// SwiftShader Software Renderer
//
// Copyright(c) 2005-2012 TransGaming Inc.
//
// All rights reserved. No part of this software may be copied, distributed, transmitted,
// transcribed, stored in a retrieval system, translated into any human or computer
// language by any means, or disclosed to third parties without the explicit written
// agreement of TransGaming Inc. Without such an agreement, no rights or licenses, express
// or implied, including but not limited to any patent rights, are granted to you.
//

// ResourceManager.cpp: Implements the ResourceManager class, which tracks and 
// retrieves objects which may be shared by multiple Contexts.

#include "ResourceManager.h"

#include "Buffer.h"
#include "Fence.h"
#include "Program.h"
#include "Renderbuffer.h"
#include "Sampler.h"
#include "Shader.h"
#include "Texture.h"

namespace es2
{
ResourceManager::ResourceManager()
{
    mRefCount = 1;
}

ResourceManager::~ResourceManager()
{
    while(!mBufferMap.empty())
    {
        deleteBuffer(mBufferMap.begin()->first);
    }

    while(!mProgramMap.empty())
    {
        deleteProgram(mProgramMap.begin()->first);
    }

    while(!mShaderMap.empty())
    {
        deleteShader(mShaderMap.begin()->first);
    }

    while(!mRenderbufferMap.empty())
    {
        deleteRenderbuffer(mRenderbufferMap.begin()->first);
    }

    while(!mTextureMap.empty())
    {
        deleteTexture(mTextureMap.begin()->first);
    }

	while(!mSamplerMap.empty())
	{
		deleteSampler(mSamplerMap.begin()->first);
	}

	while(!mFenceSyncMap.empty())
	{
		deleteFenceSync(mFenceSyncMap.begin()->first);
	}
}

void ResourceManager::addRef()
{
    mRefCount++;
}

void ResourceManager::release()
{
    if(--mRefCount == 0)
    {
        delete this;
    }
}

// Returns an unused buffer name
GLuint ResourceManager::createBuffer()
{
    GLuint handle = mBufferNameSpace.allocate();

    mBufferMap[handle] = NULL;

    return handle;
}

// Returns an unused shader/program name
GLuint ResourceManager::createShader(GLenum type)
{
    GLuint handle = mProgramShaderNameSpace.allocate();

    if(type == GL_VERTEX_SHADER)
    {
        mShaderMap[handle] = new VertexShader(this, handle);
    }
    else if(type == GL_FRAGMENT_SHADER)
    {
        mShaderMap[handle] = new FragmentShader(this, handle);
    }
    else UNREACHABLE();

    return handle;
}

// Returns an unused program/shader name
GLuint ResourceManager::createProgram()
{
    GLuint handle = mProgramShaderNameSpace.allocate();

    mProgramMap[handle] = new Program(this, handle);

    return handle;
}

// Returns an unused texture name
GLuint ResourceManager::createTexture()
{
    GLuint handle = mTextureNameSpace.allocate();

    mTextureMap[handle] = NULL;

    return handle;
}

// Returns an unused renderbuffer name
GLuint ResourceManager::createRenderbuffer()
{
    GLuint handle = mRenderbufferNameSpace.allocate();

    mRenderbufferMap[handle] = NULL;

    return handle;
}

// Returns an unused sampler name
GLuint ResourceManager::createSampler()
{
	GLuint handle = mSamplerHandleAllocator.allocate();

	mSamplerMap[handle] = NULL;

	return handle;
}

// Returns the next unused fence name, and allocates the fence
GLuint ResourceManager::createFenceSync(GLenum condition, GLbitfield flags)
{
	GLuint handle = mFenceSyncHandleAllocator.allocate();

	mFenceSyncMap[handle] = new FenceSync(handle, condition, flags);

	return handle;
}

void ResourceManager::deleteBuffer(GLuint buffer)
{
    BufferMap::iterator bufferObject = mBufferMap.find(buffer);

    if(bufferObject != mBufferMap.end())
    {
        mBufferNameSpace.release(bufferObject->first);
        if(bufferObject->second) bufferObject->second->release();
        mBufferMap.erase(bufferObject);
    }
}

void ResourceManager::deleteShader(GLuint shader)
{
    ShaderMap::iterator shaderObject = mShaderMap.find(shader);

    if(shaderObject != mShaderMap.end())
    {
        if(shaderObject->second->getRefCount() == 0)
        {
            mProgramShaderNameSpace.release(shaderObject->first);
            delete shaderObject->second;
            mShaderMap.erase(shaderObject);
        }
        else
        {
            shaderObject->second->flagForDeletion();
        }
    }
}

void ResourceManager::deleteProgram(GLuint program)
{
    ProgramMap::iterator programObject = mProgramMap.find(program);

    if(programObject != mProgramMap.end())
    {
        if(programObject->second->getRefCount() == 0)
        {
            mProgramShaderNameSpace.release(programObject->first);
            delete programObject->second;
            mProgramMap.erase(programObject);
        }
        else
        { 
            programObject->second->flagForDeletion();
        }
    }
}

void ResourceManager::deleteTexture(GLuint texture)
{
    TextureMap::iterator textureObject = mTextureMap.find(texture);

    if(textureObject != mTextureMap.end())
    {
        mTextureNameSpace.release(textureObject->first);
        if(textureObject->second) textureObject->second->release();
        mTextureMap.erase(textureObject);
    }
}

