<script>
import { mapGetters, mapActions } from 'vuex';
import { getLocationHash, doesHashExistInUrl } from '../../lib/utils/url_utility';
import Flash from '../../flash';
import * as constants from '../constants';
import eventHub from '../event_hub';
import noteableNote from './noteable_note.vue';
import noteableDiscussion from './noteable_discussion.vue';
import discussionFilterNote from './discussion_filter_note.vue';
import systemNote from '../../vue_shared/components/notes/system_note.vue';
import commentForm from './comment_form.vue';
import placeholderNote from '../../vue_shared/components/notes/placeholder_note.vue';
import placeholderSystemNote from '../../vue_shared/components/notes/placeholder_system_note.vue';
import skeletonLoadingContainer from '../../vue_shared/components/notes/skeleton_note.vue';
import OrderedLayout from '~/vue_shared/components/ordered_layout.vue';
import highlightCurrentUser from '~/behaviors/markdown/highlight_current_user';
import { __ } from '~/locale';
import initUserPopovers from '~/user_popovers';

export default {
  name: 'NotesApp',
  components: {
    noteableNote,
    noteableDiscussion,
    systemNote,
    commentForm,
    placeholderNote,
    placeholderSystemNote,
    skeletonLoadingContainer,
    discussionFilterNote,
    OrderedLayout,
  },
  props: {
    noteableData: {
      type: Object,
      required: true,
    },
    notesData: {
      type: Object,
      required: true,
    },
    userData: {
      type: Object,
      required: false,
      default: () => ({}),
    },
    shouldShow: {
      type: Boolean,
      required: false,
      default: true,
    },
    helpPagePath: {
      type: String,
      required: false,
      default: '',
    },
  },
  data() {
    return {
      isFetching: false,
      currentFilter: null,
    };
  },
  computed: {
    ...mapGetters([
      'isNotesFetched',
      'discussions',
      'convertedDisscussionIds',
      'getNotesDataByProp',
      'isLoading',
      'commentsDisabled',
      'getNoteableData',
      'userCanReply',
      'discussionTabCounter',
      'sortDirection',
    ]),
    sortDirDesc() {
      return this.sortDirection === constants.DESC;
    },
    discussionTabCounterText() {
      return this.isLoading ? '' : this.discussionTabCounter;
    },
    noteableType() {
      return this.noteableData.noteableType;
    },
    allDiscussions() {
      if (this.isLoading) {
        const prerenderedNotesCount = parseInt(this.notesData.prerenderedNotesCount, 10) || 0;

        return new Array(prerenderedNotesCount).fill({
          isSkeletonNote: true,
        });
      }

      return this.discussions;
    },
    canReply() {
      return this.userCanReply && !this.commentsDisabled;
    },
    slotKeys() {
      return this.sortDirDesc ? ['form', 'comments'] : ['comments', 'form'];
    },
  },
  watch: {
    shouldShow() {
      if (!this.isNotesFetched) {
        this.fetchNotes();
      }
    },
    discussionTabCounterText(val) {
      if (this.discussionsCount) {
        this.discussionsCount.textContent = val;
      }
    },
  },
  created() {
    this.discussionsCount = document.querySelector('.js-discussions-count');

    this.setNotesData(this.notesData);
    this.setNoteableData(this.noteableData);
    this.setUserData(this.userData);
    this.setTargetNoteHash(getLocationHash());
    eventHub.$once('fetchNotesData', this.fetchNotes);
  },
  mounted() {
    if (this.shouldShow) {
      this.fetchNotes();
    }

    const { parentElement } = this.$el;
    if (parentElement && parentElement.classList.contains('js-vue-notes-event')) {
      parentElement.addEventListener('toggleAward', event => {
        const { awardName, noteId } = event.detail;
        this.toggleAward({ awardName, noteId });
      });
    }

