//
// Created by erki on 16.02.21.
//

#include "OperationFinder.hpp"

#include <iostream>
#include <sstream>

using namespace clang;
using namespace clang::ast_matchers;

namespace
{

StatementMatcher AssignmentMatcher =
    binaryOperation(isAssignmentOperator(),
                    hasLHS(expr().bind("lhs")),
                    hasRHS(expr().bind("rhs"))).bind("assignment");

StatementMatcher ArithmeticMatcher =
    binaryOperation(hasAnyOperatorName("+", "-", "/", "*", "<", ">",
                                       "<=", ">=", "==", "<<", ">>", "%"),
                    hasLHS(expr().bind("lhs")),
                    hasRHS(expr().bind("lhs"))).bind("arithmetic");

StatementMatcher UnaryArithmeticMatcher =
    unaryOperator(hasAnyOperatorName("!", "++", "--"),
                  hasUnaryOperand(expr().bind("lhs"))).bind("unary_arithmetic");

StatementMatcher CompoundMatcher =
    compoundStmt().bind("compound_stmt");

bool isInMainFile(const MatchFinder::MatchResult &result, const SourceLocation &loc)
{
  return result.Context->getSourceManager().isWrittenInMainFile(loc);
}

template<typename TOp>
StringRef getOpcode(const TOp *op)
{
  return op->getOpcodeStr(op->getOpcode());
}

}

void OperationFinder::addMatcher(MatchFinder &finder)
{
  finder.addMatcher(traverse(TK_IgnoreUnlessSpelledInSource, ArithmeticMatcher), this);
  finder.addMatcher(traverse(TK_IgnoreUnlessSpelledInSource, AssignmentMatcher), this);
  finder.addMatcher(traverse(TK_IgnoreUnlessSpelledInSource, CompoundMatcher), this);
  finder.addMatcher(traverse(TK_IgnoreUnlessSpelledInSource, UnaryArithmeticMatcher), this);
}

void OperationFinder::run(const MatchFinder::MatchResult &result)
{
  if (result.Nodes.getNodeAs<clang::BinaryOperator>("assignment"))
  {
    _processAssignment(result);
  }
  else if (result.Nodes.getNodeAs<clang::BinaryOperator>("arithmetic"))
  {
    _processArithmetic(result);
  }
  else if (result.Nodes.getNodeAs<clang::CompoundStmt>("compound_stmt"))
  {
    _processCompoundStmt(result);
  }
  else if (result.Nodes.getNodeAs<clang::UnaryOperator>("unary_arithmetic"))
  {
    _processUnaryArithmetic(result);
  }
}

void OperationFinder::_processAssignment(const clang::ast_matchers::MatchFinder::MatchResult& result)
{
  const BinaryOperator* op = result.Nodes.getNodeAs<BinaryOperator>("assignment");

  assert(op);

  if (!isInMainFile(result, op->getBeginLoc()))
    return;

  const auto& loc = op->getBeginLoc();
  const auto& source_manager = *result.SourceManager;


  llvm::outs()  << source_manager.getFilename(loc) << ":"
                << source_manager.getSpellingLineNumber(loc) << ":"
                << source_manager.getSpellingColumnNumber(loc) << ":"
                << "Assignment: Assigned to: ";

  _processExpressionTypes(op, op->getLHS(), op->getRHS());

  llvm::outs() << "\n";
}

void OperationFinder::_processArithmetic(const MatchFinder::MatchResult& result)
{
  const BinaryOperator* op = result.Nodes.getNodeAs<clang::BinaryOperator>("arithmetic");

  assert(op);

  if (!isInMainFile(result, op->getBeginLoc()))
    return;

  const auto& loc = op->getBeginLoc();
  const auto& source_manager = *result.SourceManager;

  llvm::outs()  << source_manager.getFilename(loc) << ":"
                << source_manager.getSpellingLineNumber(loc) << ":"
                << source_manager.getSpellingColumnNumber(loc) << ":"
                << "Arithmetic: Type: " << getOpcode(op) << " LHS: ";

  _processExpressionTypes(op, op->getLHS(), op->getRHS());

  llvm::outs() << "\n";
}

void OperationFinder::_processCompoundStmt(const clang::ast_matchers::MatchFinder::MatchResult& result)
{
  const CompoundStmt* stmt = result.Nodes.getNodeAs<CompoundStmt>("compound_stmt");

  assert(stmt);

  const CompoundAssignOperator* op = dyn_cast<CompoundAssignOperator>(stmt->getStmtExprResult());

  if (!op || !op->isCompoundAssignmentOp())
    return;

  if (!isInMainFile(result, op->getBeginLoc()))
    return;

  const auto& loc = op->getBeginLoc();
  const auto& source_manager = *result.SourceManager;

  llvm::outs()  << source_manager.getFilename(loc) << ":"
                << source_manager.getSpellingLineNumber(loc) << ":"
                << source_manager.getSpellingColumnNumber(loc) << ":"
                << "Compound assignment: Op code: " << getOpcode(op) << " ";

  _processExpressionTypes(op, op->getLHS(), op->getRHS());

  llvm::outs() << "\n";
}

void OperationFinder::_processUnaryArithmetic(const MatchFinder::MatchResult &result)
{
  const UnaryOperator* op = result.Nodes.getNodeAs<UnaryOperator>("unary_arithmetic");
  const Expr* lhs = result.Nodes.getNodeAs<Expr>("lhs");

  assert(op);
  assert(lhs);

  if (!isInMainFile(result, lhs->getBeginLoc()))
    return;

  const auto& loc = lhs->getBeginLoc();
  const auto& source_manager = *result.SourceManager;

  llvm::outs()  << source_manager.getFilename(loc) << ":"
                << source_manager.getSpellingLineNumber(loc) << ":"
                << source_manager.getSpellingColumnNumber(loc) << ":"
                << "Unary arithmetic: Type: " << getOpcode(op) << " LHS: ";

  _processExpressionTypes(op, lhs, nullptr);

  llvm::outs() << "\n";
}

void OperationFinder::_processExpressionTypes(const Expr* source, const Expr* op1, const Expr* op2)
{
  auto printTypeName = [](const QualType& t) -> void
  {
    if (t->isTypedefNameType())
    {
      const TypedefType* tdt = cast<TypedefType>(t);
      assert(tdt);
      llvm::outs() << "Typedef type: " << t.getAsString()
                   << ", underlying: " << tdt->desugar().getAsString()
                   << ".";
    }
    else if (t->isBuiltinType())
    {
      llvm::outs() << "Builtin type: " << t.getAsString() << ".";
    }
    else
    {
      llvm::outs() << "Other type: " << t.getAsString() << ".";
    }
  };

  llvm::outs() << "Expression types:\n\tExpression eval type: ";
  printTypeName(source->getType());

  if (op1)
  {
    llvm::outs() << "\n\tLHS eval type: ";
    printTypeName(op1->getType());
  }
  if (op2)
  {
    llvm::outs() << "\n\tRHS eval type: ";
    printTypeName(op2->getType());
  }
}