using Microsoft.Extensions.Caching.Memory;
using Microsoft.Extensions.Options;

namespace FictionArchive.Service.NovelService.Services.SourceAdapters.Novelpia;

public class NovelpiaAuthMessageHandler : DelegatingHandler
{
    private readonly HttpClient _httpClient;
    private readonly IMemoryCache _cache;
    private readonly NovelpiaConfiguration _configuration;
    private const string CacheKey = "novelpia_loginkey";
    private const string LoginUrl = "/proc/login";
    private const string LoginSuccessMessage = "감사합니다";
    private const string UserAgent =
        "Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Mobile Safari/537.36";

    public NovelpiaAuthMessageHandler(HttpClient httpClient, IOptions<NovelpiaConfiguration> configuration, IMemoryCache cache)
    {
        _httpClient = httpClient;
        _configuration = configuration.Value;
        _cache = cache;
    }

    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        string loginKey = await GetLoginKey();
        request.Headers.Add("cookie", $"LOGINKEY={loginKey}");
        request.Headers.UserAgent.ParseAdd(UserAgent);
        return await base.SendAsync(request, cancellationToken);
    }

    private async Task<string> GetLoginKey()
    {
        if (!_cache.TryGetValue(CacheKey, out string? loginKey))
        {
            var random = new Random();
            var characters = "0123456789abcdef";
            var firstPart = new string(Enumerable.Range(0, 32).Select(_ => characters[random.Next(characters.Length)]).ToArray());
            var secondPart = new string(Enumerable.Range(0, 32).Select(_ => characters[random.Next(characters.Length)]).ToArray());
            loginKey = firstPart + "_" + secondPart;
            
            HttpRequestMessage loginMessage = new HttpRequestMessage(HttpMethod.Post, LoginUrl);
            loginMessage.Headers.Add("cookie", $"LOGINKEY={loginKey}");
            loginMessage.Headers.UserAgent.ParseAdd(UserAgent);
            loginMessage.Content = new FormUrlEncodedContent(new Dictionary<string, string>
            {
                { "redirecturl", string.Empty },
                { "email", _configuration.Username },
                { "wd", _configuration.Password }
            });

            var response = await _httpClient.SendAsync(loginMessage);
            using (var streamReader = new StreamReader(response.Content.ReadAsStream()))
            {
                if (streamReader.ReadToEnd().Contains(LoginSuccessMessage))
                {
                    _cache.Set(CacheKey, loginKey);
                }
            }
        }

        return loginKey;
    }
}