Prefs.java

package edu.kufpg.armatus;

import android.content.Context;
import android.content.SharedPreferences;
import android.content.res.Resources;
import android.preference.CheckBoxPreference;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.PreferenceManager;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import com.google.common.base.Objects;
import com.google.common.collect.ImmutableMap;

import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

public final class Prefs {

	/**
	 * {@link CheckBoxPreference} key mapping to whether or
	 * not {@link DeviceConstants#CACHE_DIR CACHE_DIR} should be used to save persistent data (if
     * the mapped value is {@code false}). If the mapped value is {@code true}, the String to which
     * {@link #HISTORY_DIR_KEY} maps is used instead.
	 */
	@NonNull static String IS_HISTORY_DIR_CUSTOM_KEY;

	/**
	 * {@link Preference} key mapping to the String representation
	 * of a directory where persistent data can be stored. The directory is only used if the value
	 * to which {@link #IS_HISTORY_DIR_CUSTOM_KEY} maps is true.
	 */
	@NonNull static String HISTORY_DIR_KEY;

	/**
	 * {@link ListPreference} key mapping to one of three String
	 * values: "0" (for {@code READ} mode), "1" (for {@code WRITE} mode), or "2" (for {@code ARITHMETIC}
	 * mode). The mapped String represent which {@code EditMode} is currently
	 * being used.
	 */
	@NonNull static String EDIT_MODE_KEY;
	@NonNull static String EDIT_MODE_READ;
    @NonNull static String EDIT_MODE_WRITE;
    @NonNull static String EDIT_MODE_ARITHMETIC;

	/**
	 * {@link ListPreference ListPreference} key mapping to either {@link
	 * #APP_THEME_DARK} or {@link #APP_THEME_LIGHT}, depending on which theme is currently
	 * being used.
	 */
    @NonNull static String APP_THEME_KEY;

	/**
	 * One of the possible values that the {@link Preference Preference} to
	 * which {@link #APP_THEME_KEY} maps can be (the other being {@link #APP_THEME_LIGHT}).
	 */
    @NonNull static String APP_THEME_DARK;

	/**
	 * One of the possible values that the {@link Preference Preference} to
	 * which {@link #APP_THEME_KEY} maps can be (the other being {@link #APP_THEME_DARK}).
	 */
    @NonNull static String APP_THEME_LIGHT;

	/**
	 * {@link ListPreference ListPreference} key mapping to either {@link
	 * #NETWORK_SOURCE_WEB_SERVER} or {@link #NETWORK_SOURCE_BLUETOOTH_SERVER}, depending on
	 * which network source is currently being used.
	 */
    @NonNull static String NETWORK_SOURCE_KEY;

	/**
	 * One of the possible values that the {@link Preference Preference} to
	 * which {@link #NETWORK_SOURCE_KEY} maps can be (the other being {@link
	 * #NETWORK_SOURCE_BLUETOOTH_SERVER}).
	 */
    @NonNull static String NETWORK_SOURCE_WEB_SERVER;

	/**
	 * One of the possible values that the {@link Preference Preference} to
	 * which {@link #NETWORK_SOURCE_KEY} maps can be (the other being {@link
	 * #NETWORK_SOURCE_WEB_SERVER}).
	 */
    @NonNull static String NETWORK_SOURCE_BLUETOOTH_SERVER;

	/**
	 * {@link Preference Preference} key mapping to the friendly name of the
	 * Bluetooth device being used (if enabled).
	 */
    @NonNull static String BLUETOOTH_DEVICE_NAME_KEY;

	/**
	 * {@link Preference Preference} key mapping to the MAC address of the
	 * Bluetooth device being used (if enabled).
	 */
    @NonNull static String BLUETOOTH_DEVICE_ADDRESS_KEY;

    @NonNull static String SPECIAL_KEYS_VISIBLE_KEY;

