#include "OpenGlExtensions.h"

#include "Utils.h"
#include <iostream>

#if defined(WIN32) || defined(_WIN32) || defined(__WIN32__)

//====================================================
//===================== GLSL Shaders =================  
//====================================================

//Requires GL_VERSION_2_0
PFNGLCREATEPROGRAMPROC glCreateProgram = NULL;
PFNGLDELETEPROGRAMPROC glDeleteProgram = NULL;
PFNGLLINKPROGRAMPROC glLinkProgram = NULL;
PFNGLVALIDATEPROGRAMPROC glValidateProgram = NULL;
PFNGLUSEPROGRAMPROC glUseProgram = NULL;
PFNGLGETPROGRAMIVPROC glGetProgramiv = NULL;
PFNGLGETPROGRAMINFOLOGPROC glGetProgramInfoLog = NULL;
PFNGLCREATESHADERPROC glCreateShader = NULL;
PFNGLDELETESHADERPROC glDeleteShader = NULL;
PFNGLSHADERSOURCEPROC glShaderSource = NULL;
PFNGLCOMPILESHADERPROC glCompileShader = NULL;
PFNGLATTACHSHADERPROC glAttachShader = NULL;
PFNGLDETACHSHADERPROC glDetachShader = NULL;
PFNGLGETSHADERIVPROC glGetShaderiv = NULL;
PFNGLGETSHADERINFOLOGPROC glGetShaderInfoLog = NULL;
PFNGLGETATTRIBLOCATIONPROC glGetAttribLocation = NULL;
PFNGLVERTEXATTRIBPOINTERPROC glVertexAttribPointer = NULL;
PFNGLENABLEVERTEXATTRIBARRAYPROC glEnableVertexAttribArray = NULL;
PFNGLDISABLEVERTEXATTRIBARRAYPROC glDisableVertexAttribArray = NULL;
PFNGLGETUNIFORMLOCATIONPROC glGetUniformLocation = NULL;
PFNGLUNIFORMMATRIX3FVPROC glUniformMatrix3fv = NULL;
PFNGLUNIFORMMATRIX4FVPROC glUniformMatrix4fv = NULL;
PFNGLUNIFORM1IPROC glUniform1i = NULL;
PFNGLUNIFORM1FVPROC glUniform1fv = NULL;
PFNGLUNIFORM3FVPROC glUniform2fv = NULL;
PFNGLUNIFORM3FVPROC glUniform3fv = NULL;
PFNGLUNIFORM4FVPROC glUniform4fv = NULL;
PFNGLVERTEXATTRIB1FPROC glVertexAttrib1f = NULL;
PFNGLVERTEXATTRIB2FPROC glVertexAttrib2f = NULL;
PFNGLVERTEXATTRIB3FPROC glVertexAttrib3f = NULL;
PFNGLVERTEXATTRIB4FPROC glVertexAttrib4f = NULL;
PFNGLVERTEXATTRIB2FVPROC glVertexAttrib2fv = NULL;
PFNGLVERTEXATTRIB3FVPROC glVertexAttrib3fv = NULL;
PFNGLVERTEXATTRIB4FVPROC glVertexAttrib4fv = NULL;
PFNGLGETACTIVEATTRIBPROC glGetActiveAttrib = NULL;
PFNGLGETACTIVEUNIFORMPROC glGetActiveUniform = NULL;


//=======================================
//=========== Multitexture ==============
//=======================================

//Requires GL version 1.3
PFNGLACTIVETEXTUREPROC glActiveTexture = NULL;

//=======================================
//========== Vertex buffer ==============
//=======================================

//Requires GL_VERSION_1_5
PFNGLGENBUFFERSPROC glGenBuffers = NULL;
PFNGLDELETEBUFFERSPROC glDeleteBuffers = NULL;
PFNGLBINDBUFFERPROC glBindBuffer = NULL;
PFNGLBUFFERDATAPROC glBufferData = NULL;
PFNGLBUFFERSUBDATAPROC glBufferSubData = NULL;
PFNGLMAPBUFFERPROC glMapBuffer = NULL;
PFNGLUNMAPBUFFERPROC glUnmapBuffer = NULL;

//=========================================
//============ Frame buffer ===============
//=========================================

