// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/version.h"

#include <algorithm>

#include "base/logging.h"
#include "base/string_number_conversions.h"
#include "base/string_split.h"
#include "base/string_util.h"

Version::Version() {
}

Version::~Version() {
}

Version::Version(const std::string& version_str) {
  std::vector<std::string> numbers;
  base::SplitString(version_str, '.', &numbers);
  if (numbers.empty())
    return;
  std::vector<uint16> parsed;
  for (std::vector<std::string>::iterator i = numbers.begin();
       i != numbers.end(); ++i) {
    int num;
    if (!base::StringToInt(*i, &num))
      return;
    if (num < 0)
      return;
    const uint16 max = 0xFFFF;
    if (num > max)
      return;
    // This throws out things like +3, or 032.
    if (base::IntToString(num) != *i)
      return;
    parsed.push_back(static_cast<uint16>(num));
  }
  components_.swap(parsed);
}

bool Version::IsValid() const {
  return (!components_.empty());
}

bool Version::IsOlderThan(const std::string& version_str) const {
  Version proposed_ver(version_str);
  if (!proposed_ver.IsValid())
    return false;
  return (CompareTo(proposed_ver) < 0);
}

// TODO(cpu): remove this method.
Version* Version::GetVersionFromString(const std::string& version_str) {
  Version* vers = new Version(version_str);
  if (vers->IsValid()) {
    return vers;
  }
  delete vers;
  return NULL;
}

// TODO(cpu): remove this method.
Version* Version::Clone() const {
  DCHECK(IsValid());
  return new Version(*this);
}

bool Version::Equals(const Version& that) const {
  DCHECK(IsValid());
  DCHECK(that.IsValid());
  return (CompareTo(that) == 0);
}

int Version::CompareTo(const Version& other) const {
  DCHECK(IsValid());
  DCHECK(other.IsValid());
  size_t count = std::min(components_.size(), other.components_.size());
  for (size_t i = 0; i < count; ++i) {
    if (components_[i] > other.components_[i])
      return 1;
    if (components_[i] < other.components_[i])
      return -1;
  }
  if (components_.size() > other.components_.size()) {
    for (size_t i = count; i < components_.size(); ++i)
      if (components_[i] > 0)
        return 1;
  } else if (components_.size() < other.components_.size()) {
    for (size_t i = count; i < other.components_.size(); ++i)
      if (other.components_[i] > 0)
        return -1;
  }
  return 0;
}

const std::string Version::GetString() const {
  DCHECK(IsValid());
  std::string version_str;
  size_t count = components_.size();
  for (size_t i = 0; i < count - 1; ++i) {
    version_str.append(base::IntToString(components_[i]));
    version_str.append(".");
  }
  version_str.append(base::IntToString(components_[count - 1]));
  return version_str;
}