void ResourceManager::deleteRenderbuffer(GLuint renderbuffer)
{
    RenderbufferMap::iterator renderbufferObject = mRenderbufferMap.find(renderbuffer);

    if(renderbufferObject != mRenderbufferMap.end())
    {
        mRenderbufferNameSpace.release(renderbufferObject->first);
        if(renderbufferObject->second) renderbufferObject->second->release();
        mRenderbufferMap.erase(renderbufferObject);
    }
}

void ResourceManager::deleteSampler(GLuint sampler)
{
	auto samplerObject = mSamplerMap.find(sampler);

	if(samplerObject != mSamplerMap.end())
	{
		mSamplerHandleAllocator.release(samplerObject->first);
		if(samplerObject->second) samplerObject->second->release();
		mSamplerMap.erase(samplerObject);
	}
}

void ResourceManager::deleteFenceSync(GLuint fenceSync)
{
	auto fenceObjectIt = mFenceSyncMap.find(fenceSync);

	if(fenceObjectIt != mFenceSyncMap.end())
	{
		mFenceSyncHandleAllocator.release(fenceObjectIt->first);
		if(fenceObjectIt->second) fenceObjectIt->second->release();
		mFenceSyncMap.erase(fenceObjectIt);
	}
}

Buffer *ResourceManager::getBuffer(unsigned int handle)
{
    BufferMap::iterator buffer = mBufferMap.find(handle);

    if(buffer == mBufferMap.end())
    {
        return NULL;
    }
    else
    {
        return buffer->second;
    }
}

Shader *ResourceManager::getShader(unsigned int handle)
{
    ShaderMap::iterator shader = mShaderMap.find(handle);

    if(shader == mShaderMap.end())
    {
        return NULL;
    }
    else
    {
        return shader->second;
    }
}

Texture *ResourceManager::getTexture(unsigned int handle)
{
    if(handle == 0) return NULL;

    TextureMap::iterator texture = mTextureMap.find(handle);

    if(texture == mTextureMap.end())
    {
        return NULL;
    }
    else
    {
        return texture->second;
    }
}

Program *ResourceManager::getProgram(unsigned int handle)
{
    ProgramMap::iterator program = mProgramMap.find(handle);

    if(program == mProgramMap.end())
    {
        return NULL;
    }
    else
    {
        return program->second;
    }
}

Renderbuffer *ResourceManager::getRenderbuffer(unsigned int handle)
{
    RenderbufferMap::iterator renderbuffer = mRenderbufferMap.find(handle);

    if(renderbuffer == mRenderbufferMap.end())
    {
        return NULL;
    }
    else
    {
		if (!renderbuffer->second)
		{
			Renderbuffer *renderbufferObject = new Renderbuffer(handle, new Colorbuffer(0, 0, GL_RGBA4_OES, 0));
			mRenderbufferMap[handle] = renderbufferObject;
			renderbufferObject->addRef();
		}
        return renderbuffer->second;
    }
}

Sampler *ResourceManager::getSampler(unsigned int handle)
{
	auto sampler = mSamplerMap.find(handle);

	if(sampler == mSamplerMap.end())
	{
		return NULL;
	}
	else
	{
		return sampler->second;
	}
}

FenceSync *ResourceManager::getFenceSync(unsigned int handle)
{
	auto fenceObjectIt = mFenceSyncMap.find(handle);

	if(fenceObjectIt == mFenceSyncMap.end())
	{
		return NULL;
	}
	else
	{
		return fenceObjectIt->second;
	}
}

void ResourceManager::setRenderbuffer(GLuint handle, Renderbuffer *buffer)
{
    mRenderbufferMap[handle] = buffer;
}

void ResourceManager::checkBufferAllocation(unsigned int buffer)
{
    if(buffer != 0 && !getBuffer(buffer))
    {
        Buffer *bufferObject = new Buffer(buffer);
        mBufferMap[buffer] = bufferObject;
        bufferObject->addRef();
    }
}

void ResourceManager::checkTextureAllocation(GLuint texture, TextureType type)
{
    if(!getTexture(texture) && texture != 0)
    {
        Texture *textureObject;

        if(type == TEXTURE_2D)
        {
            textureObject = new Texture2D(texture);
        }
        else if(type == TEXTURE_CUBE)
        {
            textureObject = new TextureCubeMap(texture);
        }
		else if(type == TEXTURE_EXTERNAL)
		{
			textureObject = new TextureExternal(texture);
		}
		else if(type == TEXTURE_3D)
		{
			textureObject = new Texture3D(texture);
		}
		else if(type == TEXTURE_2D_ARRAY)
		{
			textureObject = new Texture2DArray(texture);
		}
		else
        {
            UNREACHABLE();
            return;
        }

        mTextureMap[texture] = textureObject;
        textureObject->addRef();
    }
}

void ResourceManager::checkSamplerAllocation(GLuint sampler)
{
	if(sampler != 0 && !getSampler(sampler))
	{
		Sampler *samplerObject = new Sampler(sampler);
		mSamplerMap[sampler] = samplerObject;
		samplerObject->addRef();
		// Samplers cannot be created via Bind
	}
}

bool ResourceManager::isSampler(GLuint sampler)
{
	return mSamplerMap.find(sampler) != mSamplerMap.end();
}

}