#include "Material.h"
#include "Utilities.h"
#include "WICTextureLoader11.h"

using namespace DirectX;

UINT Material::init(ID3D11Device* pD3DDevice, LPCTSTR textureFileName)
{
    UINT error = 0;

    error = createVertexShader(pD3DDevice);
    CheckError(error);

    error = createPixelShader(pD3DDevice);
    CheckError(error);

    error = createMatrixBuffer(pD3DDevice);
    CheckError(error);

    error = createTextureAndSamplerState(pD3DDevice, textureFileName);
    CheckError(error);

    return 0;
}

void Material::render(ID3D11DeviceContext* pD3DDeviceContext)
{
    // set shader stages
    pD3DDeviceContext->VSSetShader(_pVertexShader, nullptr, 0);
    pD3DDeviceContext->PSSetShader(_pPixelShader, nullptr, 0);

    // set input layout
    pD3DDeviceContext->IASetInputLayout(_pInputLayout);

    // set shader resources
    pD3DDeviceContext->VSSetConstantBuffers(0, 1, &_pMatrixBuffer);

    // set texture
    pD3DDeviceContext->PSSetShaderResources(0, 1, &_pTexture);

    // set sampler state
    pD3DDeviceContext->PSSetSamplers(0, 1, &_pSamplerState);
}

void Material::deInit()
{
    safeRelease(_pSamplerState);
    safeRelease(_pTexture);
    safeRelease(_pMatrixBuffer);
    safeRelease(_pInputLayout);
    safeRelease(_pPixelShader);
    safeRelease(_pVertexShader);
}

void Material::setMatrixBuffer(ID3D11DeviceContext* pD3DDeviceContext, const XMFLOAT4X4& worldMatrix, const XMFLOAT4X4& viewMatrix, const XMFLOAT4X4& projectionMatrix)
{
    // unpack matrix data
    XMMATRIX w = XMLoadFloat4x4(&worldMatrix);
    XMMATRIX v = XMLoadFloat4x4(&viewMatrix);
    XMMATRIX p = XMLoadFloat4x4(&projectionMatrix);

    XMMATRIX wvp = w * v * p;
    
    // set matrix data
    D3D11_MAPPED_SUBRESOURCE bufferData = {};
    HRESULT hr = pD3DDeviceContext->Map(_pMatrixBuffer, 0, D3D11_MAP_WRITE_DISCARD, 0, &bufferData);
    if (FAILED(hr)) return;

    MatrixBuffer* matrixBuffer = static_cast<MatrixBuffer*>(bufferData.pData);

    XMStoreFloat4x4(static_cast<XMFLOAT4X4*>(&matrixBuffer->WorldViewProjectionMatrix), XMMatrixTranspose(wvp));
    XMStoreFloat4x4(static_cast<XMFLOAT4X4*>(&matrixBuffer->WorldMatrix), XMMatrixTranspose(w));

    pD3DDeviceContext->Unmap(_pMatrixBuffer, 0);
}

UINT Material::createVertexShader(ID3D11Device* pD3DDevice)
{
    HRESULT hr = {};
    ID3DBlob* pCompiledShaderCode = nullptr;

    // part 1 get compiled shader code
    
    // option 1: load high level shader code & compile
    //hr = D3DCompileFromFile(
    //    L"ColorVertexShader.hlsl", // shader file name
    //    nullptr, // optional macro defines
    //    nullptr, // pre compiled included shader code
    //    "main", // shader entry point (start function)
    //    "vs_4_0", // shader type & version
    //    0, 0, // optional flags
    //    &pCompiledShaderCode, // compiled shader code memory
    //    nullptr // error messages
    //);

    // option 2: load compiled shader code
    hr = D3DReadFileToBlob(L"ColorVertexShader.cso", &pCompiledShaderCode);
    //hr = D3DReadFileToBlob(L"TextureVertexShader.cso", &pCompiledShaderCode);
    //hr = D3DReadFileToBlob(L"LightingVertexShader.cso", &pCompiledShaderCode);

    CheckFailed(hr, 60);

