using System.Net.Http.Headers;
using System.Net.Http.Json;

namespace JobTrackerApi.Services;

public sealed record MaintenanceJobDefinition(string Id, string Title, string Description, bool Available, string? RunsUrl);

public sealed class MaintenanceJobDispatcher(IConfiguration configuration, IHttpClientFactory httpClientFactory)
{
    public const string CvBenchmarkJobId = "cv-benchmark";

    public IReadOnlyList<MaintenanceJobDefinition> GetJobs()
    {
        var settings = ReadSettings();
        return
        [
            new(
                CvBenchmarkJobId,
                "CV extraction benchmark",
                "Runs the private CV corpus benchmark on the production host and publishes its report to Admin/System.",
                settings.IsConfigured,
                settings.RunsUrl)
        ];
    }

    public async Task DispatchAsync(string jobId, CancellationToken cancellationToken)
    {
        if (!string.Equals(jobId, CvBenchmarkJobId, StringComparison.Ordinal))
        {
            throw new KeyNotFoundException("Unknown maintenance job.");
        }

        var settings = ReadSettings();
        if (!settings.IsConfigured)
        {
            throw new InvalidOperationException("Maintenance job dispatch is not configured.");
        }

        using var request = new HttpRequestMessage(
            HttpMethod.Post,
            $"{settings.BaseUrl}/api/v1/repos/{Uri.EscapeDataString(settings.Owner)}/{Uri.EscapeDataString(settings.Repository)}/actions/workflows/maintenance.yml/dispatches");
        request.Headers.Authorization = new AuthenticationHeaderValue("token", settings.Token);
        request.Content = JsonContent.Create(new
        {
            @ref = "main",
            inputs = new Dictionary<string, string> { ["job"] = jobId }
        });

        using var response = await httpClientFactory.CreateClient("maintenance-jobs")
            .SendAsync(request, cancellationToken);
        if (!response.IsSuccessStatusCode)
        {
            throw new HttpRequestException(
                $"Gitea rejected the maintenance workflow dispatch with HTTP {(int)response.StatusCode}.",
                null,
                response.StatusCode);
        }
    }

    private Settings ReadSettings()
    {
        var baseUrl = (configuration["MaintenanceJobs:GiteaBaseUrl"] ?? "https://git.cesnimda.uk").Trim().TrimEnd('/');
        var owner = (configuration["MaintenanceJobs:GiteaOwner"] ?? "cesnimda").Trim();
        var repository = (configuration["MaintenanceJobs:GiteaRepository"] ?? "jobtrackingapp").Trim();
        var token = (configuration["MaintenanceJobs:GiteaToken"] ?? string.Empty).Trim();
        var configured = Uri.TryCreate(baseUrl, UriKind.Absolute, out var uri)
            && uri.Scheme == Uri.UriSchemeHttps
            && !string.IsNullOrWhiteSpace(owner)
            && !string.IsNullOrWhiteSpace(repository)
            && !string.IsNullOrWhiteSpace(token);
        var runsUrl = configured ? $"{baseUrl}/{owner}/{repository}/actions" : null;
        return new Settings(baseUrl, owner, repository, token, configured, runsUrl);
    }

    private sealed record Settings(string BaseUrl, string Owner, string Repository, string Token, bool IsConfigured, string? RunsUrl);
}