package gitlet;

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

import static gitlet.Utils.*;

/**
 * Driver class for Gitlet, a subset of the Git version-control system.
 *
 * @author Abraham Briones
 */
public class Main {

    /**
     * Usage: java gitlet.Main ARGS, where ARGS contains
     * <COMMAND> <OPERAND1> <OPERAND2> ...
     */
    public static void main(String[] args) throws IOException {

        File CWD = new File(System.getProperty("user.dir"));
        File GITLET_DIR = join(CWD, ".gitlet");


        String[] commandArray = new String[]{"add", "commit", "status", "checkoutBranch", "branch", "rm", "log"};
        List<String> commandList = new ArrayList<>(Arrays.asList(commandArray));
        GitletException error;
        Repository repo = null;

        if (args.length == 0) {
            error = new GitletException("Please enter a command");
            System.out.println(error.getMessage());
            System.exit(0);

        } else if (commandList.contains(args[0]) && !GITLET_DIR.exists()) {
            error = new GitletException("Not in an initialized Gitlet directory.");
            System.out.println(error.getMessage());
            System.exit(0);
        } else {
            String firstArg = args[0];
            String message;
            String fileName;
            String branchName;
            String commitID;
            /*
            If the repository file exists, load that as the repostiory. Otherwise, make a new repo
            object.
             */
            repo = Repository.REPO_FILE.exists()
                    ? readObject(Repository.REPO_FILE, Repository.class)
                    : new Repository();
            switch (firstArg) {
                case "init":
                    if (GITLET_DIR.exists()) {
                        error = new GitletException("A Gitlet version-control system already " +
                                "exists in the current directory.");
                        System.out.println(error.getMessage());
                        System.exit(0);
                    }
                    validateNumArgs(args, 1);
                    repo.setUpPersistence();
                    break;
                case "add":
                    validateNumArgs(args, 2);
                    fileName = args[1];
                    repo.addFile(fileName);
                    break;
                case "commit":
                    validateNumArgs(args, 2);
                    message = args[1];
                    repo.makeCommit(message);
//                    System.out.print("THE REPOSITORY IS TRACKING THESE COMMITS:\n");
//                    System.out.println(repo.getRepoCommits().toString().replace("[", "\n\t["));
                    break;
                case "rm":
                    validateNumArgs(args, 2);
                    fileName = args[1];
                    repo.removeFile(fileName);
                    break;
                case "log":
                    validateNumArgs(args, 1);
                    repo.printRepoLog();
                    break;
                case "global-log":
                    validateNumArgs(args, 1);
                    repo.printRepoGlobalLog();
                    break;
                case "status":
                    validateNumArgs(args, 1);
                    repo.printRepoStatus();
                    break;
                case "branch":
                    validateNumArgs(args, 2);
                    branchName = args[1];
                    repo.branch(branchName);
                    break;
                case "checkout":
                    if (args.length == 2) {
                        branchName = args[1];
                        repo.checkout(branchName);
                    } else if (args.length == 3) {
                        fileName = args[2];
                        repo.checkoutFile(fileName);
                    } else if (args.length == 4) {
                        commitID = args[1];
                        fileName = args[3];
                        repo.checkout(commitID, fileName);
                    }

                    break;
                default:
                    error = new GitletException("No command with that name exists.");
                    System.out.println(error.getMessage());
            }
            repo.saveRepo();
        }

    }


    public static void validateNumArgs(String[] args, int n) {
        if (args.length != n) {
            GitletException error = new GitletException("Incorrect operands.");
            System.out.println(error.getMessage());
            System.exit(0);
        }
    }
}