#include "deck.h"

#define MARGIN		18
#define RATIO		1.414
#define N_SLIDES	30

struct Deck
{
    DeckChangeNotify	notify;	/* Called on slide add/delete/reorder */
    gpointer		data;

    int			view_width;
    int			thumb_width;
};

Deck *
deck_new (DeckChangeNotify notify,
	  gpointer data)
{
    Deck *deck = g_new0 (Deck, 1);

    deck->notify = notify;
    deck->data = data;
    
    return deck;
}

void
deck_set_main_width (Deck *deck, int view_width)
{
    deck->view_width = view_width;
}

static int
get_slide_height (int view_width)
{
    return (view_width - 2 * MARGIN) / RATIO;
}

int
deck_get_main_slide_height (Deck *deck)
{
    return get_slide_height (deck->view_width);
}

int
deck_get_thumb_slide_height (Deck *deck)
{
    return get_slide_height (deck->thumb_width);
}

static void
deck_paint (Deck *deck,
	    cairo_t *cr,
	    int	orig_x,
	    int orig_y,
	    int width,
	    gboolean is_thumbnail)
{
    int height;
    int i;
    
    height = get_slide_height (width);

    width -= 2 * MARGIN;
    
    for (i = 0; i < N_SLIDES; ++i)
    {
	double x, y;

	x = orig_x + MARGIN;
	y = orig_y + MARGIN + i * (MARGIN + height);

	cairo_save (cr);

	cairo_set_source_rgba (cr, 0, 0, 0, 0.6);
	cairo_translate (cr, 2, 2);
	cairo_rectangle (cr, x, y, width, height);
	cairo_fill (cr);
	cairo_restore (cr);
	
	cairo_set_source_rgba (cr, 1, 1, 1, 1);
	cairo_rectangle (cr, x, y, width, height);
	cairo_fill (cr);

	cairo_rectangle (cr, x + 0.5, y + 0.5, width - 1, height - 1);
	
	cairo_set_source_rgba (cr, 0, 0, 0, 1);
	cairo_set_line_width (cr, 1);
	cairo_stroke (cr);

	cairo_set_source_rgba (cr, (i + 1.0) / N_SLIDES, 0,
			       1 - (i + 1.0) / N_SLIDES, 1);

	if (is_thumbnail)
	{
	    cairo_rectangle (cr, x + width/2 - 4, y + height/2 - 4,
			     8, 8);
	}
	else
	{
	    cairo_rectangle (cr, x + width/2 - 10, y + height/2 - 10,
			     20, 20);
	}

	cairo_fill (cr);
    }
}

void
deck_paint_main (Deck          *deck,
		 cairo_t       *cr,
		 int		orig_x,
		 int		orig_y)
{
    deck_paint (deck, cr, orig_x, orig_y, deck->view_width, FALSE);
}

void
deck_paint_thumbs (Deck *deck,
		   cairo_t *cr,
		   int x,
		   int y)
{
    deck_paint (deck, cr, x, y, deck->thumb_width, TRUE);
}

/* Returns the slide the user is likely looking
 * at, given the viewport.
 */
int
deck_get_view_slide (Deck *deck,
		     GdkRectangle *viewport)
{
    int slide_height = deck_get_main_slide_height (deck);
    
    /* Compute the y-coordinate of the first visible top edge of a slide */
    return (viewport->y - MARGIN) / (MARGIN + slide_height) + 1;
}

/* Returns the y coordinate of the nth slide given
 * the viewport
 */
int
deck_get_main_slide_location (Deck *deck,
			      int nth_slide)
{
    int slide_height = deck_get_main_slide_height (deck);
    
    return nth_slide * (MARGIN + slide_height) + MARGIN;
}

int
deck_get_thumb_slide_location (Deck *deck,
			       int nth_slide)
{
    int slide_height = deck_get_thumb_slide_height (deck);

    return nth_slide * (MARGIN + slide_height) + MARGIN;
}

int
deck_get_main_height (Deck *deck)
{
    int slide_height = deck_get_main_slide_height (deck);
    
    return N_SLIDES * slide_height + (N_SLIDES + 1) * MARGIN;
}


void
deck_set_thumb_width (Deck *deck, int thumb_width)
{
    deck->thumb_width = thumb_width;
}

int
deck_get_thumb_height (Deck *deck)
{
    int thumb_height = deck_get_thumb_slide_height (deck);
    
    return N_SLIDES * thumb_height + (N_SLIDES + 1) * MARGIN;
}