ANTOOZA-BACKEND/Infrastructure/Storage/LocalFileStorage.cs

using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using SharedKernel.Storage;

namespace Infrastructure.Storage;

public sealed class LocalFileStorage : IFileStorage
{
    private readonly string _basePath;
    private readonly ILogger<LocalFileStorage> _log;

    public LocalFileStorage(IWebHostEnvironment env, IOptions<StorageOptions> opts, ILogger<LocalFileStorage> log)
    {
        // StorageOptions.BasePath 가 설정돼있으면 외부 경로 사용 (deploy 영향 X)
        // 미설정이면 WebHostEnvironment.WebRootPath 로 폴백 (기존 동작)
        _basePath = string.IsNullOrWhiteSpace(opts.Value.BasePath) ? env.WebRootPath : opts.Value.BasePath;
        _log = log;
    }

    public async Task<FileUploadResult?> SaveFileAsync(IFormFile? file, FileStoragePath path, string[] allowedExtensions, CancellationToken ct = default)
    {
        if (file is null || file.Length <= 0)
        {
            return null;
        }

        var ext = Path.GetExtension(file.FileName).ToLowerInvariant();
        if (!allowedExtensions.Contains(ext))
        {
            throw new ArgumentException("허용되지 않는 파일 확장자입니다.");
        }

        var rel = path.ToRelativePath();
        var dir = CombineUnderWebRoot(rel);

        Directory.CreateDirectory(dir); // 경로 생성(없으면)

        var fileName = $"{Guid.NewGuid():N}{ext}";
        var fullPath = Path.Combine(dir, fileName);

        await using (var fs = new FileStream(fullPath, FileMode.CreateNew, FileAccess.Write, FileShare.None))
        {
            await file.CopyToAsync(fs, ct);
        }

        var url = "/" + $"{rel}/{fileName}".Replace("\\", "/");

        short? width = null, height = null;
        if (IsImageExtension(ext))
        {
            using var readStream = new FileStream(fullPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite | FileShare.Read);
            var dim = ImageDimensionHelper.GetDimensions(readStream);
            if (dim.HasValue)
            {
                width = dim.Value.Width;
                height = dim.Value.Height;
            }
        }

        return new FileUploadResult(url, fileName, file.Length, ext, width, height);
    }

    public async Task<FileUploadResult?> SaveBytesAsync(ReadOnlyMemory<byte> bytes, string extension, FileStoragePath path, CancellationToken ct = default)
    {
        if (bytes.Length <= 0)
        {
            return null;
        }

        var ext = FileUtils.NormalizeExtension(extension);
        if (ext is not (".jpg" or ".png" or ".gif" or ".bmp" or ".webp"))
        {
            throw new ArgumentException("허용되지 않는 파일 확장자입니다.");
        }

        var rel = path.ToRelativePath();
        var dir = CombineUnderWebRoot(rel);

        Directory.CreateDirectory(dir); // 경로 생성(없으면)

        var fileName = $"{Guid.NewGuid():N}{ext}";
        var fullPath = Path.Combine(dir, fileName);

        await File.WriteAllBytesAsync(fullPath, bytes.ToArray(), ct);

        var url = "/" + $"{rel}/{fileName}".Replace("\\", "/");

        short? width = null, height = null;
        var dim = ImageDimensionHelper.GetDimensions(bytes);
        if (dim.HasValue)
        {
            width = dim.Value.Width;
            height = dim.Value.Height;
        }

        return new FileUploadResult(url, fileName, bytes.Length, ext, width, height);
    }

    public void DeleteByUrl(string? url)
    {
        if (string.IsNullOrWhiteSpace(url))
        {
            return;
        }

        if (!FileUtils.IsLocalPublicUrl(url))
        {
            _log.LogWarning("삭제가 불가한 주소입니다. {0}", url);
            return;
        }

        var fullPath = CombineUnderWebRoot(url.TrimStart('/'));

        if (!File.Exists(fullPath))
        {
            _log.LogWarning("파일을 찾을 수 없습니다. {0}", fullPath);
            return;
        }

        try
        {
            File.Delete(fullPath);

            _log.LogInformation("파일이 삭제됨 : {0}", fullPath);
        }
        catch (Exception e)
        {
            _log.LogError(e, "파일 삭제 중 오류가 발생했습니다. {0}", fullPath);
        }
    }

    private static bool IsImageExtension(string ext)
    {
        return ext is ".jpg" or ".jpeg" or ".png" or ".gif" or ".webp" or ".bmp";
    }

    private string CombineUnderWebRoot(string relative)
    {
        var basePath = Path.GetFullPath(_basePath);
        var fullPath = Path.GetFullPath(Path.Combine(_basePath, relative));

        if (!fullPath.StartsWith(basePath, StringComparison.OrdinalIgnoreCase))
        {
            throw new UnauthorizedAccessException("경로를 찾을 수 없습니다.");
        }

        return fullPath;
    }
}