParam } = this.props.query;
        const lastMessage = data.slice(-1)[0] || {};
        const pageValue = pageParam === 'before_mid' ? lastMessage.mid : moment.utc(lastMessage.updated).valueOf();
        let newFilter = Object.assign({}, filterParams);
        newFilter[pageParam] = pageValue;
        const nextpage = `?${qs.stringify(newFilter)}`;
        this.setState({ msgs: data, nextpage: nextpage })
      }).catch(ex => {
        console.log(ex);
      });
  }

  render() {
    const { tag } = qs.parse(this.props.location.search || {});
    const nodes = (
      <React.Fragment>
        {
          tag && (
            <p className="page">
              <Link to={{ pathname: `/tag/${tag}` }}>
                <span>← All posts with tag&nbsp;</span><b>{tag}</b>
              </Link>
            </p>
          )
        }
        {
          this.state.msgs.map(msg =>
            <Message key={msg.mid} data={msg} visitor={this.props.visitor} />)
        }
        {
          this.state.msgs.length >= 20 && (
            <p className="page">
              <Link to={{ pathname: this.props.location.pathname, search: this.state.nextpage }} rel="prev">Next →</Link>
            </p>
          )
        }
      </React.Fragment>
    );
    return this.state.msgs.length > 0 ? (
      <div className="msgs" id="content">{nodes}</div>
    ) : <div className="msgs" id="content"><Spinner /><Spinner /><Spinner /><Spinner /></div>;
  }
}

Feed.propTypes = {
  msgs: PropTypes.array,
  query: PropTypes.shape({
    baseUrl: PropTypes.string.isRequired,
    search: PropTypes.object,
    pageParam: PropTypes.string.isRequired
  })
};