Unity Multi-Project Selection Wizard

ProjectSelectWizard.cs

#if UNITY_EDITOR
using System;
using System.IO;
using System.Linq;
using UnityEditor;
using UnityEngine;

public class ProjectSelectWizard : ScriptableWizard
{
    private static readonly string ProjectsFolder = "Projects";
    private static readonly string CurrentProjectFile = "CurrentProject.txt";
    private static readonly string ProjectFilesFilter = "*.asset";

    private static ProjectSelectWizard wizard = null;

    private string[] projectFolders = null;
    private string currentProject;
    private int selectionIndex;

    private ProjectSelectWizard()
    {
        // Build list of available projects (subfolders in the Projects folder)
        string projectsFolder = Path.Combine(Directory.GetCurrentDirectory(), ProjectsFolder);
        projectFolders = Directory.GetDirectories(projectsFolder).Select(path => Path.GetFileName(path)).ToArray();

        // Read current project from file
        string currentProjectFile = Path.Combine(projectsFolder, CurrentProjectFile);
        currentProject = File.Exists(currentProjectFile) ? File.ReadAllText(currentProjectFile) : "none";

        selectionIndex = Array.IndexOf(projectFolders, currentProject);
    }

    private void SwitchProject(string projectFolderName)
    {
        string unityProjectFolder = Path.Combine(Directory.GetCurrentDirectory(), "ProjectSettings");
        string currentProjectFolder = Path.Combine(Directory.GetCurrentDirectory(), ProjectsFolder, projectFolderName);
        string backupFolder = Path.Combine(Directory.GetCurrentDirectory(), ProjectsFolder, "Backup");
        string currentProjectFile = Path.Combine(Directory.GetCurrentDirectory(), ProjectsFolder, CurrentProjectFile);

        // Backup current project settings, to prevent losing uncommited changes
        // Ensure the directory exists before copying
        Directory.CreateDirectory(backupFolder);
        // Clear the backup folder
        foreach (string file in Directory.GetFiles(backupFolder))
        {
            File.Delete(file);
        }
        // Copy current project settings to backup folder
        foreach (string file in Directory.GetFiles(unityProjectFolder))
        {
            File.Copy(file, Path.Combine(backupFolder, Path.GetFileName(file)));
        }

        // Copy and overwrite project setting files to the ProjectSettings folder
        foreach (string file in Directory.GetFiles(currentProjectFolder, ProjectFilesFilter))
        {
            File.Copy(file, Path.Combine(unityProjectFolder, Path.GetFileName(file)), true);
        }

        // Update current project name in file
        File.WriteAllText(currentProjectFile, projectFolderName);
    }

    [MenuItem("Broxzier/Select Project", priority = 30)]
    public static void OpenProjectSelectionWizard()
    {
        if (wizard == null)
        {
            wizard = DisplayWizard<ProjectSelectWizard>("Select Project");
        }
    }

    private void OnGUI()
    {
        GUILayout.Label($"Current project: {currentProject}", EditorStyles.largeLabel);
        GUILayout.Label("Select a project", EditorStyles.boldLabel);
        selectionIndex = GUILayout.SelectionGrid(selectionIndex, projectFolders, 1, EditorStyles.radioButton);
        if (selectionIndex != -1)
        {
            GUILayout.FlexibleSpace();
            if (GUILayout.Button($"Switch to: {projectFolders[selectionIndex]}"))
            {
                SwitchProject(projectFolders[selectionIndex]);
                wizard.Close();
            }
        }
    }

    private void OnDestroy()
    {
        wizard = null;
    }
}
#endif