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//
//  Licensed to the Apache Software Foundation (ASF) under one or more
//  contributor license agreements.  See the NOTICE file distributed with
//  this work for additional information regarding copyright ownership.
//  The ASF licenses this file to You 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
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////////////////////////////////////////////////////////////////////////////////

package mx.utils
{

import flash.system.Capabilities;
import flash.utils.getDefinitionByName;

/**
 *  The Platform utility class contains several static methods to check what
 *  desktop or mobile platform the application is running on.
 *  
 *  @langversion 3.0
 *  @playerversion Flash 10
 *  @playerversion AIR 2.0
 *  @productversion Flex 4.12
 */
public class Platform
{
    include "../core/Version.as";

    private static var _instance: Platform;
	
	protected static var _initialized:Boolean;
	protected static var _isAndroid:Boolean;
	protected static var _isIOS:Boolean;
	protected static var _isIPad:Boolean;
	protected static var _isBlackBerry:Boolean;
	protected static var _isMobile:Boolean;
	protected static var _isMac:Boolean;
	protected static var _isWindows:Boolean;
	protected static var _isLinux:Boolean;
	protected static var _isDesktop:Boolean;
	protected static var _isBrowser:Boolean;
	protected static var _isAir:Boolean;
    private static var _osVersion: String = null;
	/**
	 * This value is set from AndroidVersionMediaQueryParserOverride
	 * 
	 */
	mx_internal static var androidVersionOverride:String;
	
	/**
	 *  Returns true if the application is running on IOS.
	 *
	 *  @langversion 3.0
	 *  @playerversion Flash 10
	 *  @playerversion AIR 2.0
	 *  @productversion Flex 4.12
	 */
	public static function get isIOS():Boolean
	{
		getPlatforms();
		
		return _isIOS;
	}
	
	/**
	 *  Returns true if the application is running on an iPad.
	 *  Note this returns false in the AIR mobile device simulator.
	 *
	 *  @langversion 3.0
	 *  @playerversion Flash 10
	 *  @playerversion AIR 2.0
	 *  @productversion Flex 4.12
	 */
	public static function get isIPad():Boolean
	{
		getPlatforms();
		
		return _isIPad;
	}
	
	/**
	 *  Returns true if the application is running on a BlackBerry.
	 *
	 *  @langversion 3.0
	 *  @playerversion Flash 10
	 *  @playerversion AIR 2.0
	 *  @productversion Flex 4.12
	 */
	public static function get isBlackBerry():Boolean
	{
		getPlatforms();
		
		return _isBlackBerry;
	}
	
	/**
	 *  Returns true if the application is running on Android.
	 *
	 *  @langversion 3.0
	 *  @playerversion Flash 10
	 *  @playerversion AIR 2.0
	 *  @productversion Flex 4.12
	 */
	public static function get isAndroid():Boolean
	{
		getPlatforms();
		
		return _isAndroid;
	}
	
	/**
	 *  Returns true if the application is running on Windows.
	 *
	 *  @langversion 3.0
	 *  @playerversion Flash 10
	 *  @playerversion AIR 2.0
	 *  @productversion Flex 4.12
	 */
	public static function get isWindows():Boolean
	{
		getPlatforms();
		
		return _isWindows;
	}
	
	/**
	 *  Returns true if the application is running on a Mac.
	 *
	 *  @langversion 3.0
	 *  @playerversion Flash 10
	 *  @playerversion AIR 2.0
	 *  @productversion Flex 4.12
	 */
	public static function get isMac():Boolean
	{
		getPlatforms();
		
		return _isMac;
	}
	
	/**
	 *  Returns true if the application is running on Linux.
	 *
	 *  @langversion 3.0
	 *  @playerversion Flash 10
	 *  @playerversion AIR 2.0
	 *  @productversion Flex 4.12
	 */
	public static function get isLinux():Boolean
	{
		getPlatforms();
		
		return _isLinux;
	}
	
	/**
	 *  Returns true if the application is running on a Desktop OS.
	 *
	 *  @langversion 3.0
	 *  @playerversion Flash 10
	 *  @playerversion AIR 2.0
	 *  @productversion Flex 4.12
	 */
	public static function get isDesktop():Boolean
	{
		getPlatforms();
		
		return _isDesktop;
	}
	
	/**
	 *  Returns true if the application is running on a Mobile device.
	 *
	 *  @langversion 3.0
	 *  @playerversion Flash 10
	 *  @playerversion AIR 2.0
	 *  @productversion Flex 4.12
	 */
	public static function get isMobile():Boolean
	{
		getPlatforms();
		