//Requires GL_ARB_framebuffer_object
PFNGLISRENDERBUFFERPROC glIsRenderbuffer = NULL;
PFNGLBINDRENDERBUFFERPROC glBindRenderbuffer = NULL;
PFNGLDELETERENDERBUFFERSPROC glDeleteRenderbuffers = NULL;
PFNGLGENRENDERBUFFERSPROC glGenRenderbuffers = NULL;
PFNGLRENDERBUFFERSTORAGEPROC glRenderbufferStorage = NULL;
PFNGLGETRENDERBUFFERPARAMETERIVPROC glGetRenderbufferParameteriv = NULL;
PFNGLISFRAMEBUFFERPROC glIsFramebuffer = NULL;
PFNGLBINDFRAMEBUFFERPROC glBindFramebuffer = NULL;
PFNGLDELETEFRAMEBUFFERSPROC glDeleteFramebuffers = NULL;
PFNGLGENFRAMEBUFFERSPROC glGenFramebuffers = NULL;
PFNGLCHECKFRAMEBUFFERSTATUSPROC glCheckFramebufferStatus = NULL;
PFNGLFRAMEBUFFERTEXTURE1DPROC glFramebufferTexture1D = NULL;
PFNGLFRAMEBUFFERTEXTURE2DPROC glFramebufferTexture2D = NULL;
PFNGLFRAMEBUFFERTEXTURE3DPROC glFramebufferTexture3D = NULL;
PFNGLFRAMEBUFFERRENDERBUFFERPROC glFramebufferRenderbuffer = NULL;
PFNGLGETFRAMEBUFFERATTACHMENTPARAMETERIVPROC glGetFramebufferAttachmentParameteriv = NULL;
PFNGLBLITFRAMEBUFFERPROC glBlitFramebuffer = NULL;
PFNGLRENDERBUFFERSTORAGEMULTISAMPLEPROC glRenderbufferStorageMultisample = NULL;
PFNGLGENERATEMIPMAPPROC glGenerateMipmap = NULL;
PFNGLFRAMEBUFFERTEXTURELAYERPROC glFramebufferTextureLayer = NULL;



//===========================================
//============ Uniform buffer ===============
//===========================================

//Requires GL_ARB_uniform_buffer_object
PFNGLGETUNIFORMINDICESPROC glGetUniformIndices = NULL;
PFNGLGETACTIVEUNIFORMSIVPROC glGetActiveUniformsiv = NULL;
PFNGLGETACTIVEUNIFORMNAMEPROC glGetActiveUniformName = NULL;
PFNGLGETUNIFORMBLOCKINDEXPROC glGetUniformBlockIndex = NULL;
PFNGLGETACTIVEUNIFORMBLOCKIVPROC glGetActiveUniformBlockiv = NULL;
PFNGLGETACTIVEUNIFORMBLOCKNAMEPROC glGetActiveUniformBlockName = NULL;
PFNGLUNIFORMBLOCKBINDINGPROC glUniformBlockBinding = NULL;
PFNGLBINDBUFFERBASEPROC glBindBufferBase = NULL;


PFNGLGENVERTEXARRAYSPROC glGenVertexArrays = NULL;
PFNGLBINDVERTEXARRAYPROC glBindVertexArray = NULL;
PFNGLDELETEVERTEXARRAYSPROC glDeleteVertexArray = NULL;

#endif 

namespace ZL {

	bool BindOpenGlFunctions()
	{
#if defined(WIN32) || defined(_WIN32) || defined(__WIN32__)
		//char* extensionList = (char*)glGetString(GL_EXTENSIONS);
		char* glVersion = (char*)glGetString(GL_VERSION);
		bool ok = true;

		//Requires OpenGL 2.0 or above
		if (glVersion[0] >= '2')
		{

			glActiveTexture = (PFNGLACTIVETEXTUREPROC)wglGetProcAddress("glActiveTexture");

			glGenBuffers = (PFNGLGENBUFFERSPROC)wglGetProcAddress("glGenBuffers");
			glDeleteBuffers = (PFNGLDELETEBUFFERSPROC)wglGetProcAddress("glDeleteBuffers");
			glBindBuffer = (PFNGLBINDBUFFERPROC)wglGetProcAddress("glBindBuffer");
			glBufferData = (PFNGLBUFFERDATAPROC)wglGetProcAddress("glBufferData");
			glBufferSubData = (PFNGLBUFFERSUBDATAPROC)wglGetProcAddress("glBufferSubData");
			glMapBuffer = (PFNGLMAPBUFFERPROC)wglGetProcAddress("glMapBuffer");
			glUnmapBuffer = (PFNGLUNMAPBUFFERPROC)wglGetProcAddress("glUnmapBuffer");

