#include "Rendering/SceneRenderFeatureHost.h"

#include "Debug/Logger.h"

#include <string>

namespace XCEngine {
namespace Rendering {
namespace {

Containers::String BuildFeatureGraphPassName(
    const Containers::String& basePassName,
    SceneRenderInjectionPoint injectionPoint,
    const SceneRenderFeaturePass& featurePass,
    size_t featureIndex) {
    std::string name = basePassName.CStr();
    if (!name.empty()) {
        name += '.';
    }

    name += ToString(injectionPoint);
    name += '.';
    name += featurePass.GetName() != nullptr
        ? featurePass.GetName()
        : "FeaturePass";
    name += '.';
    name += std::to_string(featureIndex);
    return Containers::String(name.c_str());
}

} // namespace

void SceneRenderFeatureHost::AddFeaturePass(std::unique_ptr<SceneRenderFeaturePass> featurePass) {
    if (featurePass != nullptr) {
        m_featurePasses.push_back(std::move(featurePass));
    }
}

size_t SceneRenderFeatureHost::GetFeaturePassCount() const {
    return m_featurePasses.size();
}

SceneRenderFeaturePass* SceneRenderFeatureHost::GetFeaturePass(size_t index) const {
    return index < m_featurePasses.size()
        ? m_featurePasses[index].get()
        : nullptr;
}

bool SceneRenderFeatureHost::Initialize(const RenderContext& context) {
    size_t initializedCount = 0u;
    for (const std::unique_ptr<SceneRenderFeaturePass>& featurePassOwner : m_featurePasses) {
        SceneRenderFeaturePass* featurePass = featurePassOwner.get();
        if (featurePass == nullptr) {
            continue;
        }

        if (featurePass->Initialize(context)) {
            ++initializedCount;
            continue;
        }

        Debug::Logger::Get().Error(
            Debug::LogCategory::Rendering,
            (Containers::String("SceneRenderFeatureHost initialize failed: ") +
                featurePass->GetName()).CStr());
        for (size_t shutdownIndex = initializedCount; shutdownIndex > 0u; --shutdownIndex) {
            SceneRenderFeaturePass* initializedPass = m_featurePasses[shutdownIndex - 1u].get();
            if (initializedPass != nullptr) {
                initializedPass->Shutdown();
            }
        }
        return false;
    }

    return true;
}

void SceneRenderFeatureHost::Shutdown() {
    for (auto featurePassIt = m_featurePasses.rbegin(); featurePassIt != m_featurePasses.rend(); ++featurePassIt) {
        if (*featurePassIt != nullptr) {
            (*featurePassIt)->Shutdown();
        }
    }
}

bool SceneRenderFeatureHost::Prepare(const FrameExecutionContext& executionContext) const {
    for (const std::unique_ptr<SceneRenderFeaturePass>& featurePassOwner : m_featurePasses) {
        SceneRenderFeaturePass* featurePass = featurePassOwner.get();
        if (featurePass == nullptr || !featurePass->IsActive(executionContext.sceneData)) {
            continue;
        }

        if (!featurePass->Prepare(executionContext)) {
            Debug::Logger::Get().Error(
                Debug::LogCategory::Rendering,
                (Containers::String("SceneRenderFeatureHost prepare failed: ") +
                    featurePass->GetName()).CStr());
            return false;
        }
    }

    return true;
}

bool SceneRenderFeatureHost::Record(
    const SceneRenderFeaturePassRenderGraphContext& context,
    SceneRenderInjectionPoint injectionPoint,
    bool* recordedAnyPass) const {
    bool hasRecordedPass = false;
    bool clearAttachments = context.clearAttachments;

    for (size_t featureIndex = 0u; featureIndex < m_featurePasses.size(); ++featureIndex) {
        const std::unique_ptr<SceneRenderFeaturePass>& featurePassOwner = m_featurePasses[featureIndex];
        SceneRenderFeaturePass* featurePass = featurePassOwner.get();
        if (featurePass == nullptr ||
            !featurePass->SupportsInjectionPoint(injectionPoint) ||
            !featurePass->IsActive(context.sceneData)) {
            continue;
        }

        const SceneRenderFeaturePassRenderGraphContext featureContext = {
            context.graphBuilder,
            BuildFeatureGraphPassName(
                context.passName,
                injectionPoint,
                *featurePass,
                featureIndex),
            context.renderContext,
            context.sceneData,
            context.surface,
            context.sourceSurface,
            context.sourceColorView,
            context.sourceColorState,
            context.sourceColorTexture,
            context.colorTargets,
            context.depthTarget,
            clearAttachments,
            context.executionSucceeded,
            context.beginPassCallback,
            context.endPassCallback,
            context.blackboard
        };
        if (!featurePass->RecordRenderGraph(featureContext)) {
            Debug::Logger::Get().Error(
                Debug::LogCategory::Rendering,
                (Containers::String("SceneRenderFeatureHost record failed at injection point '") +
                    ToString(injectionPoint) +
                    "': " +
                    featurePass->GetName()).CStr());
            if (recordedAnyPass != nullptr) {
                *recordedAnyPass = hasRecordedPass;
            }
            return false;
        }

        hasRecordedPass = true;
        clearAttachments = false;
    }

    if (recordedAnyPass != nullptr) {
        *recordedAnyPass = hasRecordedPass;
    }
    return true;
}

bool SceneRenderFeatureHost::Execute(
    const FrameExecutionContext& executionContext,
    SceneRenderInjectionPoint injectionPoint) const {
    const RenderPassContext passContext = BuildRenderPassContext(executionContext);

    for (const std::unique_ptr<SceneRenderFeaturePass>& featurePassOwner : m_featurePasses) {
        SceneRenderFeaturePass* featurePass = featurePassOwner.get();
        if (featurePass == nullptr ||
            !featurePass->SupportsInjectionPoint(injectionPoint) ||
            !featurePass->IsActive(executionContext.sceneData)) {
            continue;
        }

        if (!featurePass->Execute(passContext)) {
            Debug::Logger::Get().Error(
                Debug::LogCategory::Rendering,
                (Containers::String("SceneRenderFeatureHost execute failed at injection point '") +
                    ToString(injectionPoint) +
                    "': " +
                    featurePass->GetName()).CStr());
            return false;
        }
    }

    return true;
}

} // namespace Rendering
} // namespace XCEngine