#include "ZoneLoaderFactoryIW3.h"

#include "ContentLoaderIW3.h"
#include "Game/GameLanguage.h"
#include "Game/IW3/GameIW3.h"
#include "Game/IW3/IW3.h"
#include "Game/IW3/ZoneConstantsIW3.h"
#include "Loading/Processor/ProcessorAuthedBlocks.h"
#include "Loading/Processor/ProcessorCaptureData.h"
#include "Loading/Processor/ProcessorInflate.h"
#include "Loading/Steps/StepAddProcessor.h"
#include "Loading/Steps/StepAllocXBlocks.h"
#include "Loading/Steps/StepDumpData.h"
#include "Loading/Steps/StepLoadHash.h"
#include "Loading/Steps/StepLoadSignature.h"
#include "Loading/Steps/StepLoadZoneContent.h"
#include "Loading/Steps/StepLoadZoneSizes.h"
#include "Loading/Steps/StepRemoveProcessor.h"
#include "Loading/Steps/StepSkipBytes.h"
#include "Loading/Steps/StepVerifyFileName.h"
#include "Loading/Steps/StepVerifyHash.h"
#include "Loading/Steps/StepVerifyMagic.h"
#include "Loading/Steps/StepVerifySignature.h"
#include "Utils/ClassUtils.h"
#include "Utils/Endianness.h"
#include "Utils/Logging/Log.h"

#include <cassert>
#include <cstring>
#include <filesystem>
#include <type_traits>

using namespace IW3;
namespace fs = std::filesystem;

namespace
{
    void SetupBlock(ZoneMemory& zoneMemory)
    {
#define XBLOCK_DEF(name, type) std::make_unique<XBlock>(STR(name), name, type)

        zoneMemory.AddBlock(XBLOCK_DEF(IW3::XFILE_BLOCK_TEMP, XBlockType::BLOCK_TYPE_TEMP));
        zoneMemory.AddBlock(XBLOCK_DEF(IW3::XFILE_BLOCK_RUNTIME, XBlockType::BLOCK_TYPE_RUNTIME));
        zoneMemory.AddBlock(XBLOCK_DEF(IW3::XFILE_BLOCK_LARGE_RUNTIME, XBlockType::BLOCK_TYPE_RUNTIME));
        zoneMemory.AddBlock(XBLOCK_DEF(IW3::XFILE_BLOCK_PHYSICAL_RUNTIME, XBlockType::BLOCK_TYPE_RUNTIME));
        zoneMemory.AddBlock(XBLOCK_DEF(IW3::XFILE_BLOCK_VIRTUAL, XBlockType::BLOCK_TYPE_NORMAL));
        zoneMemory.AddBlock(XBLOCK_DEF(IW3::XFILE_BLOCK_LARGE, XBlockType::BLOCK_TYPE_NORMAL));
        zoneMemory.AddBlock(XBLOCK_DEF(IW3::XFILE_BLOCK_PHYSICAL, XBlockType::BLOCK_TYPE_NORMAL));
        zoneMemory.AddBlock(XBLOCK_DEF(IW3::XFILE_BLOCK_VERTEX, XBlockType::BLOCK_TYPE_NORMAL));
        zoneMemory.AddBlock(XBLOCK_DEF(IW3::XFILE_BLOCK_INDEX, XBlockType::BLOCK_TYPE_NORMAL));

#undef XBLOCK_DEF
    }

    std::unique_ptr<cryptography::IPublicKeyAlgorithm> SetupRsa(const bool isOfficial)
    {
        if (isOfficial)
        {
            auto rsa = cryptography::CreateRsa(cryptography::HashingAlgorithm::RSA_HASH_SHA256, cryptography::RsaPaddingMode::RSA_PADDING_PSS);

            if (!rsa->SetKey(ZoneConstants::RSA_PUBLIC_KEY_INFINITY_WARD, sizeof(ZoneConstants::RSA_PUBLIC_KEY_INFINITY_WARD)))
            {
                con::error("Invalid public key for signature checking");
                return nullptr;
            }

            return rsa;
        }
        else
        {
            assert(false);

