import { searchForTerm, isValidSearchTerm } from 'discourse/lib/search';
import { createWidget } from 'discourse/widgets/widget';
import { h } from 'virtual-dom';
import DiscourseURL from 'discourse/lib/url';

const searchData = {};

export function initSearchData() {
  searchData.loading = false;
  searchData.results = {};
  searchData.noResults = false;
  searchData.term = undefined;
  searchData.typeFilter = null;
  searchData.invalidTerm = false;
  searchData.topicId = null;
}

initSearchData();

// Helps with debouncing and cancelling promises
const SearchHelper = {
  _activeSearch: null,
  _cancelSearch: null,

  // for cancelling debounced search
  cancel() {
    if (this._activeSearch) {
      this._activeSearch.abort();
    }

    this._cancelSearch = true;
    Ember.run.later(() => this._cancelSearch = false, 400);
  },

  perform(widget) {
    if (this._cancelSearch){
      this._cancelSearch = null;
      return;
    }

    if (this._activeSearch) {
      this._activeSearch.abort();
      this._activeSearch = null;
    }

    const { term, typeFilter, contextEnabled } = searchData;
    const searchContext = contextEnabled ? widget.searchContext() : null;
    const fullSearchUrl = widget.fullSearchUrl();

    if (!isValidSearchTerm(term)) {
      searchData.noResults = true;
      searchData.results = [];
      searchData.loading = false;
      searchData.invalidTerm = true;

      widget.scheduleRerender();
    } else {
      searchData.invalidTerm = false;
      this._activeSearch = searchForTerm(term, { typeFilter, searchContext, fullSearchUrl });
      this._activeSearch.then(content => {
        searchData.noResults = content.resultTypes.length === 0;

        if (content.grouped_search_result) {
          searchData.term = content.grouped_search_result.term;
        }

        searchData.results = content;

        if (searchContext && searchContext.type === 'topic') {
          widget.appEvents.trigger('post-stream:refresh', { force: true });
          searchData.topicId = searchContext.id;
        } else {
          searchData.topicId = null;
        }
      }).finally(() => {
        searchData.loading = false;
        widget.scheduleRerender();
        this._activeSearch = null;
      });
    }
  }
};

export default createWidget('search-menu', {
  tagName: 'div.search-menu',
  searchData,

  fullSearchUrl(opts) {
    const contextEnabled = searchData.contextEnabled;

    const ctx = contextEnabled ? this.searchContext() : null;
    const type = ctx ? Ember.get(ctx, 'type') : null;

    if (contextEnabled && type === 'topic') {
      return;
    }

    let url = '/search';
    const params = [];

    if (searchData.term) {
      let query = '';

      query += `q=${encodeURIComponent(searchData.term)}`;

      if (contextEnabled && ctx) {
        if (this.currentUser &&
            ctx.id.toString().toLowerCase() === this.currentUser.username_lower &&
            type === "private_messages") {
          query += ' in:private';
        } else {
          query += encodeURIComponent(" " + type + ":" + ctx.id);
        }
      }

      if (query) params.push(query);
    }

    if (opts && opts.expanded) params.push('expanded=true');

    if (params.length > 0) {
      url = `${url}?${params.join("&")}`;
    }

    return Discourse.getURL(url);
  },

  panelContents() {
    const contextEnabled = searchData.contextEnabled;

    let searchInput = [
      this.attach('search-term', { value: searchData.term, contextEnabled }),
    ];
    if (searchData.term && searchData.loading) {
      searchInput.push(h('div.searching', h('div.spinner')));
    }

    const results = [
      h('div.search-input', searchInput),
      this.attach('search-context', {
        contextEnabled,
        url: this.fullSearchUrl({ expanded: true })
      })
    ];

    if (searchData.term && !searchData.loading) {
      results.push(this.attach('search-menu-results', {
        term: searchData.term,
        noResults: searchData.noResults,
        results: searchData.results,
        invalidTerm: searchData.invalidTerm,
        searchContextEnabled: searchData.contextEnabled,
      }));
    }

    return results;
  },

  searchService() {
    if (!this._searchService) {
      this._searchService = this.register.lookup('search-service:main');
    }
    return this._searchService;
  },

  searchContext() {
    if (!this._searchContext) {
      this._searchContext = this.searchService().get('searchContext');
    }
    return this._searchContext;
  },

  html(attrs) {
    searchData.contextEnabled = attrs.contextEnabled;
    const searchContext = this.searchContext();

    const shouldTriggerSearch = (
      (searchData.contextEnabled !== attrs.contextEnabled) ||
      (searchContext &&
       searchContext.type === 'topic' &&
       searchData.topicId !== null &&
       searchData.topicId !== searchContext.id
      )
    );

    if (shouldTriggerSearch && searchData.term) {
      this.triggerSearch();
    }

    return this.attach('menu-panel', { maxWidth: 500, contents: () => this.panelContents() });
  },

  clickOutside() {
    this.sendWidgetAction('toggleSearchMenu');
  },

  keyDown(e) {
    if (searchData.loading || searchData.noResults) {
      return;
    }

    if (e.which === 65 /* a */) {
      let focused = $('header .results .search-link:focus');
      if (focused.length === 1) {
        if ($('#reply-control.open').length === 1) {
          // add a link and focus composer

          this.appEvents.trigger('composer:insert-text', focused[0].href, {ensureSpace: true});
          this.appEvents.trigger('header:keyboard-trigger', {type: 'search'});

          e.preventDefault();
          $('#reply-control.open textarea').focus();
          return false;
        }
      }
    }

    const up = e.which === 38;
    const down = e.which === 40;
    if (up || down) {

      let focused = $('header .panel-body *:focus')[0];

      if (!focused) {
        return;
      }

      let links = $('header .panel-body .results a');
      let results = $('header .panel-body .results .search-link');

      let prevResult;
      let result;

      links.each((idx,item) => {
        if ($(item).hasClass('search-link')) {
          prevResult = item;
        }

        if (item === focused) {
          result = prevResult;
        }
      });

      let index = -1;

      if (result) {
        index = results.index(result);
      }

      if (index === -1 && down) {
        $('header .panel-body .search-link:first').focus();
      } else if (index === 0 && up) {
        $('header .panel-body input:first').focus();
      } else if (index > -1) {
        index += (down ? 1 : -1);
        if (index >= 0 && index < results.length) {
          $(results[index]).focus();
        }
      }

      e.preventDefault();
      return false;
    }
  },

  triggerSearch() {
    searchData.noResults = false;
    this.searchService().set('highlightTerm', searchData.term);
    searchData.loading = true;
    Ember.run.debounce(SearchHelper, SearchHelper.perform, this, 400);
  },

  moreOfType(type) {
    searchData.typeFilter = type;
    this.triggerSearch();
  },

  searchContextChanged(enabled) {
    // This indicates the checkbox has been clicked, NOT that the context has changed.
    searchData.typeFilter = null;
    this.sendWidgetAction('searchMenuContextChanged', enabled);
    searchData.contextEnabled = enabled;
    this.triggerSearch();
  },

  searchTermChanged(term) {
    searchData.typeFilter = null;
    searchData.term = term;
    this.triggerSearch();
  },

  fullSearch() {
    if (!isValidSearchTerm(searchData.term)) { return; }

    searchData.results = [];
    searchData.loading = false;
    SearchHelper.cancel();
    const url = this.fullSearchUrl();
    if (url) {
      this.sendWidgetEvent('linkClicked');
      DiscourseURL.routeTo(url);
    } else if (searchData.contextEnabled) {
      this.triggerSearch();
    }
  }
});