/*
 * Copyright 2020 Northwestern Inclusive Technology Lab
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import * as larkin from '../larkin/client/larkin';
import {EventTarget} from './events';
import {Application} from './applications';

// * v11.system
// v11.system implements objects and methods related to observing
// the state of the platform that the V11 runtime is being on top off.
// Includes v11.system.platform: an object of specific platform info
const PLATFORM_APPLE = 'apple';
const PLATFORM_WINDOWS = 'windows';
const PLATFORM_LINUX = 'linux';
const PLATFORM_UNKNOWN = 'unknown';

interface Version extends larkin.Version {
  code: string;
}

interface Platform {
  type: string;
  version: Version;
}

interface SystemAPI {
  platform: Platform;
  isApple: boolean;
  isWindows: boolean;
  isLinux: boolean;

  getApplications(): Array<Application>;
  getApplicationByName(name: string): Application | undefined;
  getApplicationById(id: string): Application | undefined;
}

const sysMajorVer = larkin.platform.version.major;
const sysMinorVer = larkin.platform.version.minor;
const sysPatchVer = larkin.platform.version.patch;
const systemVersionCombined = `${sysMajorVer}.${sysMinorVer}.${sysPatchVer}`;
const systemVersion: Version = {
  ...larkin.platform.version,
  code: systemVersionCombined,
};

const systemPlatform: Platform = {
  type: larkin.platform.type,
  version: systemVersion,
};

const isPlatform = (platform: string) => {
  return systemPlatform.type === platform;
};

class System extends EventTarget implements SystemAPI {
  platform = systemPlatform;
  isApple = isPlatform(PLATFORM_APPLE);
  isWindows = isPlatform(PLATFORM_WINDOWS);
  isLinux = isPlatform(PLATFORM_LINUX);

  constructor() {
    super(larkin.notifications.addEventListener);
  }

  getApplications(): Array<Application> {
    return larkin.applications.getApplications().map(application => {
      return new Application(application);
    });
  }

  // TODO(tommymchugh): Assert that this is 0 later on
  getApplicationByName(name: string): Application | undefined {
    const qualifiedApps = this.getApplications()!.filter(application => {
      return application.name === name;
    });

    if (qualifiedApps.length > 0) {
      return qualifiedApps[0];
    }
    return undefined;
  }

  getApplicationById(id: string): Application | undefined {
    const qualifiedApps = this.getApplications()!.filter(application => {
      return application.id === id;
    });

    if (qualifiedApps.length > 0) {
      return qualifiedApps[0];
    }
    return undefined;
  }
}
export const system: SystemAPI = new System();