#include "CMaterial.h"
#include <Common/CHashFNV1A.h>
#include <Core/CDrawUtil.h>
#include <Core/CRenderer.h>
#include <Core/CResCache.h>
#include <OpenGL/GLCommon.h>
#include <OpenGL/CShaderGenerator.h>

#include <iostream>
#include <gl/glew.h>

u64 CMaterial::sCurrentMaterial = 0;
CColor CMaterial::sCurrentTint = CColor::skWhite;

CMaterial::CMaterial()
{
    mpShader = nullptr;
    mShaderStatus = eNoShader;
    mRecalcHash = true;
    mEnableBloom = false;
    mVersion = eUnknownVersion;
    mOptions = eNoSettings;
    mVtxDesc = eNoAttributes;
    mBlendSrcFac = GL_ONE;
    mBlendDstFac = GL_ZERO;
    mLightingEnabled = true;
    mEchoesUnknownA = 0;
    mEchoesUnknownB = 0;
    mpIndirectTexture = nullptr;
}

CMaterial::CMaterial(EGame version, EVertexDescription vtxDesc)
{
    mpShader = nullptr;
    mShaderStatus = eNoShader;
    mRecalcHash = true;
    mEnableBloom = (version == eCorruption);
    mVersion = version;
    mOptions = eDepthWrite;
    mVtxDesc = vtxDesc;
    mBlendSrcFac = GL_ONE;
    mBlendDstFac = GL_ZERO;
    mLightingEnabled = true;
    mEchoesUnknownA = 0;
    mEchoesUnknownB = 0;
    mpIndirectTexture = nullptr;
}

CMaterial::~CMaterial()
{
    for (u32 iPass = 0; iPass < mPasses.size(); iPass++)
        delete mPasses[iPass];

    delete mpShader;
}

CMaterial* CMaterial::Clone()
{
    CMaterial *pOut = new CMaterial();
    pOut->mName = mName;
    pOut->mEnableBloom = mEnableBloom;
    pOut->mVersion = mVersion;
    pOut->mOptions = mOptions;
    pOut->mVtxDesc = mVtxDesc;
    for (u32 iKonst = 0; iKonst < 4; iKonst++)
        pOut->mKonstColors[iKonst] = mKonstColors[iKonst];
    pOut->mBlendSrcFac = mBlendSrcFac;
    pOut->mBlendDstFac = mBlendDstFac;
    pOut->mLightingEnabled = mLightingEnabled;
    pOut->mEchoesUnknownA = mEchoesUnknownA;
    pOut->mEchoesUnknownB = mEchoesUnknownB;
    pOut->mpIndirectTexture = mpIndirectTexture;
    pOut->mIndTextureToken = CToken(pOut->mpIndirectTexture);

    pOut->mPasses.resize(mPasses.size());
    for (u32 iPass = 0; iPass < mPasses.size(); iPass++)
        pOut->mPasses[iPass] = mPasses[iPass]->Clone(pOut);

    return pOut;
}

void CMaterial::GenerateShader()
{
    delete mpShader;
    mpShader = CShaderGenerator::GenerateShader(*this);

    if (!mpShader->IsValidProgram()) mShaderStatus = eShaderFailed;
    else mShaderStatus = eShaderExists;
}

bool CMaterial::SetCurrent(ERenderOptions Options)
{
    // Bind textures
    const char *skpSamplers[8] = {
        "Texture0", "Texture1", "Texture2", "Texture3",
        "Texture4", "Texture5", "Texture6", "Texture7"
    };

    // Skip material setup if the currently bound material is identical
    if (sCurrentMaterial != HashParameters())
    {
        // Shader setup
        if (mShaderStatus == eNoShader) GenerateShader();
        mpShader->SetCurrent();

        if (mShaderStatus == eShaderFailed)
            return false;

        // Set RGB blend equation - force to ZERO/ONE if alpha is disabled
        GLenum srcRGB, dstRGB, srcAlpha, dstAlpha;

        if (Options & eNoAlpha) {
            srcRGB = GL_ONE;
            dstRGB = GL_ZERO;
        } else {
            srcRGB = mBlendSrcFac;
            dstRGB = mBlendDstFac;
        }

        // Set alpha blend equation
        bool AlphaBlended = ((mBlendSrcFac == GL_SRC_ALPHA) && (mBlendDstFac == GL_ONE_MINUS_SRC_ALPHA));

        if ((mEnableBloom) && (Options & eEnableBloom) && (!AlphaBlended)) {
            srcAlpha = mBlendSrcFac;
            dstAlpha = mBlendDstFac;
        } else {
            srcAlpha = GL_ZERO;
            dstAlpha = GL_ZERO;
        }

        glBlendFuncSeparate(srcRGB, dstRGB, srcAlpha, dstAlpha);

        // Set konst inputs
        for (u32 iKonst = 0; iKonst < 4; iKonst++)
            CGraphics::sPixelBlock.Konst[iKonst] = mKonstColors[iKonst].ToVector4f();