	/**
	 * Maps special {@link Preference Preference} keys to their default values
	 * when the default values are impossible to know before runtime (e.g., the external cache
	 * directory, which {@link #IS_HISTORY_DIR_CUSTOM_KEY} maps to by default).
	 */
    @NonNull static Map<String, ?> DYNAMIC_PREF_DEFAULTS_MAP;

    @NonNull static String IS_FIRST_TIME_KEY;

	/**
	 * {@link Preference} key used to choose the Bluetooth device if Bluetooth communications
	 * are enabled.
	 */
    @NonNull static String CHOOSE_BLUETOOTH_DEVICE_KEY;

    @NonNull static String SHOW_LINE_NUMBERS_KEY;

	/**
	 * {@link Preference} key used for resetting preferences back to their default values.
	 */
    @NonNull static String RESTORE_DEFAULTS_KEY;

	private Prefs() {}

	static void initPrefs(@NonNull final Context context) {
        final Resources r = context.getResources();
        
		IS_HISTORY_DIR_CUSTOM_KEY = r.getString(R.string.pref_is_history_dir_custom);
		HISTORY_DIR_KEY = r.getString(R.string.pref_history_dir);
		EDIT_MODE_KEY = r.getString(R.string.pref_edit_mode);
		EDIT_MODE_READ = r.getString(R.string.pref_edit_mode_read);
		EDIT_MODE_WRITE = r.getString(R.string.pref_edit_mode_write);
		EDIT_MODE_ARITHMETIC = r.getString(R.string.pref_edit_mode_arithmetic);
		APP_THEME_KEY = r.getString(R.string.pref_app_theme);
		APP_THEME_DARK = r.getString(R.string.pref_app_theme_dark);
		APP_THEME_LIGHT = r.getString(R.string.pref_app_theme_light);
		NETWORK_SOURCE_KEY = r.getString(R.string.pref_network_source);
		NETWORK_SOURCE_WEB_SERVER = r.getString(R.string.pref_network_source_web);
		NETWORK_SOURCE_BLUETOOTH_SERVER = r.getString(R.string.pref_network_source_bluetooth);
		BLUETOOTH_DEVICE_NAME_KEY = r.getString(R.string.pref_bluetooth_device_name);
		BLUETOOTH_DEVICE_ADDRESS_KEY = r.getString(R.string.pref_bluetooth_device_address);
		SPECIAL_KEYS_VISIBLE_KEY = r.getString(R.string.pref_special_keys_visible);
		IS_FIRST_TIME_KEY = r.getString(R.string.pref_is_first_time);

		CHOOSE_BLUETOOTH_DEVICE_KEY = r.getString(R.string.pref_choose_bluetooth_device);
        SHOW_LINE_NUMBERS_KEY = r.getString(R.string.pref_show_line_numbers);
		RESTORE_DEFAULTS_KEY = r.getString(R.string.pref_restore_defaults);

		DYNAMIC_PREF_DEFAULTS_MAP = mapDynamicPrefDefaults();
		PreferenceManager.setDefaultValues(context, R.xml.preferences, true);
		getPrefsEditor(context).commit();

		if (isFirstTime(context)) {
			restoreDyanmicPrefDefaultValues(context);
			setSpecialKeysVisible(context, false);
			setIsFirstTime(context, false);
		}
	}

	/**
	 * Convenience for retrieving the app's default {@link SharedPreferences}.
	 * @param context The {@link Context} to use.
	 * @return The app's {@code SharedPreferences}.
	 */
	@NonNull public static SharedPreferences getPrefs(@NonNull final Context context) {
		return PreferenceManager.getDefaultSharedPreferences(context);
	}

	/**
	 * Convenience for retrieving the {@code Editor} that can change the app's
	 * {@link SharedPreferences}.
	 * @param context The {@link Context} to use.
	 * @return The app's {@code SharedPreferences.Editor}.
	 */
	@NonNull public static SharedPreferences.Editor getPrefsEditor(@NonNull final Context context) {
		return getPrefs(context).edit();
	}

