/*
 * Copyright (C) 2018 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_COMMAND_H
#define AAPT_COMMAND_H

#include <functional>
#include <ostream>
#include <string>
#include <unordered_set>
#include <vector>

#include "androidfw/StringPiece.h"

#include "util/Maybe.h"

namespace aapt {

class Command {
 public:
  explicit Command(const android::StringPiece& name) : name_(name.to_string()),
                                                       fullname_(name.to_string()) { }
  explicit Command(const android::StringPiece& name, const android::StringPiece& short_name)
      : name_(name.to_string()), short_name_(short_name.to_string()), fullname_(name.to_string()) {}
  virtual ~Command() = default;

  void AddRequiredFlag(const android::StringPiece& name, const android::StringPiece& description,
      std::string* value);
  void AddRequiredFlagList(const android::StringPiece& name, const android::StringPiece&
      description, std::vector<std::string>* value);
  void AddOptionalFlag(const android::StringPiece& name, const android::StringPiece& description,
      Maybe<std::string>* value);
  void AddOptionalFlagList(const android::StringPiece& name,
      const android::StringPiece& description, std::vector<std::string>* value);
  void AddOptionalFlagList(const android::StringPiece& name,
      const android::StringPiece& description, std::unordered_set<std::string>* value);
  void AddOptionalSwitch(const android::StringPiece& name, const android::StringPiece& description,
      bool* value);
  void AddOptionalSubcommand(std::unique_ptr<Command>&& subcommand, bool experimental = false);

  void SetDescription(const android::StringPiece& name);

  /** Prints the help menu of the command. */
  void Usage(std::ostream* out);

  /**
   * Parses the command line arguments, sets the flag variable values, and runs the action of
   * the command. If the arguments fail to parse to the command and its subcommands, then the action
   * will not be run and the usage will be printed instead.
   **/
  int Execute(const std::vector<android::StringPiece>& args, std::ostream* outError);

  /** The action to preform when the command is executed. */
  virtual int Action(const std::vector<std::string>& args) = 0;

 private:
  struct Flag {
    std::string name;
    std::string description;
    std::function<bool(const android::StringPiece& value)> action;
    bool required;
    size_t num_args;

    bool parsed;
  };

  std::string description_;
  std::string name_;
  std::string short_name_;
  std::string fullname_;
  std::vector<Flag> flags_;
  std::vector<std::unique_ptr<Command>> subcommands_;
  std::vector<std::unique_ptr<Command>> experimental_subcommands_;
};

}  // namespace aapt

#endif  // AAPT_COMMAND_H