#pragma once

#include "3rdparty/easylogging++.h"
#include "common.h"
#include "llir_type.h"
#include <cassert>
#include <list>
#include <memory>
#include <shared_mutex>
#include <string>
#include <tuple>
#include <unordered_set>
#include <vector>

namespace antlrSysY {

DEF_PTR_T(Value);
DEF_PTR_T(BasicBlock);
DEF_PTR_T(User);
DEF_PTR_T(Function);
DEF_PTR_T(Instruction);
DEF_PTR_T(Constant);
DEF_PTR_T(ConstantInt);

// typedef std::tuple<ValuePtr_t, UserPtr_t, int> UseEdge_t;
struct Use {
  ValuePtr_t value;
  User *user;
  unsigned op_index;
};
//                  Define, User, operand-index
// for Instruction, inst `uses` op, so inst is the user

class Value {
public:
  std::string name;
  TypePtr_t type;
  std::list<Use> use_list; // a list of use-edge from this value

  Value(const std::string &name, TypePtr_t type) : name(name), type(type) {}
  virtual ~Value() = default;

  template <typename TT>
  static bool is(std::shared_ptr<Value> ptr) {
    if (ptr.get()) {
      // auto &r = *ptr.get();
      // return typeid(r) == typeid(TT);
      return dynamic_cast<TT *>(ptr.get()) != nullptr;
    }
    LOG(WARNING) << "Comparing with nullptr";
    assert(0);
    return false;
  }

  // it is caller's duty to check before use `asType`
  template <typename TT>
  static std::shared_ptr<TT> as(std::shared_ptr<Value> ptr) {
    return std::dynamic_pointer_cast<TT>(ptr);
  }

  virtual std::string to_string() {
    return name + ": " + type->to_string();
  }

  virtual std::string to_IR_string() {
    panic("No applicable for IR gen");
  }

  void u_remove_use(User *user) {
    // use_list.erase(
    //   std::remove_if(
    //     use_list.begin(), use_list.end(), [user](const UseEdge_t &use) { return std::get<1>(use) == user; }
    //   ),
    //   use_list.end()
    // );
    for (auto itr = use_list.begin(); itr != use_list.end();) {
      if (itr->user == user) {
        itr = use_list.erase(itr);
      }
      else {
        ++itr;
      }
    }
  }
};

class User : public Value {
public:
  std::vector<ValuePtr_t> operand_list;

  User(const std::string &name, TypePtr_t type) : Value(name, type) {}
  void Add_Operand(ValuePtr_t op) {
    op->use_list.push_back({op, this, (unsigned)operand_list.size()});
    operand_list.push_back(op);
  }
  // make anything that use this value use the new value
  void u_replace_users(ValuePtr_t value) {
    if (value == nullptr) {
      assert(!use_list.size() && "No one should use this");
      return;
    }
    for (auto use : use_list) {
      auto user                 = use.user;
      auto index                = use.op_index;
      user->operand_list[index] = value;
      assert(value);
      value->use_list.push_back({value, user, index});
    }
    // all original uses are gone
    use_list.clear();
  }
  // remove this user from its operands
  void u_remove_from_usees() {
    for (auto op : operand_list) {
      assert(op);
      op->u_remove_use(this);
    }
  }
};

class FParam : public Value {
public:
  int ir_seqno = -1;
  FParam(const std::string &name, TypePtr_t type) : Value(name, type) {}
  virtual std::string to_string() override {
    return type->to_string() + " @" + name + " %" + std::to_string(ir_seqno);
  }
  virtual std::string to_IR_string() override {
    return type->to_IR_string() + " %" + std::to_string(ir_seqno);
  }
};

typedef std::list<std::shared_ptr<antlrSysY::BasicBlock>>::iterator BasicBlockListNode_t;