			glCreateProgram = (PFNGLCREATEPROGRAMPROC)wglGetProcAddress("glCreateProgram");
			glDeleteProgram = (PFNGLDELETEPROGRAMPROC)wglGetProcAddress("glDeleteProgram");
			glLinkProgram = (PFNGLLINKPROGRAMPROC)wglGetProcAddress("glLinkProgram");
			glValidateProgram = (PFNGLVALIDATEPROGRAMPROC)wglGetProcAddress("glValidateProgram");
			glUseProgram = (PFNGLUSEPROGRAMPROC)wglGetProcAddress("glUseProgram");
			glGetProgramiv = (PFNGLGETPROGRAMIVPROC)wglGetProcAddress("glGetProgramiv");
			glGetProgramInfoLog = (PFNGLGETPROGRAMINFOLOGPROC)wglGetProcAddress("glGetProgramInfoLog");
			glCreateShader = (PFNGLCREATESHADERPROC)wglGetProcAddress("glCreateShader");


			glDeleteShader = (PFNGLDELETESHADERPROC)wglGetProcAddress("glDeleteShader");
			glShaderSource = (PFNGLSHADERSOURCEPROC)wglGetProcAddress("glShaderSource");
			glCompileShader = (PFNGLCOMPILESHADERPROC)wglGetProcAddress("glCompileShader");
			glAttachShader = (PFNGLATTACHSHADERPROC)wglGetProcAddress("glAttachShader");
			glDetachShader = (PFNGLDETACHSHADERPROC)wglGetProcAddress("glDetachShader");
			glGetShaderiv = (PFNGLGETSHADERIVPROC)wglGetProcAddress("glGetShaderiv");
			glGetShaderInfoLog = (PFNGLGETSHADERINFOLOGPROC)wglGetProcAddress("glGetShaderInfoLog");
			glGetAttribLocation = (PFNGLGETATTRIBLOCATIONPROC)wglGetProcAddress("glGetAttribLocation");
			glVertexAttribPointer = (PFNGLVERTEXATTRIBPOINTERPROC)wglGetProcAddress("glVertexAttribPointer");
			glEnableVertexAttribArray = (PFNGLENABLEVERTEXATTRIBARRAYPROC)wglGetProcAddress("glEnableVertexAttribArray");

			glDisableVertexAttribArray = (PFNGLDISABLEVERTEXATTRIBARRAYPROC)wglGetProcAddress("glDisableVertexAttribArray");
			glGetUniformLocation = (PFNGLGETUNIFORMLOCATIONPROC)wglGetProcAddress("glGetUniformLocation");
			glUniformMatrix3fv = (PFNGLUNIFORMMATRIX3FVPROC)wglGetProcAddress("glUniformMatrix3fv");
			glUniformMatrix4fv = (PFNGLUNIFORMMATRIX4FVPROC)wglGetProcAddress("glUniformMatrix4fv");
			glUniform1i = (PFNGLUNIFORM1IPROC)wglGetProcAddress("glUniform1i");
			glUniform1fv = (PFNGLUNIFORM1FVPROC)wglGetProcAddress("glUniform1fv");
			glUniform2fv = (PFNGLUNIFORM2FVPROC)wglGetProcAddress("glUniform2fv");
			glUniform3fv = (PFNGLUNIFORM3FVPROC)wglGetProcAddress("glUniform3fv");
			glUniform4fv = (PFNGLUNIFORM4FVPROC)wglGetProcAddress("glUniform4fv");

			glVertexAttrib1f = (PFNGLVERTEXATTRIB1FPROC)wglGetProcAddress("glVertexAttrib1f");
			glVertexAttrib2f = (PFNGLVERTEXATTRIB2FPROC)wglGetProcAddress("glVertexAttrib2f");
			glVertexAttrib3f = (PFNGLVERTEXATTRIB3FPROC)wglGetProcAddress("glVertexAttrib3f");
			glVertexAttrib4f = (PFNGLVERTEXATTRIB4FPROC)wglGetProcAddress("glVertexAttrib4f");
			glVertexAttrib2fv = (PFNGLVERTEXATTRIB2FVPROC)wglGetProcAddress("glVertexAttrib2fv");
			glVertexAttrib3fv = (PFNGLVERTEXATTRIB3FVPROC)wglGetProcAddress("glVertexAttrib3fv");
			glVertexAttrib4fv = (PFNGLVERTEXATTRIB4FVPROC)wglGetProcAddress("glVertexAttrib4fv");
			glGetActiveAttrib = (PFNGLGETACTIVEATTRIBPROC)wglGetProcAddress("glGetActiveAttrib");
			glGetActiveUniform = (PFNGLGETACTIVEUNIFORMPROC)wglGetProcAddress("glGetActiveUniform");


