import { debounce } from "discourse-common/utils/decorators";
import { headerOffset } from "discourse/lib/offset-calculator";
import isElementInViewport from "discourse/lib/is-element-in-viewport";
import { withPluginApi } from "discourse/lib/plugin-api";

const PLUGIN_ID = "new-user-narrative";

function initialize(api) {
  const messageBus = api.container.lookup("service:message-bus");
  const currentUser = api.getCurrentUser();
  const appEvents = api.container.lookup("service:app-events");

  api.modifyClass("component:site-header", {
    pluginId: PLUGIN_ID,
    didInsertElement() {
      this._super(...arguments);
      this.dispatch("header:search-context-trigger", "header");
    },
  });

  api.modifyClass("controller:topic", {
    pluginId: PLUGIN_ID,

    subscribe() {
      this._super(...arguments);

      this.messageBus.subscribe(`/topic/${this.model.id}`, (data) => {
        const topic = this.model;

        // scroll only for discobot (-2 is discobot id)
        if (
          topic.isPrivateMessage &&
          this.currentUser &&
          this.currentUser.id !== data.user_id &&
          data.user_id === -2 &&
          data.type === "created"
        ) {
          const postNumber = data.post_number;
          const notInPostStream =
            topic.get("highest_post_number") <= postNumber;
          const postNumberDifference = postNumber - topic.currentPost;

          if (
            notInPostStream &&
            postNumberDifference > 0 &&
            postNumberDifference < 7
          ) {
            this._scrollToDiscobotPost(data.post_number);
          }
        }
      });
      // No need to unsubscribe, core unsubscribes /topic/* routes
    },

    @debounce(500)
    _scrollToDiscobotPost(postNumber) {
      const post = document.querySelector(
        `.topic-post article#post_${postNumber}`
      );

      if (!post || isElementInViewport(post)) {
        return;
      }

      const viewportOffset = post.getBoundingClientRect();

      window.scrollTo({
        top: window.scrollY + viewportOffset.top - headerOffset(),
        behavior: "smooth",
      });
    },
  });

  api.attachWidgetAction("header", "headerSearchContextTrigger", function () {
    if (this.site.mobileView) {
      this.state.skipSearchContext = false;
    } else {
      this.state.contextEnabled = true;
      this.state.searchContextType = "topic";
    }
  });

  if (messageBus && currentUser) {
    messageBus.subscribe(`/new_user_narrative/tutorial_search`, () => {
      appEvents.trigger("header:search-context-trigger");
    });
  }
}

export default {
  name: "new-user-narrative",

  initialize(container) {
    const siteSettings = container.lookup("service:site-settings");
    if (siteSettings.discourse_narrative_bot_enabled) {
      withPluginApi("0.8.7", initialize);
    }
  },
};