#include <iostream>

// opencv
#include <highgui.h>
#include <cv.h>

const char* cascade_path = "/usr/share/opencv/haarcascades/haarcascade_frontalface_alt.xml";
CvHaarClassifierCascade* cascade = (CvHaarClassifierCascade*)cvLoad(cascade_path, 0, 0, 0 );
//CvHaarClassifierCascade* cascade = cvLoadHaarClassifierCascade(cascade_path, cvSize(1,1));
CvMemStorage* storage = cvCreateMemStorage( 0 );

void
detect_and_draw( IplImage* img, double scale = 1.4 )
{
    IplImage* gray = cvCreateImage( cvGetSize(img), IPL_DEPTH_8U, 1 );
    IplImage* small_img = cvCreateImage(
        cvSize(cvRound(img->width/scale), cvRound(img->height/scale)),
        IPL_DEPTH_8U,
        1 );
    cvCvtColor( img, gray, CV_BGR2GRAY );
    cvResize( gray, small_img, CV_INTER_LINEAR );
    cvEqualizeHist( small_img, small_img );

    // Detect objects
    cvClearMemStorage( storage );
    CvSeq* objects = cvHaarDetectObjects( small_img,
                                          cascade,
                                          storage,
                                          1.1,
                                          2,
                                          0,
                                          cvSize(30, 30) );
    // loop through found objects and draw boxes around them
    CvScalar color[] =  {{255,0,0}, {0,255,0}};
/*

//    if ( objects->total < 2 ) {
//        return;
//    }

    CvRect* face_rec1 = (CvRect*) cvGetSeqElem( objects, 0 );
    CvMat *face_mat1, x;
    face_mat1 = cvGetSubRect(img,
                 &x,
                 cvRect(face_rec1->x, face_rec1->y, face_rec1->width, face_rec1->height));
    IplImage* face_img1 = cvCreateImage( cvGetSize(&x), IPL_DEPTH_8U, 1 );
    cvCopy(face_mat1, face_img1);

//    CvRect* face_rec2 = (CvRect*) cvGetSeqElem( objects, 1 );
//    cvGetSubRect(img,
//                 face_rec2,
//                 cvRect(face_rec2->x, face_rec2->y, face_rec2->width, face_rec2->height));
*/

    for( int i = 0; i < (objects ? objects->total : 0); i++ ) {
        CvRect* rec = (CvRect*) cvGetSeqElem( objects, i );
        int x = rec->x * scale; int x2 = (rec->x + rec->width) * scale;
        int y = rec->y * scale; int y2 = (rec->y + rec->height) * scale;
        cvRectangle( img,
                     cvPoint(x, y),
                     cvPoint(x2, y2),
                     color[i % 2]);
    }

    cvReleaseImage( &gray );
    cvReleaseImage( &small_img );
}


/* VIDEO */
int
main( int argc, char** argv )
{
    cvNamedWindow( "Example", CV_WINDOW_AUTOSIZE );
    CvCapture* capture;
    capture = cvCreateCameraCapture( 0 );
//    capture = cvCreateFileCapture( argv[1] );

    IplImage* frame;
    while(1) {
        frame = cvQueryFrame( capture );
        if ( !frame ) continue;

        /* edge detection
        IplImage* out = cvCreateImage( cvGetSize(frame) , IPL_DEPTH_8U, 1 );
        IplImage* gray = cvCreateImage( cvGetSize(frame) , IPL_DEPTH_8U, 1 );

        cvCvtColor( frame, gray, CV_BGR2GRAY );
        cvCanny( gray, out, 10, 100, 3 );
        cvShowImage( "Example", out );

        cvReleaseImage( &out );
        cvReleaseImage( &gray );
        */

        detect_and_draw( frame );
        cvShowImage( "Example", frame );

        char c = cvWaitKey( 33 );
        if ( c == 27 ) break;
    }
    cvReleaseCapture( &capture );
    cvDestroyWindow ( "Example" );
    return 0;
}


/* IMAGE
int
main( int argc, char** argv )
{
    IplImage* img = cvLoadImage( argv[1] );
    cvNamedWindow( "Example", CV_WINDOW_AUTOSIZE );

    IplImage* out = cvCreateImage( cvGetSize(img), IPL_DEPTH_8U, 3 );
    cvSmooth( img, out, CV_GAUSSIAN, 9, 9 );

    cvShowImage( "Example", out );
    cvWaitKey( 0 );
    cvReleaseImage( &img );
    cvDestroyWindow( "Example" );

    return 0;
}
*/