#include "composite_widget.h"

#include "string.h"
#include <stddef.h>

static composite_widget_vtable_t const composite_widget_vtable = {
	{
		composite_widget_draw,
		composite_widget_get_focus,
		widget_model_to_screen,
		widget_contains_coordinate,
		composite_widget_on_mouse_down,
		composite_widget_on_mouse_up,
		composite_widget_on_mouse_move,
		composite_widget_on_key_down,
		composite_widget_on_key_up
	},
	composite_widget_add_child
};

void composite_widget_init( composite_widget_t *widget, widget_t *parent, const int x, const int y, const int w, const int h, const vga_color_t background_color )
{
	memset( widget, 0, sizeof( composite_widget_t ) );

	widget_init( &widget->base, parent, x, y, w, h, background_color );	

	widget->nof_children = 0;
	widget->focused_child = NULL;
	memset( widget->children, 0, MAX_NOF_WIDGET_CHILDREN * sizeof( widget_t * ) );

	((widget_t *)widget)->vtable = (widget_vtable_t *)&composite_widget_vtable;
}

void composite_widget_draw( void *obj, graphics_context_t *context )
{
	composite_widget_t *widget = obj;

	widget_draw( obj, context );

	for( int i = widget->nof_children - 1; i >= 0; i-- ) {
		widget_t *child = widget->children[i];
		child->vtable->draw( child, context );
	}
}

void composite_widget_get_focus( void *obj, widget_t *widget )
{
	composite_widget_t *o = obj;

	o->focused_child = widget;

	widget_get_focus( o, widget );
}

void composite_widget_add_child( void *obj, widget_t *child )
{
	composite_widget_t *widget = obj;

	if( widget->nof_children >= MAX_NOF_WIDGET_CHILDREN ) {
		// TODO: kernel_panic, but in an indirect way because
		// the GUI framework should not depend on the kernel.
		// Maybe something like a runtime context similar to
		// the graphics context?
		return;
	}

	widget->children[widget->nof_children++] = child;
}

void composite_widget_on_mouse_down( void *obj, const int x, const int y )
{
	composite_widget_t *widget = obj;

	for( int i = 0; i < widget->nof_children; i++ ) {
		widget_t *child = widget->children[i];
		if( child->vtable->contains_coordinate( child, x - widget->base.x, y - widget->base.y ) ) {
			child->vtable->on_mouse_down( child, x - widget->base.x, y - widget->base.y );
			break;
		}	
	}
}

void composite_widget_on_mouse_up( void *obj, const int x, const int y )
{
	composite_widget_t *widget = obj;

	for( int i = 0; i < widget->nof_children; i++ ) {
		widget_t *child = widget->children[i];
		if( child->vtable->contains_coordinate( child, x - widget->base.x, y - widget->base.y ) ) {
			child->vtable->on_mouse_up( child, x - widget->base.x, y - widget->base.y );
			break;
		}	
	}
}

void composite_widget_on_mouse_move( void *obj, const int old_x, const int old_y, const int x, const int y )
{
	composite_widget_t *widget = obj;
	widget_t *moved_out_from = NULL;

	// TODO: have a mouse leave and mouse enter event instead

	for( int i = 0; i < widget->nof_children; i++ ) {
		widget_t *child = widget->children[i];
		if( child->vtable->contains_coordinate( child, old_x - widget->base.x, old_y - widget->base.y ) ) {
			child->vtable->on_mouse_move( child, old_x - widget->base.x, old_y - widget->base.y, x - widget->base.x, y - widget->base.y );
			moved_out_from = child;
			break;
		}	
	}

	for( int i = 0; i < widget->nof_children; i++ ) {
		widget_t *child = widget->children[i];
		if( child->vtable->contains_coordinate( child, x - widget->base.x, y - widget->base.y ) ) {
			if( moved_out_from != NULL ) {
				child->vtable->on_mouse_move( child, old_x - widget->base.x, old_y - widget->base.y, x - widget->base.x, y - widget->base.y );
				break;
			}
		}	
	}
}

void composite_widget_on_key_down( void *obj, char c )
{
	composite_widget_t *widget = obj;

	if( widget->focused_child != NULL ) {
		widget->focused_child->vtable->on_key_down( widget->focused_child, c );
	}
}

void composite_widget_on_key_up( void *obj, char c )
{
	composite_widget_t *widget = obj;

	if( widget->focused_child != NULL ) {
		widget->focused_child->vtable->on_key_up( widget->focused_child, c );
	}
}