//
//  GLProgramManager.cpp
//  OpenSpades
//
//  Created by yvt on 7/13/13.
//  Copyright (c) 2013 yvt.jp. All rights reserved.
//

#include "GLProgramManager.h"
#include "../Core/FileManager.h"
#include "../Core/Math.h"
#include "GLProgram.h"
#include "GLShader.h"
#include "../Core/Exception.h"
#include "../Core/Debug.h"
#include "GLShadowShader.h"
#include "GLDynamicLightShader.h"
#include "IGLShadowMapRenderer.h"
#include "GLShadowMapShader.h"
#include "../Core/Stopwatch.h"

namespace spades {
	namespace draw {
		GLProgramManager::GLProgramManager(IGLDevice *d,
										   IGLShadowMapRenderer *smr):
		device(d), shadowMapRenderer(smr){
			SPADES_MARK_FUNCTION();
		}
		
		GLProgramManager::~GLProgramManager() {
			SPADES_MARK_FUNCTION();
			
			for(std::map<std::string, GLProgram *>::iterator it = programs.begin(); it != programs.end(); it++){
				delete it->second;
			}
			for(std::map<std::string, GLShader *>::iterator it = shaders.begin(); it != shaders.end(); it++){
				delete it->second;
			}
		}
		
		GLProgram *GLProgramManager::RegisterProgram(const std::string &name) {
			SPADES_MARK_FUNCTION();
			
			std::map<std::string, GLProgram *>::iterator it;
			it = programs.find(name);
			if(it == programs.end()){
				GLProgram *prog = CreateProgram(name);
				programs[name] = prog;
				return prog;
			}else{
				return it->second;
			}
		}
		
		GLShader *GLProgramManager::RegisterShader(const std::string &name) {
			SPADES_MARK_FUNCTION();
			
			std::map<std::string, GLShader *>::iterator it;
			it = shaders.find(name);
			if(it == shaders.end()){
				GLShader *prog = CreateShader(name);
				shaders[name] = prog;
				return prog;
			}else{
				return it->second;
			}
		}
		
		GLProgram *GLProgramManager::CreateProgram(const std::string &name) {
			SPADES_MARK_FUNCTION();
			
			SPLog("Loading GLSL program '%s'", name.c_str());
			std::string text = FileManager::ReadAllBytes(name.c_str());
			std::vector<std::string> lines = SplitIntoLines(text);
			
			GLProgram *p = new GLProgram(device, name);
			
			for(size_t i = 0; i < lines.size(); i++){
				std::string text = TrimSpaces(lines[i]);
				if(text.empty())
					break;
				
				if(text == "*shadow*"){
					std::vector<GLShader *> shaders = GLShadowShader::RegisterShader(this);
					for(size_t i = 0; i < shaders.size(); i++)
						p->Attach(shaders[i]);
					continue;
				}else if(text == "*dlight*"){
					std::vector<GLShader *> shaders = GLDynamicLightShader::RegisterShader(this);
					for(size_t i = 0; i < shaders.size(); i++)
						p->Attach(shaders[i]);
					continue;
				}else if(text == "*shadowmap*"){
					std::vector<GLShader *> shaders = GLShadowMapShader::RegisterShader(this);
					for(size_t i = 0; i < shaders.size(); i++)
						p->Attach(shaders[i]);
					continue;
				}else if(text[0] == '*'){
					SPRaise("Unknown special shader: %s",text.c_str());
				}
				GLShader *s = CreateShader(text);
				
				p->Attach(s);
			}
			
			Stopwatch sw;
			p->Link();
			SPLog("Successfully linked GLSL program '%s' in %.3fms", name.c_str(), sw.GetTime() * 1000.);
			//p->Validate();
			return p;
		}
		
		GLShader *GLProgramManager::CreateShader(const std::string &name) {
			SPADES_MARK_FUNCTION();
			
			SPLog("Loading GLSL shader '%s'", name.c_str());
			std::string text = FileManager::ReadAllBytes(name.c_str());
			GLShader::Type type;
			
			if(name.find(".fs") != std::string::npos)
				type = GLShader::FragmentShader;
			else if(name.find(".vs") != std::string::npos)
				type = GLShader::VertexShader;
			else
				SPRaise("Failed to determine the type of a shader: %s",
						name.c_str());
			
			GLShader *s = new GLShader(device, type);
			s->AddSource(text);
			
			Stopwatch sw;
			s->Compile();
			SPLog("Successfully compiled GLSL program '%s' in %.3fms", name.c_str(),
				  sw.GetTime() * 1000.);
			return s;
		}
		
	}
}