/***************************************************************************************
 *
 * histogram.cc is part of SimpleSkyCam.
 *
 *****************************************************************************************/

#include "simpleskycam.h"
#include "histogram.h"
#include "gui.h"
#include "configuration.h"
#include "video.h"


GtkWidget *histogram_da = NULL;
int histogram[3][256];    		// 6* hist_width min, max, min , max.....
int histogram_max;				// max vlaue

extern GtkBuilder *_builder_;			// work around for threads

void cb_histogramda_draw(GtkWidget *area, cairo_t *cr, int w, int h, gpointer data) {
	int clientw, clienth, px, py2;
	GdkRGBA color;
	char txt[255];

	if (histogram_da == NULL) // should only be called once
		histogram_da = GTK_WIDGET(gtk_builder_get_object (GTK_BUILDER(_builder_), "histogram-da"));
	clienth = gtk_widget_get_allocated_height(histogram_da);
	clientw = gtk_widget_get_allocated_width(histogram_da);

	//
	// put the drawing area on the screen
    cairo_paint(cr);
    cairo_fill (cr);

    if (histogram_max == 0) return;

    for (int chan = 0; chan < 3; chan++) {
		switch (chan) {
		case 0:
			color.blue = 0.0;
			color.red = 1.0;
			color.green = 0.0;
			color.alpha = 0.5;
			break;
		case 1:
			color.blue = 0.0;
			color.red = 0.0;
			color.green = 1.0;
			color.alpha = 0.5;
			break;
		case 2:
			color.blue = 1.0;
			color.red = 0.0;
			color.green = 0.0;
			color.alpha = 0.5;
			break;
		}
		gdk_cairo_set_source_rgba(cr, &color);

    	for (int i = 0; i < 256; i++) {
			px = 16 + ((clientw-32) * i) / 256;
			py2 = (clienth-16) - ((clienth-32) * histogram[chan][i]) / histogram_max;

    		if (i == 0) cairo_move_to(cr, px, py2);
    		else 		cairo_line_to(cr, px, py2);

    	}
		cairo_stroke(cr);
    }

	// draw some text
    snprintf (txt, 255, "%d", histogram_max);

	for (int i = 0; i < 5; i++) {
		int dx, dy;

		switch (i) {
		case 0:
			cairo_set_source_rgb(cr, 1.0, 1.0, 1.0);
			dx = -1;
			dy = 0;
			break;
		case 1:
			dx = +1;
			dy = 0;
			break;
		case 2:
			dx = 0;
			dy = -1;
			break;
		case 3:
			dx = 0;
			dy = +1;
			break;
		case 4:
			cairo_set_source_rgb(cr, 0.1, 0.1, 0.1);
			dx = 0;
			dy = 0;
			break;
		}

		cairo_select_font_face (cr, "sans-serif", CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_BOLD);
		cairo_set_font_size (cr, 12);
		cairo_move_to (cr, 10+dx, 15+dy);
		cairo_show_text(cr, txt);
		cairo_stroke(cr);
	}
};


/*
 * test function
 */
void histogram_update(VideoFrame *vf) {

	// save some time
	static int to = 0;
	if ((++to) % 8 == 0) return;

	int chan, i, x, y;

	if (vf == NULL) return;
	if (vf->w <= 0 ) return;

	for (chan = 0; chan < 3; chan++) for (i = 0; i < 256; i++)
		histogram[chan][i] = 0;

	for (i = 0, x = 0; x < vf->w; x++) {
		for (y = 0; y < vf->h; y++) {
			for (chan = 0; chan < 3; chan++) {
				histogram[chan][vf->data[i++]]++;
			}
		}
	}

	if (histogram_da)
		gdk_window_invalidate_rect(gtk_widget_get_window(histogram_da), NULL, true);

	for (histogram_max = 0, chan = 0; chan < 3; chan++) for (i = 0; i < 256; i++)
		if (histogram_max < histogram[chan][i]) histogram_max = histogram[chan][i];
};



void cb_histogramda_motion (GtkWidget *widget, GdkEvent *event, gpointer data) {
//	printf ("%s:%d %s\n", __FILE__, __LINE__, __FUNCTION__);
};


void cb_histogramda_btnpress (GtkWidget *widget, gpointer data) {
	printf ("%s:%d %s\n", __FILE__, __LINE__, __FUNCTION__);
};


void cb_histogramda_btnrelease (GtkWidget *widget, gpointer data) {
	printf ("%s:%d %s\n", __FILE__, __LINE__, __FUNCTION__);
};