	/**
	 * Initializes {@link #DYNAMIC_PREF_DEFAULTS_MAP} by mapping {@link
	 * Preference Preference} keys to their default values when the default
	 * values are impossible to know before runtime.
	 * @return a map of {@code Preference} keys to their dynamic default values.
	 */
	@NonNull private static Map<String, ?> mapDynamicPrefDefaults() {
		return ImmutableMap.of(HISTORY_DIR_KEY, DeviceConstants.CACHE_DIR);
	}

	/**
	 * Restores the preferences that are impossible to know before runtime to their
	 * default values.
	 */
	static void restoreDyanmicPrefDefaultValues(@NonNull final Context context) {
		SharedPreferences.Editor editor = getPrefsEditor(context);
		for (Entry<String, ?> entry : DYNAMIC_PREF_DEFAULTS_MAP.entrySet()) {
			if (entry.getValue() instanceof String) {
				editor.putString(entry.getKey(), (String) entry.getValue());
			} else if (entry.getValue() instanceof Boolean) {
				editor.putBoolean(entry.getKey(), (Boolean) entry.getValue());
			} else if (entry.getValue() instanceof Integer) {
				editor.putInt(entry.getKey(), (Integer) entry.getValue());
			} else if (entry.getValue() instanceof Float) {
				editor.putFloat(entry.getKey(), (Float) entry.getValue());
			} else if (entry.getValue() instanceof Long) {
				editor.putLong(entry.getKey(), (Long) entry.getValue());
			} else if (entry.getValue() instanceof Set) {
				@SuppressWarnings("unchecked")
				Set<String> set = (Set<String>) entry.getValue();
				editor.putStringSet(entry.getKey(), set);
			}
		}
		editor.commit();
	}

	public static String getBluetoothDeviceAddress(@NonNull final Context context) {
		return getPrefs(context).getString(BLUETOOTH_DEVICE_ADDRESS_KEY, null);
	}

	public static String getBluetoothDeviceName(@NonNull final Context context) {
		return getPrefs(context).getString(BLUETOOTH_DEVICE_NAME_KEY, null);
	}

	public static EditMode getEditMode(@NonNull final Context context) {
		String editMode = getPrefs(context).getString(EDIT_MODE_KEY, null);
		if (editMode.equals(EDIT_MODE_READ)) {
			return EditMode.READ;
		} else if (editMode.equals(EDIT_MODE_WRITE)) {
			return EditMode.WRITE;
		} else if (editMode.equals(EDIT_MODE_ARITHMETIC)) {
			return EditMode.ARITHMETIC;
		} else {
            return null;
        }
	}

	public static String getHistoryDir(@NonNull final Context context) {
		return getPrefs(context).getString(HISTORY_DIR_KEY, null);
	}

	public static NetworkSource getNetworkSource(@NonNull final Context context) {
		String source = getPrefs(context).getString(NETWORK_SOURCE_KEY, null);
		if (source.equals(NETWORK_SOURCE_WEB_SERVER)) {
			return NetworkSource.WEB_SERVER;
		} else if (source.equals(NETWORK_SOURCE_BLUETOOTH_SERVER)) {
			return NetworkSource.BLUETOOTH_SERVER;
		} else {
            return null;
        }
	}

    public static boolean getShowLineNumbers(@NonNull final Context context) {
        return getPrefs(context).getBoolean(SHOW_LINE_NUMBERS_KEY, false);
    }

	public static boolean getSpecialKeysVisible(@NonNull final Context context) {
		return getPrefs(context).getBoolean(SPECIAL_KEYS_VISIBLE_KEY, false);
	}

