Server/OwnChar.Server/ServerContext.cs

using Castle.Core.Logging;
using Microsoft.EntityFrameworkCore;
using OwnChar.Data.Model.Base;
using OwnChar.Server.Api;
using OwnChar.Server.Api.Endpoint;
using OwnChar.Server.Api.Endpoint.Implementations;
using OwnChar.Server.Api.Plugins;
using OwnChar.Server.Data;
using Pilz.Configuration;
using Pilz.Cryptography;
using Pilz.Plugins.Advanced;
using System.Net;

namespace OwnChar.Server;

internal class ServerContext(ISettings settings) : IServer
{
    private readonly Dictionary<string, UserAccountBase> users = [];
    private readonly HttpListener httpListener = new();
    private readonly ApiBuilder apiBuilder = new();

    public DbContext? Data { get; private set; }

    public ISettings Settings { get; } = settings;

    public ILogger Log { get; set; } = NullLogger.Instance;

    public void Start(string[] args)
    {
        Log.Info("Prepairing server");

        // Load database
        Log.Debug("Loading database");
        var settings = Settings.Get<ServerSettings>();
        Data = new DatabaseContext(settings.DbServer, settings.DbUser, settings.DbPassword);

        // Built-in endpoints
        Log.Debug("Loading internal api endpoints");
        var apibuilder = new ApiBuilder();
        new LoginApi(this).Initialize(apibuilder);
        new UsersApi(this).Initialize(apibuilder);
        new GroupsApi(this).Initialize(apibuilder);
        new CharactersApi(this).Initialize(apibuilder);

        // Plugin endpoints
        Log.Debug("Loading plugin api endpoints");
        var endpoints = PluginFeatureController.Instance.Features.Get(ApiEndpointFeature.FeatureType).OfType<IApiEndpoint>();
        if (endpoints.Any())
        {
            foreach (var endpoint in endpoints)
                endpoint.Initialize(apibuilder);
        }

        // Run server
        Log.Info("Starting webserver");
        httpListener.Start();
        Listen();
    }

    private void Listen()
    {
        var apiUrl = Settings.Get<ServerSettings>().ApiUrl;
        if (string.IsNullOrWhiteSpace(apiUrl))
            throw new NullReferenceException("ApiUrl is empty!");

        while (httpListener.IsListening)
        {
            var context = httpListener.GetContext();

            if (context.Request.HttpMethod != HttpMethod.Post.Method
                || context.Request.ContentType is not string contentType
                || contentType.Contains("application/json")
                || context.Request.AcceptTypes is null
                || context.Request.AcceptTypes.Contains("application/json"))
            {
                close();
                continue;
            }

            // Parse url
            var path = context.Request.Url?.PathAndQuery.Replace(apiUrl, string.Empty);
            if (string.IsNullOrWhiteSpace(path) || context.Request.ContentLength64 <= 0)
            {
                close();
                continue;
            }

            // Find mapped function and get target type
            if (!apiBuilder.Handlers.TryGetValue(new(path, context.Request.HttpMethod), out var postAction))
            {
                close();
                return;
            }
            // ...

            // Read input content
            using StreamReader input = new(context.Request.InputStream);
            var contentJson = input.ReadToEnd();

            // Deserialize request
            if (JsonHelpers.DeserializeRequest<T>(contentJson) is not T request)
            {
                close();
                continue;
            }

            // Set response parameters
            context.Response.StatusCode = (int)args.ResponseStatusCode;
            context.Response.StatusDescription = args.ResponseStatusDescription;

            // Write response content
            if (args.ResponseContent != null)
            {
                context.Response.ContentType = ContentTypes.CONTENT_TYPE_JSON;
                using StreamWriter output = new(context.Response.OutputStream);
                output.Write(args.ResponseContent);
            }

            close();
            void close() => context.Response.OutputStream.Close();
        }
    }

    public string Login(UserAccountBase account)
    {
        var secret = new UniquieID(UniquieIDGenerationMode.GenerateOnInit).ID;
        users.Add(secret, account);
        Log.DebugFormat("Logged-in out user with secret {0}", secret);
        return secret;
    }

    public void Logout(string secret)
    {
        users.Remove(secret);
        Log.DebugFormat("Logged-out user with secret {0}", secret);
    }

    public bool IsLoggedIn(string secret)
    {
        Log.DebugFormat("Deleting user with secret {0}", secret);
        return users.ContainsKey(secret);
    }

    public void CheckLogin(string secret)
    {
        Log.DebugFormat("Checking login for user with secret {0}", secret);
        if (!IsLoggedIn(secret))
            throw new UnauthorizedAccessException();
    }

    public UserAccountBase? GetUser(string secret)
    {
        Log.DebugFormat("Getting user with secret {0}", secret);
        if (users.TryGetValue(secret, out UserAccountBase? value))
            return value;
        return null;
    }
}