GitPatch.java

package org.variantsync.diffdetective.diff.git;

import java.util.List;

import org.eclipse.jgit.diff.DiffEntry;
import org.variantsync.diffdetective.diff.text.TextBasedDiff;
import org.variantsync.diffdetective.util.Source;
import org.variantsync.diffdetective.variation.diff.Time;
import org.variantsync.diffdetective.variation.diff.VariationDiff; // For Javadoc

/**
 * Interface for patches from a git repository.
 * A git patch is a {@link TextBasedDiff} from which {@link VariationDiff}s can be created.
 *
 */
public interface GitPatch extends Source, TextBasedDiff {
    /**
     * Minimal default implementation of {@link GitPatch}
     * @param getDiff The diff in text form.
     * @param getChangeType The change type of this patch (e.g., file insertion or modification).
     * @param oldFileName The name of the patched file before the edit.
     * @param newFileName The name of the patched file after the edit.
     * @param getCommitHash The hash of the commit introducing the change.
     * @param getParentCommitHash The hash of the parent commit regarding which the diff was created.
     */
    record SimpleGitPatch(String getDiff, DiffEntry.ChangeType getChangeType, String oldFileName, String newFileName, String getCommitHash, String getParentCommitHash)
        implements GitPatch {
        @Override
        public String getFileName(Time time) {
            if (time == Time.BEFORE) {
                return oldFileName;
            } else {
                return newFileName;
            }
        }

        @Override
        public GitPatch shallowClone() {
            return new SimpleGitPatch(getDiff, getChangeType, oldFileName, newFileName, getCommitHash, getParentCommitHash);
        }

        @Override
        public String toString() {
            return oldFileName + "@ " + getParentCommitHash + " (parent) to " + newFileName + " @ " + getCommitHash + " (child)";
        }

        @Override
        public String getSourceExplanation() {
            return "SimpleGitPatch";
        }

        @Override
        public List<Object> getSourceArguments() {
            return List.of(getChangeType(), oldFileName(), newFileName(), getCommitHash(), getParentCommitHash());
        }
    }

    /**
     * Returns the change type of this patch (e.g., file insertion or modification).
     */
    DiffEntry.ChangeType getChangeType();

    /**
     * Returns the name of the patched file at the given time.
     */
    String getFileName(Time time);

    /**
     * Returns the hash of the commit introducing the change.
     */
    String getCommitHash();

    /**
     * Returns the hash of the parent commit regarding which the diff was created.
     */
    String getParentCommitHash();

    /**
     * Creates a shallow clone.
     * A shallow clone should return the very same values for the methods of this interface.
     * Other behaviour is unspecified.
     * @return A clone that acts equal with respect to this interface.
     */
    GitPatch shallowClone();
}