const React = require('react');
const cx = require('classnames');

const {Icon} = require('../Icon');
const {SearchActions} = require('./SearchActions');

const DOWN_ARROW_KEY_CODE = 40;
const UP_ARROW_KEY_CODE = 38;
const ENTER_KEY_CODE = 13;

class SearchBar extends React.Component {
  static defaultProps = {
    underlay: false,
    heading: false,
    open: false
  }

  constructor(props) {
    super(props);
    this.state = {
      inputClassName: [],
      searchTerm: this._determineSearchTerm() || '',
      selectedSuggestionIdx: -1,
      suggestions: []
    }
  }

  componentDidMount() {
    SearchActions.getSuggestions.completed.listen(this._onGetSuggestionsCompleted);
    this.input.addEventListener('keydown', this._handleKeyDown);

    const underlay = this.underlay;
    underlay && underlay.addEventListener('click', this._handleClickAway);
  }

  componentWillUnmount() {
    this.input.removeEventListener('keydown', this._handleKeyDown);

    const underlay = this.underlay;
    underlay && underlay.removeEventListener('click', this._handleClickAway);
  }

  componentWillReceiveProps(newProps) {
    if (newProps.open || newProps.active) { this._autoFocus(); }
  }

  _determineSearchTerm() {
    const urlParams = location.search.substring(1).split('&');
    const query = urlParams.filter(set => set.split('=')[0] === 'q');
    return query.length && decodeURIComponent(query[0].split('=')[1]);
  }

  _autoFocus = () => {
    this.input.focus();

    // Force the cursor to go to the end of the input text
    this.input.value = this.state.searchTerm;
  }

  autoFocus = () => {
    this._autoFocus();
  }

  _unFocus = () => {
    this.input.blur();
  }

  unFocus = () => {
    this._unFocus();
  }

  _wiggle = () => {
    this._autoFocus();
    this._addInputClass('wiggle');
    window.setTimeout(() => this._removeInputClass('wiggle'), 1000);
  }

  wiggle = () => {
    this._wiggle();
  }

  _addInputClass = (className) => {
    this.setState({
      inputClassName: this.state.inputClassName.concat(className)});
  }

  _removeInputClass = (className) => {
    this.setState({
      inputClassName: this.state.inputClassName.filter(cn => cn !== className)});
  }

  _onGetSuggestionsCompleted = response => {
    this.setState({
      suggestions: response,
      selectedSuggestionIdx: !response.length ?
          -1
        : this.state.selectedSuggestionIdx
    });
  }

  _handleClickAway = (event) => {
    const {handleClickAway} = this.props;
    handleClickAway(event);
  }

  _handleFormInput = (event) => {
    SearchActions.getSuggestions(event.target.value, this.props.config);
    this.setState({searchTerm: event.target.value});
  }

  _handleClickSuggestion = (suggestion) => {
    this.setState({searchTerm: suggestion}, () => this._handleSubmitForm());
  }

  _handleKeyDown = (event) => {
    const {searchTerm, selectedSuggestionIdx, suggestions} = this.state;

    if (event.which === DOWN_ARROW_KEY_CODE) {
      this._handleMoveDownSelection();
    }
    else if (event.which === UP_ARROW_KEY_CODE) {
      this._handleMoveUpSelection();
    }
    else if (event.which === ENTER_KEY_CODE) {
      this._handleSubmitForm();
    }
  }

  _handleMoveDownSelection = () => {
    const {selectedSuggestionIdx, suggestions} = this.state;
    const newIdx = Math.min(
        selectedSuggestionIdx + 1, suggestions.length - 1);
    this.setState({
      selectedSuggestionIdx: newIdx,
      searchTerm: suggestions[newIdx].text
    });
  }

  _handleMoveUpSelection = () => {
    const {selectedSuggestionIdx, suggestions} = this.state;
    const newIdx = Math.max(selectedSuggestionIdx - 1, 0);
    this.setState({
      selectedSuggestionIdx: newIdx,
      searchTerm: suggestions[newIdx].text
    });
  }

  _handleSuggestionMouseEnter = (idx) => {
    this.setState({
      selectedSuggestionIdx: idx,
      searchTerm: this.state.suggestions[idx].text
    });
  }

  _handleClearInput = () => {
    this.setState({
      searchTerm: '',
      selectedSuggestionIdx: -1,
      suggestions: []
    });
    this._autoFocus();
  }

  _handleSubmitForm = (event) => {
    if (event) {
      event.preventDefault();
    }
    const {config} = this.props;

    window.location = `${config.projects.url}/search?q=${
      encodeURIComponent(this.state.searchTerm)}`;
  }

  render() {
    const {active, className, config, heading, underlay, open} = this.props;
    const {
      inputClassName, searchTerm, selectedSuggestionIdx, suggestions
    } = this.state;

    return (
      <div className={cx("search-bar", className)}>
        {underlay &&
          <div className="search-underlay" ref={ref => this.underlay = ref}/>}
        <div className="search-form-container">
          <form
              className="search-form"
              onSubmit={this._handleSubmitForm}>
            <Icon name="search" className="icon-search"/>
            <input
                className={cx("search-input", inputClassName)}
                ref={ref => this.input = ref}
                type="text"
                placeholder="Search"
                onChange={this._handleFormInput}
                value={searchTerm}/>
            {!!searchTerm.length &&
              <Icon
                  name="close"
                  className="icon-close"
                  onClick={this._handleClearInput}/>
            }
          </form>
          <a
              className={cx(
                "search-home-link",
                {"search-home-link__active-hidden": !searchTerm.length})}
              href={`${config.projects.url}/search`}>
            Browse by topic
            <Icon name="navigateright"/>
          </a>
        </div>
        {!!suggestions.length &&
          <div className="search-suggestions">
            {suggestions.map((term, idx) => (
              <div
                  key={term.text}
                  className={cx(
                    "suggestion-item",
                    {"suggestion-item__active": idx === selectedSuggestionIdx})}
                  onClick={this._handleSubmitForm}
                  onMouseEnter={e => this._handleSuggestionMouseEnter(idx)}>
                <p>{term.text}</p>
              </div>))
            }
          </div>
        }
      </div>
      )
  }
}

module.exports = {SearchBar}