pyLyricFlow/LyricFlow.Core.Backend/LyricFlow.Core/Services/FileService.cs

using LyricFlow.Core.Dtos;

namespace LyricFlow.Core.Services;

public class FileService
{
    // MARK: - File Read And Write
    #region File Read And Write

    public FileReadResultDto ReadFile(string path)
    {
        try
        {
            var fullPath = Path.GetFullPath(path);
            return new FileReadResultDto(true, $"Loaded {Path.GetFileName(fullPath)}", File.ReadAllText(fullPath), fullPath);
        }
        catch (Exception ex)
        {
            return new FileReadResultDto(false, ex.Message, null, null);
        }
    }

    public FileWriteResultDto WriteFile(string path, string content)
    {
        try
        {
            var fullPath = Path.GetFullPath(path);
            var directory = Path.GetDirectoryName(fullPath);
            if (!string.IsNullOrWhiteSpace(directory))
            {
                Directory.CreateDirectory(directory);
            }

            File.WriteAllText(fullPath, content);
            return new FileWriteResultDto(true, $"Saved to {Path.GetFileName(fullPath)}", fullPath);
        }
        catch (Exception ex)
        {
            return new FileWriteResultDto(false, ex.Message, null);
        }
    }

    #endregion

    // MARK: - File System Mutations
    #region File System Mutations

    public FileWriteResultDto CreateFile(string path)
    {
        try
        {
            var fullPath = Path.GetFullPath(path);
            var directory = Path.GetDirectoryName(fullPath);
            if (!string.IsNullOrWhiteSpace(directory))
            {
                Directory.CreateDirectory(directory);
            }

            using (File.Create(fullPath))
            {
            }

            return new FileWriteResultDto(true, $"Created {Path.GetFileName(fullPath)}", fullPath);
        }
        catch (Exception ex)
        {
            return new FileWriteResultDto(false, ex.Message, null);
        }
    }

    public FileWriteResultDto CreateDirectory(string path)
    {
        try
        {
            var fullPath = Path.GetFullPath(path);
            Directory.CreateDirectory(fullPath);
            return new FileWriteResultDto(true, $"Created {Path.GetFileName(fullPath)}", fullPath);
        }
        catch (Exception ex)
        {
            return new FileWriteResultDto(false, ex.Message, null);
        }
    }

    public FileWriteResultDto Rename(string oldPath, string newPath, string? rootPath)
    {
        try
        {
            var oldFullPath = Path.GetFullPath(oldPath);
            var newFullPath = Path.GetFullPath(newPath);
            if (!IsWithinRoot(rootPath, oldFullPath) || !IsWithinRoot(rootPath, newFullPath))
            {
                return new FileWriteResultDto(false, "Operation blocked because the target is outside the current project root.", null);
            }

            if (Directory.Exists(oldFullPath))
            {
                Directory.Move(oldFullPath, newFullPath);
            }
            else
            {
                File.Move(oldFullPath, newFullPath);
            }

            return new FileWriteResultDto(true, $"Renamed to {Path.GetFileName(newFullPath)}", newFullPath);
        }
        catch (Exception ex)
        {
            return new FileWriteResultDto(false, ex.Message, null);
        }
    }

    public FileWriteResultDto Delete(string path, string? rootPath)
    {
        try
        {
            var fullPath = Path.GetFullPath(path);
            if (!IsWithinRoot(rootPath, fullPath))
            {
                return new FileWriteResultDto(false, "Operation blocked because the target is outside the current project root.", null);
            }

            if (!string.IsNullOrWhiteSpace(rootPath) && Path.GetFullPath(rootPath) == fullPath)
            {
                return new FileWriteResultDto(false, "Deleting the project root is not allowed.", null);
            }

            var target = TrashTarget(fullPath);
            if (Directory.Exists(fullPath))
            {
                Directory.Move(fullPath, target);
            }
            else
            {
                File.Move(fullPath, target);
            }

            return new FileWriteResultDto(true, $"Moved {Path.GetFileName(fullPath)} to LyricFlow trash", target);
        }
        catch (Exception ex)
        {
            return new FileWriteResultDto(false, ex.Message, null);
        }
    }

    #endregion

    // MARK: - Workspace Safety
    #region Workspace Safety

    public bool IsWithinRoot(string? rootPath, string candidatePath)
    {
        if (string.IsNullOrWhiteSpace(rootPath))
        {
            return true;
        }

        try
        {
            var rootFullPath = Path.GetFullPath(rootPath);
            var candidateFullPath = Path.GetFullPath(candidatePath);
            var relativePath = Path.GetRelativePath(rootFullPath, candidateFullPath);
            return !relativePath.StartsWith("..", StringComparison.Ordinal) && !Path.IsPathRooted(relativePath);
        }
        catch
        {
            return false;
        }
    }

    #endregion

    // MARK: - Trash Helpers
    #region Trash Helpers

    private static string TrashTarget(string path)
    {
        var trashDir = AppPaths.ExplorerTrashDirectory();
        var timestamp = DateTime.Now.ToString("yyyyMMdd-HHmmss");
        var name = Path.GetFileName(path);
        var target = Path.Combine(trashDir, $"{timestamp}-{name}");
        var counter = 1;
        while (File.Exists(target) || Directory.Exists(target))
        {
            target = Path.Combine(trashDir, $"{timestamp}-{counter}-{name}");
            counter++;
        }

        return target;
    }

    #endregion
}