using System.Net.Http.Json;
using System.Reflection;
using System.Text.Json.Serialization;

namespace LMEMappeCatastaliApp.Services;

public sealed class AppUpdateService
{
    private const string LatestReleaseUrl = "https://gitea.lmcloud.it/api/v1/repos/livio/LMEMappeCatastaliApp/releases/latest";
    private readonly HttpClient _httpClient = new() { Timeout = TimeSpan.FromSeconds(20) };

    public static string CurrentVersion =>
        typeof(AppUpdateService).Assembly
            .GetCustomAttribute<AssemblyInformationalVersionAttribute>()?
            .InformationalVersion.Split('+')[0]
        ?? AppInfo.Current.VersionString;

    public async Task<AppUpdateResult> CheckAsync(CancellationToken cancellationToken = default)
    {
        var release = await _httpClient.GetFromJsonAsync<GiteaRelease>(LatestReleaseUrl, cancellationToken)
            ?? throw new InvalidDataException("Risposta aggiornamenti non valida.");
        var latestText = (release.TagName ?? string.Empty).TrimStart('v', 'V');
        _ = Version.TryParse(CurrentVersion, out var current);
        _ = Version.TryParse(latestText, out var latest);
        var apk = release.Assets?.FirstOrDefault(item => item.Name?.EndsWith(".apk", StringComparison.OrdinalIgnoreCase) == true);
        return new(latest is not null && current is not null && latest > current, latestText, release.HtmlUrl ?? string.Empty, apk?.BrowserDownloadUrl ?? release.HtmlUrl ?? string.Empty, release.Body ?? string.Empty);
    }

    private sealed class GiteaRelease
    {
        [JsonPropertyName("tag_name")] public string? TagName { get; set; }
        [JsonPropertyName("html_url")] public string? HtmlUrl { get; set; }
        [JsonPropertyName("assets")] public GiteaAsset[]? Assets { get; set; }
        [JsonPropertyName("body")] public string? Body { get; set; }
    }

    private sealed class GiteaAsset
    {
        [JsonPropertyName("name")] public string? Name { get; set; }
        [JsonPropertyName("browser_download_url")] public string? BrowserDownloadUrl { get; set; }
    }
}

public sealed record AppUpdateResult(bool IsAvailable, string Version, string ReleaseUrl, string DownloadUrl, string ReleaseNotes);