// IR 指令体系：
// - 二元运算/比较、load/store、call、br/condbr、ret、phi、alloca 等
// - 指令操作数与结果类型管理，支持打印与优化
#include "ir/IR.h"

#include <stdexcept>

#include "utils/Log.h"

namespace ir {
User::User(std::shared_ptr<Type> ty, std::string name)
    : Value(std::move(ty), std::move(name)) {}

size_t User::GetNumOperands() const { return operands_.size(); }

Value* User::GetOperand(size_t index) const {
  if (index >= operands_.size()) {
    throw std::out_of_range("User operand index out of range");
  }
  return operands_[index];
}

void User::SetOperand(size_t index, Value* value) {
  if (index >= operands_.size()) {
    throw std::out_of_range("User operand index out of range");
  }
  if (!value) {
    throw std::runtime_error(FormatError("ir", "User operand 不能为空"));
  }
  auto* old = operands_[index];
  if (old == value) {
    return;
  }
  if (old) {
    old->RemoveUse(this, index);
  }
  operands_[index] = value;
  value->AddUse(this, index);
}

void User::AddOperand(Value* value) {
  if (!value) {
    throw std::runtime_error(FormatError("ir", "User operand 不能为空"));
  }
  size_t operand_index = operands_.size();
  operands_.push_back(value);
  value->AddUse(this, operand_index);
}

Instruction::Instruction(Opcode op, std::shared_ptr<Type> ty, std::string name)
    : User(std::move(ty), std::move(name)), opcode_(op) {}

Opcode Instruction::GetOpcode() const { return opcode_; }

bool Instruction::IsTerminator() const {
  return opcode_ == Opcode::Ret || opcode_ == Opcode::Br || opcode_ == Opcode::CondBr;
}

BasicBlock* Instruction::GetParent() const { return parent_; }

void Instruction::SetParent(BasicBlock* parent) { parent_ = parent; }

BinaryInst::BinaryInst(Opcode op, std::shared_ptr<Type> ty, Value* lhs,
                       Value* rhs, std::string name)
    : Instruction(op, std::move(ty), std::move(name)) {
  if (op != Opcode::Add && op != Opcode::Sub && op != Opcode::Mul && op != Opcode::Div && op != Opcode::Mod) {
    throw std::runtime_error(FormatError("ir", "BinaryInst 当前只支持算术操作"));
  }
  if (!lhs || !rhs) {
    throw std::runtime_error(FormatError("ir", "BinaryInst 缺少操作数"));
  }
  if (!type_ || !lhs->GetType() || !rhs->GetType()) {
    throw std::runtime_error(FormatError("ir", "BinaryInst 缺少类型信息"));
  }
  if (lhs->GetType()->GetKind() != rhs->GetType()->GetKind() ||
      type_->GetKind() != lhs->GetType()->GetKind()) {
    throw std::runtime_error(FormatError("ir", "BinaryInst 类型不匹配"));
  }
  if (!type_->IsInt32() && !type_->IsFloat32()) {
    throw std::runtime_error(FormatError("ir", "BinaryInst 当前只支持 i32 和 float"));
  }
  AddOperand(lhs);
  AddOperand(rhs);
}

Value* BinaryInst::GetLhs() const { return GetOperand(0); }

Value* BinaryInst::GetRhs() const { return GetOperand(1); }

ReturnInst::ReturnInst(std::shared_ptr<Type> void_ty, Value* val)
    : Instruction(Opcode::Ret, std::move(void_ty), "") {
  if (!type_ || !type_->IsVoid()) {
    throw std::runtime_error(FormatError("ir", "ReturnInst 返回类型必须为 void"));
  }
  // val may be nullptr to represent a void return; only add operand when
  // a returned value is present.
  if (val) {
    AddOperand(val);
  }
}

Value* ReturnInst::GetValue() const { return GetOperand(0); }

AllocaInst::AllocaInst(std::shared_ptr<Type> ptr_ty, std::string name)
    : Instruction(Opcode::Alloca, std::move(ptr_ty), std::move(name)) {
  if (!type_ || !type_->IsPointer()) {
    throw std::runtime_error(FormatError("ir", "AllocaInst 类型必须为指针"));
  }
}

LoadInst::LoadInst(std::shared_ptr<Type> val_ty, Value* ptr, std::string name)
    : Instruction(Opcode::Load, std::move(val_ty), std::move(name)) {
  if (!ptr) {
    throw std::runtime_error(FormatError("ir", "LoadInst 缺少 ptr"));
  }
  if (!ptr->GetType() || !ptr->GetType()->IsPointer()) {
    throw std::runtime_error(FormatError("ir", "LoadInst ptr 必须为指针类型"));
  }
  const auto* ptr_ty = static_cast<const PointerType*>(ptr->GetType().get());
  if (!type_ || *type_ != *ptr_ty->GetPointeeType()) {
    throw std::runtime_error(FormatError("ir", "LoadInst 类型不匹配"));
  }
  AddOperand(ptr);
}

