/*
 * This source file is part of RmlUi, the HTML/CSS Interface Middleware
 *
 * For the latest information, see http://github.com/mikke89/RmlUi
 *
 * Copyright (c) 2008-2010 CodePoint Ltd, Shift Technology Ltd
 * Copyright (c) 2019 The RmlUi Team, and contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 */

#include "DecoratorTiledBox.h"
#include "../../Include/RmlUi/Core/Element.h"
#include "../../Include/RmlUi/Core/Geometry.h"

namespace Rml {

struct DecoratorTiledBoxData
{
	DecoratorTiledBoxData(Element* host_element, int num_textures) : num_textures(num_textures)
	{
		geometry = new Geometry[num_textures];
		for (int i = 0; i < num_textures; i++)
			geometry[i].SetHostElement(host_element);
	}

	~DecoratorTiledBoxData()
	{
		delete[] geometry;
	}

	const int num_textures;
	Geometry* geometry;
};

DecoratorTiledBox::DecoratorTiledBox()
{
}

DecoratorTiledBox::~DecoratorTiledBox()
{
}

// Initialises the tiles for the decorator.
bool DecoratorTiledBox::Initialise(const Tile* _tiles, const Texture* _textures)
{
	// Load the textures.
	for (int i = 0; i < 9; i++)
	{
		tiles[i] = _tiles[i];
		tiles[i].texture_index = AddTexture(_textures[i]);
	}

	// All corners must have a valid texture.
	for (int i = TOP_LEFT_CORNER; i <= BOTTOM_RIGHT_CORNER; i++)
	{
		if (tiles[i].texture_index == -1)
			return false;
	}
	// Check that the centre tile has been specified.
	if (tiles[CENTRE].texture_index < 0)
		return false;

	// If only one side of the left / right edges have been configured, then mirror the tile for the other side.
	if (tiles[LEFT_EDGE].texture_index == -1 && tiles[RIGHT_EDGE].texture_index > -1)
	{
		tiles[LEFT_EDGE] = tiles[RIGHT_EDGE];
		tiles[LEFT_EDGE].orientation = FLIP_HORIZONTAL;
	}
	else if (tiles[RIGHT_EDGE].texture_index == -1 && tiles[LEFT_EDGE].texture_index > -1)
	{
		tiles[RIGHT_EDGE] = tiles[LEFT_EDGE];
		tiles[RIGHT_EDGE].orientation = FLIP_HORIZONTAL;
	}
	else if (tiles[LEFT_EDGE].texture_index == -1 && tiles[RIGHT_EDGE].texture_index == -1)
		return false;

	// If only one side of the top / bottom edges have been configured, then mirror the tile for the other side.
	if (tiles[TOP_EDGE].texture_index == -1 && tiles[BOTTOM_EDGE].texture_index > -1)
	{
		tiles[TOP_EDGE] = tiles[BOTTOM_EDGE];
		tiles[TOP_EDGE].orientation = FLIP_VERTICAL;
	}
	else if (tiles[BOTTOM_EDGE].texture_index == -1 && tiles[TOP_EDGE].texture_index > -1)
	{
		tiles[BOTTOM_EDGE] = tiles[TOP_EDGE];
		tiles[BOTTOM_EDGE].orientation = FLIP_VERTICAL;
	}
	else if (tiles[TOP_EDGE].texture_index == -1 && tiles[BOTTOM_EDGE].texture_index == -1)
		return false;

	return true;
}

// Called on a decorator to generate any required per-element data for a newly decorated element.
DecoratorDataHandle DecoratorTiledBox::GenerateElementData(Element* element) const
{
	// Initialise the tiles for this element.
	for (int i = 0; i < 9; i++)
	{
		RMLUI_ASSERT(tiles[i].texture_index >= 0);
		tiles[i].CalculateDimensions(element, *GetTexture(tiles[i].texture_index));
	}

	Vector2f padded_size = element->GetBox().GetSize(Box::PADDING);


