/*
 * Copyright (C) 2010, 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:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS 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 APPLE INC. OR ITS 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.
 */

#ifndef TextPosition_h
#define TextPosition_h

#include "wtf/Allocator.h"
#include "wtf/Assertions.h"
#include "wtf/Vector.h"
#include "wtf/WTFExport.h"
#include "wtf/text/WTFString.h"
#include <memory>

namespace WTF {

// An abstract number of element in a sequence. The sequence has a first
// element.  This type should be used instead of integer because 2
// contradicting traditions can call a first element '0' or '1' which makes
// integer type ambiguous.
class OrdinalNumber final {
  DISALLOW_NEW();

 public:
  static OrdinalNumber fromZeroBasedInt(int zeroBasedInt) {
    return OrdinalNumber(zeroBasedInt);
  }
  static OrdinalNumber fromOneBasedInt(int oneBasedInt) {
    return OrdinalNumber(oneBasedInt - 1);
  }
  OrdinalNumber() : m_zeroBasedValue(0) {}

  int zeroBasedInt() const { return m_zeroBasedValue; }
  int oneBasedInt() const { return m_zeroBasedValue + 1; }

  bool operator==(OrdinalNumber other) const {
    return m_zeroBasedValue == other.m_zeroBasedValue;
  }
  bool operator!=(OrdinalNumber other) const { return !((*this) == other); }

  static OrdinalNumber first() { return OrdinalNumber(0); }
  static OrdinalNumber beforeFirst() { return OrdinalNumber(-1); }

 private:
  OrdinalNumber(int zeroBasedInt) : m_zeroBasedValue(zeroBasedInt) {}
  int m_zeroBasedValue;
};

// TextPosition structure specifies coordinates within an text resource. It is
// used mostly
// for saving script source position.
class TextPosition final {
  DISALLOW_NEW();

 public:
  TextPosition(OrdinalNumber line, OrdinalNumber column)
      : m_line(line), m_column(column) {}
  TextPosition() {}
  bool operator==(const TextPosition& other) const {
    return m_line == other.m_line && m_column == other.m_column;
  }
  bool operator!=(const TextPosition& other) const {
    return !((*this) == other);
  }
  WTF_EXPORT OrdinalNumber toOffset(const Vector<unsigned>&);

  // A 'minimum' value of position, used as a default value.
  static TextPosition minimumPosition() {
    return TextPosition(OrdinalNumber::first(), OrdinalNumber::first());
  }

  // A value with line value less than a minimum; used as an impossible
  // position.
  static TextPosition belowRangePosition() {
    return TextPosition(OrdinalNumber::beforeFirst(),
                        OrdinalNumber::beforeFirst());
  }

  // A value corresponding to a position with given offset within text having
  // the specified line ending offsets.
  WTF_EXPORT static TextPosition fromOffsetAndLineEndings(
      unsigned,
      const Vector<unsigned>&);

  OrdinalNumber m_line;
  OrdinalNumber m_column;
};

WTF_EXPORT std::unique_ptr<Vector<unsigned>> lineEndings(const String&);

}  // namespace WTF

using WTF::OrdinalNumber;

using WTF::TextPosition;

using WTF::lineEndings;

#endif  // TextPosition_h