using System.Net;
using Amazon.S3;
using Amazon.S3.Model;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using mws.backend.dotnet.application.Common;
using mws.backend.dotnet.application.Documents;

namespace mws.backend.dotnet.infrastructure.Storage;

public class S3DocumentContentStore(
    IAmazonS3 s3,
    IOptions<MinioOptions> opt,
    ILogger<S3DocumentContentStore> log) : IDocumentContentStore
{
    private string Bucket => opt.Value.Bucket;

    private static string Key(Guid projectId, Guid documentId) => $"{projectId:N}/{documentId:N}.html";

    public Task EnsureBucketAsync(Guid projectId, CancellationToken ct) => Task.CompletedTask;

    public async Task UploadAsync(Guid projectId, Guid documentId, string contentType, Stream body, CancellationToken ct)
    {
        try
        {
            await s3.PutObjectAsync(new PutObjectRequest
            {
                BucketName = Bucket,
                Key = Key(projectId, documentId),
                InputStream = body,
                ContentType = contentType,
                AutoCloseStream = false,
            }, ct);
        }
        catch (AmazonS3Exception ex)
        {
            log.LogError(ex, "MinIO upload failed for document {DocumentId}", documentId);
            throw new StorageUnavailableException("Document upload failed", ex);
        }
    }

    public async Task<Stream> DownloadAsync(Guid projectId, Guid documentId, CancellationToken ct)
    {
        try
        {
            var response = await s3.GetObjectAsync(Bucket, Key(projectId, documentId), ct);
            return response.ResponseStream;
        }
        catch (AmazonS3Exception ex) when (ex.StatusCode == HttpStatusCode.NotFound)
        {
            return Stream.Null;
        }
        catch (AmazonS3Exception ex)
        {
            log.LogError(ex, "MinIO download failed for document {DocumentId}", documentId);
            throw new StorageUnavailableException("Document download failed", ex);
        }
    }

    public async Task<bool> ExistsAsync(Guid projectId, Guid documentId, CancellationToken ct)
    {
        try
        {
            await s3.GetObjectMetadataAsync(Bucket, Key(projectId, documentId), ct);
            return true;
        }
        catch (AmazonS3Exception ex) when (ex.StatusCode == HttpStatusCode.NotFound)
        {
            return false;
        }
    }

    public async Task DeleteAsync(Guid projectId, Guid documentId, CancellationToken ct)
    {
        try
        {
            await s3.DeleteObjectAsync(Bucket, Key(projectId, documentId), ct);
        }
        catch (AmazonS3Exception ex)
        {
            log.LogWarning(ex, "MinIO delete failed for document {DocumentId}", documentId);
        }
    }
}