package ganarchy.friendcode.util;

import ganarchy.friendcode.FriendCode;

import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Properties;

import static org.apache.commons.lang3.SystemUtils.USER_HOME;
import static org.apache.commons.lang3.SystemUtils.getEnvironmentVariable;

/**
 * Config utils.
 */
public class ConfigUtil {
    /**
     * The message stored in the config. Could probably use some improvement.
     */
    private static final String CONFIG_MESSAGE =
        "This is the friendcode config file."
            + " It's created when you open your world to a friend code.";
    /**
     * The (cached) global friendcode config dir.
     */
    private static File confdir;

    /**
     * Creates and returns the global friendcode config dir.
     */
    public static File getGlobalConfig() {
        if (confdir != null) {
            return confdir;
        }
        var configHome = getEnvironmentVariable("XDG_CONFIG_HOME", "");
        if (!configHome.isEmpty()) {
            confdir = Path.of(configHome, "mc_friendcode").toFile();
        } else {
            confdir = Path.of(USER_HOME, ".config", "mc_friendcode").toFile();
        }
        confdir.mkdirs();
        return confdir;
    }

    /**
     * Returns the path to the global friendcode config file.
     */
    public static Path getGlobalConfigFilePath() {
        return getGlobalConfig().toPath().resolve("config.properties");
    }

    /**
     * Retrieves the settings from the global config file and stores them in
     * the given object.
     *
     * @param properties Where to store the read config.
     * @return Whether reading was successful.
     */
    public static boolean getSettings(Properties properties) {
        try {
            var inputStream = Files.newInputStream(
                getGlobalConfigFilePath()
            );
            var reader = new InputStreamReader(
                inputStream, StandardCharsets.UTF_8
            );
            properties.load(reader);
            return true;
        } catch (IOException e) {
            return false;
        }
    }

    /**
     * Updates the global config file with the settings in the given object.
     *
     * @param properties The settings to add to the config.
     * @return Whether writing was successful.
     */
    public static boolean updateSettings(Properties properties) {
        var prop = new Properties();
        if (!getSettings(prop)) {
            FriendCode.LOGGER.warn(
                "Couldn't read global config." +
                    " If it doesn't exist, it will be created."
            );
        }
        prop.putAll(properties);
        try {
            var outputStream = Files.newOutputStream(
                getGlobalConfigFilePath()
            );
            var writer = new OutputStreamWriter(
                outputStream, StandardCharsets.UTF_8
            );
            prop.store(writer, CONFIG_MESSAGE);
            return true;
        } catch (IOException e) {
            return false;
        }
    }
}