            // TODO: Load custom RSA key here
            return nullptr;
        }
    }

    void AddAuthHeaderSteps(const ZoneLoaderInspectionResult& inspectResult, ZoneLoader& zoneLoader, const std::string& fileName)
    {
        // Unsigned zones do not have an auth header
        if (!inspectResult.m_is_signed)
            return;

        // If file is signed setup a RSA instance.
        auto rsa = SetupRsa(inspectResult.m_is_official);

        zoneLoader.AddLoadingStep(step::CreateStepVerifyMagic(ZoneConstants::MAGIC_AUTH_HEADER));
        zoneLoader.AddLoadingStep(step::CreateStepSkipBytes(4)); // Skip reserved

        auto subHeaderHash = step::CreateStepLoadHash(sizeof(DB_AuthHash::bytes), 1);
        auto* subHeaderHashPtr = subHeaderHash.get();
        zoneLoader.AddLoadingStep(std::move(subHeaderHash));

        auto subHeaderHashSignature = step::CreateStepLoadSignature(sizeof(DB_AuthSignature::bytes));
        auto* subHeaderHashSignaturePtr = subHeaderHashSignature.get();
        zoneLoader.AddLoadingStep(std::move(subHeaderHashSignature));

        zoneLoader.AddLoadingStep(step::CreateStepVerifySignature(std::move(rsa), subHeaderHashSignaturePtr, subHeaderHashPtr));

        auto subHeaderCapture = processor::CreateProcessorCaptureData(sizeof(DB_AuthSubHeader));
        auto* subHeaderCapturePtr = subHeaderCapture.get();
        zoneLoader.AddLoadingStep(step::CreateStepAddProcessor(std::move(subHeaderCapture)));

        zoneLoader.AddLoadingStep(step::CreateStepVerifyFileName(fileName, sizeof(DB_AuthSubHeader::fastfileName)));
        zoneLoader.AddLoadingStep(step::CreateStepSkipBytes(4)); // Skip reserved

        auto masterBlockHashes =
            step::CreateStepLoadHash(sizeof(DB_AuthHash::bytes), static_cast<unsigned>(std::extent_v<decltype(DB_AuthSubHeader::masterBlockHashes)>));
        auto* masterBlockHashesPtr = masterBlockHashes.get();
        zoneLoader.AddLoadingStep(std::move(masterBlockHashes));

        zoneLoader.AddLoadingStep(step::CreateStepVerifyHash(cryptography::CreateSha256(), 0, subHeaderHashPtr, subHeaderCapturePtr));
        zoneLoader.AddLoadingStep(step::CreateStepRemoveProcessor(subHeaderCapturePtr));

        // Skip the rest of the first chunk
        zoneLoader.AddLoadingStep(step::CreateStepSkipBytes(ZoneConstants::AUTHED_CHUNK_SIZE - sizeof(DB_AuthHeader)));

        zoneLoader.AddLoadingStep(step::CreateStepAddProcessor(
            processor::CreateProcessorAuthedBlocks(ZoneConstants::AUTHED_CHUNK_COUNT_PER_GROUP,
                                                   ZoneConstants::AUTHED_CHUNK_SIZE,
                                                   static_cast<unsigned>(std::extent_v<decltype(DB_AuthSubHeader::masterBlockHashes)>),
                                                   cryptography::CreateSha256(),
                                                   masterBlockHashesPtr)));
    }
} // namespace