	// Calculate the natural dimensions of tile corners and edges.
	const Vector2f natural_top_left = tiles[TOP_LEFT_CORNER].GetNaturalDimensions(element);
	const Vector2f natural_top = tiles[TOP_EDGE].GetNaturalDimensions(element);
	const Vector2f natural_top_right = tiles[TOP_RIGHT_CORNER].GetNaturalDimensions(element);

	const Vector2f natural_bottom_left = tiles[BOTTOM_LEFT_CORNER].GetNaturalDimensions(element);
	const Vector2f natural_bottom = tiles[BOTTOM_EDGE].GetNaturalDimensions(element);
	const Vector2f natural_bottom_right = tiles[BOTTOM_RIGHT_CORNER].GetNaturalDimensions(element);

	const Vector2f natural_left = tiles[LEFT_EDGE].GetNaturalDimensions(element);
	const Vector2f natural_right = tiles[RIGHT_EDGE].GetNaturalDimensions(element);

	// Initialize the to-be-determined dimensions of the tiles.
	Vector2f top_left = natural_top_left;
	Vector2f top = natural_top;
	Vector2f top_right = natural_top_right;

	Vector2f bottom_left = natural_bottom_left;
	Vector2f bottom = natural_bottom;
	Vector2f bottom_right = natural_bottom_right;
	
	Vector2f left = natural_left;
	Vector2f right = natural_right;

	// Scale the top corners down if appropriate. If they are scaled, then the left and right edges are also scaled
	// if they shared a width with their corner. Best solution? Don't know.
	if (padded_size.x < top_left.x + top_right.x)
	{
		float minimum_width = top_left.x + top_right.x;

		top_left.x = padded_size.x * (top_left.x / minimum_width);
		if (natural_top_left.x == natural_left.x)
			left.x = top_left.x;

		top_right.x = padded_size.x * (top_right.x / minimum_width);
		if (natural_top_right.x == natural_right.x)
			right.x = top_right.x;
	}

	// Scale the bottom corners down if appropriate. If they are scaled, then the left and right edges are also scaled
	// if they shared a width with their corner. Best solution? Don't know.
	if (padded_size.x < bottom_left.x + bottom_right.x)
	{
		float minimum_width = bottom_left.x + bottom_right.x;

		bottom_left.x = padded_size.x * (bottom_left.x / minimum_width);
		if (natural_bottom_left.x == natural_left.x)
			left.x = bottom_left.x;

		bottom_right.x = padded_size.x * (bottom_right.x / minimum_width);
		if (natural_bottom_right.x == natural_right.x)
			right.x = bottom_right.x;
	}

	// Scale the left corners down if appropriate. If they are scaled, then the top and bottom edges are also scaled
	// if they shared a width with their corner. Best solution? Don't know.
	if (padded_size.y < top_left.y + bottom_left.y)
	{
		float minimum_height = top_left.y + bottom_left.y;

		top_left.y = padded_size.y * (top_left.y / minimum_height);
		if (natural_top_left.y == natural_top.y)
			top.y = top_left.y;

		bottom_left.y = padded_size.y * (bottom_left.y / minimum_height);
		if (natural_bottom_left.y == natural_bottom.y)
			bottom.y = bottom_left.y;
	}

	// Scale the right corners down if appropriate. If they are scaled, then the top and bottom edges are also scaled
	// if they shared a width with their corner. Best solution? Don't know.
	if (padded_size.y < top_right.y + bottom_right.y)
	{
		float minimum_height = top_right.y + bottom_right.y;

		top_right.y = padded_size.y * (top_right.y / minimum_height);
		if (natural_top_right.y == natural_top.y)
			top.y = top_right.y;

		bottom_right.y = padded_size.y * (bottom_right.y / minimum_height);
		if (natural_bottom_right.y == natural_bottom.y)
			bottom.y = bottom_right.y;
	}

	const int num_textures = GetNumTextures();
	DecoratorTiledBoxData* data = new DecoratorTiledBoxData(element, num_textures);

	// Generate the geometry for the top-left tile.
	tiles[TOP_LEFT_CORNER].GenerateGeometry(data->geometry[tiles[TOP_LEFT_CORNER].texture_index].GetVertices(),
											data->geometry[tiles[TOP_LEFT_CORNER].texture_index].GetIndices(),
											element,
											Vector2f(0, 0),
											top_left,
											top_left);
	// Generate the geometry for the top edge tiles.
	tiles[TOP_EDGE].GenerateGeometry(data->geometry[tiles[TOP_EDGE].texture_index].GetVertices(),
									 data->geometry[tiles[TOP_EDGE].texture_index].GetIndices(),
									 element,
									 Vector2f(top_left.x, 0),
									 Vector2f(padded_size.x - (top_left.x + top_right.x), top.y),
									 top);
	// Generate the geometry for the top-right tile.
	tiles[TOP_RIGHT_CORNER].GenerateGeometry(data->geometry[tiles[TOP_RIGHT_CORNER].texture_index].GetVertices(),
											 data->geometry[tiles[TOP_RIGHT_CORNER].texture_index].GetIndices(),
											 element,
											 Vector2f(padded_size.x - top_right.x, 0),
											 top_right,
											 top_right);

