/*
Technitium DNS Server
Copyright (C) 2024  Shreyas Zare (shreyas@technitium.com)

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace LogExporter.Strategy
{
    public class HttpExportStrategy : IExportStrategy
    {
        private readonly string _endpoint;
        private readonly string _method;
        private readonly Dictionary<string, string> _headers;
        private readonly HttpClient _httpClient;
        private bool disposedValue;

        public HttpExportStrategy(string endpoint, string method, Dictionary<string, string> headers)
        {
            _endpoint = endpoint;
            _method = method;
            _headers = headers;
            _httpClient = new HttpClient();
        }

        public async Task ExportLogsAsync(List<LogEntry> logs, CancellationToken cancellationToken = default)
        {
            var jsonLogs = new StringBuilder(logs.Count);
            foreach (var log in logs)
            {
                jsonLogs.AppendLine(log.ToString());
            }
            var request = new HttpRequestMessage
            {
                RequestUri = new Uri(_endpoint),
                Method = new HttpMethod(_method),
                Content = new StringContent(jsonLogs.ToString(), Encoding.UTF8, "application/json")
            };

            foreach (var header in _headers)
            {
                request.Headers.Add(header.Key, header.Value);
            }

            var response = await _httpClient.SendAsync(request, cancellationToken);
            if (!response.IsSuccessStatusCode)
            {
                throw new Exception($"Failed to export logs to {_endpoint}: {response.StatusCode}");
            }
        }

        protected virtual void Dispose(bool disposing)
        {
            if (!disposedValue)
            {
                if (disposing)
                {
                    _httpClient.Dispose();
                }

                disposedValue = true;
            }
        }

        public void Dispose()
        {
            // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
            Dispose(disposing: true);
            GC.SuppressFinalize(this);
        }
    }
}