/*
 * Helpers for ui data structures.
 */

// TOP

static UI_Item*
ui_list_add_item(Partition *arena, UI_List *list, UI_Item item){
    UI_Item_Node *node = push_array(arena, UI_Item_Node, 1);
    zdll_push_back(list->first, list->last, node);
    list->count += 1;
    node->fixed = item;
    return(&node->fixed);
}

static UI_Control
ui_list_to_ui_control(Partition *arena, UI_List *list){
    UI_Control control = {0};
    control.items = push_array(arena, UI_Item, list->count);
    if (list->count > 0){
        control.bounding_box = list->first->fixed.rectangle;
    }
    for (UI_Item_Node *node = list->first;
         node != 0;
         node = node->next){
        control.items[control.count++] = node->fixed;
        if (control.bounding_box.x0 > node->fixed.rectangle.x0){
            control.bounding_box.x0 = node->fixed.rectangle.x0;
        }
        if (control.bounding_box.x1 < node->fixed.rectangle.x1){
            control.bounding_box.x1 = node->fixed.rectangle.x1;
        }
        if (control.bounding_box.y0 > node->fixed.rectangle.y0){
            control.bounding_box.y0 = node->fixed.rectangle.y0;
        }
        if (control.bounding_box.y1 < node->fixed.rectangle.y1){
            control.bounding_box.y1 = node->fixed.rectangle.y1;
        }
    }
    return(control);
}

static void
ui_control_set_top(UI_Control *control, int32_t top_y){
    control->bounding_box.y0 = top_y;
}

static void
ui_control_set_bottom(UI_Control *control, int32_t bottom_y){
    control->bounding_box.y1 = bottom_y;
}

static UI_Item*
ui_control_get_mouse_hit(UI_Control *control, int32_t mx, int32_t my){
    if (control->bounding_box.x0 <= mx && mx < control->bounding_box.x1 &&
        control->bounding_box.y0 <= my && my < control->bounding_box.y1){
        int32_t count = control->count;
        UI_Item *item = control->items + count - 1;
        for (int32_t i = 0; i < count; ++i, item -= 1){
            i32_Rect r = item->rectangle;
            if (r.x0 <= mx && mx < r.x1 && r.y0 <= my && my < r.y1){
                return(item);
            }
        }
    }
    return(0);
}

// BOTTOM