#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cassert>

#include "../rwbase.h"
#include "../rwerror.h"
#include "../rwplg.h"
#include "../rwpipeline.h"
#include "../rwobjects.h"
#include "../rwanim.h"
#include "../rwengine.h"
#include "../rwplugins.h"
#ifdef RW_OPENGL
#include <GL/glew.h>
#endif
#include "rwgl3.h"
#include "rwgl3shader.h"
#include "rwgl3plg.h"

#include "rwgl3impl.h"

namespace rw {
namespace gl3 {

#ifdef RW_OPENGL

// MatFX

Shader *envShader;

static void*
matfxOpen(void *o, int32, int32)
{
#include "shaders/matfx_gl3.inc"
	matFXGlobals.pipelines[PLATFORM_GL3] = makeMatFXPipeline();
	envShader = Shader::fromStrings(matfx_env_vert_src, matfx_env_frag_src);
	return o;
}

static void*
matfxClose(void *o, int32, int32)
{
	return o;
}

void
initMatFX(void)
{
	Driver::registerPlugin(PLATFORM_GL3, 0, ID_MATFX,
	                       matfxOpen, matfxClose);
	registerUniform("u_texMatrix");
	registerUniform("u_coefficient");
}

#define U(s) currentShader->uniformLocations[findUniform(s)]

void
matfxDefaultRender(InstanceDataHeader *header, InstanceData *inst)
{
	Material *m;
	RGBAf col;
	GLfloat surfProps[4];
	m = inst->material;

	simpleShader->use();

	convColor(&col, &m->color);
	glUniform4fv(U("u_matColor"), 1, (GLfloat*)&col);

	surfProps[0] = m->surfaceProps.ambient;
	surfProps[1] = m->surfaceProps.specular;
	surfProps[2] = m->surfaceProps.diffuse;
	surfProps[3] = 0.0f;
	glUniform4fv(U("u_surfaceProps"), 1, surfProps);

	setTexture(0, m->texture);

	rw::setRenderState(VERTEXALPHA, inst->vertexAlpha || m->color.alpha != 0xFF);

	flushCache();
	glDrawElements(header->primType, inst->numIndex,
	               GL_UNSIGNED_SHORT, (void*)(uintptr)inst->offset);
}

void
calcEnvTexMatrix(Frame *f, float32 *mat)
{
	Matrix cam;
	if(f){
		// PS2 style - could be simplified by the shader
		cam = *((Camera*)engine->currentCamera)->getFrame()->getLTM();
		cam.pos = { 0.0, 0.0, 0.0 };
		cam.right.x = -cam.right.x;
		cam.right.y = -cam.right.y;
		cam.right.z = -cam.right.z;

		Matrix inv;
		Matrix::invert(&inv, f->getLTM());
		inv.pos = { -1.0, -1.0, -1.0 };
		inv.right.x *= -0.5f;
		inv.right.y *= -0.5f;
		inv.right.z *= -0.5f;
		inv.up.x *= -0.5f;
		inv.up.y *= -0.5f;
		inv.up.z *= -0.5f;
		inv.at.x *= -0.5f;
		inv.at.y *= -0.5f;
		inv.at.z *= -0.5f;
		inv.pos.x *= -0.5f;
		inv.pos.y *= -0.5f;
		inv.pos.z *= -0.5f;

		Matrix m;
		Matrix::mult(&m, &inv, &cam);

		memcpy(mat, &m, 64);
		mat[3] = mat[7] = mat[11] = 0.0f;
		mat[15] = 1.0f;

	}else{
		// D3D - TODO: find out what PS2 does
		mat[0]  = 0.5f;
		mat[1]  = 0.0f;
		mat[2]  = 0.0f;
		mat[3]  = 0.0f;

		mat[4]  = 0.0f;
		mat[5]  = -0.5f;
		mat[6]  = 0.0f;
		mat[7]  = 0.0f;

		mat[8]  = 0.0f;
		mat[9]  = 0.0f;
		mat[10] = 1.0f;
		mat[11] = 0.0f;

		mat[12] = 0.5f;
		mat[13] = 0.5f;
		mat[14] = 0.0f;
		mat[15] = 0.0f;
	}
}

void
matfxEnvRender(InstanceDataHeader *header, InstanceData *inst)
{
	Material *m;
	RGBAf col;
	GLfloat surfProps[4];
	float32 texMat[16];
	m = inst->material;

	matfxDefaultRender(header, inst);