class Function : public Value {
public:
  std::vector<std::shared_ptr<FParam>> fparam_list;
  std::list<std::shared_ptr<BasicBlock>> bb_list;
  // we use empty basic_block to represent lib function
  Function(const std::string &name, TypePtr_t ret_type) : Value(name, std::make_shared<FunctionType>(ret_type)) {}
  std::shared_ptr<FunctionType> get_type() {
    return std::dynamic_pointer_cast<FunctionType>(type);
  }
  bool is_libfunc() {
    return bb_list.size() == 0;
  }
  virtual std::string to_string() override {
    std::string params_str;
    for (auto fparam : fparam_list) {
      params_str += fparam->to_string() + ",";
    }
    return name + "(" + params_str + ") -> " + type->to_string();
  }
};

class BasicBlock : public Value {
public:
  int ir_seqno = -1;
  std::list<InstructionPtr_t> inst_list;
  std::shared_ptr<Function> parent;
  BasicBlockListNode_t itr;
  std::list<BasicBlockPtr_t> successors;
  std::list<BasicBlockPtr_t> predecessors;

  BasicBlockPtr_t IDOM;                         // dominating node
  std::unordered_set<BasicBlockPtr_t> idom_set; // immediate dominated nodes
  std::unordered_set<BasicBlockPtr_t> DOM_set;  // dominated nodes
  std::unordered_set<BasicBlockPtr_t> DF_set;
  int dom_level;
  int _dom_helper_index;
  int dom_dfs_in;
  int dom_dfs_out;

  BasicBlock(const std::string &name, std::shared_ptr<Function> parent) : Value(name, TypeHelper::TYPE_LABEL) {
    this->parent = parent;
  }
};

class Constant : public Value {
public:
  Constant(const std::string &name, TypePtr_t type) : Value(name, type) {}
};

class ConstantInt : public Constant {
public:
  int value;
  ConstantInt(const std::string &name, int value) : Constant(name, TypeHelper::TYPE_I32), value(value) {}
  static std::shared_ptr<ConstantInt> make_shared(int value) {
    return std::make_shared<ConstantInt>("", value);
  }
  virtual std::string to_string() override {
    std::string str = type->to_string() + " " + std::to_string(value);
    return str;
  }
  virtual std::string to_IR_string() override {
    return type->to_IR_string() + " " + std::to_string(value);
  }
};

class ConstantArr : public Constant {
public:
  std::vector<ValuePtr_t> value_list;
  ConstantArr(const std::string &name, const std::vector<ValuePtr_t> &value_list, std::shared_ptr<ArrayType> type)
    : Constant(name, type), value_list(value_list) {}

  int real_size() const {
    return std::dynamic_pointer_cast<ArrayType>(type)->element_count;
  }
  static std::shared_ptr<ConstantArr> make_shared(
    const std::string &name,
    const std::vector<ValuePtr_t> &value_list,
    std::shared_ptr<ArrayType> type
  ) {
    return std::make_shared<ConstantArr>(name, value_list, type);
  }
  virtual std::string to_string() override {
    std::string str = "{";
    for (auto elem : value_list) {
      if (elem)
        str += elem->to_string() + ", ";
      else
        str += "{...}, ";
    }
    if (real_size() > value_list.size()) {
      str += std::to_string(real_size() - value_list.size()) + " zeros";
    }
    str += "}";
    return str;
  }
};

typedef std::shared_ptr<Constant> ConstantPtr_t;

// emmm, actually it is more of a Instruction type
class GlobalVar : public Value {
public:
  ConstantPtr_t init_value;
  bool is_const;
  GlobalVar(const std::string &name, TypePtr_t type, ConstantPtr_t init_value, bool is_const)
    : Value(name, PointerType::make_shared(type)), init_value(init_value), is_const(is_const) {}
  static std::shared_ptr<GlobalVar> make_shared(
    const std::string &name,
    TypePtr_t type,
    ConstantPtr_t init_value,
    bool is_const
  ) {
    return std::make_shared<GlobalVar>(name, type, init_value, is_const);
  }
  virtual std::string to_IR_string() override {
    std::string str = type->to_IR_string() + " @" + name;
    return str;
  }
};

std::shared_ptr<ConstantArr> gen_arr_hierarchy(
  const std::shared_ptr<ArrayType> array_type,
  const std::vector<ValuePtr_t> &const_array,
  int base,
  int length
);

} // namespace antlrSysY