	// Generate the geometry for the left side.
	tiles[LEFT_EDGE].GenerateGeometry(data->geometry[tiles[LEFT_EDGE].texture_index].GetVertices(),
									  data->geometry[tiles[LEFT_EDGE].texture_index].GetIndices(),
									  element,
									  Vector2f(0, top_left.y),
									  Vector2f(left.x, padded_size.y - (top_left.y + bottom_left.y)),
									  left);

	// Generate the geometry for the right side.
	tiles[RIGHT_EDGE].GenerateGeometry(data->geometry[tiles[RIGHT_EDGE].texture_index].GetVertices(),
									   data->geometry[tiles[RIGHT_EDGE].texture_index].GetIndices(),
									   element,
									   Vector2f((padded_size.x - right.x), top_right.y),
									   Vector2f(right.x, padded_size.y - (top_right.y + bottom_right.y)),
									   right);

	// Generate the geometry for the bottom-left tile.
	tiles[BOTTOM_LEFT_CORNER].GenerateGeometry(data->geometry[tiles[BOTTOM_LEFT_CORNER].texture_index].GetVertices(),
											   data->geometry[tiles[BOTTOM_LEFT_CORNER].texture_index].GetIndices(),
											   element,
											   Vector2f(0, padded_size.y - bottom_left.y),
											   bottom_left,
											   bottom_left);
	// Generate the geometry for the bottom edge tiles.
	tiles[BOTTOM_EDGE].GenerateGeometry(data->geometry[tiles[BOTTOM_EDGE].texture_index].GetVertices(),
										data->geometry[tiles[BOTTOM_EDGE].texture_index].GetIndices(),
										element,
										Vector2f(bottom_left.x, padded_size.y - bottom.y),
										Vector2f(padded_size.x - (bottom_left.x + bottom_right.x), bottom.y),
										bottom);
	// Generate the geometry for the bottom-right tile.
	tiles[BOTTOM_RIGHT_CORNER].GenerateGeometry(data->geometry[tiles[BOTTOM_RIGHT_CORNER].texture_index].GetVertices(),
												data->geometry[tiles[BOTTOM_RIGHT_CORNER].texture_index].GetIndices(),
												element,
												Vector2f(padded_size.x - bottom_right.x, padded_size.y - bottom_right.y),
												bottom_right,
												bottom_right);

	// Generate the centre geometry.
	Vector2f centre_dimensions = tiles[CENTRE].GetNaturalDimensions(element);
	Vector2f centre_surface_dimensions(padded_size.x - (left.x + right.x),
											padded_size.y - (top.y + bottom.y));

	tiles[CENTRE].GenerateGeometry(data->geometry[tiles[CENTRE].texture_index].GetVertices(),
									data->geometry[tiles[CENTRE].texture_index].GetIndices(),
									element,
									Vector2f(left.x, top.y),
									centre_surface_dimensions,
									centre_dimensions);

	// Set the textures on the geometry.
	const Texture* texture = nullptr;
	int texture_index = 0;
	while ((texture = GetTexture(texture_index)) != nullptr)
		data->geometry[texture_index++].SetTexture(texture);

	return reinterpret_cast<DecoratorDataHandle>(data);
}

// Called to release element data generated by this decorator.
void DecoratorTiledBox::ReleaseElementData(DecoratorDataHandle element_data) const
{
	delete reinterpret_cast< DecoratorTiledBoxData* >(element_data);
}

// Called to render the decorator on an element.
void DecoratorTiledBox::RenderElement(Element* element, DecoratorDataHandle element_data) const
{
	Vector2f translation = element->GetAbsoluteOffset(Box::PADDING).Round();
	DecoratorTiledBoxData* data = reinterpret_cast< DecoratorTiledBoxData* >(element_data);

	for (int i = 0; i < data->num_textures; i++)
		data->geometry[i].Render(translation);
}

} // namespace Rml