/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef AAPT_XML_XMLUTIL_H
#define AAPT_XML_XMLUTIL_H

#include <string>

#include "ResourceValues.h"
#include "util/Maybe.h"

namespace aapt {
namespace xml {

constexpr const char* kSchemaAuto = "http://schemas.android.com/apk/res-auto";
constexpr const char* kSchemaPublicPrefix =
    "http://schemas.android.com/apk/res/";
constexpr const char* kSchemaPrivatePrefix =
    "http://schemas.android.com/apk/prv/res/";
constexpr const char* kSchemaAndroid =
    "http://schemas.android.com/apk/res/android";
constexpr const char* kSchemaTools = "http://schemas.android.com/tools";
constexpr const char* kSchemaAapt = "http://schemas.android.com/aapt";

/**
 * Result of extracting a package name from a namespace URI declaration.
 */
struct ExtractedPackage {
  /**
   * The name of the package. This can be the empty string, which means that the
   * package
   * should be assumed to be the package being compiled.
   */
  std::string package;

  /**
   * True if the package's private namespace was declared. This means that
   * private resources
   * are made visible.
   */
  bool private_namespace;
};

/**
 * Returns an ExtractedPackage struct if the namespace URI is of the form:
 * http://schemas.android.com/apk/res/<package> or
 * http://schemas.android.com/apk/prv/res/<package>
 *
 * Special case: if namespaceUri is http://schemas.android.com/apk/res-auto,
 * returns an empty package name.
 */
Maybe<ExtractedPackage> ExtractPackageFromNamespace(
    const std::string& namespace_uri);

/**
 * Returns an XML Android namespace for the given package of the form:
 *
 * http://schemas.android.com/apk/res/<package>
 *
 * If privateReference == true, the package will be of the form:
 *
 * http://schemas.android.com/apk/prv/res/<package>
 */
std::string BuildPackageNamespace(const android::StringPiece& package,
                                  bool private_reference = false);

/**
 * Interface representing a stack of XML namespace declarations. When looking up
 * the package
 * for a namespace prefix, the stack is checked from top to bottom.
 */
struct IPackageDeclStack {
  virtual ~IPackageDeclStack() = default;

  /**
   * Returns an ExtractedPackage struct if the alias given corresponds with a
   * package declaration.
   */
  virtual Maybe<ExtractedPackage> TransformPackageAlias(
      const android::StringPiece& alias, const android::StringPiece& local_package) const = 0;
};

/**
 * Helper function for transforming the original Reference inRef to a fully
 * qualified reference
 * via the IPackageDeclStack. This will also mark the Reference as private if
 * the namespace of the package declaration was private.
 */
void TransformReferenceFromNamespace(IPackageDeclStack* decl_stack,
                                     const android::StringPiece& local_package, Reference* in_ref);

}  // namespace xml
}  // namespace aapt

#endif /* AAPT_XML_XMLUTIL_H */