			if (glActiveTexture == NULL ||
				glGenBuffers == NULL ||
				glDeleteBuffers == NULL ||
				glBindBuffer == NULL ||
				glBufferData == NULL ||
				glBufferSubData == NULL ||
				glMapBuffer == NULL ||
				glCreateProgram == NULL ||
				glDeleteProgram == NULL ||
				glLinkProgram == NULL ||
				glValidateProgram == NULL ||
				glUseProgram == NULL ||
				glGetProgramiv == NULL ||
				glGetProgramInfoLog == NULL ||
				glCreateShader == NULL ||
				glDeleteShader == NULL ||
				glShaderSource == NULL ||
				glCompileShader == NULL ||
				glAttachShader == NULL ||
				glDetachShader == NULL ||
				glGetShaderiv == NULL ||
				glGetShaderInfoLog == NULL ||
				glGetAttribLocation == NULL ||
				glVertexAttribPointer == NULL ||
				glEnableVertexAttribArray == NULL ||
				glDisableVertexAttribArray == NULL ||
				glGetUniformLocation == NULL ||
				glUniformMatrix3fv == NULL ||
				glUniformMatrix4fv == NULL ||
				glUniform1i == NULL ||
				glUniform1fv == NULL ||
				glUniform2fv == NULL ||
				glUniform3fv == NULL ||
				glUniform4fv == NULL ||
				glEnableVertexAttribArray == NULL ||
				glVertexAttrib1f == NULL ||
				glVertexAttrib2f == NULL ||
				glVertexAttrib3f == NULL ||
				glVertexAttrib4f == NULL ||
				glVertexAttrib2fv == NULL ||
				glVertexAttrib3fv == NULL ||
				glVertexAttrib4fv == NULL ||
				glGetActiveAttrib == NULL ||
				glGetActiveUniform == NULL)
			{
				ok = false;
			}


		}
		else
		{
			ok = false;
		}


			glIsRenderbuffer = (PFNGLISRENDERBUFFERPROC)wglGetProcAddress("glIsRenderbuffer");
			glBindRenderbuffer = (PFNGLBINDRENDERBUFFERPROC)wglGetProcAddress("glBindRenderbuffer");
			glDeleteRenderbuffers = (PFNGLDELETERENDERBUFFERSPROC)wglGetProcAddress("glDeleteRenderbuffers");
			glGenRenderbuffers = (PFNGLGENRENDERBUFFERSPROC)wglGetProcAddress("glGenRenderbuffers");
			glRenderbufferStorage = (PFNGLRENDERBUFFERSTORAGEPROC)wglGetProcAddress("glRenderbufferStorage");
			glGetRenderbufferParameteriv = (PFNGLGETRENDERBUFFERPARAMETERIVPROC)wglGetProcAddress("glGetRenderbufferParameteriv");
			glIsFramebuffer = (PFNGLISFRAMEBUFFERPROC)wglGetProcAddress("glIsFramebuffer");
			glBindFramebuffer = (PFNGLBINDFRAMEBUFFERPROC)wglGetProcAddress("glBindFramebuffer");
			glDeleteFramebuffers = (PFNGLDELETEFRAMEBUFFERSPROC)wglGetProcAddress("glDeleteFramebuffers");
			glGenFramebuffers = (PFNGLGENFRAMEBUFFERSPROC)wglGetProcAddress("glGenFramebuffers");
			glCheckFramebufferStatus = (PFNGLCHECKFRAMEBUFFERSTATUSPROC)wglGetProcAddress("glCheckFramebufferStatus");
			glFramebufferTexture1D = (PFNGLFRAMEBUFFERTEXTURE1DPROC)wglGetProcAddress("glFramebufferTexture1D");
			glFramebufferTexture2D = (PFNGLFRAMEBUFFERTEXTURE2DPROC)wglGetProcAddress("glFramebufferTexture2D");
			glFramebufferTexture3D = (PFNGLFRAMEBUFFERTEXTURE3DPROC)wglGetProcAddress("glFramebufferTexture3D");
			glFramebufferRenderbuffer = (PFNGLFRAMEBUFFERRENDERBUFFERPROC)wglGetProcAddress("glFramebufferRenderbuffer");
			glGetFramebufferAttachmentParameteriv = (PFNGLGETFRAMEBUFFERATTACHMENTPARAMETERIVPROC)wglGetProcAddress("glGetFramebufferAttachmentParameteriv");
			glBlitFramebuffer = (PFNGLBLITFRAMEBUFFERPROC)wglGetProcAddress("glBlitFramebuffer");
			glRenderbufferStorageMultisample = (PFNGLRENDERBUFFERSTORAGEMULTISAMPLEPROC)wglGetProcAddress("glRenderbufferStorageMultisample");
			glGenerateMipmap = (PFNGLGENERATEMIPMAPPROC)wglGetProcAddress("glGenerateMipmap");
			glFramebufferTextureLayer = (PFNGLFRAMEBUFFERTEXTURELAYERPROC)wglGetProcAddress("glFramebufferTextureLayer");

