#include "graphics/tinygl/zblit.h"
#include "graphics/tinygl/zgl.h"
#include "graphics/pixelbuffer.h"
#include "common/array.h"
#include <math.h>

namespace Graphics {

Common::Point transformPoint(float x, float y, int rotation);
Common::Rect rotateRectangle(int x, int y, int width, int height, int rotation, int originX, int originY);

struct BlitImage {
public:
	BlitImage() { }

	void loadData(const Graphics::Surface &surface, uint32 colorKey, bool applyColorKey) {
		Graphics::PixelFormat textureFormat(4, 8, 8, 8, 8, 0, 8, 16, 24);
		_surface.create(surface.w, surface.h, textureFormat);
		Graphics::PixelBuffer buffer(surface.format, (byte *)surface.getPixels());
		Graphics::PixelBuffer dataBuffer(textureFormat, (byte *)_surface.getPixels());
		dataBuffer.copyBuffer(0, 0, surface.w * surface.h, buffer);
		if (applyColorKey) {
			for (int x = 0;  x < surface.w; x++) {
				for (int y = 0; y < surface.h; y++) {
					uint32 pixel = dataBuffer.getValueAt(y * surface.w + x);
					if (pixel == colorKey) {
						dataBuffer.setPixelAt(y * surface.w + x, 0, 255, 255, 255); // Color keyed pixels become transparent white.
					}
				}
			}
		}

		// Create opaque lines data.
		// A line of pixels can not wrap more that one line of the image, since it would break
		// blitting of bitmaps with a non-zero x position.
		Graphics::PixelBuffer srcBuf = dataBuffer;
		_lines.clear();
		for (int y = 0; y < surface.h; y++) {
			int start = -1;
			for (int x = 0; x < surface.w; ++x) {
				// We found a transparent pixel, so save a line from 'start' to the pixel before this.
				uint8 r, g, b, a;
				srcBuf.getARGBAt(x, a, r, g, b);
				if (a == 0 && start >= 0) {
					_lines.push_back(Line(start, y, x - start, srcBuf.getRawBuffer(start)));
					start = -1;
				} else if (a != 0 && start == -1) {
					start = x;
				}
			}
			// end of the bitmap line. if start is an actual pixel save the line.
			if (start >= 0) {
				_lines.push_back(Line(start, y, surface.w- start, srcBuf.getRawBuffer(start)));
			}
			srcBuf.shiftBy(surface.w);
		}
	}

	~BlitImage() {
		_surface.free();
	}

	struct Line {
		int _x;
		int _y;
		int _length;
		byte *_pixels;
		Graphics::PixelBuffer _buf; // This is needed for the conversion.

		Line() { }
		Line(int x, int y, int length, byte *pixels) : _buf(TinyGL::gl_get_context()->fb->cmode, length * TinyGL::gl_get_context()->fb->cmode.bytesPerPixel, DisposeAfterUse::NO) {
			_x = x;
			_y = y;
			_length = length;
			// Performing texture to screen conversion.
			Graphics::PixelFormat textureFormat(4, 8, 8, 8, 8, 0, 8, 16, 24);
			Graphics::PixelBuffer srcBuf(textureFormat, pixels);
			_buf.copyBuffer(0, 0, length, srcBuf);
			_pixels = _buf.getRawBuffer();
		}

		Line(const Line& other) : _buf(TinyGL::gl_get_context()->fb->cmode, other._length * TinyGL::gl_get_context()->fb->cmode.bytesPerPixel, DisposeAfterUse::NO) {
			_x = other._x;
			_y = other._y;
			_length = other._length;
			_buf.copyBuffer(0, 0, _length, other._buf);
			_pixels = _buf.getRawBuffer();
		}

		~Line() {
			_buf.free();
		}
	};

	Common::Array<Line> _lines;
	Graphics::Surface _surface;
};

BlitImage *tglGenBlitImage() {
	TinyGL::GLContext *c = TinyGL::gl_get_context();
	BlitImage *image = new BlitImage();
	c->blitImages.push_back(image);
	return image;
}

void tglUploadBlitImage(BlitImage *blitImage, const Graphics::Surface& surface, uint32 colorKey, bool applyColorKey) {
	if (blitImage != nullptr) {
		blitImage->loadData(surface, colorKey, applyColorKey);
	}
}

void tglDeleteBlitImage(BlitImage *blitImage) {
	if (blitImage != nullptr) {
		TinyGL::GLContext *c = TinyGL::gl_get_context();
		for (uint32 i = 0; i < c->blitImages.size(); i++) {
			if (c->blitImages[i] == blitImage) {
				c->blitImages.remove_at(i);
				break;
			}
		}
		delete blitImage;
	}
}

