using System.Text.Json;
using DotBased.Monads;
using Manager.YouTube.Models.Innertube;
using Manager.YouTube.Parsers;
using Manager.YouTube.Util;

namespace Manager.YouTube;

public static class NetworkService
{
    public static async Task<Result<ClientState>> GetClientStateAsync(YouTubeClient client)
    {
        var origin = "https://www.youtube.com/";
        var httpRequest = new HttpRequestMessage
        {
            Method = HttpMethod.Get,
            RequestUri = new Uri(origin)
        };
        httpRequest.Headers.IfModifiedSince = new DateTimeOffset(DateTime.UtcNow);
        httpRequest.Headers.UserAgent.ParseAdd(client.UserAgent);
        
        if (client.SapisidCookie != null)
        {
            httpRequest.Headers.Authorization = AuthenticationUtilities.GetSapisidHashHeader(client.SapisidCookie.Value, origin);
            httpRequest.Headers.Add("Origin", origin);
        }
        
        var http = client.GetHttpClient();
        if (http == null)
        {
            return ResultError.Fail("Unable to get http client!");
        }
        
        var response = await http.SendAsync(httpRequest);
        if (!response.IsSuccessStatusCode)
        {
            var responseResult = await response.Content.ReadAsStringAsync();
            return Result<ClientState>.Fail(ResultError.Fail(responseResult));
        }
        var responseHtml = await response.Content.ReadAsStringAsync();
        var clientStateResult = HtmlParser.GetJsonFromScriptFunction(responseHtml, "ytcfg.set");
        if (clientStateResult is { IsSuccess: false, Error: not null })
        {
            return clientStateResult.Error;
        }

        ClientState? clientState;
        try
        {
            clientState = JsonSerializer.Deserialize<ClientState>(clientStateResult.Value);
        }
        catch (Exception e)
        {
            return ResultError.Error(e, "Error while parsing JSON!");
        }
        
        return clientState == null ? ResultError.Fail("Unable to parse client state!") : clientState;
    }
}