import {
  default as computed,
  observes
} from "discourse-common/utils/decorators";
import { renderAvatar } from "discourse/helpers/user-avatar";
import userSearch from "../lib/user-search";
import WizardI18n from "../lib/wizard-i18n";
import Handlebars from "handlebars";
import { isEmpty } from "@ember/utils";

const template = function (params) {
  const options = params.options;
  let html = "<div class='autocomplete'>";

  if (options.users) {
    html += "<ul>";
    options.users.forEach((u) => {
      html += `<li><a href title="${u.name}">`;
      html += renderAvatar(u, { imageSize: "tiny" });
      html += `<span class='username'>${u.username}</span>`;
      if (u.name) {
        html += `<span class='name'>${u.name}</span>`;
      }
      html += `</a></li>`;
    });
    html += "</ul>";
  }

  html += "</div>";

  return new Handlebars.SafeString(html).string;
};

export default Ember.TextField.extend({
  attributeBindings: ["autofocus", "maxLength"],
  autocorrect: false,
  autocapitalize: false,
  name: "user-selector",
  id: "custom-member-selector",

  @computed("placeholderKey")
  placeholder(placeholderKey) {
    return placeholderKey ? WizardI18n(placeholderKey) : "";
  },

  @observes("usernames")
  _update() {
    if (this.get("canReceiveUpdates") === "true") {
      this.didInsertElement({ updateData: true });
    }
  },

  didInsertElement(opts) {
    this._super();
    let self = this,
      selected = [],
      groups = [],
      includeMentionableGroups =
        this.get("includeMentionableGroups") === "true",
      includeMessageableGroups =
        this.get("includeMessageableGroups") === "true",
      includeGroups = this.get("includeGroups") === "true",
      allowedUsers = this.get("allowedUsers") === "true";

    function excludedUsernames() {
      // hack works around some issues with allowAny eventing
      const usernames = self.get("single") ? [] : selected;
      return usernames;
    }
    $(this.element)
      .val(this.get("usernames"))
      .autocomplete({
        template,
        disabled: this.get("disabled"),
        single: this.get("single"),
        allowAny: this.get("allowAny"),
        updateData: opts && opts.updateData ? opts.updateData : false,

        dataSource(term) {
          const termRegex = /[^a-zA-Z0-9_\-\.@\+]/;
          let results = userSearch({
            term: term.replace(termRegex, ""),
            topicId: self.get("topicId"),
            exclude: excludedUsernames(),
            includeGroups,
            allowedUsers,
            includeMentionableGroups,
            includeMessageableGroups,
          });

          return results;
        },

        transformComplete(v) {
          if (v.username || v.name) {
            if (!v.username) {
              groups.push(v.name);
            }
            return v.username || v.name;
          } else {
            let excludes = excludedUsernames();
            return v.usernames.filter(function (item) {
              return excludes.indexOf(item) === -1;
            });
          }
        },

        onChangeItems(items) {
          let hasGroups = false;
          items = items.map(function (i) {
            if (groups.indexOf(i) > -1) {
              hasGroups = true;
            }
            return i.username ? i.username : i;
          });
          self.set("usernames", items.join(","));
          self.set("hasGroups", hasGroups);

          selected = items;
          if (self.get("onChangeCallback")) {
            self.sendAction("onChangeCallback");
          }
        },

        reverseTransform(i) {
          return { username: i };
        },
      });
  },

  willDestroyElement() {
    this._super();
    $(this.element).autocomplete("destroy");
  },

  // THIS IS A HUGE HACK TO SUPPORT CLEARING THE INPUT
  @observes("usernames")
  _clearInput: function () {
    if (arguments.length > 1) {
      if (isEmpty(this.get("usernames"))) {
        $(this.element).parent().find("a").click();
      }
    }
  },
});