FORCEINLINE bool clipBlitImage(BlitImage *blitImage, TinyGL::GLContext *c, int &srcWidth, int &srcHeight, int &width, int &height, int &dstX, int &dstY, int &clampWidth, int &clampHeight) {
	if (srcWidth == 0 || srcHeight == 0) {
		srcWidth = blitImage->_surface.w;
		srcHeight = blitImage->_surface.h;
	}

	if (width == 0 && height == 0) {
		width = srcWidth;
		height = srcHeight;
	}

	if (dstX >= c->fb->xsize|| dstY >= c->fb->ysize)
		return false;

	if (dstX + width > c->fb->xsize)
		clampWidth = c->fb->xsize - dstX;
	else
		clampWidth = width;

	if (dstY + height > c->fb->ysize)
		clampHeight = c->fb->ysize - dstY;
	else
		clampHeight = height;

	if (dstX < 0) 
		dstX = 0;
	if (dstY < 0)
		dstY = 0;

	return true;
}

template <bool disableColoring>
void tglBlitRLE(BlitImage *blitImage, int dstX, int dstY, int srcX, int srcY, int srcWidth, int srcHeight, float aTint, float rTint, float gTint, float bTint) {
	TinyGL::GLContext *c = TinyGL::gl_get_context();

	int clampWidth, clampHeight;
	int width = srcWidth, height = srcHeight;
	if (clipBlitImage(blitImage, c, srcWidth, srcHeight, width, height, dstX, dstY, clampWidth, clampHeight) == false)
		return;

	Graphics::PixelBuffer srcBuf(blitImage->_surface.format, (byte *)blitImage->_surface.getPixels());
	srcBuf.shiftBy(srcX + (srcY * blitImage->_surface.w));

	Graphics::PixelBuffer dstBuf(c->fb->cmode, c->fb->getPixelBuffer());

	const int kBytesPerPixel = 2;

	int lineIndex = 0;
	int maxY = srcY + clampHeight;
	int maxX = srcX + clampWidth;
	while (lineIndex < blitImage->_lines.size() && blitImage->_lines[lineIndex]._y < srcY) {
		lineIndex++;
	}
	while (lineIndex < blitImage->_lines.size() && blitImage->_lines[lineIndex]._y < maxY) {
		const BlitImage::Line &l = blitImage->_lines[lineIndex];
		if (l._x < maxX && l._x + l._length > srcX) {
			int length = l._length;
			int skipStart = (l._x < srcX) ? (srcX - l._x) : 0;
			length -= skipStart;
			int skipEnd   = (l._x + l._length > maxX) ? (l._x + l._length - maxX) : 0;
			length -= skipEnd;
			if (disableColoring) {
				memcpy(dstBuf.getRawBuffer((l._y - srcY) * c->fb->xsize + MAX(l._x - srcX, 0)),
					l._pixels + skipStart * kBytesPerPixel, length * kBytesPerPixel);
			} else {
				int xStart = MAX(l._x - srcX, 0);
				for(int x = xStart; x < xStart + length; x++) {
					byte aDst, rDst, gDst, bDst;
					srcBuf.getARGBAt((l._y - srcY) *c->fb->xsize + x, aDst, rDst, gDst, bDst);
					c->fb->writePixel((dstX + x) + (dstY + (l._y - srcY)) * c->fb->xsize, aDst * aTint, rDst * rTint, gDst * gTint, bDst * bTint);
				}
			}
		}
		lineIndex++;
	}
}

template <bool disableBlending, bool disableColoring, bool flipVertical, bool flipHorizontal>
void tglBlitSimple(BlitImage *blitImage, int dstX, int dstY, int srcX, int srcY, int srcWidth, int srcHeight, float aTint, float rTint, float gTint, float bTint) {
	TinyGL::GLContext *c = TinyGL::gl_get_context();

	int clampWidth, clampHeight;
	int width = srcWidth, height = srcHeight;
	if (clipBlitImage(blitImage, c, srcWidth, srcHeight, width, height, dstX, dstY, clampWidth, clampHeight) == false)
		return;

	Graphics::PixelBuffer srcBuf(blitImage->_surface.format, (byte *)blitImage->_surface.getPixels());

	if (flipVertical) {
		srcBuf.shiftBy(srcX + ((srcY + srcHeight - 1) * blitImage->_surface.w));
	} else {
		srcBuf.shiftBy(srcX + (srcY * blitImage->_surface.w));
	}

