using FinalFactory.Rendezvous.Contracts;

namespace FinalFactory.Rendezvous.Client;

public sealed class RendezvousPublisherClient : IRendezvousPublisherClient
{
    private readonly RendezvousHttpTransport _transport;
    private readonly IRendezvousDelay _delay;

    public RendezvousPublisherClient(
        HttpClient httpClient,
        RendezvousClientOptions? options = null,
        IRendezvousDelay? delay = null)
    {
        _delay = delay ?? new SystemRendezvousDelay();
        _transport = new(httpClient, options, _delay);
    }

    public async Task<RendezvousClientResult<PublishedSession>> RegisterAsync(
        RegisterSessionRequest request,
        string publisherCredential,
        CancellationToken cancellationToken = default)
    {
        if (request is null)
        {
            throw new ArgumentNullException(nameof(request));
        }

        RegisterSessionRequest body = CopyRegistration(request);
        RendezvousClientResult<RegisterSessionResponse> result = await _transport.SendSafeAsync<RegisterSessionResponse>(
            () => RendezvousHttpTransport.JsonRequest(HttpMethod.Post, "v1/sessions", body, publisherCredential),
            cancellationToken).ConfigureAwait(false);
        return result.IsSuccess && result.Value is not null
            ? RendezvousClientResult.Success(new PublishedSession(result.Value))
            : RendezvousClientResult.Failure<PublishedSession>(
                result.Error,
                result.Message,
                result.RetryAfterSeconds);
    }

    public async Task<RendezvousClientResult<RenewLeaseResponse>> RenewAsync(
        PublishedSession session,
        string publisherCredential,
        CancellationToken cancellationToken = default)
    {
        if (session is null)
        {
            throw new ArgumentNullException(nameof(session));
        }

        RendezvousClientResult<RenewLeaseResponse> result = await _transport.SendSafeAsync<RenewLeaseResponse>(
            () => RendezvousHttpTransport.JsonRequest(
                HttpMethod.Post,
                $"v1/sessions/{session.ListingId}/renew",
                new RenewLeaseRequest { LeaseToken = session.LeaseToken },
                publisherCredential),
            cancellationToken).ConfigureAwait(false);
        if (result.IsSuccess && result.Value is not null)
        {
            session.ExpiresAt = result.Value.ExpiresAt;
            session.LeaseRenewAfterSeconds = result.Value.RenewAfterSeconds;
        }

        return result;
    }

    public Task<RendezvousClientResult<bool>> UpdateAsync(
        PublishedSession session,
        UpdateSessionRequest request,
        string publisherCredential,
        CancellationToken cancellationToken = default)
    {
        if (session is null)
        {
            throw new ArgumentNullException(nameof(session));
        }

        if (request is null)
        {
            throw new ArgumentNullException(nameof(request));
        }

        UpdateSessionRequest body = new()
        {
            ContractVersion = request.ContractVersion,
            LeaseToken = session.LeaseToken,
            BuildVersion = request.BuildVersion,
            DisplayName = request.DisplayName,
            Capacity = CopyCapacity(request.Capacity),
            Metadata = CopyMetadata(request.Metadata),
            DedicatedFallback = RendezvousEndpoint.Copy(request.DedicatedFallback),
        };
        return _transport.SendSafeAsync<bool>(
            () => RendezvousHttpTransport.JsonRequest(
                HttpMethod.Put,
                $"v1/sessions/{session.ListingId}",
                body,
                publisherCredential),
            cancellationToken);
    }

    public Task<RendezvousClientResult<bool>> DeregisterAsync(
        PublishedSession session,
        string publisherCredential,
        CancellationToken cancellationToken = default)
    {
        if (session is null)
        {
            throw new ArgumentNullException(nameof(session));
        }

        return _transport.SendSafeAsync<bool>(
            () => RendezvousHttpTransport.JsonRequest(
                HttpMethod.Delete,
                $"v1/sessions/{session.ListingId}",
                new DeleteSessionRequest { LeaseToken = session.LeaseToken },
                publisherCredential),
            cancellationToken);
    }

    public SessionLeaseMaintainer CreateLeaseMaintainer(
        PublishedSession session,
        string publisherCredential) => new(
            this,
            session ?? throw new ArgumentNullException(nameof(session)),
            RendezvousHttpTransport.RequireCredential(publisherCredential),
            _delay);

    private static RegisterSessionRequest CopyRegistration(RegisterSessionRequest request) => new()
    {
        ContractVersion = request.ContractVersion,
        IdempotencyKey = request.IdempotencyKey,
        GameId = request.GameId,
        EnvironmentId = request.EnvironmentId,
        RegionId = request.RegionId,
        ProtocolVersion = request.ProtocolVersion,
        BuildVersion = request.BuildVersion,
        DisplayName = request.DisplayName,
        Visibility = request.Visibility,
        Capacity = CopyCapacity(request.Capacity),
        Metadata = CopyMetadata(request.Metadata),
        DedicatedFallback = RendezvousEndpoint.Copy(request.DedicatedFallback),
    };

    private static SessionCapacity CopyCapacity(SessionCapacity capacity) => new()
    {
        CurrentPlayers = capacity.CurrentPlayers,
        MaximumPlayers = capacity.MaximumPlayers,
    };

    private static Dictionary<string, string> CopyMetadata(Dictionary<string, string> metadata) =>
        new(metadata, StringComparer.Ordinal);

}