// Copyright (c) 2013 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 "tools/gn/source_dir.h"

#include "base/logging.h"
#include "tools/gn/filesystem_utils.h"
#include "tools/gn/source_file.h"

namespace {

void AssertValueSourceDirString(const std::string& s) {
  DCHECK(!s.empty());
  DCHECK(s[0] == '/');
  DCHECK(EndsWithSlash(s));
}

}  // namespace

SourceDir::SourceDir() {
}

SourceDir::SourceDir(const base::StringPiece& p)
    : value_(p.data(), p.size()) {
  if (!EndsWithSlash(value_))
    value_.push_back('/');
  AssertValueSourceDirString(value_);
}

SourceDir::~SourceDir() {
}

SourceFile SourceDir::ResolveRelativeFile(const base::StringPiece& p) const {
  SourceFile ret;

  // It's an error to resolve an empty string or one that is a directory
  // (indicated by a trailing slash) because this is the function that expects
  // to return a file.
  if (p.empty() || (p.size() > 0 && p[p.size() - 1] == '/'))
    return SourceFile();
  if (p[0] == '/') {
    // Absolute path.
    ret.value_.assign(p.data(), p.size());
    return ret;
  }

  ret.value_.reserve(value_.size() + p.size());
  ret.value_.assign(value_);
  ret.value_.append(p.data(), p.size());

  NormalizePath(&ret.value_);
  return ret;
}

SourceDir SourceDir::ResolveRelativeDir(const base::StringPiece& p) const {
  SourceDir ret;

  if (p.empty())
    return ret;
  if (p[0] == '/') {
    // Absolute path.
    return SourceDir(p);
  }

  ret.value_.reserve(value_.size() + p.size());
  ret.value_.assign(value_);
  ret.value_.append(p.data(), p.size());

  NormalizePath(&ret.value_);
  if (!EndsWithSlash(ret.value_))
    ret.value_.push_back('/');
  AssertValueSourceDirString(ret.value_);

  return ret;
}

base::FilePath SourceDir::Resolve(const base::FilePath& source_root) const {
  if (is_null())
    return base::FilePath();

  std::string converted;
  if (is_system_absolute()) {
    converted = value_;
    ConvertPathToSystem(&converted);
    return base::FilePath(UTF8ToFilePath(converted));
  }

  // String the double-leading slash for source-relative paths.
  converted.assign(&value_[2], value_.size() - 2);
  ConvertPathToSystem(&converted);
  return source_root.Append(UTF8ToFilePath(converted));
}

void SourceDir::SwapInValue(std::string* v) {
  value_.swap(*v);
  AssertValueSourceDirString(value_);
}