	MatFX *fx = MatFX::get(m);
	int32 idx = fx->getEffectIndex(MatFX::ENVMAP);
	MatFX::Env *env = &fx->fx[idx].env;

	envShader->use();

	convColor(&col, &m->color);
	glUniform4fv(U("u_matColor"), 1, (GLfloat*)&col);

	surfProps[0] = m->surfaceProps.ambient;
	surfProps[1] = m->surfaceProps.specular;
	surfProps[2] = m->surfaceProps.diffuse;
	surfProps[3] = 0.0f;
	glUniform4fv(U("u_surfaceProps"), 1, surfProps);

	glUniform1fv(U("u_coefficient"), 1, &env->coefficient);

	calcEnvTexMatrix(env->frame, texMat);
	glUniformMatrix4fv(U("u_texMatrix"), 1, GL_FALSE, texMat);

	setTexture(0, env->tex);

	rw::setRenderState(VERTEXALPHA, 1);
	rw::setRenderState(SRCBLEND, BLENDONE);
	rw::setRenderState(DESTBLEND, BLENDONE);

	flushCache();
	glDrawElements(header->primType, inst->numIndex,
	               GL_UNSIGNED_SHORT, (void*)(uintptr)inst->offset);

	rw::setRenderState(SRCBLEND, BLENDSRCALPHA);
	rw::setRenderState(DESTBLEND, BLENDINVSRCALPHA);
}

void
matfxRenderCB(Atomic *atomic, InstanceDataHeader *header)
{
	setWorldMatrix(atomic->getFrame()->getLTM());
	lightingCB();

	glBindBuffer(GL_ARRAY_BUFFER, header->vbo);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, header->ibo);
	setAttribPointers(header);

	InstanceData *inst = header->inst;
	int32 n = header->numMeshes;

	rw::setRenderState(ALPHATESTFUNC, 1);
	rw::setRenderState(ALPHATESTREF, 50);

	int32 fx;
	while(n--){
		fx = MatFX::getEffects(inst->material);
		switch(fx){
		case MatFX::ENVMAP:
			matfxEnvRender(header, inst);
			break;
		default:
			matfxDefaultRender(header, inst);
		}
		inst++;
	}
}

ObjPipeline*
makeMatFXPipeline(void)
{
	ObjPipeline *pipe = new ObjPipeline(PLATFORM_GL3);
	pipe->instanceCB = defaultInstanceCB;
	pipe->uninstanceCB = defaultUninstanceCB;
	pipe->renderCB = matfxRenderCB;
	pipe->pluginID = ID_MATFX;
	pipe->pluginData = 0;
	return pipe;
}

// Skin

Shader *skinShader;

static void*
skinOpen(void *o, int32, int32)
{
#include "shaders/simple_gl3.inc"
#include "shaders/skin_gl3.inc"
	skinGlobals.pipelines[PLATFORM_GL3] = makeSkinPipeline();
	skinShader = Shader::fromStrings(skin_vert_src, simple_frag_src);
	return o;
}

static void*
skinClose(void *o, int32, int32)
{
	return o;
}

void
initSkin(void)
{
	Driver::registerPlugin(PLATFORM_GL3, 0, ID_SKIN,
	                       skinOpen, skinClose);
	registerUniform("u_boneMatrices");
}

enum
{
	ATTRIB_WEIGHTS = ATTRIB_TEXCOORDS7+1,
	ATTRIB_INDICES
};

void
skinInstanceCB(Geometry *geo, InstanceDataHeader *header)
{
	AttribDesc attribs[14], *a;
	uint32 stride;

	//
	// Create attribute descriptions
	//
	a = attribs;
	stride = 0;

	// Positions
	a->index = ATTRIB_POS;
	a->size = 3;
	a->type = GL_FLOAT;
	a->normalized = GL_FALSE;
	a->offset = stride;
	stride += 12;
	a++;

	// Normals
	// TODO: compress
	bool hasNormals = !!(geo->geoflags & Geometry::NORMALS);
	if(hasNormals){
		a->index = ATTRIB_NORMAL;
		a->size = 3;
		a->type = GL_FLOAT;
		a->normalized = GL_FALSE;
		a->offset = stride;
		stride += 12;
		a++;
	}

	// Prelighting
	bool isPrelit = !!(geo->geoflags & Geometry::PRELIT);
	if(isPrelit){
		a->index = ATTRIB_COLOR;
		a->size = 4;
		a->type = GL_UNSIGNED_BYTE;
		a->normalized = GL_TRUE;
		a->offset = stride;
		stride += 4;
		a++;
	}

	// Texture coordinates
	for(int32 n = 0; n < geo->numTexCoordSets; n++){
		a->index = ATTRIB_TEXCOORDS0+n;
		a->size = 2;
		a->type = GL_FLOAT;
		a->normalized = GL_FALSE;
		a->offset = stride;
		stride += 8;
		a++;
	}

	// Weights
	a->index = ATTRIB_WEIGHTS;
	a->size = 4;
	a->type = GL_FLOAT;
	a->normalized = GL_FALSE;
	a->offset = stride;
	stride += 16;
	a++;

	// Indices
	a->index = ATTRIB_INDICES;
	a->size = 4;
	a->type = GL_UNSIGNED_BYTE;
	a->normalized = GL_FALSE;
	a->offset = stride;
	stride += 4;
	a++;

	header->numAttribs = a - attribs;
	for(a = attribs; a != &attribs[header->numAttribs]; a++)
		a->stride = stride;
	header->attribDesc = new AttribDesc[header->numAttribs];
	memcpy(header->attribDesc, attribs,
	       header->numAttribs*sizeof(AttribDesc));

	//
	// Allocate and fill vertex buffer
	//
	Skin *skin = Skin::get(geo);
	uint8 *verts = new uint8[header->totalNumVertex*stride];
	header->vertexBuffer = verts;

