import PropTypes from "prop-types";

import { FormattedMessage } from "react-intl";

import ImmutablePropTypes from "react-immutable-proptypes";
import ImmutablePureComponent from "react-immutable-pure-component";
import { connect } from "react-redux";

import { debounce } from "lodash";

import { TimelineHint } from "mastodon/components/timeline_hint";
import BundleColumnError from "mastodon/features/ui/components/bundle_column_error";
import { normalizeForLookup } from "mastodon/reducers/accounts_map";
import { getAccountHidden } from "mastodon/selectors";

import {
  lookupAccount,
  fetchAccount,
  fetchFollowing,
  expandFollowing,
} from "../../actions/accounts";
import ColumnBackButton from "../../components/column_back_button";
import { LoadingIndicator } from "../../components/loading_indicator";
import ScrollableList from "../../components/scrollable_list";
import AccountContainer from "../../containers/account_container";
import LimitedAccountHint from "../account_timeline/components/limited_account_hint";
import HeaderContainer from "../account_timeline/containers/header_container";
import Column from "../ui/components/column";

const mapStateToProps = (state, { params: { acct, id } }) => {
  const accountId = id || state.getIn(["accounts_map", normalizeForLookup(acct)]);

  if (!accountId) {
    return {
      isLoading: true,
    };
  }

  return {
    accountId,
    remote: !!(state.getIn(["accounts", accountId, "acct"]) !== state.getIn(["accounts", accountId, "username"])),
    remoteUrl: state.getIn(["accounts", accountId, "url"]),
    isAccount: !!state.getIn(["accounts", accountId]),
    accountIds: state.getIn(["user_lists", "following", accountId, "items"]),
    hasMore: !!state.getIn(["user_lists", "following", accountId, "next"]),
    isLoading: state.getIn(["user_lists", "following", accountId, "isLoading"], true),
    suspended: state.getIn(["accounts", accountId, "suspended"], false),
    hidden: getAccountHidden(state, accountId),
    blockedBy: state.getIn(["relationships", accountId, "blocked_by"], false),
  };
};

const RemoteHint = ({ url }) => (
  <TimelineHint url={url} resource={<FormattedMessage id='timeline_hint.resources.follows' defaultMessage='Follows' />} />
);

RemoteHint.propTypes = {
  url: PropTypes.string.isRequired,
};

class Following extends ImmutablePureComponent {

  static propTypes = {
    params: PropTypes.shape({
      acct: PropTypes.string,
      id: PropTypes.string,
    }).isRequired,
    accountId: PropTypes.string,
    dispatch: PropTypes.func.isRequired,
    accountIds: ImmutablePropTypes.list,
    hasMore: PropTypes.bool,
    isLoading: PropTypes.bool,
    blockedBy: PropTypes.bool,
    isAccount: PropTypes.bool,
    suspended: PropTypes.bool,
    hidden: PropTypes.bool,
    remote: PropTypes.bool,
    remoteUrl: PropTypes.string,
    multiColumn: PropTypes.bool,
  };

  _load () {
    const { accountId, isAccount, dispatch } = this.props;

    if (!isAccount) {
      dispatch(fetchAccount(accountId));
    }
    dispatch(fetchFollowing(accountId));
  }

  componentDidMount () {
    const { params: { acct }, accountId, dispatch } = this.props;

    if (accountId) {
      this._load();
    } else {
      dispatch(lookupAccount(acct));
    }
  }

  componentDidUpdate (prevProps) {
    const { params: { acct }, accountId, dispatch } = this.props;

    if (prevProps.accountId !== accountId && accountId) {
      this._load();
    } else if (prevProps.params.acct !== acct) {
      dispatch(lookupAccount(acct));
    }
  }

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

  render () {
    const { accountId, accountIds, hasMore, blockedBy, isAccount, multiColumn, isLoading, suspended, hidden, remote, remoteUrl } = this.props;

    if (!isAccount) {
      return (
        <BundleColumnError multiColumn={multiColumn} errorType='routing' />
      );
    }

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

    let emptyMessage;

    const forceEmptyState = blockedBy || suspended || hidden;

    if (suspended) {
      emptyMessage = <FormattedMessage id='empty_column.account_suspended' defaultMessage='Account suspended' />;
    } else if (hidden) {
      emptyMessage = <LimitedAccountHint accountId={accountId} />;
    } else if (blockedBy) {
      emptyMessage = <FormattedMessage id='empty_column.account_unavailable' defaultMessage='Profile unavailable' />;
    } else if (remote && accountIds.isEmpty()) {
      emptyMessage = <RemoteHint url={remoteUrl} />;
    } else {
      emptyMessage = <FormattedMessage id='account.follows.empty' defaultMessage="This user doesn't follow anyone yet." />;
    }

    const remoteMessage = remote ? <RemoteHint url={remoteUrl} /> : null;

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

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

}

export default connect(mapStateToProps)(Following);