#pragma once

#include <memory>
#include <string>
#include <unordered_map>
#include <vector>

#include "SysYParser.h"
#include "ir/IR.h"

enum class SymbolKind { Object, Function };

struct ConstantData {
  enum class Kind { Int, Float };

  Kind kind = Kind::Int;
  int int_value = 0;
  float float_value = 0.0f;

  static ConstantData FromInt(int value);
  static ConstantData FromFloat(float value);

  bool IsInt() const { return kind == Kind::Int; }
  bool IsFloat() const { return kind == Kind::Float; }
  int AsInt() const;
  float AsFloat() const;
  ConstantData CastTo(const std::shared_ptr<ir::Type>& dst_type) const;
  std::shared_ptr<ir::Type> GetType() const;
};

struct SymbolInfo {
  std::string name;
  SymbolKind kind = SymbolKind::Object;
  std::shared_ptr<ir::Type> type;
  bool is_const = false;
  bool is_global = false;
  bool is_parameter = false;
  bool is_array_parameter = false;
  bool is_builtin = false;

  SysYParser::ConstDefContext* const_def = nullptr;
  SysYParser::VarDefContext* var_def = nullptr;
  SysYParser::FuncDefContext* func_def = nullptr;

  bool has_const_value = false;
  ConstantData const_value{};
};

class SemanticContext {
 public:
  SymbolInfo* CreateSymbol(SymbolInfo symbol);

  void BindConstDef(SysYParser::ConstDefContext* node, const SymbolInfo* symbol);
  void BindVarDef(SysYParser::VarDefContext* node, const SymbolInfo* symbol);
  void BindFuncDef(SysYParser::FuncDefContext* node, const SymbolInfo* symbol);
  void BindLVal(SysYParser::LValContext* node, const SymbolInfo* symbol);
  void BindCall(SysYParser::UnaryExpContext* node, const SymbolInfo* symbol);
  void SetExprType(const void* node, std::shared_ptr<ir::Type> type);

  const SymbolInfo* ResolveConstDef(const SysYParser::ConstDefContext* node) const;
  const SymbolInfo* ResolveVarDef(const SysYParser::VarDefContext* node) const;
  const SymbolInfo* ResolveFuncDef(const SysYParser::FuncDefContext* node) const;
  const SymbolInfo* ResolveLVal(const SysYParser::LValContext* node) const;
  const SymbolInfo* ResolveCall(const SysYParser::UnaryExpContext* node) const;
  std::shared_ptr<ir::Type> ResolveExprType(const void* node) const;

 private:
  std::vector<std::unique_ptr<SymbolInfo>> owned_symbols_;
  std::unordered_map<const SysYParser::ConstDefContext*, const SymbolInfo*> const_defs_;
  std::unordered_map<const SysYParser::VarDefContext*, const SymbolInfo*> var_defs_;
  std::unordered_map<const SysYParser::FuncDefContext*, const SymbolInfo*> func_defs_;
  std::unordered_map<const SysYParser::LValContext*, const SymbolInfo*> lvals_;
  std::unordered_map<const SysYParser::UnaryExpContext*, const SymbolInfo*> calls_;
  std::unordered_map<const void*, std::shared_ptr<ir::Type>> expr_types_;
};

SemanticContext RunSema(SysYParser::CompUnitContext& comp_unit);