	Graphics::PixelBuffer dstBuf(c->fb->cmode, c->fb->getPixelBuffer());

	for (int l = 0; l < clampHeight; l++) {
		for (int r = 0; r < clampWidth; ++r) {
			byte aDst, rDst, gDst, bDst;
			if (flipHorizontal) {
				srcBuf.getARGBAt(clampWidth - r, aDst, rDst, gDst, bDst);
			} else {
				srcBuf.getARGBAt(r, aDst, rDst, gDst, bDst);
			}
			if (disableColoring) {
				if (disableBlending && aDst != 0) {
					dstBuf.setPixelAt((dstX + r) + (dstY + l) * c->fb->xsize, aDst, rDst, gDst, bDst);
				} else {
					c->fb->writePixel((dstX + r) + (dstY + l) * c->fb->xsize, aDst, rDst, gDst, bDst);
				}
			} else {
				if (disableBlending && aDst * aTint != 0) {
					dstBuf.setPixelAt((dstX + r) + (dstY + l) * c->fb->xsize, aDst * aTint, rDst * rTint, gDst * gTint, bDst * bTint);
				} else {
					c->fb->writePixel((dstX + r) + (dstY + l) * c->fb->xsize, aDst * aTint, rDst * rTint, gDst * gTint, bDst * bTint);
				}
			}
		}
		if (flipVertical) {
			srcBuf.shiftBy(-blitImage->_surface.w);
		} else {
			srcBuf.shiftBy(blitImage->_surface.w);
		}
	}
}

template <bool disableBlending, bool disableColoring, bool flipVertical, bool flipHorizontal>
void tglBlitScale(BlitImage *blitImage, int dstX, int dstY, int width, int height, int srcX, int srcY, int srcWidth, int srcHeight,
					 float aTint, float rTint, float gTint, float bTint) {
	TinyGL::GLContext *c = TinyGL::gl_get_context();

	int clampWidth, clampHeight;
	if (clipBlitImage(blitImage, c, srcWidth, srcHeight, width, height, dstX, dstY, clampWidth, clampHeight) == false)
		return;

	Graphics::PixelBuffer srcBuf(blitImage->_surface.format, (byte *)blitImage->_surface.getPixels());
	srcBuf.shiftBy(srcX + (srcY * blitImage->_surface.w));

	Graphics::PixelBuffer dstBuf(c->fb->cmode, c->fb->getPixelBuffer());

	for (int l = 0; l < clampHeight; l++) {
		for (int r = 0; r < clampWidth; ++r) {
			byte aDst, rDst, gDst, bDst;
			int xSource, ySource;
			if (flipVertical) {
				ySource = clampHeight - l - 1;
			} else {
				ySource = l;
			}

			if (flipHorizontal) {
				xSource = clampWidth - r - 1;
			} else {
				xSource = r;
			}

			srcBuf.getARGBAt(((ySource * srcHeight) / height) * blitImage->_surface.w + ((xSource * srcWidth) / width), aDst, rDst, gDst, bDst);

			if (disableColoring) {
				if (disableBlending && aDst != 0) {
					dstBuf.setPixelAt((dstX + r) + (dstY + l) * c->fb->xsize, aDst, rDst, gDst, bDst);
				} else {
					c->fb->writePixel((dstX + r) + (dstY + l) * c->fb->xsize, aDst, rDst, gDst, bDst);
				}
			} else {
				if (disableBlending && aDst * aTint != 0) {
					dstBuf.setPixelAt((dstX + r) + (dstY + l) * c->fb->xsize, aDst * aTint, rDst * rTint, gDst * gTint, bDst * bTint);
				} else {
					c->fb->writePixel((dstX + r) + (dstY + l) * c->fb->xsize, aDst * aTint, rDst * rTint, gDst * gTint, bDst * bTint);
				}
			}
		}
	}
}

template <bool disableBlending, bool disableColoring, bool flipVertical, bool flipHorizontal>
void tglBlitRotoScale(BlitImage *blitImage, int dstX, int dstY, int width, int height, int srcX, int srcY, int srcWidth, int srcHeight, int rotation,
							 int originX, int originY, float aTint, float rTint, float gTint, float bTint) {
	TinyGL::GLContext *c = TinyGL::gl_get_context();

	int clampWidth, clampHeight;
	if (clipBlitImage(blitImage, c, srcWidth, srcHeight, width, height, dstX, dstY, clampWidth, clampHeight) == false)
		return;

	Graphics::PixelBuffer srcBuf(blitImage->_surface.format, (byte *)blitImage->_surface.getPixels());
	srcBuf.shiftBy(srcX + (srcY * blitImage->_surface.w));