    // part 2 create vertex shader object
    hr = pD3DDevice->CreateVertexShader(pCompiledShaderCode->GetBufferPointer(), pCompiledShaderCode->GetBufferSize(), nullptr, &_pVertexShader);
    CheckFailed(hr, 62);

    UINT error = createInputLayout(pD3DDevice, pCompiledShaderCode);
    CheckError(error);

    safeRelease(pCompiledShaderCode);

    return 0;
}

UINT Material::createPixelShader(ID3D11Device* pD3DDevice)
{
    HRESULT hr = {};
    ID3DBlob* pCompiledShaderCode = nullptr;

    hr = D3DReadFileToBlob(L"ColorPixelShader.cso", &pCompiledShaderCode);
    //hr = D3DReadFileToBlob(L"TexturePixelShader.cso", &pCompiledShaderCode);
    //hr = D3DReadFileToBlob(L"LightingPixelShader.cso", &pCompiledShaderCode);
    CheckFailed(hr, 64);

    hr = pD3DDevice->CreatePixelShader(pCompiledShaderCode->GetBufferPointer(), pCompiledShaderCode->GetBufferSize(), nullptr, &_pPixelShader);
    CheckFailed(hr, 66);

    safeRelease(pCompiledShaderCode);

    return 0;
}

UINT Material::createInputLayout(ID3D11Device* pD3DDevice, ID3DBlob* pCompiledVertexShaderCode)
{
    // https://learn.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-semantics
    D3D11_INPUT_ELEMENT_DESC elements[4] = {};

    // position
    elements[0].SemanticName = "POSITION";
    elements[0].Format = DXGI_FORMAT_R32G32B32_FLOAT;

    // normal
    elements[1].SemanticName = "NORMAL";
    elements[1].Format = DXGI_FORMAT_R32G32B32_FLOAT;
    elements[1].AlignedByteOffset = D3D11_APPEND_ALIGNED_ELEMENT;

    // uv
    elements[2].SemanticName = "TEXCOORD";
    elements[2].Format = DXGI_FORMAT_R32G32_FLOAT;
    elements[2].AlignedByteOffset = D3D11_APPEND_ALIGNED_ELEMENT;

    // color
    elements[3].SemanticName = "COLOR";
    elements[3].Format = DXGI_FORMAT_R32G32B32A32_FLOAT;
    elements[3].AlignedByteOffset = D3D11_APPEND_ALIGNED_ELEMENT;

    HRESULT hr = pD3DDevice->CreateInputLayout(elements, std::size(elements), pCompiledVertexShaderCode->GetBufferPointer(), pCompiledVertexShaderCode->GetBufferSize(), &_pInputLayout);
    CheckFailed(hr, 68);

    return 0;
}

UINT Material::createMatrixBuffer(ID3D11Device* pD3DDevice)
{
    D3D11_BUFFER_DESC desc = {};
    desc.ByteWidth = sizeof(MatrixBuffer);
    desc.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
    desc.Usage = D3D11_USAGE_DYNAMIC;
    desc.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;

    HRESULT hr = pD3DDevice->CreateBuffer(&desc, nullptr, &_pMatrixBuffer);
    CheckFailed(hr, 61);

    return 0;
}

UINT Material::createTextureAndSamplerState(ID3D11Device* pD3DDevice, LPCTSTR textureFileName)
{
    // load texture
    HRESULT hr = CreateWICTextureFromFile(pD3DDevice, textureFileName, nullptr, &_pTexture);
    CheckFailed(hr, 63);

    // create sampler state
    D3D11_SAMPLER_DESC samplerDesc = {};
    samplerDesc.AddressU = D3D11_TEXTURE_ADDRESS_WRAP;
    samplerDesc.AddressV = D3D11_TEXTURE_ADDRESS_WRAP;
    samplerDesc.AddressW = D3D11_TEXTURE_ADDRESS_WRAP; // CAUTION: has to be set always
    samplerDesc.Filter = D3D11_FILTER_MIN_MAG_MIP_LINEAR;

    hr = pD3DDevice->CreateSamplerState(&samplerDesc, &_pSamplerState);
    CheckFailed(hr, 65);
    
    return 0;
}