import React from 'react';
import { connect } from 'react-redux';
import ImmutablePureComponent from 'react-immutable-pure-component';
import PropTypes from 'prop-types';
import ImmutablePropTypes from 'react-immutable-proptypes';
import { debounce } from 'lodash';
import LoadingIndicator from '../../components/loading_indicator';
import { expandFollowing, fetchAccount, fetchFollowing } from '../../actions/accounts';
import { FormattedMessage } from 'react-intl';
import AccountContainer from '../../containers/account_container';
import Column from '../ui/components/column';
import HeaderContainer from '../account_timeline/containers/header_container';
import ColumnBackButton from '../../components/column_back_button';
import ScrollableList from '../../components/scrollable_list';
import MissingIndicator from 'mastodon/components/missing_indicator';

const mapStateToProps = (state, props) => ({
  isAccount : !!state.getIn(['accounts', props.params.accountId]),
  accountIds: state.getIn(['user_lists', 'following', props.params.accountId, 'items']),
  hasMore   : !!state.getIn(['user_lists', 'following', props.params.accountId, 'next']),
  blockedBy : state.getIn(['relationships', props.params.accountId, 'blocked_by'], false),
});

export default @connect(mapStateToProps)
class Following extends ImmutablePureComponent {

  static propTypes = {
    params            : PropTypes.object.isRequired,
    dispatch          : PropTypes.func.isRequired,
    shouldUpdateScroll: PropTypes.func,
    accountIds        : ImmutablePropTypes.list,
    hasMore           : PropTypes.bool,
    blockedBy         : PropTypes.bool,
    isAccount         : PropTypes.bool,
    multiColumn       : PropTypes.bool,
  };

  componentWillMount() {
    if (!this.props.accountIds) {
      this.props.dispatch(fetchAccount(this.props.params.accountId));
      this.props.dispatch(fetchFollowing(this.props.params.accountId));
    }
  }

  componentWillReceiveProps(nextProps) {
    if (nextProps.params.accountId !== this.props.params.accountId && nextProps.params.accountId) {
      this.props.dispatch(fetchAccount(nextProps.params.accountId));
      this.props.dispatch(fetchFollowing(nextProps.params.accountId));
    }
  }

  handleLoadMore = debounce(() => {
    this.props.dispatch(expandFollowing(this.props.params.accountId));
  }, 300, { leading: true });

  render() {
    const { shouldUpdateScroll, accountIds, hasMore, blockedBy, isAccount, multiColumn } = this.props;

    if (!isAccount) {
      return (
        <Column >
          <MissingIndicator />
        </Column >
      );
    }

    if (!accountIds) {
      return (
        <Column >
          <LoadingIndicator />
        </Column >
      );
    }

    const emptyMessage = blockedBy ? (<FormattedMessage
      id='empty_column.account_unavailable'
      defaultMessage='Profile unavailable'
    />) : (<FormattedMessage
      id='account.follows.empty'
      defaultMessage="This user doesn't follow anyone yet."
    />);

    return (
      <Column >
        <ColumnBackButton multiColumn={multiColumn} />

        <ScrollableList
          scrollKey='following'
          hasMore={hasMore}
          onLoadMore={this.handleLoadMore}
          shouldUpdateScroll={shouldUpdateScroll}
          prepend={<HeaderContainer
            accountId={this.props.params.accountId}
            hideTabs
          />}
          alwaysPrepend
          emptyMessage={emptyMessage}
          bindToDocument={!multiColumn}
        >
          {blockedBy ? [] : accountIds.map(id =>
            (<AccountContainer
              key={id}
              id={id}
              withNote={false}
            />),
          )}
        </ScrollableList >
      </Column >
    );
  }

}