	Graphics::PixelBuffer dstBuf(c->fb->cmode, c->fb->getPixelBuffer());

	// Transform destination rectangle accordingly.
	Common::Rect destinationRectangle = rotateRectangle(dstX, dstY, width, height, rotation, originX, originY);

	if (dstX + destinationRectangle.width() > c->fb->xsize)
		clampWidth = c->fb->xsize - dstX;
	else
		clampWidth = destinationRectangle.width();

	if (dstY + destinationRectangle.height() > c->fb->ysize)
		clampHeight = c->fb->ysize - dstY;
	else
		clampHeight = destinationRectangle.height();

	uint32 invAngle = 360 - (rotation % 360);
	float invCos = cos(invAngle * M_PI / 180.0f);
	float invSin = sin(invAngle * M_PI / 180.0f	);

	int icosx = (int)(invCos * (65536.0f * srcWidth / width));
	int isinx = (int)(invSin * (65536.0f * srcWidth / width));
	int icosy = (int)(invCos * (65536.0f * srcHeight / height));
	int isiny = (int)(invSin * (65536.0f * srcHeight / height));

	int xd = (srcX + originX) << 16;
	int yd = (srcY + originY) << 16;
	int cx = originX;
	int cy = originY;

	int ax = -icosx * cx;
	int ay = -isiny * cx;
	int sw = width - 1;
	int sh = height - 1;

	for (int l = 0; l < clampHeight; l++) {
		int t = cy - l;
		int sdx = ax + (isinx * t) + xd;
		int sdy = ay - (icosy * t) + yd;
		for (int r = 0; r < clampWidth; ++r) {
			byte aDst, rDst, gDst, bDst;

			int dx = (sdx >> 16);
			int dy = (sdy >> 16);

			if (flipHorizontal)
				dx = sw - dx;
			if (flipVertical)
				dy = sh - dy;

			if ((dx >= 0) && (dy >= 0) && (dx < srcWidth) && (dy < srcHeight)) {
				srcBuf.getARGBAt(dy * blitImage->_surface.w + dx, aDst, rDst, gDst, bDst);
				if (disableColoring) {
					if (disableBlending && aDst != 0) {
						dstBuf.setPixelAt((dstX + r) + (dstY + l) * c->fb->xsize, aDst, rDst, gDst, bDst);
					} else {
						c->fb->writePixel((dstX + r) + (dstY + l) * c->fb->xsize, aDst, rDst, gDst, bDst);
					}
				} else {
					if (disableBlending && aDst * aTint != 0) {
						dstBuf.setPixelAt((dstX + r) + (dstY + l) * c->fb->xsize, aDst * aTint, rDst * rTint, gDst * gTint, bDst * bTint);
					} else {
						c->fb->writePixel((dstX + r) + (dstY + l) * c->fb->xsize, aDst * aTint, rDst * rTint, gDst * gTint, bDst * bTint);
					}
				}
			}
			sdx += icosx;
			sdy += isiny;
		}
	}
}

//Utility function.
template <bool disableBlending, bool disableColoring, bool disableTransform, bool flipVertical, bool flipHorizontal>
FORCEINLINE void tglBlitGeneric(BlitImage *blitImage, const BlitTransform &transform) {
	if (disableTransform) {
		if (disableBlending && flipVertical == false && flipHorizontal == false) {
			tglBlitRLE<disableColoring>(blitImage, transform._destinationRectangle.left, transform._destinationRectangle.top,
				transform._sourceRectangle.left, transform._sourceRectangle.top, transform._sourceRectangle.width() , transform._sourceRectangle.height(),
				transform._aTint, transform._rTint, transform._gTint, transform._bTint);
		} else {
			tglBlitSimple<disableBlending, disableColoring, flipVertical, flipHorizontal>(blitImage, transform._destinationRectangle.left, transform._destinationRectangle.top,
				transform._sourceRectangle.left, transform._sourceRectangle.top, transform._sourceRectangle.width() , transform._sourceRectangle.height(),
				transform._aTint, transform._rTint, transform._gTint, transform._bTint);
		}
	} else {
		if (transform._rotation == 0) {
			tglBlitScale<disableBlending, disableColoring, flipVertical, flipHorizontal>(blitImage, transform._destinationRectangle.left, transform._destinationRectangle.top,
				transform._destinationRectangle.width(), transform._destinationRectangle.height(), transform._sourceRectangle.left, transform._sourceRectangle.top, transform._sourceRectangle.width() , transform._sourceRectangle.height(), transform._aTint, transform._rTint, transform._gTint, transform._bTint);
		} else 
		{
			tglBlitRotoScale<disableBlending, disableColoring, flipVertical, flipHorizontal>(blitImage, transform._destinationRectangle.left, transform._destinationRectangle.top,
				transform._destinationRectangle.width(), transform._destinationRectangle.height(), transform._sourceRectangle.left, transform._sourceRectangle.top, transform._sourceRectangle.width() , transform._sourceRectangle.height(), transform._rotation, 
				transform._originX, transform._originY, transform._aTint, transform._rTint, transform._gTint, transform._bTint);
		}
	}
}

