package envoy.client.data;

import java.io.*;
import java.util.*;
import java.util.logging.Level;
import java.util.prefs.Preferences;

import dev.kske.eventbus.core.*;

import envoy.util.*;

import envoy.client.event.EnvoyCloseEvent;

/**
 * Manages all application settings, which are different objects that can be changed during runtime
 * and serialized them by using either the file system or the {@link Preferences} API.
 *
 * @author Leon Hofmeister
 * @author Maximilian Käfer
 * @author Kai S. K. Engelbart
 * @since Envoy Client v0.2-alpha
 */
public final class Settings {

	// Actual settings accessible by the rest of the application
	private Map<String, SettingsItem<?>> items;

	/**
	 * Settings are stored in this file.
	 */
	private static final File settingsFile =
		new File(ClientConfig.getInstance().getHomeDirectory(), "settings.ser");

	/**
	 * Singleton instance of this class.
	 */
	private static Settings settings = new Settings();

	/**
	 * The way to instantiate the settings. Is set to private to deny other instances of that
	 * object.
	 *
	 * @since Envoy Client v0.2-alpha
	 */
	private Settings() {
		EventBus.getInstance().registerListener(this);

		// Load settings from settings file
		try {
			items = SerializationUtils.read(settingsFile, HashMap.class);
		} catch (ClassNotFoundException | IOException e) {
			items = new HashMap<>();
		}
		supplementDefaults();
	}

	/**
	 * This method is used to ensure that there is only one instance of Settings.
	 *
	 * @return the instance of Settings
	 * @since Envoy Client v0.2-alpha
	 */
	public static Settings getInstance() { return settings; }

	/**
	 * Updates the preferences when the save button is clicked.
	 *
	 * @throws IOException if an error occurs while saving the themes
	 * @since Envoy Client v0.2-alpha
	 */
	@Event(EnvoyCloseEvent.class)
	private void save() {
		EnvoyLog.getLogger(Settings.class).log(Level.INFO, "Saving settings...");

		// Save settings to settings file
		try {
			SerializationUtils.write(settingsFile, items);
		} catch (final IOException e) {
			EnvoyLog.getLogger(Settings.class).log(Level.SEVERE, "Unable to save settings file: ",
				e);
		}
	}

	private void supplementDefaults() {
		items.putIfAbsent("enterToSend", new SettingsItem<>(true, "Enter to send",
			"Sends a message by pressing the enter key."));
		items.putIfAbsent("hideOnClose",
			new SettingsItem<>(false, "Hide on close", "Hides the chat window when it is closed."));
		items.putIfAbsent("currentTheme", new SettingsItem<>("dark", "Current Theme Name",
			"The name of the currently selected theme."));
		items.putIfAbsent("downloadLocation",
			new SettingsItem<>(new File(System.getProperty("user.home") + "/Downloads/"),
				"Download location",
				"The location where files will be saved to"));
		items.putIfAbsent("autoSaveDownloads", new SettingsItem<>(false, "Save without asking?",
			"Should downloads be saved without asking?"));
		items.putIfAbsent("askForConfirmation",
			new SettingsItem<>(true, "Ask for confirmation",
				"Will ask for confirmation before doing certain things"));
	}

	/**
	 * @return the name of the currently active theme
	 * @since Envoy Client v0.2-alpha
	 */
	public String getCurrentTheme() { return (String) items.get("currentTheme").get(); }

	/**
	 * Sets the name of the current theme.
	 *
	 * @param themeName the name to set
	 * @since Envoy Client v0.2-alpha
	 */
	public void setCurrentTheme(String themeName) {
		((SettingsItem<String>) items.get("currentTheme")).set(themeName);
	}

	/**
	 * @return true if the currently used theme is one of the default themes
	 * @since Envoy Client v0.1-beta
	 */
	public boolean isUsingDefaultTheme() {
		final var theme = getCurrentTheme();
		return theme.equals("dark") || theme.equals("light");
	}

	/**
	 * @return {@code true}, if pressing the {@code Enter} key suffices to send a message. Otherwise
	 *         it has to be pressed in conjunction with the {@code Control} key.
	 * @since Envoy Client v0.2-alpha
	 */
	public Boolean isEnterToSend() { return (Boolean) items.get("enterToSend").get(); }

	/**
	 * Changes the keystrokes performed by the user to send a message.
	 *
	 * @param enterToSend If set to {@code true} a message can be sent by pressing the {@code Enter}
	 *                    key. Otherwise it has to be pressed in conjunction with the
	 *                    {@code Control} key.
	 * @since Envoy Client v0.2-alpha
	 */
	public void setEnterToSend(boolean enterToSend) {
		((SettingsItem<Boolean>) items.get("enterToSend")).set(enterToSend);
	}

	/**
	 * @return whether Envoy will prompt a dialogue before saving an {@link envoy.data.Attachment}
	 * @since Envoy Client v0.2-beta
	 */
	public Boolean isDownloadSavedWithoutAsking() {
		return (Boolean) items.get("autoSaveDownloads").get();
	}

	/**
	 * Sets whether Envoy will prompt a dialogue before saving an {@link envoy.data.Attachment}.
	 *
	 * @param autosaveDownload whether a download should be saved without asking before
	 * @since Envoy Client v0.2-beta
	 */
	public void setDownloadSavedWithoutAsking(boolean autosaveDownload) {
		((SettingsItem<Boolean>) items.get("autoSaveDownloads")).set(autosaveDownload);
	}

	/**
	 * @return the path where downloads should be saved
	 * @since Envoy Client v0.2-beta
	 */
	public File getDownloadLocation() { return (File) items.get("downloadLocation").get(); }

	/**
	 * Sets the path where downloads should be saved.
	 *
	 * @param downloadLocation the path to set
	 * @since Envoy Client v0.2-beta
	 */
	public void setDownloadLocation(File downloadLocation) {
		((SettingsItem<File>) items.get("downloadLocation")).set(downloadLocation);
	}

	/**
	 * @return the current on close mode.
	 * @since Envoy Client v0.3-alpha
	 */
	public Boolean isHideOnClose() { return (Boolean) items.get("hideOnClose").get(); }

	/**
	 * Sets the current on close mode.
	 *
	 * @param hideOnClose whether the application should be minimized on close
	 * @since Envoy Client v0.3-alpha
	 */
	public void setHideOnClose(boolean hideOnClose) {
		((SettingsItem<Boolean>) items.get("hideOnClose")).set(hideOnClose);
	}

	/**
	 * @return whether a confirmation dialog should be displayed before certain actions
	 * @since Envoy Client v0.2-alpha
	 */
	public Boolean isAskForConfirmation() {
		return (Boolean) items.get("askForConfirmation").get();
	}

	/**
	 * Changes the behavior of calling certain functionality by displaying a confirmation dialog
	 * before executing it.
	 *
	 * @param askForConfirmation whether confirmation dialogs should be displayed before certain
	 *                           actions
	 * @since Envoy Client v0.2-alpha
	 */
	public void setAskForConfirmation(boolean askForConfirmation) {
		((SettingsItem<Boolean>) items.get("askForConfirmation")).set(askForConfirmation);
	}

	/**
	 * @return the items
	 */
	public Map<String, SettingsItem<?>> getItems() { return items; }

	/**
	 * @param items the items to set
	 */
	public void setItems(Map<String, SettingsItem<?>> items) { this.items = items; }
}