#ifndef CONFIG_H
#define CONFIG_H

#include <cstdlib>
#include <string>
#include <fstream>
#include <map>
using namespace std;

/**
* @brief Object for handling user settings loaded from a file.
*
* These settings are currently all related to the screen (resolution and windowed or fullscreen).
* If custom controls are implemented in a later release, they will be loaded here. If a setting exists
* but is not found in the config file, it is set to a default value and written to the file.
*
* @author Justin Wernick
* @author David Schneider
*/
class Config
{
    public:
        /**
        * @brief Constructs a Config object from a file with the given path.
        *
        * Opens the file and reads all of the settings in the file. The read settings are
        * bound to the settings that have keys defined in the class. And settings missing from
        * the file are set to default values, and the default values are written to the file.
        *
        * @param [in] filename The path of the file in which the settings are stored.
        */
        Config(const string& filename);

        //Assignment and copy operations are handled by the compiler generated versions

        /**
        * @brief Function for accessing the screen width setting in pixels.
        *
        * @return The desired width of the screen in pixels.
        */
        unsigned int screenWidth() const;

        /**
        * @brief Function for accessing the screen height setting in pixels.
        *
        * @return The desired height of the screen in pixels.
        */
        unsigned int screenHeight() const;

        /**
        * @brief Function for accessing whether the game should be displayed in fullscreen or windowed mode.
        *
        * @return The desired fullscreen setting. A result of true means fullscreen mode, while a result of false means windowed mode.
        */
        bool fullscreen() const;

    private:
        /**
        * @brief Reads all of the settings defined in a file into a map.
        *
        * Reads each line that is in the format "key=value" in a file into a map.
        * Lines that do not contain a '=' are ignored.
        *
        * @param [in] file An opened filestream object at the beginning of the file to be read. After the function call, file will be at the end of the file.
        * @param [out] map The map that is populated with settings.
        */
        void readFile(ifstream& file, map<string,string>& map);

        /**
        * @brief Initialises the Config option's parameters to those in the readValues map.
        *
        * Parameters with a key that does not appear in readValues are initialised to a default value.
        * The default value, and its key, are then added to the unfoundValues map.
        *
        * @param [in] readValues A map containing all of the settings read in from a config file.
        * @param [out] unfoundValues A map that is populated with and settings not found in readValues.
        */
        void fillValues(const map<string, string>& readValues, map<string, string>& unfoundValues);

        /**
        * @brief Helper function for fillValues. Finds the value for a single key.
        *
        * If the given key does not appear, it is added to the unfoundValues map with the given default
        *
        * @param [in] readValues A map containing all of the settings read in from a config file.
        * @param [out] unfoundValues A map that is populated with and settings not found in readValues.
        * @param [in] key The key of the setting to be found in readValues.
        * @param [in] defaultValue The value to return and add to unfoundValues if the setting is not found in readValues.
        *
        * @return The value corresponding to the requested key.
        */
        string extractValue(const map<string, string>& readValues, map<string, string>& unfoundValues, const string& key, const string& defaultValue);

        /**
        * @brief Writes settings that were not found in the file to the file with default values.
        *
        * @param [in] file The opened filestream to which the key=value pairs are written.
        * @param [in] unfoundValues The map of key value pairs to be written to the file.
        */
        void writeUnfoundValues(ofstream& file, const map<string, string>& unfoundValues);

        /**
        * @brief Initializes the screen width in pixels from a given string.
        *
        * @param [in] screenWidthStr A string representing the desired screen width, read from a file.
        */
        void setScreenWidth(const string& screenWidthStr);

        /**
        * @brief Initializes the screen height in pixels from a given string.
        *
        * @param [in] screenHeightStr A string representing the desired screen height, read from a file.
        */
        void setScreenHeight(const string& screenHeightStr);

        /**
        * @brief Initializes the fullscreen setting from a given string.
        *
        * @param [in] fullscreenStr A string representing whether the screen should be in fullscreen mode ("true") or windowed mode (anything else).
        */
        void setFullscreen(const string& fullscreenStr);

        unsigned int _screenWidth; ///< The desired width of the screen in pixels.
        unsigned int _screenHeight; ///< The desired height of the screen in pixels.
        bool _fullscreen; ///< The desired fullscreen or windowed setting.

        static const string SCREEN_WIDTH_KEY; ///< The key for the screen width setting, initialized to "screen_width".
        static const string SCREEN_HEIGHT_KEY; ///< The key for the screen height setting, initialized to "screen_height".
        static const string FULLSCREEN_KEY; ///< The key for the fullscreen setting, initialized to "fullscreen".

        static const string SCREEN_WIDTH_DEFAULT; ///< The default value for the screen width setting, initialized to 800.
        static const string SCREEN_HEIGHT_DEFAULT; ///< The default value for the screen height setting, initialized to 600.
        static const string FULLSCREEN_DEFAULT; ///< The default value for the fullscreen setting, initialized to false.
};

#endif // CONFIG_H