/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

import { html } from "../vendor/lit.all.mjs";
import { MozLitElement } from "../lit-utils.mjs";

export const PLATFORM_LINUX = "linux";
export const PLATFORM_MACOS = "macosx";
export const PLATFORM_WINDOWS = "win";

export default class MozButtonGroup extends MozLitElement {
  static queries = {
    defaultSlotEl: "slot:not([name])",
    primarySlotEl: "slot[name=primary]",
  };

  static properties = {
    platform: { state: true },
  };

  // Use a relative URL in storybook to get faster reloads on style changes.
  static stylesheetUrl = window.IS_STORYBOOK
    ? "./moz-button-group/moz-button-group.css"
    : "chrome://global/content/elements/moz-button-group.css";

  constructor() {
    super();
    this.#detectPlatform();
  }

  #detectPlatform() {
    if (typeof AppConstants !== "undefined") {
      this.platform = AppConstants.platform;
    } else if (navigator.platform.includes("Linux")) {
      this.platform = PLATFORM_LINUX;
    } else if (navigator.platform.includes("Mac")) {
      this.platform = PLATFORM_MACOS;
    } else {
      this.platform = PLATFORM_WINDOWS;
    }
  }

  onSlotchange(e) {
    for (let child of this.defaultSlotEl.assignedNodes()) {
      if (!(child instanceof Element)) {
        // Text nodes won't support classList or getAttribute.
        continue;
      }
      // Bug 1791816: These should check moz-button instead of button.
      if (
        child.localName == "button" &&
        (child.classList.contains("primary") ||
          child.getAttribute("type") == "submit" ||
          child.hasAttribute("autofocus"))
      ) {
        child.slot = "primary";
      }
    }
  }

  render() {
    let slots = [
      html`
        <slot @slotchange=${this.onSlotchange}></slot>
      `,
      html`
        <slot name="primary"></slot>
      `,
    ];
    if (this.platform == PLATFORM_WINDOWS) {
      slots = [slots[1], slots[0]];
    }
    return html`
      <link rel="stylesheet" href=${this.constructor.stylesheetUrl} />
      ${slots}
    `;
  }
}
customElements.define("moz-button-group", MozButtonGroup);