GitInterface.java

import java.io.IOException;
import java.security.NoSuchAlgorithmException;
    public interface GitInterface {

        /**
         * Stages a file for the next commit.
         *
         * @param filePath The path to the file to be staged.
         */
         void stage(String filePath) throws IOException, NoSuchAlgorithmException;
    
        /**
         * Creates a commit with the given author and message.
         * It should capture the current state of the repository,
         * update the HEAD, and return the commit hash.
         *
         * @param author  The name of the author making the commit.
         * @param message The commit message describing the changes.
         * @return The SHA1 hash of the new commit.
         */
         String commit(String author, String message) throws IOException, NoSuchAlgorithmException;
    
        /**
         * EXTRA CREDIT: Checks out a specific commit given its hash.
         * This should update the working directory to match the
         * state of the repository at that commit.
         *
         * @param commitHash The SHA1 hash of the commit to check out.
         */
         //void checkout(String commitHash) throws IOException, NoSuchAlgorithmException;
    }