Value* LoadInst::GetPtr() const { return GetOperand(0); }

StoreInst::StoreInst(std::shared_ptr<Type> void_ty, Value* val, Value* ptr)
    : Instruction(Opcode::Store, std::move(void_ty), "") {
  if (!val) {
    throw std::runtime_error(FormatError("ir", "StoreInst 缺少 value"));
  }
  if (!ptr) {
    throw std::runtime_error(FormatError("ir", "StoreInst 缺少 ptr"));
  }
  if (!type_ || !type_->IsVoid()) {
    throw std::runtime_error(FormatError("ir", "StoreInst 返回类型必须为 void"));
  }
  if (!ptr->GetType() || !ptr->GetType()->IsPointer()) {
    throw std::runtime_error(FormatError("ir", "StoreInst ptr 必须为指针类型"));
  }
  const auto* ptr_ty = static_cast<const PointerType*>(ptr->GetType().get());
  if (!val->GetType() || *val->GetType() != *ptr_ty->GetPointeeType()) {
    throw std::runtime_error(FormatError("ir", "StoreInst 类型不匹配"));
  }
  AddOperand(val);
  AddOperand(ptr);
}

Value* StoreInst::GetValue() const { return GetOperand(0); }

Value* StoreInst::GetPtr() const { return GetOperand(1); }

CmpInst::CmpInst(Opcode op, Predicate pred, Value* lhs, Value* rhs, std::string name)
    : Instruction(op, Type::GetInt32Type(), std::move(name)), pred_(pred), lhs_(lhs), rhs_(rhs) {
  if (op != Opcode::ICmp && op != Opcode::FCmp) {
    throw std::runtime_error(FormatError("ir", "CmpInst 仅支持 ICmp 和 FCmp"));
  }
  if (!lhs || !rhs) {
    throw std::runtime_error(FormatError("ir", "CmpInst 缺少操作数"));
  }
  AddOperand(lhs);
  AddOperand(rhs);
}

BranchInst::BranchInst(BasicBlock* target)
    : Instruction(Opcode::Br, Type::GetVoidType(), "") {
  if (!target) {
    throw std::runtime_error(FormatError("ir", "BranchInst 缺少目标基本块"));
  }
  AddOperand(target);
}

BasicBlock* BranchInst::GetTarget() const { return static_cast<BasicBlock*>(GetOperand(0)); }

CondBranchInst::CondBranchInst(Value* cond, BasicBlock* true_bb, BasicBlock* false_bb)
    : Instruction(Opcode::CondBr, Type::GetVoidType(), "") {
  if (!cond || !true_bb || !false_bb) {
    throw std::runtime_error(FormatError("ir", "CondBranchInst 缺少操作数"));
  }
  AddOperand(cond);
  AddOperand(true_bb);
  AddOperand(false_bb);
}

Value* CondBranchInst::GetCond() const { return GetOperand(0); }
BasicBlock* CondBranchInst::GetTrueBlock() const { return static_cast<BasicBlock*>(GetOperand(1)); }
BasicBlock* CondBranchInst::GetFalseBlock() const { return static_cast<BasicBlock*>(GetOperand(2)); }

CallInst::CallInst(Function* callee, std::vector<Value*> args, std::string name)
    : Instruction(Opcode::Call, callee->GetType(), std::move(name)) {
  if (!callee) {
    throw std::runtime_error(FormatError("ir", "CallInst 缺少被调用函数"));
  }
  AddOperand(callee);
  for (auto* arg : args) {
    if (!arg) {
      throw std::runtime_error(FormatError("ir", "CallInst 参数不能为空"));
    }
    AddOperand(arg);
  }
}

PhiInst::PhiInst(std::shared_ptr<Type> ty, std::string name)
    : Instruction(Opcode::Phi, std::move(ty), std::move(name)) {}

void PhiInst::AddIncoming(Value* val, BasicBlock* block) {
  if (!val || !block) {
    throw std::runtime_error(FormatError("ir", "PhiInst AddIncoming 参数不能为空"));
  }
  AddOperand(val);
  AddOperand(block);
}

GetElementPtrInst::GetElementPtrInst(std::shared_ptr<Type> ty, Value* ptr,
                                     std::vector<Value*> indices, std::string name)
    : Instruction(Opcode::GEP, std::move(ty), std::move(name)) {
  if (!ptr) {
    throw std::runtime_error(FormatError("ir", "GetElementPtrInst 缺少指针"));
  }
  AddOperand(ptr);
  for (auto* idx : indices) {
    if (!idx) {
      throw std::runtime_error(FormatError("ir", "GetElementPtrInst 索引不能为空"));
    }
    AddOperand(idx);
  }
}

Function* CallInst::GetCallee() const {
  return static_cast<Function*>(GetOperand(0));
}

const std::vector<Value*>& CallInst::GetArgs() const {
  // 返回参数列表（跳过被调用函数）
  static std::vector<Value*> args;
  args.clear();
  for (size_t i = 1; i < GetNumOperands(); ++i) {
    args.push_back(GetOperand(i));
  }
  return args;
}

const std::vector<std::pair<Value*, BasicBlock*>>& PhiInst::GetIncomings() const {
  // Phi 指令的操作数是成对的：值和基本块
  static std::vector<std::pair<Value*, BasicBlock*>> incomings;
  incomings.clear();
  for (size_t i = 0; i < GetNumOperands(); i += 2) {
    Value* val = GetOperand(i);
    BasicBlock* block = static_cast<BasicBlock*>(GetOperand(i + 1));
    incomings.emplace_back(val, block);
  }
  return incomings;
}

Value* GetElementPtrInst::GetPtr() const {
  return GetOperand(0);
}

const std::vector<Value*>& GetElementPtrInst::GetIndices() const {
  // 返回索引列表（跳过指针）
  static std::vector<Value*> indices;
  indices.clear();
  for (size_t i = 1; i < GetNumOperands(); ++i) {
    indices.push_back(GetOperand(i));
  }
  return indices;
}

}  // namespace ir
