Foxchat.NET/Foxchat.Identity/Services/ChatInstanceResolverService.cs

using Foxchat.Core.Federation;
using Foxchat.Core.Models.Http;
using Foxchat.Identity.Database;
using Foxchat.Identity.Database.Models;
using Microsoft.EntityFrameworkCore;

namespace Foxchat.Identity.Services;

public class ChatInstanceResolverService(ILogger logger, RequestSigningService requestSigningService, IdentityContext db, InstanceConfig config)
{
    private readonly ILogger _logger = logger.ForContext<ChatInstanceResolverService>();

    public async Task<ChatInstance> ResolveChatInstanceAsync(string domain)
    {
        var instance = await db.ChatInstances.Where(c => c.Domain == domain).FirstOrDefaultAsync();
        if (instance != null) return instance;

        _logger.Information("Unknown chat instance {Domain}, fetching its data", domain);

        var resp = await requestSigningService.RequestAsync<Hello.HelloResponse>(
            HttpMethod.Post,
            domain, "/_fox/chat/hello",
            userId: null,
            body: new Hello.HelloRequest(config.Domain)
        );

        instance = new ChatInstance
        {
            Domain = domain,
            BaseUrl = $"https://{domain}",
            PublicKey = resp.PublicKey,
            Status = ChatInstance.InstanceStatus.Active,
        };
        await db.AddAsync(instance);
        await db.SaveChangesAsync();

        return instance;
    }
}