using System.Net.Http.Headers;
using System.Text;

namespace LMEMappeCatastaliApp.Services;

public sealed class CloudSyncService
{
    private readonly HttpClient _httpClient = new() { Timeout = TimeSpan.FromMinutes(3) };

    public async Task UploadAsync(string endpoint, string userName, string password, string localPath, CancellationToken cancellationToken = default)
    {
        var target = BuildTarget(endpoint);
        using var request = new HttpRequestMessage(HttpMethod.Put, target);
        ApplyCredentials(request, userName, password);
        request.Content = new StreamContent(File.OpenRead(localPath));
        request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/zip");
        using var response = await _httpClient.SendAsync(request, cancellationToken);
        response.EnsureSuccessStatusCode();
    }

    public async Task<string> DownloadAsync(string endpoint, string userName, string password, CancellationToken cancellationToken = default)
    {
        using var request = new HttpRequestMessage(HttpMethod.Get, BuildTarget(endpoint));
        ApplyCredentials(request, userName, password);
        using var response = await _httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
        response.EnsureSuccessStatusCode();
        var directory = Path.Combine(FileSystem.CacheDirectory, "CloudSync");
        Directory.CreateDirectory(directory);
        var path = Path.Combine(directory, $"LME-cloud-{DateTime.Now:yyyyMMdd-HHmmss}.lmebackup.zip");
        await using var input = await response.Content.ReadAsStreamAsync(cancellationToken);
        await using var output = File.Create(path);
        await input.CopyToAsync(output, cancellationToken);
        return path;
    }

    private static Uri BuildTarget(string endpoint)
    {
        if (!Uri.TryCreate(endpoint?.Trim(), UriKind.Absolute, out var uri)
            || (uri.Scheme != Uri.UriSchemeHttps && uri.Scheme != Uri.UriSchemeHttp))
        {
            throw new ArgumentException("Inserisci un indirizzo WebDAV http o https valido.");
        }
        return uri.AbsolutePath.EndsWith(".zip", StringComparison.OrdinalIgnoreCase)
            ? uri
            : new Uri($"{uri.ToString().TrimEnd('/')}/LMEMappeCatastali-sync.lmebackup.zip");
    }

    private static void ApplyCredentials(HttpRequestMessage request, string userName, string password)
    {
        if (string.IsNullOrWhiteSpace(userName)) return;
        var value = Convert.ToBase64String(Encoding.UTF8.GetBytes($"{userName}:{password}"));
        request.Headers.Authorization = new AuthenticationHeaderValue("Basic", value);
    }
}