// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Diagnostics;
using System.Net;
using System.Text.Json.Nodes;
using Microsoft.Extensions.Logging;
using Microsoft.NET.Build.Containers.Resources;

namespace Microsoft.NET.Build.Containers;

internal class DefaultBlobOperations : IBlobOperations
{
    private readonly Uri _baseUri;
    private readonly HttpClient _client;
    private readonly ILogger _logger;
    private readonly string _registryName;

    public DefaultBlobOperations(Uri baseUri, string registryName, HttpClient client, ILogger logger)
    {
        _baseUri = baseUri;
        _client = client;
        _logger = logger;
        _registryName = registryName;
        Upload = new DefaultBlobUploadOperations(_baseUri, _client, _logger);
    }

    public IBlobUploadOperations Upload { get; }

    public async Task<bool> ExistsAsync(string repositoryName, string digest, CancellationToken cancellationToken)
    {
        cancellationToken.ThrowIfCancellationRequested();
        using HttpResponseMessage response = await _client.SendAsync(new HttpRequestMessage(HttpMethod.Head, new Uri(_baseUri, $"/v2/{repositoryName}/blobs/{digest}")), cancellationToken).ConfigureAwait(false);
        return response.StatusCode switch
        {
            HttpStatusCode.OK => true,
            HttpStatusCode.NotFound => false,
            HttpStatusCode.Unauthorized or HttpStatusCode.Forbidden => throw new UnableToAccessRepositoryException(_registryName, repositoryName),
            _ => await LogAndThrowContainerHttpException<bool>(response, cancellationToken).ConfigureAwait(false)
        };
    }

    public async Task<JsonNode> GetJsonAsync(string repositoryName, string digest, CancellationToken cancellationToken)
    {
        cancellationToken.ThrowIfCancellationRequested();
        HttpResponseMessage response = await GetAsync(repositoryName, digest, cancellationToken).ConfigureAwait(false);

        JsonNode? configDoc = JsonNode.Parse(await response.Content.ReadAsStringAsync(cancellationToken).ConfigureAwait(false));
        Debug.Assert(configDoc is not null);

        return configDoc;
    }

    public async Task<Stream> GetStreamAsync(string repositoryName, string digest, CancellationToken cancellationToken)
    {
        cancellationToken.ThrowIfCancellationRequested();
        HttpResponseMessage response = await GetAsync(repositoryName, digest, cancellationToken).ConfigureAwait(false);

        return await response.Content.ReadAsStreamAsync(cancellationToken).ConfigureAwait(false);
    }

    private async Task<HttpResponseMessage> GetAsync(string repositoryName, string digest, CancellationToken cancellationToken)
    {
        cancellationToken.ThrowIfCancellationRequested();
        using HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, new Uri(_baseUri, $"/v2/{repositoryName}/blobs/{digest}")).AcceptManifestFormats();
        HttpResponseMessage response = await _client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancellationToken).ConfigureAwait(false);
        return response.StatusCode switch
        {
            HttpStatusCode.OK => response,
            HttpStatusCode.Unauthorized or HttpStatusCode.Forbidden => throw new UnableToAccessRepositoryException(_registryName, repositoryName),
            _ => await LogAndThrowContainerHttpException<HttpResponseMessage>(response, cancellationToken).ConfigureAwait(false)
        };
    }

    private async Task<T> LogAndThrowContainerHttpException<T>(HttpResponseMessage response, CancellationToken cancellationToken)
    {
        await response.LogHttpResponseAsync(_logger, cancellationToken).ConfigureAwait(false);
        throw new ContainerHttpException(Resource.GetString(nameof(Strings.RegistryPullFailed)), response.RequestMessage?.RequestUri?.ToString(), response.StatusCode);
    }
}