	/**
	 * Returns the resource ID of the current app theme (either {@code ThemeLight} or
	 * {@code ThemeDark}.
	 * @return the current app theme's resource ID.
	 */
	@Nullable public static Theme getTheme(@NonNull final Context context) {
		String theme = getPrefs(context).getString(APP_THEME_KEY, null);
		if (Objects.equal(theme, APP_THEME_LIGHT)) {
			return Theme.LIGHT;
		} else if (Objects.equal(theme, APP_THEME_DARK)) {
			return Theme.DARK;
		} else {
            return null;
        }
	}

    public static boolean isBluetoothSource(@NonNull final Context context) {
        return Objects.equal(getNetworkSource(context), NetworkSource.BLUETOOTH_SERVER);
    }

	private static boolean isFirstTime(@NonNull final Context context) {
		return getPrefs(context).getBoolean(IS_FIRST_TIME_KEY, true);
	}

	public static boolean isHistoryDirCustom(@NonNull final Context context) {
		return getPrefs(context).getBoolean(IS_HISTORY_DIR_CUSTOM_KEY, false);
	}

    public static boolean isWebSource(@NonNull final Context context) {
        return Objects.equal(getNetworkSource(context), NetworkSource.WEB_SERVER);
    }

	public static void refreshTheme(Context context) {
		setTheme(context, getTheme(context));
	}

	public static void setBluetoothDeviceAddress(Context context, String address) {
		getPrefsEditor(context).putString(BLUETOOTH_DEVICE_ADDRESS_KEY, address).commit();
	}

	public static void setBluetoothDeviceName(Context context, String friendlyName) {
		getPrefsEditor(context).putString(BLUETOOTH_DEVICE_NAME_KEY, friendlyName).commit();
	}

	public static void setEditMode(Context context, EditMode editMode) {
		SharedPreferences.Editor editor = getPrefsEditor(context);
		switch (editMode) {
		case READ:
			editor.putString(EDIT_MODE_KEY, EDIT_MODE_READ);
			break;
		case WRITE:
			editor.putString(EDIT_MODE_KEY, EDIT_MODE_WRITE);
			break;
		case ARITHMETIC:
			editor.putString(EDIT_MODE_KEY, EDIT_MODE_ARITHMETIC);
			break;
		}
		editor.commit();
	}

	public static void setHistoryDir(Context context, String dir) {
		getPrefsEditor(context).putString(HISTORY_DIR_KEY, dir).commit();
	}

	public static void setIsFirstTime(Context context, boolean isFirstTime) {
		getPrefsEditor(context).putBoolean(IS_FIRST_TIME_KEY, isFirstTime).commit();
	}

	public static void setIsHistoryDirCustom(Context context, boolean custom) {
		getPrefsEditor(context).putBoolean(IS_HISTORY_DIR_CUSTOM_KEY, custom).commit();
	}

	public static void setNetworkSource(Context context, NetworkSource source) {
		SharedPreferences.Editor editor = getPrefsEditor(context);
		switch (source) {
		case WEB_SERVER:
			editor.putString(NETWORK_SOURCE_KEY, NETWORK_SOURCE_WEB_SERVER);
			break;
		case BLUETOOTH_SERVER:
			editor.putString(NETWORK_SOURCE_KEY, NETWORK_SOURCE_BLUETOOTH_SERVER);
			break;
		}
		editor.commit();
	}

    public static void setShowLineNumbers(@NonNull final Context context, final boolean newShowLineNumbers) {
        getPrefsEditor(context).putBoolean(SHOW_LINE_NUMBERS_KEY, newShowLineNumbers).commit();
    }

	public static void setSpecialKeysVisible(Context context, boolean visible) {
		getPrefsEditor(context).putBoolean(SPECIAL_KEYS_VISIBLE_KEY, visible).commit();
	}

	public static void setTheme(Context context, Theme theme) {
		SharedPreferences.Editor editor = getPrefsEditor(context);
		switch (theme) {
		case LIGHT:
			editor.putString(APP_THEME_KEY, APP_THEME_LIGHT);
			context.setTheme(R.style.ThemeLight);
			break;
		case DARK:
			editor.putString(APP_THEME_KEY, APP_THEME_DARK);
			context.setTheme(R.style.ThemeDark);
			break;
		}
		editor.commit();
	}

	public enum EditMode {
		READ, WRITE, ARITHMETIC
	}

	public enum Theme {
		LIGHT, DARK
	}

	public enum NetworkSource {
		WEB_SERVER, BLUETOOTH_SERVER
	}
}