    window.addEventListener('hashchange', this.handleHashChanged);
  },
  updated() {
    this.$nextTick(() => {
      highlightCurrentUser(this.$el.querySelectorAll('.gfm-project_member'));
      initUserPopovers(this.$el.querySelectorAll('.js-user-link'));
    });
  },
  beforeDestroy() {
    this.stopPolling();
    window.removeEventListener('hashchange', this.handleHashChanged);
  },
  methods: {
    ...mapActions([
      'setLoadingState',
      'fetchDiscussions',
      'poll',
      'toggleAward',
      'setNotesData',
      'setNoteableData',
      'setUserData',
      'setLastFetchedAt',
      'setTargetNoteHash',
      'toggleDiscussion',
      'setNotesFetchedState',
      'expandDiscussion',
      'startTaskList',
      'convertToDiscussion',
      'stopPolling',
    ]),
    discussionIsIndividualNoteAndNotConverted(discussion) {
      return discussion.individual_note && !this.convertedDisscussionIds.includes(discussion.id);
    },
    handleHashChanged() {
      const noteId = this.checkLocationHash();

      if (noteId) {
        this.setTargetNoteHash(getLocationHash());
      }
    },
    fetchNotes() {
      if (this.isFetching) return null;

      this.isFetching = true;

      return this.fetchDiscussions(this.getFetchDiscussionsConfig())
        .then(this.initPolling)
        .then(() => {
          this.setLoadingState(false);
          this.setNotesFetchedState(true);
          eventHub.$emit('fetchedNotesData');
          this.isFetching = false;
        })
        .then(this.$nextTick)
        .then(this.startTaskList)
        .then(this.checkLocationHash)
        .catch(() => {
          this.setLoadingState(false);
          this.setNotesFetchedState(true);
          Flash(__('Something went wrong while fetching comments. Please try again.'));
        });
    },
    initPolling() {
      if (this.isPollingInitialized) {
        return;
      }

      this.setLastFetchedAt(this.getNotesDataByProp('lastFetchedAt'));

      this.poll();
      this.isPollingInitialized = true;
    },
    checkLocationHash() {
      const hash = getLocationHash();
      const noteId = hash && hash.replace(/^note_/, '');

      if (noteId) {
        const discussion = this.discussions.find(d => d.notes.some(({ id }) => id === noteId));

        if (discussion) {
          this.expandDiscussion({ discussionId: discussion.id });
        }
      }

      return noteId;
    },
    startReplying(discussionId) {
      return this.convertToDiscussion(discussionId)
        .then(this.$nextTick)
        .then(() => eventHub.$emit('startReplying', discussionId));
    },
    getFetchDiscussionsConfig() {
      const defaultConfig = { path: this.getNotesDataByProp('discussionsPath') };

      if (doesHashExistInUrl(constants.NOTE_UNDERSCORE)) {
        return {
          ...defaultConfig,
          filter: constants.DISCUSSION_FILTERS_DEFAULT_VALUE,
          persistFilter: false,
        };
      }
      return defaultConfig;
    },
  },
  systemNote: constants.SYSTEM_NOTE,
};
</script>

<template>
  <div v-show="shouldShow" id="notes">
    <ordered-layout :slot-keys="slotKeys">
      <template #form>
        <comment-form
          v-if="!commentsDisabled"
          class="js-comment-form"
          :noteable-type="noteableType"
        />
      </template>
      <template #comments>
        <ul id="notes-list" class="notes main-notes-list timeline">
          <template v-for="discussion in allDiscussions">
            <skeleton-loading-container v-if="discussion.isSkeletonNote" :key="discussion.id" />
            <template v-else-if="discussion.isPlaceholderNote">
              <placeholder-system-note
                v-if="discussion.placeholderType === $options.systemNote"
                :key="discussion.id"
                :note="discussion.notes[0]"
              />
              <placeholder-note v-else :key="discussion.id" :note="discussion.notes[0]" />
            </template>
            <template v-else-if="discussionIsIndividualNoteAndNotConverted(discussion)">
              <system-note
                v-if="discussion.notes[0].system"
                :key="discussion.id"
                :note="discussion.notes[0]"
              />
              <noteable-note
                v-else
                :key="discussion.id"
                :note="discussion.notes[0]"
                :show-reply-button="canReply"
                @startReplying="startReplying(discussion.id)"
              />
            </template>
            <noteable-discussion
              v-else
              :key="discussion.id"
              :discussion="discussion"
              :render-diff-file="true"
              :help-page-path="helpPagePath"
            />
          </template>
          <discussion-filter-note v-show="commentsDisabled" />
        </ul>
      </template>
    </ordered-layout>
  </div>
</template>
