using HyperBooru.ApiModels;
using System.Net;
using System.Net.Http.Json;

namespace HyperBooru.ApiClient;

public sealed class HBSession : IDisposable {
    public Media Media   { get; private init; }
    public Tag   Tag     { get; private init; }
    public Feed  Feed    { get; private init; }
    public User  User    { get; private init; }
    public Uri   BaseUri { get; private init; }

    internal HttpClient HttpClient { get; private init; }

    public HBSession (
        Uri baseUri,
        bool skipCertificateCheck) {

        BaseUri = new($"{baseUri.Scheme}://{baseUri.Host}:{baseUri.Port}/");

        var handler = new HttpClientHandler() {
            AllowAutoRedirect = true,
            UseCookies        = true,
            CookieContainer   = new CookieContainer()
        };

        if(skipCertificateCheck) {
            handler.ClientCertificateOptions = ClientCertificateOption.Manual;
            handler.ServerCertificateCustomValidationCallback =
                (request, cert, certChain, policyErrors) => true;
        }

        HttpClient = new(new ErrorHandler(handler)) {
            BaseAddress = BaseUri
        };

        Media = new(this);
        Tag   = new(this);
        Feed  = new(this);
        User  = new(this);
    }

    public async Task LoginAsync(string username, string password) {
        var formData = new FormUrlEncodedContent(new[] {
            new KeyValuePair<string, string>("username", username),
            new KeyValuePair<string, string>("password", password)
        });

        var resp = await HttpClient.PostAsync($"/Login", formData);

        if(resp.StatusCode == HttpStatusCode.Forbidden) {
            throw new Exception("Invalid username or password");
        } else if(!resp.IsSuccessStatusCode) {
            var content = await resp.Content.ReadAsStringAsync();
            throw new Exception($"Unknown error while logging in: {content}");
        }
    }

    public async Task LogoutAsync() =>
        await HttpClient.PostAsync("/Logout", null);

    public void Dispose() =>
        HttpClient.Dispose();
}

public class ErrorHandler : DelegatingHandler {
    public ErrorHandler(HttpMessageHandler innerHandler) : base(innerHandler) {}

    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken ct) {
        var resp = await base.SendAsync(request, ct);

        if(resp.IsSuccessStatusCode)
            return resp;

        HBException e;
        try {
            e = await resp.Content.ReadFromJsonAsync<HBException>(ct) ??
                throw new NullReferenceException();
        } catch {
            throw new HBException("An unknown error occurred");
        }

        throw e;
    }
}