//------------------------------------------------------------------------------
// CLING - the C++ LLVM-based InterpreterG :)
// author:  Axel Naumann <axel@cern.ch>
//
// This file is dual-licensed: you can choose to license it under the University
// of Illinois Open Source License or the GNU Lesser General Public License. See
// LICENSE.TXT for details.
//------------------------------------------------------------------------------

#include "InputValidator.h"

#include "MetaLexer.h"

namespace cling {
  InputValidator::ValidationResult
  InputValidator::validate(llvm::StringRef line) {
    ValidationResult Res = kComplete;

    Token Tok;
    const char* curPos = line.data();
    do {
      MetaLexer::LexPunctuatorAndAdvance(curPos, Tok);
      int kind = (int)Tok.getKind();

      // If there is " or ' we don't need to look for balancing until we 
      // enounter matching " or '
      if (kind >= (int)tok::quote && kind <= (int)tok::apostrophe) {
        MetaLexer::LexQuotedStringAndAdvance(curPos, Tok);
        if (kind != (int)Tok.getKind()) {
           Res = kIncomplete;
           m_ParenStack.push(kind);
           break;
        }
        continue;
      }

      // In case when we need closing brace.
      if (kind >= (int)tok::l_square && kind <= (int)tok::r_brace) {
        // The closing paren kind is open paren kind + 1 (i.e odd number)
        if (kind % 2) {
          // closing the right one?
          if (m_ParenStack.empty()) {
            Res = kMismatch;
            break;
          }
          int prev = m_ParenStack.top();
          if (prev != kind - 1) {
            Res = kMismatch;
            break;
          }
          m_ParenStack.pop();
        } 
        else
          m_ParenStack.push(kind);
      }
    }
    while (Tok.isNot(tok::eof));

    if (!m_ParenStack.empty() && Res != kMismatch)
      Res = kIncomplete;

    if (!m_Input.empty()) {
      if (!m_ParenStack.empty() && (m_ParenStack.top() == tok::quote 
                                    || m_ParenStack.top() == tok::apostrophe))
        m_Input.append("\\n");
      else 
        m_Input.append("\n");
    }
    else
      m_Input = "";

    m_Input.append(line);

    return Res;
  }

  void InputValidator::reset() {
    m_Input = "";
    while (!m_ParenStack.empty())
      m_ParenStack.pop();
  }
} // end namespace cling