/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#include "engines/util.h"
#include "mads/compression.h"
#include "mads/graphics.h"
#include "mads/mads.h"
#include "mads/msprite.h"
#include "mads/msurface.h"
#include "mads/resources.h"

namespace MADS {

MADSEngine *MSurface::_vm = nullptr;

MSurface::MSurface() {
	pixels = nullptr;
}

MSurface::MSurface(int width, int height) { 
	pixels = nullptr;
	setSize(width, height); 
}

MSurface::~MSurface() {
	Graphics::Surface::free();
}

void MSurface::setSize(int width, int height) {
	Graphics::Surface::free();
	Graphics::Surface::create(width, height, Graphics::PixelFormat::createFormatCLUT8());
}

int MSurface::scaleValue(int value, int scale, int err) {
	int scaled = 0;
	while (value--) {
		err -= scale;
		while (err < 0) {
			scaled++;
			err += 100;
		}
	}
	return scaled;
}

void MSurface::drawSprite(const Common::Point &pt, SpriteInfo &info, const Common::Rect &clipRect) {

	enum {
		kStatusSkip,
		kStatusScale,
		kStatusDraw
	};

	// NOTE: The current clipping code assumes that the top left corner of the clip
	// rectangle is always 0, 0
	assert(clipRect.top == 0 && clipRect.left == 0);

	// TODO: Put err* and scaled* into SpriteInfo
	int errX = info.hotX * info.scaleX % 100;
	int errY = info.hotY * info.scaleY % 100;
	int scaledWidth = scaleValue(info.width, info.scaleX, errX);
	int scaledHeight = scaleValue(info.height, info.scaleY, errY);

	int x = pt.x, y = pt.y;
	int clipX = 0, clipY = 0;
	// Clip the sprite's width and height according to the clip rectangle's dimensions
	// This clips the sprite to the bottom and right
	if (x >= 0) {
		scaledWidth = MIN<int>(x + scaledWidth, clipRect.right) - x;
	} else {
		clipX = x;
		scaledWidth = x + scaledWidth;
	}
	if (y >= 0) {
		scaledHeight = MIN<int>(y + scaledHeight, clipRect.bottom) - y;
	} else {
		clipY = y;
		scaledHeight = y + scaledHeight;
	}

	// Check if sprite is inside the screen. If it's not, there's no need to draw it
	if (scaledWidth + x <= 0 || scaledHeight + y <= 0)	// check left and top (in case x,y are negative)
		return;
	if (scaledWidth <= 0 || scaledHeight <= 0)			// check right and bottom
		return;
	int heightAmt = scaledHeight;

	byte *src = info.sprite->getData();
	byte *dst = getBasePtr(x - info.hotX - clipX, y - info.hotY - clipY);

	int status = kStatusSkip;
	byte *scaledLineBuf = new byte[scaledWidth];

	while (heightAmt > 0) {

		if (status == kStatusSkip) {
			// Skip line
			errY -= info.scaleY;
			if (errY < 0)
				status = kStatusScale;
			else
				src += info.width;
		} else {

			if (status == kStatusScale) {
				// Scale current line
				byte *lineDst = scaledLineBuf;
				int curErrX = errX;
				int width = scaledWidth;
				byte *tempSrc = src;
				int startX = clipX;
				while (width > 0) {
					byte pixel = *tempSrc++;
					curErrX -= info.scaleX;
					while (curErrX < 0) {
						if (startX == 0) {
							*lineDst++ = pixel;
							width--;
						} else {
							startX++;
						}
						curErrX += 100;
					}
				}
				src += info.width;
				status = kStatusDraw;
			}

			if (status == kStatusDraw && clipY == 0) {
				// Draw previously scaled line
				// TODO Implement different drawing types (depth, shadow etc.)
				byte *tempDst = dst;
				for (int lineX = 0; lineX < scaledWidth; lineX++) {
					byte pixel = scaledLineBuf[lineX];

					if (info.encoding & 0x80) {

						if (pixel == 0x80) {
							pixel = 0;
						} else {
							byte destPixel = *tempDst;
							byte r, g, b;
							r = CLIP((info.palette[destPixel * 3] * pixel) >> 10, 0, 31);
							g = CLIP((info.palette[destPixel * 3 + 1] * pixel) >> 10, 0, 31);
							b = CLIP((info.palette[destPixel * 3 + 2] * pixel) >> 10, 0, 31);
							pixel = info.inverseColorTable[(b << 10) | (g << 5) | r];
						}
					}

					if (pixel)
						*tempDst = pixel;

					tempDst++;
				}
				dst += pitch;
				heightAmt--;
				// TODO depth etc.
				//depthAddress += Destination -> Width;

				errY += 100;
				if (errY >= 0)
					status = kStatusSkip;
			} else if (status == kStatusDraw && clipY < 0) {
				clipY++;

				errY += 100;
				if (errY >= 0)
					status = kStatusSkip;
			}

		}

	}
	
	delete[] scaledLineBuf;

}

void MSurface::empty() {
	Common::fill(getBasePtr(0, 0), getBasePtr(0, h), _vm->_palette->BLACK);
}

void MSurface::updateScreen() { 
	g_system->copyRectToScreen((const byte *)pixels, pitch, 0, 0, w, h);
	g_system->updateScreen(); 
}

void MSurface::copyFrom(MSurface *src, const Common::Rect &srcBounds, 
		const Common::Point &destPos, int transparentColor) {
	// Validation of the rectangle and position	
	int destX = destPos.x, destY = destPos.y;		
	if ((destX >= w) || (destY >= h))
		return;

	Common::Rect copyRect = srcBounds;
	if (destX < 0) {
		copyRect.left += -destX;
		destX = 0;
	} else if (destX + copyRect.width() > w) {
		copyRect.right -= destX + copyRect.width() - w;
	}
	if (destY < 0) {
		copyRect.top += -destY;
		destY = 0;
	} else if (destY + copyRect.height() > h) {
		copyRect.bottom -= destY + copyRect.height() - h;
	}

	if (!copyRect.isValidRect())
		return;

	// Copy the specified area

	byte *data = src->getData();
	byte *srcPtr = data + (src->getWidth() * copyRect.top + copyRect.left);
	byte *destPtr = (byte *)pixels + (destY * getWidth()) + destX;

	for (int rowCtr = 0; rowCtr < copyRect.height(); ++rowCtr) {
		if (transparentColor == -1)
			// No transparency, so copy line over
			Common::copy(srcPtr, srcPtr + copyRect.width(), destPtr);
		else {
			// Copy each byte one at a time checking for the transparency color
			for (int xCtr = 0; xCtr < copyRect.width(); ++xCtr)
				if (srcPtr[xCtr] != transparentColor) destPtr[xCtr] = srcPtr[xCtr];
		}

		srcPtr += src->getWidth();
		destPtr += getWidth();
	}
}

void MSurface::translate(Common::Array<RGB6> &palette) {
	for (int y = 0; y < this->h; ++y) {
		byte *pDest = getBasePtr(0, y);

		for (int x = 0; x < this->w; ++x, ++pDest) {
			*pDest = palette[*pDest].palIndex;
		}
	}
}

} // End of namespace MADS