using IdentityServer.PublishedLanguage.Dto;
using IdentityServer.Wrapper.Constants;
using IdentityServer.Wrapper.Models;
using Newtonsoft.Json;
using System;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Threading.Tasks;

namespace IdentityServer.Wrapper.Services
{
    internal class IdentityService : IIdentityService
    {
        private const string _contentType = "application/json";
        private readonly HttpClient _httpClient;

        public IdentityService(HttpClient httpClient, ServiceConfiguration configuration)
        {
            httpClient.BaseAddress = new Uri(configuration.BaseAddress);
            httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue(_contentType));

            _httpClient = httpClient;
        }

        public async Task<Token> Authenticate(string userName, string password)
        {
            var route = string.Format(ApiRoutes.Authentication, userName, password);
            var result = await ExecutePostRequest<Token>(route);
            return result;
        }

        public async Task<User> Authorize(string token)
        {
            var route = string.Format(ApiRoutes.Authorization, token);
            var result = await ExecutePostRequest<User>(route);
            return result;
        }

        #region Private methods
        private async Task<T> ExecuteGetRequest<T>(string route) where T : class
        {
            using (var response = await _httpClient.GetAsync(route))
            {
                if (!response.IsSuccessStatusCode)
                    throw new Exception($"Error: StatusCode: {response.StatusCode}; Reason: {response.ReasonPhrase}");

                var result = JsonConvert.DeserializeObject<T>(await response.Content.ReadAsStringAsync());
                return result;
            }
        }

        private async Task<R> ExecutePostRequest<R>(string route) where R : class
        {
            HttpContent content = new StringContent(JsonConvert.SerializeObject(string.Empty), Encoding.UTF8, _contentType);
            using (var response = await _httpClient.PostAsync(route, content))
            {
                if (!response.IsSuccessStatusCode)
                    throw new Exception($"Error: StatusCode: {response.StatusCode}; Reason: {response.ReasonPhrase}");

                var result = JsonConvert.DeserializeObject<R>(await response.Content.ReadAsStringAsync());
                return result;
            }
        }

        private async Task<R> ExecutePostRequest<R, B>(string route, B body) where R : class where B : class
        {
            HttpContent content = new StringContent(JsonConvert.SerializeObject(body), Encoding.UTF8, _contentType);
            using (var response = await _httpClient.PostAsync(route, content))
            {
                if (!response.IsSuccessStatusCode)
                    throw new Exception($"Error: StatusCode: {response.StatusCode}; Reason: {response.ReasonPhrase}");

                var result = JsonConvert.DeserializeObject<R>(await response.Content.ReadAsStringAsync());
                return result;
            }
        }
        #endregion
    }
}