#pragma once
#include "common.h"
#include "llir_type.h"
#include "llir_value.h"
#include <cassert>
#include <sstream>
#include <string>

namespace antlrSysY {
enum class InstTag {
  Add,
  Sub,
  Mod,
  Mul,
  Div,
  Lt,
  Le,
  Ge,
  Gt,
  Eq,
  Ne,
  And,
  Or,
  Br,
  Call,
  Ret,
  Alloca,
  Load,
  Store,
  GEP,
  Zext,
  Phi,
  MemPhi,
  LoadDep,
  InsertEle,
  ExtractEle
};

class Instruction : public User {
public:
  int ir_seqno = -1;
  InstTag tag;
  BasicBlockPtr_t parent_bb;
  Instruction(InstTag inst_tag, TypePtr_t type, BasicBlockPtr_t parent_bb)
    : User("", type), tag(inst_tag), parent_bb(parent_bb) {}
  virtual std::string to_string() override {
    switch (tag) {
      case InstTag::Add: return "add";
      case InstTag::Sub: return "sub";
      case InstTag::Mod: return "srem";
      case InstTag::Mul: return "mul";
      case InstTag::Div: return "sdiv";
      case InstTag::Lt: return "icmp slt";
      case InstTag::Le: return "icmp sle";
      case InstTag::Ge: return "icmp sge";
      case InstTag::Gt: return "icmp sgt";
      case InstTag::Eq: return "icmp eq";
      case InstTag::Ne: return "icmp ne";
      case InstTag::And: return "and";
      case InstTag::Or: return "or";
      case InstTag::Br: return "br";
      case InstTag::Call: return "call";
      case InstTag::Ret: return "ret";
      case InstTag::Alloca: return "alloca";
      case InstTag::Load: return "load";
      case InstTag::Store: return "store";
      case InstTag::GEP: return "GEP";
      case InstTag::Zext: return "zext";
      case InstTag::Phi: return "Phi";
      case InstTag::MemPhi: return "MemPhi";
      case InstTag::LoadDep: return "LoadDep";
      case InstTag::InsertEle: return "InsertEle";
      case InstTag::ExtractEle: return "ExtractEle";
    }
  }
};

class InstAlloca : public Instruction {
public:
  InstAlloca(TypePtr_t alloc_type, std::shared_ptr<BasicBlock> parent_bb)
    : Instruction(InstTag::Alloca, std::make_shared<PointerType>(alloc_type), parent_bb) {}
  virtual std::string to_IR_string() override {
    std::string str = type->to_IR_string() + " %" + std::to_string(ir_seqno);
    return str;
  }
};

class InstStore : public Instruction {
public:
  InstStore(std::shared_ptr<Value> value, std::shared_ptr<Value> pointer, std::shared_ptr<BasicBlock> parent_bb)
    : Instruction(InstTag::Store, TypeHelper::TYPE_VOID, parent_bb) {
    assert(value);
    Add_Operand(value);
    Add_Operand(pointer);
  }
};

class InstLoad : public Instruction {
public:
  InstLoad(std::shared_ptr<Value> value, TypePtr_t type, std::shared_ptr<BasicBlock> parent_bb)
    : Instruction(InstTag::Load, type, parent_bb) {
    Add_Operand(value);
  }
  virtual std::string to_IR_string() override {
    std::string str = type->to_IR_string() + " %" + std::to_string(ir_seqno);
    return str;
  }
};

class InstBinary : public Instruction {
public:
  InstBinary(
    InstTag inst_tag,
    TypePtr_t val_type,
    std::shared_ptr<Value> op1,
    std::shared_ptr<Value> op2,
    std::shared_ptr<BasicBlock> parent_bb
  )
    : Instruction(inst_tag, val_type, parent_bb) {
    Add_Operand(op1);
    Add_Operand(op2);
  }
  virtual std::string to_IR_string() override {
    std::string str = type->to_IR_string() + " %" + std::to_string(ir_seqno);
    return str;
  }
};

