package gitlet;

import java.io.File;
import java.io.IOException;
import java.io.Serial;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import static gitlet.Utils.*;

/**
 * The Blob class the will represent the file's contents.
 */
public class Blob implements Serializable {

    /**
     * Serial ID so Java can serialize and deserialize.
     */
    @Serial
    private static final long serialVersionUID = 1234567L;


    /**
     * The file that this particular blob will track.
     */
    private final File trackingFile;

    /**
     * The file that this particular blob will track as a string.
     */
    private final String trackingFileName;

    /**
     * The file conetnts of the file
     */
    private final byte[] trackingFileContents;

    /**
     * The file contents as a string of the tracked file.
     */
    private final String trackingFileContentsString;

    /**
     * The SHA-1 representation of the Blob object
     */
    private String blobSHA;


    /**
     * Constructor to create a new blob. It records the file and file contents.
     *
     * @param fileName THe file that this particular blob should track.
     */
    public Blob(String fileName) {
        this.trackingFileName = fileName;
        this.trackingFile = new File(fileName);
        this.trackingFileContents = Utils.readContents(this.trackingFile);
        this.trackingFileContentsString = new String(trackingFileContents);
        this.blobSHA = this.setBlobSHA();
    }

    public String getBlobSHA() {
        return this.blobSHA;
    }

    public byte[] getTrackingFileContents() {
        return this.trackingFileContents;
    }

    public String getTrackingFile() {
        return this.trackingFileName;
    }

    /**
     * The SHA-1 representation of a blob is the serilization of a list that
     * contains the variables of the blob.
     */
    private String setBlobSHA() {
        String blobContents = this.trackingFileName + this.trackingFileContentsString;
        return Utils.sha1(blobContents, this.trackingFileContents);
    }

    public void saveBlob() {
        File blobFile = join(Repository.OBJECT_DIR, this.blobSHA);
        Utils.writeObject(blobFile, this);
    }

    /**
     * @return SHA-1 of the blob object as well as the file it is tracking
     */
    @Override
    public String toString() {
        return String.format("BlobID:%s\nFile contents:\n\t%s", this.blobSHA, this.trackingFileContentsString);
    }

    /**
     * Compare the SHA-1 representation of the blobs
     *
     * @param o the blob to compare
     * @return true if the blobs are the same, false otherwise
     */
    public boolean compareBlobs(Blob o) {
        return this.getBlobSHA().equals(o.getBlobSHA());
    }
}