// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// These functions can parse a blob of data that's formatted as a simple
// key value store. Each key/value pair is stored on its own line and
// separated by the first '=' on the line.

#ifndef LIBBRILLO_BRILLO_KEY_VALUE_STORE_H_
#define LIBBRILLO_BRILLO_KEY_VALUE_STORE_H_

#include <map>
#include <string>
#include <vector>

#include <base/files/file_path.h>
#include <brillo/brillo_export.h>

namespace brillo {

class BRILLO_EXPORT KeyValueStore {
 public:
  // Creates an empty KeyValueStore.
  KeyValueStore();
  virtual ~KeyValueStore();
  // Copying is expensive; disallow accidental copies.
  KeyValueStore(const KeyValueStore&) = delete;
  KeyValueStore& operator=(const KeyValueStore&) = delete;
  KeyValueStore(KeyValueStore&&);
  KeyValueStore& operator=(KeyValueStore&&);

  // Loads the key=value pairs from the given |path|. Lines starting with '#'
  // and empty lines are ignored, and whitespace around keys is trimmed.
  // Trailing backslashes may be used to extend values across multiple lines.
  // Adds all the read key=values to the store, overriding those already defined
  // but persisting the ones that aren't present on the passed file.
  //
  // Returns true, if the entire file is loaded successfully. If an error occurs
  // while loading, keeps the pairs that were loaded before the error, and
  // returns false.
  //
  // This function does not clear its internal state before loading. To clear
  // the internal state, call Clear().
  bool Load(const base::FilePath& path);

  // Loads the key=value pairs parsing the text passed in |data|. See Load() for
  // details.
  // Returns whether the parsing succeeded.
  bool LoadFromString(const std::string& data);

  // Saves the current store to the given |path| file. See SaveToString() for
  // details on the formate of the created file.
  // Returns whether the file creation succeeded.
  bool Save(const base::FilePath& path) const;

  // Returns a string with the contents of the store as key=value lines.
  // Calling LoadFromString() and then SaveToString() may result in different
  // result if the original string contained backslash-terminated lines (i.e.
  // these values will be rewritten on single lines), comments or empty lines.
  std::string SaveToString() const;

  // Clears all the key-value pairs currently stored.
  void Clear();

  // Getter for the given key. Returns whether the key was found on the store.
  bool GetString(const std::string& key, std::string* value) const;

  // Setter for the given key. It overrides the key if already exists.
  void SetString(const std::string& key, const std::string& value);

  // Boolean getter. Returns whether the key was found on the store and if it
  // has a valid value ("true" or "false").
  bool GetBoolean(const std::string& key, bool* value) const;

  // Boolean setter. Sets the value as "true" or "false".
  void SetBoolean(const std::string& key, bool value);

  // Retrieves the keys for all values currently stored in the map.
  std::vector<std::string> GetKeys() const;

 private:
  // The map storing all the key-value pairs.
  std::map<std::string, std::string> store_;
};

}  // namespace brillo

#endif  // LIBBRILLO_BRILLO_KEY_VALUE_STORE_H_