void tglBlit(BlitImage *blitImage, const BlitTransform &transform) {
	TinyGL::GLContext *c =TinyGL::gl_get_context();
	bool disableColor = transform._aTint == 1.0f && transform._bTint == 1.0f && transform._gTint == 1.0f && transform._rTint == 1.0f;
	bool disableTransform = transform._destinationRectangle.width() == 0 && transform._destinationRectangle.height() == 0 && transform._rotation == 0;
	bool disableBlend = c->enableBlend == false;
	if (transform._flipHorizontally == false && transform._flipVertically == false) {
		if (disableColor && disableTransform && disableBlend) {
			tglBlitGeneric<true, true, true, false, false>(blitImage, transform);
		} else if (disableColor && disableTransform) {
			tglBlitGeneric<false, true, true, false, false>(blitImage, transform);
		} else if (disableTransform) {
			tglBlitGeneric<false, false, true, false, false>(blitImage, transform);
		} else {
			tglBlitGeneric<false, false, false, false, false>(blitImage, transform);
		}
	} else if (transform._flipHorizontally == false) {
		if (disableColor && disableTransform && disableBlend) {
			tglBlitGeneric<true, true, true, true, false>(blitImage, transform);
		} else if (disableColor && disableTransform) {
			tglBlitGeneric<false, true, true, true, false>(blitImage, transform);
		} else if (disableTransform) {
			tglBlitGeneric<false, false, true, true, false>(blitImage, transform);
		} else {
			tglBlitGeneric<false, false, false, true, false>(blitImage, transform);
		}
	} else {
		if (disableColor && disableTransform && disableBlend) {
			tglBlitGeneric<true, true, true, false, true>(blitImage, transform);
		} else if (disableColor && disableTransform) {
			tglBlitGeneric<false, true, true, false, true>(blitImage, transform);
		} else if (disableTransform) {
			tglBlitGeneric<false, false, true, false, true>(blitImage, transform);
		} else {
			tglBlitGeneric<false, false, false, false, true>(blitImage, transform);
		}
	}
}

void tglBlitNoBlend(BlitImage *blitImage, const BlitTransform &transform) {
	if (transform._flipHorizontally == false && transform._flipVertically == false) {
		tglBlitGeneric<true, false, false, false, false>(blitImage, transform);
	} else if(transform._flipHorizontally == false) {
		tglBlitGeneric<true, false, false, true, false>(blitImage, transform);
	} else {
		tglBlitGeneric<true, false, false, false, true>(blitImage, transform);
	}
}

void tglBlitFast(BlitImage *blitImage, int x, int y) {
	BlitTransform transform(x, y);
	tglBlitGeneric<true, true, true, false, false>(blitImage, transform);
}

Common::Point transformPoint(float x, float y, int rotation) {
	float rotateRad = rotation * M_PI / 180.0f;
	Common::Point newPoint;
	newPoint.x = x * cos(rotateRad) - y * sin(rotateRad);
	newPoint.y = x * sin(rotateRad) + y * cos(rotateRad);
	return newPoint;
}

Common::Rect rotateRectangle(int x, int y, int width, int height, int rotation, int originX, int originY) {
	Common::Point nw, ne, sw, se;
	nw = transformPoint(x - originX, y - originY, rotation);
	ne = transformPoint(x + width - originX, y - originY, rotation);
	sw = transformPoint(x + width - originX, y + height- originY, rotation);
	se = transformPoint(x - originX, y + height - originY, rotation);

	float top = MIN(nw.y, MIN(ne.y, MIN(sw.y, se.y)));
	float bottom = MAX(nw.y, MAX(ne.y, MAX(sw.y, se.y)));
	float left = MIN(nw.x, MIN(ne.x, MIN(sw.x, se.x)));
	float right = MAX(nw.x, MAX(ne.x, MAX(sw.x, se.x)));

	Common::Rect res;
	res.top = (int32)(floor(top)) + originY;
	res.bottom = (int32)(ceil(bottom)) + originY;
	res.left = (int32)(floor(left)) + originX;
	res.right = (int32)(ceil(right)) + originX;

	return res;
}

}