package gitlet;

import java.io.File;
import java.io.Serializable;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;

/** This class keeps track of the staging in
 *  Gitlet. Two main features it tracks are what
 *  needs to be added and removed in the next commit.
 *  @author Ethan Ikegami
 */
public class Staging implements Serializable {

    /** Initializes an instance given a Staging FILE. If the
     *  parameter is null or the FILE does not exist, initializes new
     *  Hashes, else gets Hashes from the given FILE. */
    public Staging(File file) {
        if (file == null || !file.exists()) {
            _currentStage = new LinkedHashMap<>();
            _removalStage = new LinkedHashSet<>();
        } else {
            Staging stage = Utils.readObject(file, Staging.class);
            _currentStage = stage.getCurrentStage();
            _removalStage = stage.getRemovalStage();
        }
    }

    /** Adds CONTENT to the stage. */
    public void add(Blob content) {
        _currentStage.put(content.getFileName(), Utils.serialize(content));
    }

    /** Removes FILENAME from the stage. */
    public void removeFrom(String fileName) {
        _currentStage.remove(fileName);
    }

    /** Adds FILENAME to the removal stage. */
    public void addRemove(String fileName) {
        _removalStage.add(fileName);
    }

    /** Removes FILENAME from the removal stage. */
    public void removeFromRemoval(String fileName) {
        _removalStage.remove(fileName);
    }

    /** Returns the current Add stage. */
    public LinkedHashMap<String, byte[]> getCurrentStage() {
        return _currentStage;
    }

    /** Returns the current Remove stage. */
    public LinkedHashSet<String> getRemovalStage() {
        return _removalStage;
    }

    /** The Add stage. */
    private LinkedHashMap<String, byte[]> _currentStage;

    /** The Remove stage. */
    private LinkedHashSet<String> _removalStage;
}