#include "Dom.h"
#include "Liveness.h"
#include "SysYIRCFGOpt.h"
#include "SysYIRPrinter.h"
#include "DCE.h"
#include "Pass.h"
#include <iostream>
#include <queue>
#include <map>
#include <set>
#include <algorithm>
#include <vector>

extern int DEBUG; // 全局调试标志
namespace sysy {

// ======================================================================
// 封装优化流程的函数：包含Pass注册和迭代运行逻辑
// ======================================================================

void PassManager::runOptimizationPipeline(Module* moduleIR, IRBuilder* builderIR, int optLevel) {
    if (DEBUG) std::cout << "--- Starting Middle-End Optimizations (Level -O" << optLevel << ") ---\n";

    /*
      中端开发框架基本流程：
      1) 分析pass
        1. 实现分析pass并引入Pass.cpp
        2. 注册分析pass
      2) 优化pass
        1. 实现优化pass并引入Pass.cpp
        2. 注册优化pass
        3. 添加优化passid
    */
    // 注册分析遍
    registerAnalysisPass<sysy::DominatorTreeAnalysisPass>();
    registerAnalysisPass<sysy::LivenessAnalysisPass>();

    // 注册优化遍
    registerOptimizationPass<SysYDelInstAfterBrPass>();
    registerOptimizationPass<SysYDelNoPreBLockPass>();
    registerOptimizationPass<SysYBlockMergePass>();

    registerOptimizationPass<SysYDelEmptyBlockPass>(builderIR);
    registerOptimizationPass<SysYCondBr2BrPass>(builderIR);
    registerOptimizationPass<SysYAddReturnPass>(builderIR);

    if (optLevel >= 1) {
      //经过设计安排优化遍的执行顺序以及执行逻辑
      if (DEBUG) std::cout << "Applying -O1 optimizations.\n";
      if (DEBUG) std::cout << "--- Running custom optimization sequence ---\n";

      this->clearPasses(); 
      this->addPass(&SysYDelInstAfterBrPass::ID);
      this->addPass(&SysYDelNoPreBLockPass::ID);
      this->addPass(&SysYBlockMergePass::ID);
      this->addPass(&SysYDelEmptyBlockPass::ID);
      this->addPass(&SysYCondBr2BrPass::ID);
      this->addPass(&SysYAddReturnPass::ID);
      this->run(); 

      this->clearPasses();
      this->addPass(&DCE::ID); 
      this->run();

      if (DEBUG) std::cout << "--- Custom optimization sequence finished ---\n";
    }

    // 2. 创建遍管理器
    // 3. 根据优化级别添加不同的优化遍
    // TODO : 根据 optLevel 添加不同的优化遍
    //        讨论 是不动点迭代进行优化遍还是手动客制化优化遍的顺序？


    if (DEBUG) {
      std::cout << "=== Final IR After Middle-End Optimizations (Level -O" << optLevel << ") ===\n";
      SysYPrinter printer(moduleIR);
      printer.printIR();
    }
}

void PassManager::clearPasses() {
  passes.clear();
}

void PassManager::addPass(void *passID) {

  PassRegistry &registry = PassRegistry::getPassRegistry();
  std::unique_ptr<Pass> P = registry.createPass(passID);
  if (!P) {
    // Error: Pass not found or failed to create
    return;
  }

  passes.push_back(std::move(P));
}

// 运行所有注册的遍
bool PassManager::run() {
  bool changed = false;
  for (const auto &p : passes) {
    bool passChanged = false; // 记录当前遍是否修改了 IR

    // 处理优化遍的分析依赖和失效
    if (p->getPassKind() == Pass::PassKind::Optimization) {
      OptimizationPass *optPass = static_cast<OptimizationPass *>(p.get());
      std::set<void *> analysisDependencies;
      std::set<void *> analysisInvalidations;
      optPass->getAnalysisUsage(analysisDependencies, analysisInvalidations);

      // PassManager 不显式运行分析依赖。
      // 而是优化遍在 runOnFunction 内部通过 AnalysisManager.getAnalysisResult 按需请求。
    }

    if (p->getGranularity() == Pass::Granularity::Module) {
      passChanged = p->runOnModule(pmodule, analysisManager);
    } else if (p->getGranularity() == Pass::Granularity::Function) {
      for (auto &funcPair : pmodule->getFunctions()) {
        Function *F = funcPair.second.get();
        passChanged = p->runOnFunction(F, analysisManager) || passChanged;

        if (passChanged && p->getPassKind() == Pass::PassKind::Optimization) {
          OptimizationPass *optPass = static_cast<OptimizationPass *>(p.get());
          std::set<void *> analysisDependencies;
          std::set<void *> analysisInvalidations;
          optPass->getAnalysisUsage(analysisDependencies, analysisInvalidations);
          for (void *invalidationID : analysisInvalidations) {
            analysisManager.invalidateAnalysis(invalidationID, F);
          }
        }
      }
    } else if (p->getGranularity() == Pass::Granularity::BasicBlock) {
      for (auto &funcPair : pmodule->getFunctions()) {
        Function *F = funcPair.second.get();
        for (auto &bbPtr : funcPair.second->getBasicBlocks()) {
          passChanged = p->runOnBasicBlock(bbPtr.get(), analysisManager) || passChanged;

          if (passChanged && p->getPassKind() == Pass::PassKind::Optimization) {
            OptimizationPass *optPass = static_cast<OptimizationPass *>(p.get());
            std::set<void *> analysisDependencies;
            std::set<void *> analysisInvalidations;
            optPass->getAnalysisUsage(analysisDependencies, analysisInvalidations);
            for (void *invalidationID : analysisInvalidations) {
              analysisManager.invalidateAnalysis(invalidationID, F);
            }
          }
        }
      }
    }
    changed = changed || passChanged;
  }
  return changed;

}


template <typename AnalysisPassType> void registerAnalysisPass() {
  PassRegistry::getPassRegistry().registerPass(&AnalysisPassType::ID,
                                               []() { return std::make_unique<AnalysisPassType>(); });
}

template <typename OptimizationPassType, typename std::enable_if<
    std::is_constructible<OptimizationPassType, IRBuilder*>::value, int>::type>
void registerOptimizationPass(IRBuilder* builder) {
    PassRegistry::getPassRegistry().registerPass(&OptimizationPassType::ID,
                                                 [builder]() { return std::make_unique<OptimizationPassType>(builder); });
}

template <typename OptimizationPassType, typename std::enable_if<
    !std::is_constructible<OptimizationPassType, IRBuilder*>::value, int>::type>
void registerOptimizationPass() {
    PassRegistry::getPassRegistry().registerPass(&OptimizationPassType::ID,
                                                 []() { return std::make_unique<OptimizationPassType>(); });
}

} // namespace sysy