using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Threading;
using System.Threading.Tasks;
using GB5Shared.Telemetry;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;

namespace FrameworkBLL.Promotion
{
    public class PromotionExchangeClient : IPromotionExchangeClient
    {
        private readonly IHttpClientFactory _HttpFactory;
        private readonly IConfiguration _Configuration;
        private readonly ILogger<PromotionExchangeClient> _Logger;

        public PromotionExchangeClient(
            IHttpClientFactory httpFactory, IConfiguration configuration, ILogger<PromotionExchangeClient> logger)
        {
            _HttpFactory   = httpFactory;
            _Configuration = configuration;
            _Logger        = logger;
        }

        public async Task<int?> UploadAsync(byte[] packageBytes, string destinationEnvironmentCode, CancellationToken ct)
        {
            try
            {
                var http = NewClient();
                using var content = new MultipartFormDataContent
                {
                    { new StringContent(destinationEnvironmentCode), "destinationEnvironmentCode" }
                };
                var fileContent = new ByteArrayContent(packageBytes);
                fileContent.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
                content.Add(fileContent, "file", "package.gbpromo");

                using var response = await http.PostAsync("PromotionExchange/UploadPackage", content, ct)
                    .ConfigureAwait(false);
                response.EnsureSuccessStatusCode();

                var body = await response.Content.ReadFromJsonAsync<UploadResponse>(cancellationToken: ct)
                    .ConfigureAwait(false);
                return body?.packageId;
            }
            catch (Exception ex)
            {
                GB5Trace.RecordError(ex, "promotion-exchange-upload-failed");
                _Logger.LogWarning(ex, "PromotionExchange upload failed for destination {Destination}", destinationEnvironmentCode);
                return null;
            }
        }

        public async Task<IReadOnlyList<PromotionExchangePendingPackageDTO>> ListPendingAsync(CancellationToken ct)
        {
            try
            {
                var http = NewClient();
                var pending = await http.GetFromJsonAsync<List<PromotionExchangePendingPackageDTO>>(
                    "PromotionExchange/ListPendingPackages", ct).ConfigureAwait(false);
                return pending ?? new List<PromotionExchangePendingPackageDTO>();
            }
            catch (Exception ex)
            {
                GB5Trace.RecordError(ex, "promotion-exchange-list-pending-failed");
                _Logger.LogWarning(ex, "PromotionExchange list-pending failed");
                return Array.Empty<PromotionExchangePendingPackageDTO>();
            }
        }

        public async Task<byte[]?> DownloadAsync(int packageId, CancellationToken ct)
        {
            try
            {
                var http = NewClient();
                using var response = await http.GetAsync($"PromotionExchange/DownloadPackage/{packageId}", ct)
                    .ConfigureAwait(false);
                response.EnsureSuccessStatusCode();
                return await response.Content.ReadAsByteArrayAsync(ct).ConfigureAwait(false);
            }
            catch (Exception ex)
            {
                GB5Trace.RecordError(ex, "promotion-exchange-download-failed");
                _Logger.LogWarning(ex, "PromotionExchange download failed for PackageId {PackageId}", packageId);
                return null;
            }
        }

        private HttpClient NewClient()
        {
            var http = _HttpFactory.CreateClient("promotionexchange");
            var baseUrl = _Configuration["PromotionExchange:BaseUrl"] ?? "http://localhost:5330";
            http.BaseAddress = new Uri(baseUrl.TrimEnd('/') + "/");
            var apiKey = _Configuration["PromotionExchange:ApiKey"] ?? string.Empty;
            http.DefaultRequestHeaders.Remove("X-Api-Key");
            http.DefaultRequestHeaders.Add("X-Api-Key", apiKey);
            return http;
        }

        private sealed class UploadResponse
        {
            public int packageId { get; set; }
        }
    }
}