			if (glIsRenderbuffer == NULL ||
				glBindRenderbuffer == NULL ||
				glDeleteRenderbuffers == NULL ||
				glGenRenderbuffers == NULL ||
				glRenderbufferStorage == NULL ||
				glGetRenderbufferParameteriv == NULL ||
				glIsFramebuffer == NULL ||
				glBindFramebuffer == NULL ||
				glDeleteFramebuffers == NULL ||
				glGenFramebuffers == NULL ||
				glCheckFramebufferStatus == NULL ||
				glFramebufferTexture1D == NULL ||
				glFramebufferTexture2D == NULL ||
				glFramebufferTexture3D == NULL ||
				glFramebufferRenderbuffer == NULL ||
				glGetFramebufferAttachmentParameteriv == NULL ||
				glBlitFramebuffer == NULL ||
				glRenderbufferStorageMultisample == NULL ||
				glGenerateMipmap == NULL ||
				glFramebufferTextureLayer == NULL)
			{
				ok = false;
			}


			glGetUniformIndices = (PFNGLGETUNIFORMINDICESPROC)wglGetProcAddress("glGetUniformIndices");
			glGetActiveUniformsiv = (PFNGLGETACTIVEUNIFORMSIVPROC)wglGetProcAddress("glGetActiveUniformsiv");
			glGetActiveUniformName = (PFNGLGETACTIVEUNIFORMNAMEPROC)wglGetProcAddress("glGetActiveUniformName");
			glGetUniformBlockIndex = (PFNGLGETUNIFORMBLOCKINDEXPROC)wglGetProcAddress("glGetUniformBlockIndex");
			glGetActiveUniformBlockiv = (PFNGLGETACTIVEUNIFORMBLOCKIVPROC)wglGetProcAddress("glGetActiveUniformBlockiv");
			glGetActiveUniformBlockName = (PFNGLGETACTIVEUNIFORMBLOCKNAMEPROC)wglGetProcAddress("glGetActiveUniformBlockName");
			glUniformBlockBinding = (PFNGLUNIFORMBLOCKBINDINGPROC)wglGetProcAddress("glUniformBlockBinding");
			glBindBufferBase = (PFNGLBINDBUFFERBASEPROC)wglGetProcAddress("glBindBufferBase");

			if (glGetUniformIndices == NULL ||
				glGetActiveUniformsiv == NULL ||
				glGetActiveUniformName == NULL ||
				glGetUniformBlockIndex == NULL ||
				glGetActiveUniformBlockiv == NULL ||
				glGetActiveUniformBlockName == NULL ||
				glUniformBlockBinding == NULL ||
				glBindBufferBase == NULL)
			{
				ok = false;
			}


		glGenVertexArrays = (PFNGLGENVERTEXARRAYSPROC)wglGetProcAddress("glGenVertexArrays");
		glBindVertexArray = (PFNGLBINDVERTEXARRAYPROC)wglGetProcAddress("glBindVertexArray");
		glDeleteVertexArray = (PFNGLDELETEVERTEXARRAYSPROC)wglGetProcAddress("glBindVertexArray");

		if (glGenVertexArrays == NULL ||
			glBindVertexArray == NULL ||
			glDeleteVertexArray == NULL)
		{
			ok = false;
		}


		return ok;
#else
	return true;
#endif
	}

	void CheckGlError()
	{
		size_t error = glGetError();
		if (error != GL_NO_ERROR)
		{
			throw std::runtime_error("Gl error");
		}
	}
}