std::optional<ZoneLoaderInspectionResult> ZoneLoaderFactory::InspectZoneHeader(ZoneDataPeeking& filePeek) const
{
    const auto& header = filePeek.PeekStruct<ZoneHeader>();
    if (endianness::FromLittleEndian(header.m_version) == ZoneConstants::ZONE_VERSION_PC)
    {
        if (!memcmp(header.m_magic, ZoneConstants::MAGIC_UNSIGNED, std::char_traits<char>::length(ZoneConstants::MAGIC_UNSIGNED)))
        {
            return ZoneLoaderInspectionResult{
                .m_game_id = GameId::IW3,
                .m_variant_id = GameVariantId::IW3_PC,
                .m_is_official = true,
                .m_is_signed = false,
                .m_is_encrypted = false,
            };
        }
    }
    else if (endianness::FromBigEndian(header.m_version) == ZoneConstants::ZONE_VERSION_XENON)
    {
        if (!memcmp(header.m_magic, ZoneConstants::MAGIC_UNSIGNED, std::char_traits<char>::length(ZoneConstants::MAGIC_UNSIGNED)))
        {
            return ZoneLoaderInspectionResult{
                .m_game_id = GameId::IW3,
                .m_variant_id = GameVariantId::IW3_XBOX,
                .m_is_official = true,
                .m_is_signed = false,
                .m_is_encrypted = false,
            };
        }
        if (!memcmp(header.m_magic, ZoneConstants::MAGIC_SIGNED, std::char_traits<char>::length(ZoneConstants::MAGIC_SIGNED)))
        {
            return ZoneLoaderInspectionResult{
                .m_game_id = GameId::IW3,
                .m_variant_id = GameVariantId::IW3_XBOX,
                .m_is_official = true,
                .m_is_signed = true,
                .m_is_encrypted = false,
            };
        }
    }

    return std::nullopt;
}

std::unique_ptr<ZoneLoader> ZoneLoaderFactory::CreateLoaderForHeader(ZoneDataPeeking& filePeek,
                                                                     const std::string& fileName,
                                                                     std::optional<std::unique_ptr<ProgressCallback>> progressCallback) const
{
    const auto inspectResult = InspectZoneHeader(filePeek);
    if (!inspectResult)
        return nullptr;

    const auto variant = IGameVariant::GetVariantById(inspectResult->m_variant_id);

    // Create new zone
    auto zone = std::make_unique<Zone>(fileName, 0, inspectResult->m_variant_id);
    auto* zonePtr = zone.get();
    zone->m_language = GameLanguage::LANGUAGE_NONE;

    // File is supported. Now setup all required steps for loading this file.
    auto zoneLoader = std::make_unique<ZoneLoader>(std::move(zone));

    SetupBlock(zonePtr->Memory());

    // Skip the initial header that we peeked at before
    zoneLoader->AddLoadingStep(step::CreateStepSkipBytes(sizeof(ZoneHeader)));

    // Add steps for loading the auth header which also contain the signature of the zone if it is signed.
    AddAuthHeaderSteps(*inspectResult, *zoneLoader, fileName);

    zoneLoader->AddLoadingStep(step::CreateStepAddProcessor(processor::CreateProcessorInflate(ZoneConstants::AUTHED_CHUNK_SIZE)));

    if (variant->GetEndianness() == GameEndianness::LE)
    {
        // Start of the XFile struct
        zoneLoader->AddLoadingStep(step::CreateStepLoadZoneSizes());
        zoneLoader->AddLoadingStep(step::CreateStepAllocXBlocks(zonePtr));

        // Start of the zone content
        zoneLoader->AddLoadingStep(step::CreateStepLoadZoneContent(
            [zonePtr](ZoneInputStream& stream)
            {
                return std::make_unique<ContentLoader>(*zonePtr, stream);
            },
            32u,
            ZoneConstants::OFFSET_BLOCK_BIT_COUNT,
            ZoneConstants::INSERT_BLOCK,
            zonePtr,
            std::move(progressCallback)));
    }
    else
    {
        fs::path dumpFileNamePath = fs::path(fileName).filename();
        dumpFileNamePath.replace_extension(".dat");
        std::string dumpFileName = dumpFileNamePath.string();
        con::warn("Dumping xbox assets is not supported, making a full fastfile data dump to {}", dumpFileName);
        zoneLoader->AddLoadingStep(step::CreateStepDumpData(dumpFileName, 0xFFFFFFFF));
    }

    return zoneLoader;
}