import I18n from "I18n";
import { h } from "virtual-dom";
import attributeHook from "discourse-common/lib/attribute-hook";

const SVG_NAMESPACE = "http://www.w3.org/2000/svg";
let _renderers = [];

const REPLACEMENTS = {
  "d-tracking": "bell",
  "d-muted": "discourse-bell-slash",
  "d-regular": "far-bell",
  "d-watching": "discourse-bell-exclamation",
  "d-watching-first": "discourse-bell-one",
  "d-drop-expanded": "caret-down",
  "d-drop-collapsed": "caret-right",
  "d-unliked": "far-heart",
  "d-liked": "heart",
  "notification.mentioned": "at",
  "notification.group_mentioned": "at",
  "notification.quoted": "quote-right",
  "notification.replied": "reply",
  "notification.posted": "reply",
  "notification.edited": "pencil-alt",
  "notification.bookmark_reminder": "discourse-bookmark-clock",
  "notification.liked": "heart",
  "notification.liked_2": "heart",
  "notification.liked_many": "heart",
  "notification.liked_consolidated": "heart",
  "notification.private_message": "far-envelope",
  "notification.invited_to_private_message": "far-envelope",
  "notification.invited_to_topic": "hand-point-right",
  "notification.invitee_accepted": "user",
  "notification.moved_post": "sign-out-alt",
  "notification.linked": "link",
  "notification.granted_badge": "certificate",
  "notification.topic_reminder": "far-clock",
  "notification.watching_first_post": "discourse-bell-one",
  "notification.group_message_summary": "users",
  "notification.post_approved": "check",
  "notification.membership_request_accepted": "user-plus",
  "notification.membership_request_consolidated": "users"
};

export function replaceIcon(source, destination) {
  REPLACEMENTS[source] = destination;
}

export function renderIcon(renderType, id, params) {
  for (let i = 0; i < _renderers.length; i++) {
    let renderer = _renderers[i];
    let rendererForType = renderer[renderType];

    if (rendererForType) {
      const icon = { id, replacementId: REPLACEMENTS[id] };
      let result = rendererForType(icon, params || {});
      if (result) {
        return result;
      }
    }
  }
}

export function iconHTML(id, params) {
  return renderIcon("string", id, params);
}

export function iconNode(id, params) {
  return renderIcon("node", id, params);
}

export function convertIconClass(icon) {
  return icon
    .replace("far fa-", "far-")
    .replace("fab fa-", "fab-")
    .replace("fas fa-", "")
    .replace("fa-", "")
    .trim();
}

// TODO: Improve how helpers are registered for vdom compliation
if (typeof Discourse !== "undefined") {
  Discourse.__widget_helpers.iconNode = iconNode;
}

export function registerIconRenderer(renderer) {
  _renderers.unshift(renderer);
}

function iconClasses(icon, params) {
  // "notification." is invalid syntax for classes, use replacement instead
  const dClass =
    icon.replacementId && icon.id.indexOf("notification.") > -1
      ? icon.replacementId
      : icon.id;

  let classNames = `fa d-icon d-icon-${dClass} svg-icon`;

  if (params && params["class"]) {
    classNames += " " + params["class"];
  }

  return classNames;
}

function warnIfMissing(id) {
  if (
    typeof Discourse !== "undefined" &&
    Discourse.Environment === "development" &&
    !Discourse.disableMissingIconWarning &&
    Discourse.SvgIconList &&
    Discourse.SvgIconList.indexOf(id) === -1
  ) {
    console.warn(`The icon "${id}" is missing from the SVG subset.`); // eslint-disable-line no-console
  }
}

function handleIconId(icon) {
  let id = icon.replacementId || icon.id || "";

  // TODO: clean up "thumbtack unpinned" at source instead of here
  id = id.replace(" unpinned", "");

  warnIfMissing(id);
  return id;
}

// default resolver is font awesome
registerIconRenderer({
  name: "font-awesome",

  string(icon, params) {
    const id = handleIconId(icon);
    let html = `<svg class='${iconClasses(icon, params)} svg-string'`;

    if (params.label) {
      html += " aria-hidden='true'";
    }
    html += ` xmlns="${SVG_NAMESPACE}"><use xlink:href="#${id}" /></svg>`;
    if (params.label) {
      html += `<span class='sr-only'>${params.label}</span>`;
    }
    if (params.title) {
      html = `<span class="svg-icon-title" title='${I18n.t(
        params.title
      ).replace(/'/g, "&#39;")}'>${html}</span>`;
    }
    if (params.translatedtitle) {
      html = `<span class="svg-icon-title" title='${params.translatedtitle.replace(
        /'/g,
        "&#39;"
      )}'>${html}</span>`;
    }
    return html;
  },

  node(icon, params) {
    const id = handleIconId(icon);
    const classes = iconClasses(icon, params) + " svg-node";

    const svg = h(
      "svg",
      {
        attributes: { class: classes, "aria-hidden": true },
        namespace: SVG_NAMESPACE
      },
      [
        h("use", {
          "xlink:href": attributeHook("http://www.w3.org/1999/xlink", `#${id}`),
          namespace: SVG_NAMESPACE
        })
      ]
    );

    if (params.title) {
      return h(
        "span",
        {
          title: params.title,
          attributes: { class: "svg-icon-title" }
        },
        [svg]
      );
    } else {
      return svg;
    }
  }
});