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

#include "../rwbase.h"
#include "../rwerror.h"
#include "../rwplg.h"
#include "../rwrender.h"
#include "../rwengine.h"
#include "../rwpipeline.h"
#include "../rwobjects.h"
#include "../rwanim.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

#define U(i) currentShader->uniformLocations[i]

static Shader *skinShader;
static int32 u_boneMatrices;

static void*
skinOpen(void *o, int32, int32)
{
	u_boneMatrices = registerUniform("u_boneMatrices");
#include "shaders/simple_fs_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);
}

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->flags & 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->flags & 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 = rwNewT(AttribDesc, header->numAttribs, MEMDUR_EVENT | ID_GEOMETRY);
	memcpy(header->attribDesc, attribs,
	       header->numAttribs*sizeof(AttribDesc));

	//
	// Allocate and fill vertex buffer
	//
	Skin *skin = Skin::get(geo);
	uint8 *verts = rwNewT(uint8, header->totalNumVertex*stride, MEMDUR_EVENT | ID_GEOMETRY);
	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++)
			;
		instTexCoords(VERT_FLOAT2, verts + a->offset,
			geo->texCoords[n],
			header->totalNumVertex, a->stride);
	}

	// Weights
	for(a = attribs; a->index != ATTRIB_WEIGHTS; a++)
		;
	float *w = skin->weights;
	instV4d(VERT_FLOAT4, verts + a->offset,
	        (V4d*)w,
	        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,
	          (RGBA*)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");
}

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].flags = 0;
		Matrix::mult((Matrix*)m, &invMats[i], &hier->matrices[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];

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

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

	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++;
	}
	disableAttribPointers(header->attribDesc, header->numAttribs);
}

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 initSkin(void) { }

#endif

}
}