//<result> = zext <ty> <value> to <ty2>
// zext is integer type, i32
class InstZext : public Instruction {
public:
  InstZext(std::shared_ptr<Value> op, std::shared_ptr<BasicBlock> parent_bb)
    : Instruction(InstTag::Zext, TypeHelper::TYPE_I32, parent_bb) {
    Add_Operand(op);
  }
  virtual std::string to_IR_string() override {
    std::string str = type->to_IR_string() + " %" + std::to_string(ir_seqno);
    return str;
  }
};

class InstBranch : public Instruction {
public:
  // conditional branch
  InstBranch(ValuePtr_t cond, BasicBlockPtr_t true_block, BasicBlockPtr_t false_block, BasicBlockPtr_t parent_bb)
    : Instruction(InstTag::Br, TypeHelper::TYPE_VOID, parent_bb) {
    this->Add_Operand(cond);
    this->Add_Operand(true_block);
    this->Add_Operand(false_block);
  }
  // unconditional branch
  InstBranch(BasicBlockPtr_t target_block, BasicBlockPtr_t parent_bb)
    : Instruction(InstTag::Br, TypeHelper::TYPE_VOID, parent_bb) {
    this->Add_Operand(target_block);
  }
};

class InstReturn : public Instruction {
public:
  InstReturn(ValuePtr_t ret_val, BasicBlockPtr_t parent_bb)
    : Instruction(InstTag::Ret, TypeHelper::TYPE_VOID, parent_bb) {
    this->Add_Operand(ret_val);
  }
  InstReturn(BasicBlockPtr_t parent_bb) : Instruction(InstTag::Ret, TypeHelper::TYPE_VOID, parent_bb) {}
};

// call's type is the function's return type
class InstCall : public Instruction {
public:
  InstCall(FunctionPtr_t func, const std::vector<ValuePtr_t> &args, BasicBlockPtr_t parent_bb)
    : Instruction(InstTag::Call, func->get_type()->return_type, parent_bb) {
    Add_Operand(func);
    for (auto arg : args) {
      Add_Operand(arg);
    }
  }
  virtual std::string to_IR_string() override {
    if (Type::isType<VoidType>(type)) {
      panic("No ret val");
    }
    std::string str = type->to_IR_string() + " %" + std::to_string(ir_seqno);
    return str;
  }
};

// getelementptr <ty>, ptr <ptrval>{, [inrange] <ty> <idx>}*
// Example: lea arr[2][3] from arr[5][4]:
//  &arr[2][3] = GEP [5x[4xi32]], [5x[4xi32]]* arr, i32 0, i32 2, i32 3
class InstGEP : public Instruction {
public:
  ValuePtr_t aim_to;
  TypePtr_t element_type;
  InstGEP(ValuePtr_t pointer, const std::vector<ValuePtr_t> &indices, BasicBlockPtr_t parent_bb)
    : Instruction(InstTag::GEP, std::make_shared<PointerType>(extract_type(pointer, indices)), parent_bb) {
    if (Value::is<InstGEP>(pointer)) {
      aim_to = std::dynamic_pointer_cast<InstGEP>(pointer)->aim_to;
    }
    else if (Value::is<InstAlloca>(pointer) || Value::is<GlobalVar>(pointer)) {
      aim_to = pointer;
    }
    else {
      // LOG(WARNING) << "Unexpected pointer type " << pointer->to_string();
      aim_to = nullptr;
    }
    element_type = extract_type(pointer, indices);
    Add_Operand(pointer);
    for (auto index : indices) {
      Add_Operand(index);
    }
  }

  virtual std::string to_IR_string() override {
    std::string str = type->to_IR_string() + " %" + std::to_string(ir_seqno);
    return str;
  }

  // get the inner
  static TypePtr_t extract_type(ValuePtr_t pointer, const std::vector<ValuePtr_t> &indices) {
    auto pointer_type = std::dynamic_pointer_cast<PointerType>(pointer->type);
    auto pointed_type = pointer_type->pointed_type;
    if (pointed_type->type_tag == Type::TypeTag::IntegerType) {
      return pointed_type;
    }
    else if (Type::isType<ArrayType>(pointed_type)) {
      for (int i = 1; i < indices.size(); ++i) {
        pointed_type = std::dynamic_pointer_cast<ArrayType>(pointed_type)->element_type;
      }
      return pointed_type;
    }
    else {
      LOG(ERROR) << "unexpected type: " << pointer->to_string();
      assert(0);
    }
  }
};

} // namespace antlrSysY