#pragma once

#include <any>
#include <memory>
#include <unordered_map>

#include "SysYBaseVisitor.h"
#include "ir/IR.h"
#include "sem/Sema.h"

class IRGenImpl final : public SysYBaseVisitor {
 public:
  IRGenImpl(ir::Module& module, const SemanticContext& sema);

  std::any visitCompUnit(SysYParser::CompUnitContext* ctx) override;
  std::any visitFuncDef(SysYParser::FuncDefContext* ctx) override;
  std::any visitBlock(SysYParser::BlockContext* ctx) override;
  std::any visitBlockItem(SysYParser::BlockItemContext* ctx) override;
  std::any visitDecl(SysYParser::DeclContext* ctx) override;
  std::any visitConstDef(SysYParser::ConstDefContext* ctx) override;
  std::any visitVarDef(SysYParser::VarDefContext* ctx) override;
  std::any visitStmt(SysYParser::StmtContext* ctx) override;

  std::any visitExp(SysYParser::ExpContext* ctx) override;
  std::any visitAddExp(SysYParser::AddExpContext* ctx) override;
  std::any visitMulExp(SysYParser::MulExpContext* ctx) override;     // 新增
  std::any visitUnaryExp(SysYParser::UnaryExpContext* ctx) override; // 新增
  std::any visitRelExp(SysYParser::RelExpContext* ctx) override;
  std::any visitEqExp(SysYParser::EqExpContext* ctx) override;
  std::any visitLAndExp(SysYParser::LAndExpContext* ctx) override;
  std::any visitLOrExp(SysYParser::LOrExpContext* ctx) override;
  std::any visitCond(SysYParser::CondContext* ctx) override;
  std::any visitFuncRParams(SysYParser::FuncRParamsContext* ctx) override;
  std::any visitPrimaryExp(SysYParser::PrimaryExpContext* ctx) override;
  std::any visitNumber(SysYParser::NumberContext* ctx) override;
  std::any visitLVal(SysYParser::LValContext* ctx) override;
  std::any visitConstExp(SysYParser::ConstExpContext* ctx) override;
  std::any visitConstInitVal(SysYParser::ConstInitValContext* ctx) override;
  std::any visitInitVal(SysYParser::InitValContext* ctx) override;

 private:
  ir::Value* EvalExp(SysYParser::ExpContext* ctx);
  ir::Value* EvalCondValue(SysYParser::CondContext* ctx);
  void EmitCondBr(SysYParser::CondContext* ctx, ir::BasicBlock* true_bb,
                  ir::BasicBlock* false_bb);
  void EmitLOrCond(SysYParser::LOrExpContext* ctx, ir::BasicBlock* true_bb,
                   ir::BasicBlock* false_bb);
  void EmitLAndCond(SysYParser::LAndExpContext* ctx, ir::BasicBlock* true_bb,
                    ir::BasicBlock* false_bb);
  ir::Value* EmitRelEq(SysYParser::RelExpContext* ctx);
  ir::Value* EmitEq(SysYParser::EqExpContext* ctx);
  ir::Value* CastToFloat(ir::Value* v);
  ir::Value* CastToInt(ir::Value* v);
  ir::Value* MakeBool(ir::Value* v);
  ir::Value* GetLValAddress(SysYParser::LValContext* ctx);
  ir::Value* LoadIfNeeded(ir::Value* addr_or_val, const TypeDesc& ty,
                          bool as_rvalue);
  std::shared_ptr<ir::Type> ToIRType(const TypeDesc& ty);
  std::shared_ptr<ir::Type> ToIRParamType(const TypeDesc& ty);
  ir::Value* DefaultValue(const TypeDesc& ty);
  ir::AllocaInst* CreateEntryAlloca(std::shared_ptr<ir::Type> ty,
                                    const std::string& name);
  void InitArray(ir::Value* base_ptr, const TypeDesc& ty,
                 SysYParser::InitValContext* init);
  void InitConstArray(ir::Value* base_ptr, const TypeDesc& ty,
                      SysYParser::ConstInitValContext* init);
    size_t FillArrayValues(const TypeDesc& ty, SysYParser::InitValContext* init,
                                                 std::vector<ir::Value*>& values, size_t base,
                                                 size_t idx, size_t dim);
    size_t FillConstArrayValues(const TypeDesc& ty,
                                                            SysYParser::ConstInitValContext* init,
                                                            std::vector<ir::Value*>& values, size_t base,
                                                            size_t idx, size_t dim);
  size_t ArrayStride(const TypeDesc& ty, size_t dim) const;
  size_t ArrayTotalSize(const TypeDesc& ty) const;
  void PushLoop(ir::BasicBlock* break_bb, ir::BasicBlock* cont_bb);
  void PopLoop();
  ir::BasicBlock* CurrentBreak() const;
  ir::BasicBlock* CurrentContinue() const;
  ir::ConstantValue* EvalConstScalar(SysYParser::ExpContext* ctx);
  ir::ConstantValue* EvalConstScalar(SysYParser::ConstExpContext* ctx);
  ir::ConstantValue* EvalConstAdd(SysYParser::AddExpContext* ctx);
  ir::ConstantValue* EvalConstMul(SysYParser::MulExpContext* ctx);
  ir::ConstantValue* EvalConstUnary(SysYParser::UnaryExpContext* ctx);
  ir::ConstantValue* EvalConstPrimary(SysYParser::PrimaryExpContext* ctx);
  ir::ConstantValue* EvalConstNumber(SysYParser::NumberContext* ctx);
  ir::ConstantValue* EvalConstLVal(SysYParser::LValContext* ctx);
    size_t InitGlobalArray(const TypeDesc& ty, SysYParser::InitValContext* init,
                                                 std::vector<ir::ConstantValue*>& values, size_t base,
                                                 size_t idx, size_t dim);
    size_t InitGlobalConstArray(const TypeDesc& ty,
                                                            SysYParser::ConstInitValContext* init,
                                                            std::vector<ir::ConstantValue*>& values,
                                                            size_t base, size_t idx, size_t dim);
  enum class BlockFlow { Continue, Terminated };
  BlockFlow VisitBlockItemResult(SysYParser::BlockItemContext& item);

  ir::Module& module_;
  const SemanticContext& sema_;
  ir::Function* func_;
  ir::IRBuilder builder_;
  std::unordered_map<const SysYParser::VarDefContext*, ir::Value*> var_storage_;
  std::unordered_map<const SysYParser::ConstDefContext*, ir::Value*> const_storage_;
  std::unordered_map<const SysYParser::FuncFParamContext*, ir::Value*> param_storage_;
  std::unordered_map<const SysYParser::FuncDefContext*, ir::Function*> func_map_;
  std::unordered_map<const SysYParser::VarDefContext*, ir::GlobalVariable*>
      global_var_storage_;
  std::unordered_map<const SysYParser::ConstDefContext*, ir::GlobalVariable*>
      global_const_storage_;
  std::vector<std::pair<ir::BasicBlock*, ir::BasicBlock*>> loop_stack_;
};

std::unique_ptr<ir::Module> GenerateIR(SysYParser::CompUnitContext& tree,
                                       const SemanticContext& sema);