using System.Text;
using System.Text.Json;

using FabApprovalWorkerService.Models;

using static System.Net.Mime.MediaTypeNames;

namespace FabApprovalWorkerService.Services;

public interface IMonInWorkerClient {
    void PostAverage(string metricName, double metricValue);
    void PostCount(string metricName, double metricValue);
    void PostStatus(string statusName, StatusValue statusValue);
}

public class MonInWorkerClient : IMonInWorkerClient {

    private readonly IHttpClientFactory _httpClientFactory;
    private readonly IConfiguration _config;
    private readonly ILogger<MonInWorkerClient> _logger;

    private readonly string _baseUrl;
    private readonly int _retryLimit = -1;
    private readonly int _backoffInSeconds = -1;

    private readonly string _resource;

    public MonInWorkerClient(IHttpClientFactory httpClientFactory,
                             IConfiguration config,
                             ILogger<MonInWorkerClient> logger) {
        _httpClientFactory = httpClientFactory;
        if (_httpClientFactory is null) throw new ArgumentNullException("IHttpClientFactory not injected");

        _config = config ?? 
            throw new ArgumentNullException("IConfiguration not injected");

        _logger = logger ?? 
            throw new ArgumentNullException("ILogger not injected");

        _baseUrl = Environment.GetEnvironmentVariable("MonInWorkerUrl") ?? 
            throw new ArgumentNullException("MonInWorkerUrl environment variable not found");

        if (!Int32.TryParse(Environment.GetEnvironmentVariable("MonInRetries"), out _retryLimit))
            throw new ArgumentNullException("Valid MonInRetries environment variable not found");

        if (!Int32.TryParse(Environment.GetEnvironmentVariable("MonInBackoffSeconds"), out _backoffInSeconds))
            throw new ArgumentNullException("Valid MonInBackoffSeconds environment varialbe not found");

        _resource = Environment.GetEnvironmentVariable("FabApprovalWorkerServiceMonInResource") ??
            throw new ArgumentNullException("FabApprovalWorkerServiceMonInResource environment variable not found");
    }

    public async void PostStatus(string statusName, StatusValue statusValue) {
        string url = _baseUrl + "status";

        _logger.LogInformation("Attempting to send MonIn status request for resource {0} with name {1} and value {2} to url {3}",
                               _resource,
                               statusName,
                               statusValue.ToString(),
                               url);

        try {
            bool success = false;
            int retries = _retryLimit;
            while (!success && retries > 0) {
                Task.Delay(TimeSpan.FromSeconds((_retryLimit - retries) * _backoffInSeconds)).Wait();

                HttpClient httpClient = _httpClientFactory.CreateClient();

                RawMonInStatusRequest statusRequest = new RawMonInStatusRequest() {
                    resource = _resource,
                    dateTime = DateTime.Now,
                    statusName = statusName,
                    statusValue = statusValue.ToString()
                };

                StringContent statusRequestJson = new StringContent(JsonSerializer.Serialize(statusRequest),
                                                          Encoding.UTF8,
                                                          Application.Json);
                using HttpResponseMessage httpResponseMessage =
                    await httpClient.PostAsync(url, statusRequestJson);

                success = httpResponseMessage.IsSuccessStatusCode;
                retries--;
            }
        } catch (Exception ex) {
            _logger.LogError("An exception occurred when attempting to send MonIn status request for resource {0} with name {1} and value {2} to url {3}. Exception: {4}",
                             _resource,
                             statusName,
                             statusValue.ToString(),
                             url,
                             ex.Message);
        }
    }

    public async void PostCount(string metricName, double metricValue) {
        string url = _baseUrl + "count";

        _logger.LogInformation("Attempting to send MonIn count request for resource {0} with name {1} and value {2} to url {3}",
                               _resource,
                               metricName,
                               metricValue,
                               url);

        try {
            bool success = false;
            int retries = _retryLimit;
            while (!success && retries > 0) {
                Task.Delay(TimeSpan.FromSeconds((_retryLimit - retries) * _backoffInSeconds)).Wait();

                HttpClient httpClient = _httpClientFactory.CreateClient();

                MonInMetricRequest metricRequest = new MonInMetricRequest() { 
                    resource = _resource,
                    dateTime = DateTime.Now,
                    metricName = metricName,
                    metricValue = metricValue
                };

                StringContent metricRequestJson = new StringContent(JsonSerializer.Serialize(metricRequest),
                                                          Encoding.UTF8,
                                                          Application.Json);
                using HttpResponseMessage httpResponseMessage =
                    await httpClient.PostAsync(url, metricRequestJson);

                success = httpResponseMessage.IsSuccessStatusCode;
                retries--;
            }
        } catch (Exception ex) {
            _logger.LogError("An exception occurred when attempting to send MonIn count request for resource {0} with name {1} and value {2} to url {3}. Exception: {4}",
                             _resource,
                             metricName,
                             metricValue,
                             url,
                             ex.Message);
        }
    }

    public async void PostAverage(string metricName, double metricValue) {
        string url = _baseUrl + "average";

        _logger.LogInformation("Attempting to send MonIn average request for resource {0} with name {1} and value {2} to url {3}",
                               _resource,
                               metricName,
                               metricValue,
                               url);

        try {
            bool success = false;
            int retries = _retryLimit;
            while (!success && retries > 0) {
                Task.Delay(TimeSpan.FromSeconds((_retryLimit - retries) * _backoffInSeconds)).Wait();

                HttpClient httpClient = _httpClientFactory.CreateClient();

                MonInMetricRequest metricRequest = new MonInMetricRequest() {
                    resource = _resource,
                    dateTime = DateTime.Now,
                    metricName = metricName,
                    metricValue = metricValue
                };

                StringContent metricRequestJson = new StringContent(JsonSerializer.Serialize(metricRequest),
                                                          Encoding.UTF8,
                                                          Application.Json);
                using HttpResponseMessage httpResponseMessage =
                    await httpClient.PostAsync(url, metricRequestJson);

                success = httpResponseMessage.IsSuccessStatusCode;
                retries--;
            }
        } catch (Exception ex) {
            _logger.LogError("An exception occurred when attempting to send MonIn average request for resource {0} with name {1} and value {2} to url {3}. Exception: {4}",
                             _resource,
                             metricName,
                             metricValue,
                             url,
                             ex.Message);
        }
    }
}