using System.Threading.Tasks;
using eprintServer.Entities;
using System.Text.Json;

using eprintServer.Enums;
using eprintServer.Models;
using System;

namespace eprintServer.Services;

public class LinkedInOAuthService : BaseOAuthService
{
    private readonly OAuthSettingsService _settingsService;
    private readonly IHttpClientFactory _httpClientFactory;

    public LinkedInOAuthService(OAuthSettingsService settingsService, UserService userService, TokenService tokenService, IHttpClientFactory httpClientFactory) 
        : base(userService, tokenService)
    {
        _settingsService = settingsService;
        _httpClientFactory = httpClientFactory;
    }

    public async Task<(User? user, string? token, string? error)> HandleLoginCallbackAsync(string code)
    {
        var settings = await _settingsService.GetOrCreateSettingsAsync();
        var client = _httpClientFactory.CreateClient();

        // 1. Token Exchange
        var request = new HttpRequestMessage(HttpMethod.Post, "https://www.linkedin.com/oauth/v2/accessToken");
        request.Content = new FormUrlEncodedContent(new Dictionary<string, string>
        {
            ["grant_type"] = "authorization_code",
            ["code"] = code,
            ["client_id"] = settings.LinkedInClientId!,
            ["client_secret"] = settings.LinkedInClientSecret!,
            ["redirect_uri"] = "https://server.etbaaonline.com/api/v1/oauth/linkedin/callback"
        });

        var response = await client.SendAsync(request);
        var tokenData = await response.Content.ReadFromJsonAsync<JsonElement>();
        var accessToken = tokenData.GetProperty("access_token").GetString();

        // 2. User Info (OpenID Connect)
        client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", accessToken);
        var profileResponse = await client.GetAsync("https://api.linkedin.com/v2/userinfo");
        var liUser = await profileResponse.Content.ReadFromJsonAsync<JsonElement>();

        var externalUser = new ExternalUserData
        {
            Email = liUser.GetProperty("email").GetString()!,
            Name = liUser.GetProperty("name").GetString()!,
            ProviderUserId = liUser.GetProperty("sub").GetString()
        };

        return await SignInUserAsync(externalUser, Provider.LINKEDIN);
    }
}