using System.Net.Http.Headers;
using System.Text.Json;
using JOBot.Backend.DAL.Context;
using JOBot.Backend.DTOs.HeadHunterApi;
using JOBot.Backend.Infrastructure.Config;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Options;

namespace JOBot.Backend.Services;

public class ResumeService(
    AppDbContext dbContext,
    ILogger<ResumeService> logger,
    IOptions<HeadHunterConfig> config,
    HeadHunterService headHunterService)
{
    public async Task<(Status Status, List<Resume>? Resume)> GetAvailableResumes(long userId)
    {
        var user = await dbContext.Users.FirstOrDefaultAsync(x => x.UserId == userId);
        if (user == null)
        {
            return new(Status.UserNotFound, null);
        }

        if (!user.ExpiresIn.HasValue || new DateTime().AddSeconds(user.ExpiresIn.Value) > DateTime.Now)
        {
            var status = await headHunterService.UpdateUserAccessToken(user);
            if (status != HeadHunterService.Status.Success)
            {
                logger.LogError($"User {userId} has expired access and update of it was unsuccessful: {status}");
                return (Status.TokenExpired, null);
            }
        }

        using var client = new HttpClient(); //TODO: Написать wrapper для работы с HH API
        client.BaseAddress = new UriBuilder(config.Value.Links.HeadHunterApiDomain)
        {
            Port = -1,
            Scheme = "https"
        }.Uri;
        client.DefaultRequestHeaders.UserAgent.ParseAdd("Jobot BackEnd Service");
        client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", user.AccessToken);

        using var res = await client.GetAsync("/resumes/mine");

        if (!res.IsSuccessStatusCode)
        {
            logger.LogWarning(
                $"User {user.Username ?? user.UserId.ToString()} resume list is unavailable by unsuccessful status code: {res.StatusCode}");
            return new(Status.RequestError, null);
        }

        var responseDto = JsonSerializer.Deserialize<ListOfResumeResponseDto>(await res.Content.ReadAsStringAsync());
        if (responseDto == null)
            return new(Status.Error, null);

        return new(Status.Success, responseDto.Items);
    }

    public enum Status
    {
        Success,
        UserNotFound,
        Error,
        RequestError,
        TokenExpired
    }
}