/* 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/. */

"use strict";

const { Cc, Ci } = require("chrome");

loader.lazyGetter(this, "DOMUtils", () => {
  return Cc["@mozilla.org/inspector/dom-utils;1"].getService(Ci.inIDOMUtils);
});

const protocol = require("devtools/shared/protocol");
const { ActorClassWithSpec, Actor } = protocol;
const { cssPropertiesSpec } = require("devtools/shared/specs/css-properties");
const { CSS_PROPERTIES, CSS_TYPES } = require("devtools/shared/css/properties-db");
const { cssColors } = require("devtools/shared/css/color-db");

exports.CssPropertiesActor = ActorClassWithSpec(cssPropertiesSpec, {
  typeName: "cssProperties",

  initialize(conn, parent) {
    Actor.prototype.initialize.call(this, conn);
    this.parent = parent;
  },

  destroy() {
    Actor.prototype.destroy.call(this);
  },

  getCSSDatabase() {
    const properties = generateCssProperties();
    const pseudoElements = DOMUtils.getCSSPseudoElementNames();

    return { properties, pseudoElements };
  }
});

/**
 * Generate the CSS properties object. Every key is the property name, while
 * the values are objects that contain information about that property.
 *
 * @return {Object}
 */
function generateCssProperties() {
  const properties = {};
  const propertyNames = DOMUtils.getCSSPropertyNames(DOMUtils.INCLUDE_ALIASES);
  const colors = Object.keys(cssColors);

  propertyNames.forEach(name => {
    // Get the list of CSS types this property supports.
    let supports = [];
    for (let type in CSS_TYPES) {
      if (safeCssPropertySupportsType(name, DOMUtils["TYPE_" + type])) {
        supports.push(CSS_TYPES[type]);
      }
    }

    // Don't send colors over RDP, these will be re-attached by the front.
    let values = DOMUtils.getCSSValuesForProperty(name);
    if (values.includes("aliceblue")) {
      values = values.filter(x => !colors.includes(x));
      values.unshift("COLOR");
    }

    // In order to maintain any backwards compatible changes when debugging older
    // clients, take the definition from the static CSS properties database, and fill it
    // in with the most recent property definition from the server.
    const clientDefinition = CSS_PROPERTIES[name] || {};
    const serverDefinition = {
      isInherited: DOMUtils.isInheritedProperty(name),
      values,
      supports
    };
    properties[name] = Object.assign(clientDefinition, serverDefinition);
  });

  return properties;
}
exports.generateCssProperties = generateCssProperties;

/**
 * Test if a CSS is property is known using server-code.
 *
 * @param {string} name
 * @return {Boolean}
 */
function isCssPropertyKnown(name) {
  try {
    // If the property name is unknown, the cssPropertyIsShorthand
    // will throw an exception.  But if it is known, no exception will
    // be thrown; so we just ignore the return value.
    DOMUtils.cssPropertyIsShorthand(name);
    return true;
  } catch (e) {
    return false;
  }
}

exports.isCssPropertyKnown = isCssPropertyKnown;

/**
 * A wrapper for DOMUtils.cssPropertySupportsType that ignores invalid
 * properties.
 *
 * @param {String} name The property name.
 * @param {number} type The type tested for support.
 * @return {Boolean} Whether the property supports the type.
 *        If the property is unknown, false is returned.
 */
function safeCssPropertySupportsType(name, type) {
  try {
    return DOMUtils.cssPropertySupportsType(name, type);
  } catch (e) {
    return false;
  }
}
