#include <renderer/render_graph.h>
#include <renderer/rhi_module.h>
#include <utils/logger.h>

namespace extra2d {

// ========================================
// RenderPassContext 实现
// ========================================

TextureHandle
RenderPassContext::getTexture(RenderGraphResourceHandle handle) const {
  if (graph) {
    return graph->getTexture(handle);
  }
  return TextureHandle{};
}

// ========================================
// RenderGraphBuilder 实现
// ========================================

RenderGraphResourceHandle
RenderGraphBuilder::createTexture(const RenderGraphTextureDesc &desc) {
  // 实际的资源创建由 RenderGraph 管理
  // 这里只记录描述，返回临时句柄
  textureDescs_.push_back(desc);
  RenderGraphResourceHandle handle;
  handle.index = static_cast<uint32_t>(textureDescs_.size()) - 1;
  handle.type = RenderGraphResourceType::Texture;
  return handle;
}

void RenderGraphBuilder::readResource(RenderGraphResourceHandle handle) {
  // 记录资源读取依赖
  // 用于后续的依赖分析和资源生命周期管理
}

void RenderGraphBuilder::writeResource(RenderGraphResourceHandle handle) {
  // 记录资源写入依赖
}

void RenderGraphBuilder::setRenderTarget(
    const RenderGraphRenderTargetDesc &desc) {
  // 设置渲染目标
}

// ========================================
// RenderGraph 实现
// ========================================

RenderGraph::RenderGraph() = default;

RenderGraph::~RenderGraph() { shutdown(); }

RenderGraph::RenderGraph(RenderGraph &&other) noexcept
    : passes_(std::move(other.passes_)),
      executionOrder_(std::move(other.executionOrder_)),
      textures_(std::move(other.textures_)),
      nextResourceId_(other.nextResourceId_),
      builder_(std::move(other.builder_)),
      commandQueue_(std::move(other.commandQueue_)),
      outputWidth_(other.outputWidth_), outputHeight_(other.outputHeight_),
      frameIndex_(other.frameIndex_), compiled_(other.compiled_) {
  other.nextResourceId_ = 1;
  other.outputWidth_ = 1280;
  other.outputHeight_ = 720;
  other.frameIndex_ = 0;
  other.compiled_ = false;
}

RenderGraph &RenderGraph::operator=(RenderGraph &&other) noexcept {
  if (this != &other) {
    shutdown();

    passes_ = std::move(other.passes_);
    executionOrder_ = std::move(other.executionOrder_);
    textures_ = std::move(other.textures_);
    nextResourceId_ = other.nextResourceId_;
    builder_ = std::move(other.builder_);
    commandQueue_ = std::move(other.commandQueue_);
    outputWidth_ = other.outputWidth_;
    outputHeight_ = other.outputHeight_;
    frameIndex_ = other.frameIndex_;
    compiled_ = other.compiled_;

    other.nextResourceId_ = 1;
    other.outputWidth_ = 1280;
    other.outputHeight_ = 720;
    other.frameIndex_ = 0;
    other.compiled_ = false;
  }
  return *this;
}

bool RenderGraph::initialize() {
  if (!commandQueue_.initialize()) {
    E2D_LOG_ERROR("Failed to initialize CommandQueue");
    return false;
  }

  E2D_LOG_INFO("RenderGraph initialized");
  return true;
}

void RenderGraph::shutdown() {
  destroyResources();
  passes_.clear();
  executionOrder_.clear();
  commandQueue_.shutdown();
  compiled_ = false;

  E2D_LOG_INFO("RenderGraph shutdown");
}

RenderPass *RenderGraph::addPass(std::unique_ptr<RenderPass> pass) {
  if (!pass)
    return nullptr;

  RenderPass *ptr = pass.get();
  passes_.push_back(std::move(pass));
  compiled_ = false; // 添加新通道需要重新编译

  return ptr;
}

RenderPass *RenderGraph::addLambdaPass(
    const std::string &name,
    std::function<void(const RenderPassContext &)> executeFunc) {
  // 创建一个简单的 lambda 渲染通道
  class LambdaRenderPass : public RenderPass {
  public:
    std::string name;
    std::function<void(const RenderPassContext &)> func;

    LambdaRenderPass(const std::string &n,
                     std::function<void(const RenderPassContext &)> f)
        : name(n), func(f) {}

    const char *getName() const override { return name.c_str(); }

    void execute(const RenderPassContext &ctx) override {
      if (func) {
        func(ctx);
      }
    }
  };

  return addPass(std::make_unique<LambdaRenderPass>(name, executeFunc));
}

bool RenderGraph::compile() {
  if (compiled_)
    return true;

  // 清空之前的编译结果
  executionOrder_.clear();