        // Set color channels
        // COLOR0_Amb is initialized by the node instead of by the material
        CGraphics::sVertexBlock.COLOR0_Mat = CColor::skWhite.ToVector4f();

        // Set depth write - force on if alpha is disabled (lots of weird depth issues otherwise)
        if ((mOptions & eDepthWrite) || (Options & eNoAlpha)) glDepthMask(GL_TRUE);
        else glDepthMask(GL_FALSE);

        // Load uniforms
        for (u32 iPass = 0; iPass < mPasses.size(); iPass++)
            mPasses[iPass]->SetAnimCurrent(Options, iPass);

        sCurrentMaterial = HashParameters();
    }

    // If the passes are otherwise the same, update UV anims that use the model matrix
    else
    {
        for (u32 iPass = 0; iPass < mPasses.size(); iPass++)
        {
            EUVAnimMode mode = mPasses[iPass]->AnimMode();

            if ((mode == eInverseMV) || (mode == eInverseMVTranslated) ||
                (mode == eModelMatrix) || (mode == eSimpleMode))
                mPasses[iPass]->SetAnimCurrent(Options, iPass);
        }
    }

    // Bind textures
    CShader *pShader = CShader::CurrentShader();

    for (u32 iPass = 0; iPass < mPasses.size(); iPass++)
    {
        mPasses[iPass]->LoadTexture(iPass);
        GLint sampler = pShader->GetUniformLocation(skpSamplers[iPass]);
        glUniform1i(sampler, iPass);
    }

    // Bind num lights
    GLuint NumLightsLoc = pShader->GetUniformLocation("NumLights");
    glUniform1i(NumLightsLoc, CGraphics::sNumLights);

    // Update shader blocks
    CGraphics::UpdateVertexBlock();
    CGraphics::UpdatePixelBlock();

    return true;
}

u64 CMaterial::HashParameters()
{
    if (mRecalcHash)
    {
        CHashFNV1A Hash;
        Hash.Init64();

        Hash.HashLong(mVersion);
        Hash.HashLong(mOptions);
        Hash.HashLong(mVtxDesc);
        Hash.HashData(mKonstColors, sizeof(CColor) * 4);
        Hash.HashLong(mBlendSrcFac);
        Hash.HashLong(mBlendDstFac);
        Hash.HashByte(mLightingEnabled);
        Hash.HashLong(mEchoesUnknownA);
        Hash.HashLong(mEchoesUnknownB);

        for (u32 iPass = 0; iPass < mPasses.size(); iPass++)
            mPasses[iPass]->HashParameters(Hash);

        mParametersHash = Hash.GetHash64();
        mRecalcHash = false;
    }

    return mParametersHash;
}

void CMaterial::Update()
{
    mRecalcHash = true;
    mShaderStatus = eNoShader;
}

// ************ GETTERS ************
std::string CMaterial::Name() const
{
    return mName;
}

EGame CMaterial::Version() const
{
    return mVersion;
}

CMaterial::EMaterialOptions CMaterial::Options() const
{
    return mOptions;
}

EVertexDescription CMaterial::VtxDesc() const
{
    return mVtxDesc;
}

GLenum CMaterial::BlendSrcFac() const {
    return mBlendSrcFac;
}

GLenum CMaterial::BlendDstFac() const {
    return mBlendDstFac;
}

CColor CMaterial::Konst(u32 KIndex) const
{
    if (KIndex > 3) return CColor::skTransparentBlack;
    else return mKonstColors[KIndex];
}

CTexture* CMaterial::IndTexture() const
{
    return mpIndirectTexture;
}

bool CMaterial::IsLightingEnabled() const
{
    return mLightingEnabled;
}

u32 CMaterial::EchoesUnknownA() const
{
    return mEchoesUnknownA;
}

u32 CMaterial::EchoesUnknownB() const
{
    return mEchoesUnknownB;
}

u32 CMaterial::PassCount() const
{
    return mPasses.size();
}

CMaterialPass* CMaterial::Pass(u32 PassIndex) const
{
    return mPasses[PassIndex];
}


// ************ SETTERS ************
void CMaterial::SetName(const std::string& name)
{
    mName = name;
}

void CMaterial::SetOptions(EMaterialOptions Options)
{
    mOptions = Options;
    mRecalcHash = true;
}

void CMaterial::SetVertexDescription(EVertexDescription desc)
{
    mVtxDesc = desc;
    mRecalcHash = true;
}

void CMaterial::SetBlendMode(GLenum SrcFac, GLenum DstFac)
{
    mBlendSrcFac = SrcFac;
    mBlendDstFac = DstFac;
    mRecalcHash = true;
}

void CMaterial::SetKonst(CColor& Konst, u32 KIndex)
{
    mKonstColors[KIndex] = Konst;
    mRecalcHash = true;
}

void CMaterial::SetIndTexture(CTexture *pTex)
{
    mpIndirectTexture = pTex;
}

void CMaterial::SetLightingEnabled(bool Enabled)
{
    mLightingEnabled = Enabled;
    mRecalcHash = true;
}

// ************ STATIC ************
void CMaterial::KillCachedMaterial()
{
    sCurrentMaterial = 0;
}