// Copyright (c) 2005, Google Inc.

// All rights reserved.

//

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are

// met:

//

//     * Redistributions of source code must retain the above copyright

// notice, this list of conditions and the following disclaimer.

//     * Redistributions in binary form must reproduce the above

// copyright notice, this list of conditions and the following disclaimer

// in the documentation and/or other materials provided with the

// distribution.

//     * Neither the name of Google Inc. nor the names of its

// contributors may be used to endorse or promote products derived from

// this software without specific prior written permission.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

//

// Author: Sanjay Ghemawat

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <vector>

#include <assert.h>

#include "pcrecpp_internal.h"

#include "pcre_scanner.h"

using std::vector;

namespace pcrecpp {

Scanner::Scanner()

  : data_(),

    input_(data_),

    skip_(NULL),

    should_skip_(false),

    skip_repeat_(false),

    save_comments_(false),

    comments_(NULL),

    comments_offset_(0) {

}

Scanner::Scanner(const string& in)

  : data_(in),

    input_(data_),

    skip_(NULL),

    should_skip_(false),

    skip_repeat_(false),

    save_comments_(false),

    comments_(NULL),

    comments_offset_(0) {

}

Scanner::~Scanner() {

  delete skip_;

  delete comments_;

}

void Scanner::SetSkipExpression(const char* re) {

  delete skip_;

  if (re != NULL) {

    skip_ = new RE(re);

    should_skip_ = true;

    skip_repeat_ = true;

    ConsumeSkip();

  } else {

    skip_ = NULL;

    should_skip_ = false;

    skip_repeat_ = false;

  }

}

void Scanner::Skip(const char* re) {

  delete skip_;

  if (re != NULL) {

    skip_ = new RE(re);

    should_skip_ = true;

    skip_repeat_ = false;

    ConsumeSkip();

  } else {

    skip_ = NULL;

    should_skip_ = false;

    skip_repeat_ = false;

  }

}

void Scanner::DisableSkip() {

  assert(skip_ != NULL);

  should_skip_ = false;

}

void Scanner::EnableSkip() {

  assert(skip_ != NULL);

  should_skip_ = true;

  ConsumeSkip();

}

int Scanner::LineNumber() const {

  // TODO: Make it more efficient by keeping track of the last point

  // where we computed line numbers and counting newlines since then.

  // We could use std:count, but not all systems have it. :-(

  int count = 1;

  for (const char* p = data_.data(); p < input_.data(); ++p)

    if (*p == '\n')

      ++count;

  return count;

}

int Scanner::Offset() const {

  return input_.data() - data_.c_str();

}

bool Scanner::LookingAt(const RE& re) const {

  int consumed;

  return re.DoMatch(input_, RE::ANCHOR_START, &consumed, 0, 0);

}

bool Scanner::Consume(const RE& re,

                      const Arg& arg0,

                      const Arg& arg1,

                      const Arg& arg2) {

  const bool result = re.Consume(&input_, arg0, arg1, arg2);

  if (result && should_skip_) ConsumeSkip();

  return result;

}

// helper function to consume *skip_ and honour save_comments_

void Scanner::ConsumeSkip() {

  const char* start_data = input_.data();

  while (skip_->Consume(&input_)) {

    if (!skip_repeat_) {

      // Only one skip allowed.

      break;

    }

  }

  if (save_comments_) {

    if (comments_ == NULL) {

      comments_ = new vector<StringPiece>;

    }

    // already pointing one past end, so no need to +1

    int length = input_.data() - start_data;

    if (length > 0) {

      comments_->push_back(StringPiece(start_data, length));

    }

  }

}

void Scanner::GetComments(int start, int end, vector<StringPiece> *ranges) {

  // short circuit out if we've not yet initialized comments_

  // (e.g., when save_comments is false)

  if (!comments_) {

    return;

  }

  // TODO: if we guarantee that comments_ will contain StringPieces

  // that are ordered by their start, then we can do a binary search

  // for the first StringPiece at or past start and then scan for the

  // ones contained in the range, quit early (use equal_range or

  // lower_bound)

  for (vector<StringPiece>::const_iterator it = comments_->begin();

       it != comments_->end(); ++it) {

    if ((it->data() >= data_.c_str() + start &&

         it->data() + it->size() <= data_.c_str() + end)) {

      ranges->push_back(*it);

    }

  }

}

void Scanner::GetNextComments(vector<StringPiece> *ranges) {

  // short circuit out if we've not yet initialized comments_

  // (e.g., when save_comments is false)

  if (!comments_) {

    return;

  }

  for (vector<StringPiece>::const_iterator it =

         comments_->begin() + comments_offset_;

       it != comments_->end(); ++it) {

    ranges->push_back(*it);

    ++comments_offset_;

  }

}

}   // namespace pcrecpp