  // 简单的编译策略：按添加顺序执行
  // 实际实现中应该进行依赖分析和拓扑排序
  for (auto &pass : passes_) {
    if (pass->isEnabled()) {
      executionOrder_.push_back(pass.get());
    }
  }

  // 声明资源
  for (auto *pass : executionOrder_) {
    builder_.setCurrentPass(pass);
    pass->declareResources(builder_);
  }

  // 创建资源
  createResources();

  compiled_ = true;
  E2D_LOG_INFO("RenderGraph compiled with {} passes", executionOrder_.size());

  return true;
}

void RenderGraph::execute(float deltaTime, const Mat4 &viewProjection) {
  if (!compiled_) {
    if (!compile()) {
      E2D_LOG_ERROR("Failed to compile RenderGraph");
      return;
    }
  }

  // 更新全局 UBO
  commandQueue_.updateGlobalUBO(viewProjection, deltaTime, outputWidth_,
                                outputHeight_);

  // 获取 RHI 上下文
  auto *rhiModule = RHIModule::get();
  RHIContext *context = nullptr;
  if (rhiModule && rhiModule->getDevice()) {
    context = rhiModule->getDevice()->getContext();
  }

  // 创建执行上下文
  RenderPassContext ctx;
  ctx.context = context;
  ctx.commandQueue = &commandQueue_;
  ctx.graph = this;
  ctx.deltaTime = deltaTime;
  ctx.frameIndex = frameIndex_;

  // 执行所有通道
  for (auto *pass : executionOrder_) {
    if (pass->isEnabled()) {
      pass->execute(ctx);
    }
  }

  // 执行命令队列
  commandQueue_.execute();

  // 结束帧
  commandQueue_.endFrame();

  // 调用 RHI 上下文的 endFrame 进行缓冲区交换
  if (context) {
    context->endFrame();
  }

  frameIndex_++;
}

TextureHandle RenderGraph::getTexture(RenderGraphResourceHandle handle) const {
  auto it = textures_.find(handle.index);
  if (it != textures_.end()) {
    return it->second;
  }
  return TextureHandle{};
}

void RenderGraph::setOutputSize(uint32_t width, uint32_t height) {
  outputWidth_ = width;
  outputHeight_ = height;
}

void RenderGraph::createResources() {
  auto *rhiModule = RHIModule::get();
  if (!rhiModule || !rhiModule->getDevice())
    return;

  auto *device = rhiModule->getDevice();

  // 创建渲染图内部资源
  // 这里可以根据需要创建默认的后缓冲等
}

void RenderGraph::destroyResources() {
  // 释放所有渲染图管理的资源
  textures_.clear();
}

// ========================================
// GeometryRenderPass 实现
// ========================================

GeometryRenderPass::GeometryRenderPass(const std::string &name) : name_(name) {}

void GeometryRenderPass::declareResources(RenderGraphBuilder &builder) {
  // 声明几何渲染通道的资源依赖
  if (colorTarget_.isValid()) {
    builder.writeResource(colorTarget_);
  }
  if (depthTarget_.isValid()) {
    builder.writeResource(depthTarget_);
  }
}

void GeometryRenderPass::execute(const RenderPassContext &ctx) {
  // 几何渲染通道的执行逻辑
  // 通常由外部的渲染系统填充具体的绘制命令

  if (!ctx.commandQueue)
    return;

  // 清除颜色缓冲区
  ctx.commandQueue->submitClear(Color::Black, CLEAR_COLOR_FLAG);

  // 设置视口
  if (ctx.graph) {
    ctx.commandQueue->setViewport(
        0, 0, static_cast<int32_t>(ctx.graph->getOutputWidth()),
        static_cast<int32_t>(ctx.graph->getOutputHeight()));
  }
}

// ========================================
// PostProcessRenderPass 实现
// ========================================

PostProcessRenderPass::PostProcessRenderPass(const std::string &name)
    : name_(name) {}

void PostProcessRenderPass::declareResources(RenderGraphBuilder &builder) {
  // 声明后期处理通道的资源依赖
  if (inputTexture_.isValid()) {
    builder.readResource(inputTexture_);
  }
  if (outputTarget_.isValid()) {
    builder.writeResource(outputTarget_);
  }
}

void PostProcessRenderPass::execute(const RenderPassContext &ctx) {
  // 后期处理通道的执行逻辑
  // 这里可以实现全屏四边形绘制等后期处理效果

  if (!ctx.context || !ctx.commandQueue)
    return;

  // 获取命令列表
  RHICommandList *cmdList = ctx.commandQueue->getCommandList();
  if (!cmdList)
    return;

  // 绑定输入纹理
  if (inputTexture_.isValid()) {
    TextureHandle tex = ctx.getTexture(inputTexture_);
    if (tex.isValid()) {
      cmdList->setTexture(0, tex.get());
    }
  }

  // 后期处理的具体实现由子类或外部提供
}

} // namespace extra2d