using System;
using System.Net.Http;
using System.Text;
using System.Threading;
using Newtonsoft.Json;
using Serilog;
using SyncEngine.Configuration;

namespace SyncEngine.MySql
{
    public interface IShopSyncLogApiClient
    {
        void PostLog(ShopSyncLogEntry entry);
    }

    public sealed class ShopSyncLogApiClient : IShopSyncLogApiClient, IDisposable
    {
        private static readonly TimeSpan RequestTimeout = TimeSpan.FromSeconds(30);
        private readonly SyncOptions _options;
        private readonly ILogger _logger;
        private readonly HttpClient _httpClient;
        private readonly bool _ownsHttpClient;

        public ShopSyncLogApiClient(SyncOptions options, ILogger logger)
            : this(options, logger, new HttpClient { Timeout = RequestTimeout }, ownsHttpClient: true)
        {
        }

        internal ShopSyncLogApiClient(SyncOptions options, ILogger logger, HttpClient httpClient, bool ownsHttpClient)
        {
            _options = options;
            _logger = logger;
            _httpClient = httpClient;
            _ownsHttpClient = ownsHttpClient;
        }

        public void PostLog(ShopSyncLogEntry entry)
        {
            var json = BuildPayloadJson(entry);
            using (var content = new StringContent(json, Encoding.UTF8, "application/json"))
            using (var request = new HttpRequestMessage(HttpMethod.Post, _options.ShopSyncApiUrl.Trim()))
            {
                request.Content = content;
                request.Headers.TryAddWithoutValidation("X-Shop-Sync-Key", _options.ShopSyncApiKey);

                var response = _httpClient.SendAsync(request, CancellationToken.None).GetAwaiter().GetResult();
                var body = response.Content.ReadAsStringAsync().GetAwaiter().GetResult();
                if (!response.IsSuccessStatusCode)
                {
                    _logger.Warning("shop-sync/log API returned {StatusCode}: {Body}", (int)response.StatusCode, body);
                    throw new InvalidOperationException(
                        "shop-sync/log API returned " + (int)response.StatusCode + ": " + body);
                }
            }
        }

        /// <summary>Serializes entry to CI4 API JSON (testable without HTTP).</summary>
        public static string BuildPayloadJson(ShopSyncLogEntry entry)
        {
            var payload = BuildPayload(entry);
            return JsonConvert.SerializeObject(payload);
        }

        public static object BuildPayload(ShopSyncLogEntry entry)
        {
            return new
            {
                status = entry.Status,
                source_reachable = entry.SourceReachable ? 1 : 0,
                products_upserted = entry.ProductsUpserted,
                products_withdrawn = entry.ProductsWithdrawn,
                run_started_at = FormatUtcDateTime(entry.RunStartedAt),
                run_finished_at = FormatUtcDateTime(entry.RunFinishedAt),
                message = string.IsNullOrEmpty(entry.Message) ? null : entry.Message
            };
        }

        private static string FormatUtcDateTime(DateTime value)
        {
            var utc = value.Kind == DateTimeKind.Utc ? value : value.ToUniversalTime();
            return utc.ToString("yyyy-MM-dd HH:mm:ss");
        }

        public void Dispose()
        {
            if (_ownsHttpClient)
            {
                _httpClient.Dispose();
            }
        }
    }
}