Bukkit/src/main/java/org/bukkit/configuration/file/FileConfiguration.java

package org.bukkit.configuration.file;

import com.google.common.io.Files;
import org.bukkit.configuration.InvalidConfigurationException;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.bukkit.configuration.Configuration;
import org.bukkit.configuration.MemoryConfiguration;

/**
 * This is a base class for all File based implementations of {@link Configuration}
 */
public abstract class FileConfiguration extends MemoryConfiguration {
    /**
     * Creates an empty {@link FileConfiguration} with no default values.
     */
    public FileConfiguration() {
        super();
    }

    /**
     * Creates an empty {@link FileConfiguration} using the specified {@link Configuration}
     * as a source for all default values.
     *
     * @param defaults Default value provider
     */
    public FileConfiguration(Configuration defaults) {
        super(defaults);
    }

    /**
     * Saves this {@link FileConfiguration} to the specified location.
     * <p>
     * If the file does not exist, it will be created. If already exists, it will
     * be overwritten. If it cannot be overwritten or created, an exception will be thrown.
     *
     * @param file File to save to.
     * @throws IOException Thrown when the given file cannot be written to for any reason.
     * @throws IllegalArgumentException Thrown when file is null.
     */
    public void save(File file) throws IOException {
        if (file == null) {
            throw new IllegalArgumentException("File cannot be null");
        }
        
        Files.createParentDirs(file);

        String data = saveToString();

        FileWriter writer = new FileWriter(file);

        try {
            writer.write(data);
        } finally {
            writer.close();
        }
    }

    /**
     * Saves this {@link FileConfiguration} to the specified location.
     * <p>
     * If the file does not exist, it will be created. If already exists, it will
     * be overwritten. If it cannot be overwritten or created, an exception will be thrown.
     *
     * @param file File to save to.
     * @throws IOException Thrown when the given file cannot be written to for any reason.
     * @throws IllegalArgumentException Thrown when file is null.
     */
    public void save(String file) throws IOException {
        if (file == null) {
            throw new IllegalArgumentException("File cannot be null");
        }
        
        save(new File(file));
    }

    /**
     * Saves this {@link FileConfiguration} to a string, and returns it.
     *
     * @return String containing this configuration.
     */
    public abstract String saveToString();

    /**
     * Loads this {@link FileConfiguration} from the specified location.
     * <p>
     * All the values contained within this configuration will be removed, leaving
     * only settings and defaults, and the new values will be loaded from the given file.
     * <p>
     * If the file cannot be loaded for any reason, an exception will be thrown.
     *
     * @param file File to load from.
     * @throws FileNotFoundException Thrown when the given file cannot be opened.
     * @throws IOException Thrown when the given file cannot be read.
     * @throws InvalidConfigurationException Thrown when the given file is not a valid Configuration.
     * @throws IllegalArgumentException Thrown when file is null.
     */
    public void load(File file) throws FileNotFoundException, IOException, InvalidConfigurationException {
        if (file == null) {
            throw new IllegalArgumentException("File cannot be null");
        }

        load(new FileInputStream(file));
    }
    
    /**
     * Loads this {@link FileConfiguration} from the specified stream.
     * <p>
     * All the values contained within this configuration will be removed, leaving
     * only settings and defaults, and the new values will be loaded from the given stream.
     *
     * @param stream Stream to load from
     * @throws IOException Thrown when the given file cannot be read.
     * @throws InvalidConfigurationException Thrown when the given file is not a valid Configuration.
     * @throws IllegalArgumentException Thrown when stream is null.
     */
    public void load(InputStream stream) throws IOException, InvalidConfigurationException {
        if (stream == null) {
            throw new IllegalArgumentException("Stream cannot be null");
        }
        
        InputStreamReader reader = new InputStreamReader(stream);
        StringBuilder builder = new StringBuilder();
        BufferedReader input = new BufferedReader(reader);

        try {
            String line;

            while ((line = input.readLine()) != null) {
                builder.append(line);
                builder.append('\n');
            }
        } finally {
            input.close();
        }

        loadFromString(builder.toString());
    }

    /**
     * Loads this {@link FileConfiguration} from the specified location.
     * <p>
     * All the values contained within this configuration will be removed, leaving
     * only settings and defaults, and the new values will be loaded from the given file.
     * <p>
     * If the file cannot be loaded for any reason, an exception will be thrown.
     *
     * @param file File to load from.
     * @throws FileNotFoundException Thrown when the given file cannot be opened.
     * @throws IOException Thrown when the given file cannot be read.
     * @throws InvalidConfigurationException Thrown when the given file is not a valid Configuration.
     * @throws IllegalArgumentException Thrown when file is null.
     */
    public void load(String file) throws FileNotFoundException, IOException, InvalidConfigurationException {
        if (file == null) {
            throw new IllegalArgumentException("File cannot be null");
        }

        load(new File(file));
    }

    /**
     * Loads this {@link FileConfiguration} from the specified string, as opposed to from file.
     * <p>
     * All the values contained within this configuration will be removed, leaving
     * only settings and defaults, and the new values will be loaded from the given string.
     * <p>
     * If the string is invalid in any way, an exception will be thrown.
     *
     * @param contents Contents of a Configuration to load.
     * @throws InvalidConfigurationException Thrown if the specified string is invalid.
     * @throws IllegalArgumentException Thrown if contents is null.
     */
    public abstract void loadFromString(String contents) throws InvalidConfigurationException;

    @Override
    public FileConfigurationOptions options() {
        if (options == null) {
            options = new FileConfigurationOptions(this);
        }
        
        return (FileConfigurationOptions)options;
    }
}