		return _isMobile;
	}
	
	/**
	 *  Returns true if the application is running on a desktop AIR.
	 *
	 *  @langversion 3.0
	 *  @playerversion Flash 10
	 *  @playerversion AIR 2.0
	 *  @productversion Flex 4.12
	 */
	public static function get isAir():Boolean
	{
		getPlatforms();
		
		return _isAir;
	}
	
	/**
	 *  Returns true if the application is running in a browser.
	 *
	 *  @langversion 3.0
	 *  @playerversion Flash 10
	 *  @playerversion AIR 2.0
	 *  @productversion Flex 4.12
	 */
	public static function get isBrowser():Boolean
	{
		getPlatforms();
		
		return _isBrowser;
	}

    /**
     *  Returns the version of the OS the application  is running on
     *
     *  @langversion 3.0
     *  @playerversion Flash 10
     *  @playerversion AIR 2.0
     *  @productversion Flex 4.13
     */
    public static function get osVersion(): String
    {
        //We needed to compute _osVersion later than getPlatforms, because it relies on resources that  ready later
        if (_osVersion == null){
			if(mx_internal::androidVersionOverride == null)
			{
				_osVersion = computeOSVersionString();	
			}
			else
			{
				_osVersion = mx_internal::androidVersionOverride; 
			}
        }
        return _osVersion;
    }

    /* Notes on Capabilities.os for mobile apps:
        - on ADL => returns the OS where the ADL is running ( eg. Windows 7, or Mac OS )
         - on device => returns the OS of the device (eg.  iPhone OS ...  for iOS devices  )
    * */
	protected static function getPlatforms():void {
		if (!_initialized)
		{
            var cap: Class = Capabilities;
            var version:  String = Capabilities.version;
            var os: String = Capabilities.os;
            var playerType: String = Capabilities.playerType;

			_isAndroid = version.indexOf("AND") > -1;
			_isIOS = version.indexOf('IOS') > -1;
			_isBlackBerry = version.indexOf('QNX') > -1;
			_isMobile = _isAndroid || _isIOS || _isBlackBerry;
			
			_isMac = os.indexOf("Mac OS") != -1;
			_isWindows = os.indexOf("Windows") != -1;
			_isLinux = os.indexOf("Linux") != -1; // note that Android is also Linux
			_isIPad = os.indexOf('iPad') > -1;
			_isDesktop = !_isMobile;
			
			_isAir = playerType == "Desktop";
			_isBrowser = (playerType == "PlugIn" || playerType == "ActiveX");
			
			_initialized = true;
		}
	}

    /** @private
     * extract OS version information from Capabilities.os
     * os is typically a non-numeric string (such as Windows,  iPhone OS, Android, etc...)  followed by a number sequence.
     * if no number is found, OS version is set to 0.
     * os on ADL will return the host OS and not the device OS.
     *
     * That's why we need to check for a specific sequence for iOS and Android.
     * On Android, os  is the Linux kernel version (such as Linux 3.4.34-1790463).
     * So the version information must be  retrieved from an internal file.
     * Since reading files API is only available on AIR, it's delegated to PlatformMobileHelper  in mobilecomponents.swc
     * @see   spark.utils.PlatformMobileHelper
     *
     * @return version number string, or empty string if could not retrieve the version.
     * */
    private static function computeOSVersionString(): String
    {
        var os: String = Capabilities.os;
        var osVersionMatch: Array;
        var version: String = "";

        if (isIOS) {
            osVersionMatch = os.match(/iPhone OS\s([\d\.]+)/);
            if (osVersionMatch && osVersionMatch.length == 2)
                version = osVersionMatch[1];
        }
        else if (isAndroid) {
            try {
                var mobileHelperClass: Class = Class(getDefinitionByName("spark.utils::PlatformMobileHelper"));
                if (mobileHelperClass != null) {
                    version = mobileHelperClass["computeOSVersionForAndroid"]();
                }
            }
            catch (e: Error) {
                trace("Error: " + e.message);
            }
        }
        else {
            //on  other OS, extract version
            osVersionMatch = os.match(/[A-Za-z\s]+([\d\.]+)/);
            if (osVersionMatch && osVersionMatch.length == 2)
                version = osVersionMatch[1];
        }
        return version;
    }

}
}