	// Positions
	for(a = attribs; a->index != ATTRIB_POS; a++)
		;
	instV3d(VERT_FLOAT3, verts + a->offset,
	        geo->morphTargets[0].vertices,
	        header->totalNumVertex, a->stride);

	// Normals
	if(hasNormals){
		for(a = attribs; a->index != ATTRIB_NORMAL; a++)
			;
		instV3d(VERT_FLOAT3, verts + a->offset,
			geo->morphTargets[0].normals,
			header->totalNumVertex, a->stride);
	}

	// Prelighting
	if(isPrelit){
		for(a = attribs; a->index != ATTRIB_COLOR; a++)
			;
		instColor(VERT_RGBA, verts + a->offset,
			  geo->colors,
			  header->totalNumVertex, a->stride);
	}

	// Texture coordinates
	for(int32 n = 0; n < geo->numTexCoordSets; n++){
		for(a = attribs; a->index != ATTRIB_TEXCOORDS0+n; a++)
			;
		instV2d(VERT_FLOAT2, verts + a->offset,
			geo->texCoords[n],
			header->totalNumVertex, a->stride);
	}

	// Weights
	for(a = attribs; a->index != ATTRIB_WEIGHTS; a++)
		;
	instV4d(VERT_FLOAT4, verts + a->offset,
	        skin->weights,
	        header->totalNumVertex, a->stride);

	// Indices
	for(a = attribs; a->index != ATTRIB_INDICES; a++)
		;
	// not really colors of course but what the heck
	instColor(VERT_RGBA, verts + a->offset,
	          skin->indices,
	          header->totalNumVertex, a->stride);

	glGenBuffers(1, &header->vbo);
	glBindBuffer(GL_ARRAY_BUFFER, header->vbo);
	glBufferData(GL_ARRAY_BUFFER, header->totalNumVertex*stride,
	             header->vertexBuffer, GL_STATIC_DRAW);
	glBindBuffer(GL_ARRAY_BUFFER, 0);
}

void
skinUninstanceCB(Geometry *geo, InstanceDataHeader *header)
{
	assert(0 && "can't uninstance");
}

#define U(s) currentShader->uniformLocations[findUniform(s)]

static float skinMatrices[64*16];

void
updateSkinMatrices(Atomic *a)
{
	Skin *skin = Skin::get(a->geometry);
	HAnimHierarchy *hier = Skin::getHierarchy(a);
	Matrix *invMats = (Matrix*)skin->inverseMatrices;

	float *m;
	m = (float*)skinMatrices;
	for(int i = 0; i < hier->numNodes; i++){
		invMats[i].rightw = 0.0f;
		invMats[i].upw = 0.0f;
		invMats[i].atw = 0.0f;
		invMats[i].posw = 1.0f;
		Matrix::mult((Matrix*)m, &hier->matrices[i], &invMats[i]);
		m[3] = 0.0f;
		m[7] = 0.0f;
		m[11] = 0.0f;
		m[15] = 1.0f;
		m += 16;
	}
}

void
skinRenderCB(Atomic *atomic, InstanceDataHeader *header)
{
	Material *m;
	RGBAf col;
	GLfloat surfProps[4];
	int id;

	setWorldMatrix(atomic->getFrame()->getLTM());
	lightingCB();

	glBindBuffer(GL_ARRAY_BUFFER, header->vbo);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, header->ibo);
	setAttribPointers(header);

	InstanceData *inst = header->inst;
	int32 n = header->numMeshes;

	rw::setRenderState(ALPHATESTFUNC, 1);
	rw::setRenderState(ALPHATESTREF, 50);

	skinShader->use();

	updateSkinMatrices(atomic);
	glUniformMatrix4fv(U("u_boneMatrices"), 64, GL_FALSE,
	                   (GLfloat*)skinMatrices);

	while(n--){
		m = inst->material;

		convColor(&col, &m->color);
		glUniform4fv(U("u_matColor"), 1, (GLfloat*)&col);

		surfProps[0] = m->surfaceProps.ambient;
		surfProps[1] = m->surfaceProps.specular;
		surfProps[2] = m->surfaceProps.diffuse;
		surfProps[3] = 0.0f;
		glUniform4fv(U("u_surfaceProps"), 1, surfProps);

		setTexture(0, m->texture);

		rw::setRenderState(VERTEXALPHA, inst->vertexAlpha || m->color.alpha != 0xFF);

		flushCache();
		glDrawElements(header->primType, inst->numIndex,
		               GL_UNSIGNED_SHORT, (void*)(uintptr)inst->offset);
		inst++;
	}
}

ObjPipeline*
makeSkinPipeline(void)
{
	ObjPipeline *pipe = new ObjPipeline(PLATFORM_GL3);
	pipe->instanceCB = skinInstanceCB;
	pipe->uninstanceCB = skinUninstanceCB;
	pipe->renderCB = skinRenderCB;
	pipe->pluginID = ID_SKIN;
	pipe->pluginData = 1;
	return pipe;
}

#else

void initMatFX(void) { }
void initSkin(void) { }

#endif

}
}