// The Device object definition -------------------------------------------------

namespace com.keyman {
  export class Device {
    touchable: boolean;
    OS: string;
    formFactor: string;
    dyPortrait: number;
    dyLandscape: number;
    version: string;
    orientation: string|number;
    browser: string;

    // Generates a default Device value.
    constructor() {
      this.touchable = !!('ontouchstart' in window);
      this.OS = '';
      this.formFactor='desktop';
      this.dyPortrait=0;
      this.dyLandscape=0;
      this.version='0';
      this.orientation=window.orientation;
      this.browser='';
    }

    /**
     * Get device horizontal DPI for touch devices, to set actual size of active regions
     * Note that the actual physical DPI may be somewhat different.
     * 
     * @return      {number}               
     */       
    getDPI(): number {
      var t=document.createElement('DIV') ,s=t.style,dpi=96;
      if(document.readyState !== 'complete') {
        return dpi;
      }
      
      t.id='calculateDPI';
      s.position='absolute'; s.display='block';s.visibility='hidden';
      s.left='10px'; s.top='10px'; s.width='1in'; s.height='10px';
      document.body.appendChild(t);
      dpi=(typeof window.devicePixelRatio == 'undefined') ? t.offsetWidth : t.offsetWidth * window.devicePixelRatio;
      document.body.removeChild(t);
      return dpi;    
    }

    detect() : void {
      var IEVersion = Device._GetIEVersion();
      
      if(navigator && navigator.userAgent) {
        var agent=navigator.userAgent;

        if(agent.indexOf('iPad') >= 0) {
          this.OS='iOS';
          this.formFactor='tablet';
          this.dyPortrait=this.dyLandscape=0;
        }

        if(agent.indexOf('iPhone') >= 0) { 
          this.OS='iOS';
          this.formFactor='phone';
          this.dyPortrait=this.dyLandscape=25;
        }

        if(agent.indexOf('Android') >= 0) {
          this.OS='Android';
          this.formFactor='phone';    // form factor may be redefined on initialization
          this.dyPortrait=75;
          this.dyLandscape=25;
          try {
            var rx=new RegExp("(?:Android\\s+)(\\d+\\.\\d+\\.\\d+)");
            this.version=agent.match(rx)[1];
          } catch(ex) {}
        }
        if(agent.indexOf('Windows NT') >= 0) {
          this.OS='Windows';
          if(agent.indexOf('Touch') >= 0) {
            this.formFactor='phone';   // will be redefined as tablet if resolution high enough
          }
          
          // Windows Phone and Tablet PC
          if(typeof navigator.msMaxTouchPoints == 'number' && navigator.msMaxTouchPoints > 0) {
            this.touchable=true;
          }
        }
      }

      // var sxx=device.formFactor;
      // Check and possibly revise form factor according to actual screen size (adjusted for Galaxy S, maybe OK generally?)
      if(this.formFactor == 'tablet' && Math.min(screen.width,screen.height) < 400) {
        this.formFactor='phone';
      }

      if(this.formFactor == 'phone'  && Math.max(screen.width,screen.height) > 720) {
        this.formFactor='tablet';
      }

      //                           alert(sxx+'->'+device.formFactor);
      // Check for phony iOS devices (Win32 test excludes Chrome touch emulation on Windows)!
      if(this.OS == 'iOS' && !('ongesturestart' in window) && navigator.platform != 'Win32') {
        this.OS='Android';
      }
    
      // Determine application or browser
      this.browser='web';
      if(IEVersion < 999) {
        this.browser='ie';
      } else {
        if(this.OS == 'iOS' || this.OS.toLowerCase() == 'macosx') {
          this.browser='safari';
        }

        var bMatch=/Firefox|Chrome|OPR/;
        if(bMatch.test(navigator.userAgent)) {
          if((navigator.userAgent.indexOf('Firefox') >= 0) && ('onmozorientationchange' in screen)) {
            this.browser='firefox';
          } else if(navigator.userAgent.indexOf('OPR') >= 0) {
            this.browser='opera';
          } else if(navigator.userAgent.indexOf('Chrome') >= 0) {
            this.browser='chrome';
          }
        } 
      }
    }

    static _GetIEVersion() {
      var n, agent='';
      
      if('userAgent' in navigator) {
        agent=navigator.userAgent;
      }
      
      // Test first for old versions
      if('selection' in document) {         // only defined for IE and not for IE 11!!!       
        var appVer=navigator.appVersion;
        n=appVer.indexOf('MSIE ');
        if(n >= 0) {
          // Check for quirks mode page, always return 6 if so
          if((document as Document).compatMode == 'BackCompat') {
            return 6;
          }
          
          appVer=appVer.substr(n+5);
          n=appVer.indexOf('.');
          if(n > 0) {
            return parseInt(appVer.substr(0,n),10);
          }
        }              
      }
        
      // Finally test for IE 11 (and later?)
      n=agent.indexOf('Trident/');
      if(n < 0) {
        return 999;
      }
      
      agent=agent.substr(n+8);
      n=agent.indexOf('.');
      if(n > 0){
        return parseInt(agent.substr(0,n),10)+4;
      }
    
      return 999;
    }
  }
}