using System;
using System.Collections.Generic;
using System.IO;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;
using Newtonsoft.Json;

namespace RocketDiscordService
{
    public class Discordo : IDisposable
    {
        private readonly HttpClient _httpClient;
        private readonly string _webHookUrl;

        public Discordo(string webHookUrl)
        {
            _httpClient = new HttpClient();
            _webHookUrl = webHookUrl;
        }

        public async Task<string> SendMessage(DiscordMessage discordMessage)
        {
            var dataContent = CreateFormDataWithPayload(discordMessage);
            return await SendMessage(dataContent);
        }

        public async Task<string> SendMessage(DiscordMessage discordMessage, List<FileInfo> files)
        {
            var dataContent = CreateFormDataWithPayload(discordMessage);

            foreach (var fileInfo in files)
            {
                dataContent.Add(new StreamContent(File.OpenRead(fileInfo.FullName)),
                    Path.GetFileNameWithoutExtension(fileInfo.Name), fileInfo.Name);
            }

            return await SendMessage(dataContent);
        }

        public async Task<string> SendMessage(DiscordMessage discordMessage,
            List<(byte[] Buffer, string FileName, string FileNameWithExtension)> files)
        {
            var dataContent = CreateFormDataWithPayload(discordMessage);

            foreach (var tuple in files)
            {
                dataContent.Add(new ByteArrayContent(tuple.Buffer, 0, tuple.Buffer.Length), tuple.FileName,
                    tuple.FileNameWithExtension);
            }

            return await SendMessage(dataContent);
        }

        private MultipartFormDataContent CreateFormDataWithPayload(DiscordMessage discordMessage)
        {
            MultipartFormDataContent dataContent = new MultipartFormDataContent();
            dataContent.Headers.ContentType.MediaType = "multipart/form-data";
            var payloadJson = JsonConvert.SerializeObject(discordMessage);
            dataContent.Add(new StringContent(payloadJson)
            {
                Headers =
                {
                    ContentType = new MediaTypeHeaderValue("application/json")
                }
            }, "payload_json");

            return dataContent;
        }

        private async Task<string> SendMessage(HttpContent content)
        {
            var response = await _httpClient.PostAsync(_webHookUrl, content);
            content.Dispose();
            return await response.Content.ReadAsStringAsync();
        }

        public void Dispose()
        {
            _httpClient?.Dispose();
        }
    }
}