using System.Net.Http.Headers;
using System.Text;

namespace RadicadeServer.Radicade.Discord;













public static class ReportDiscord
{
	private static readonly HttpClient Http = CreateHttpClient();

	private static HttpClient CreateHttpClient()
	{
		var client = new HttpClient { Timeout = TimeSpan.FromSeconds(30) };
		client.DefaultRequestHeaders.UserAgent.ParseAdd("DiscordBot (https://radicade.app, 1.0)");
		return client;
	}


	public sealed record DiscordAttachment(string Filename, byte[] Data, string MimeType);

	public static void SendAsync(string webhookUrl, string content, DiscordPayload payload)
		=> SendAsync(webhookUrl, content, payload, null, null);

	public static void SendAsync(string webhookUrl, string content, DiscordPayload payload,
		IReadOnlyList<DiscordAttachment>? attachments, string? embedImageUrl = null)
	{
		if (string.IsNullOrWhiteSpace(webhookUrl)) return;

		_ = Task.Run(async () =>
		{
			try
			{
				using var response = attachments is { Count: > 0 }
					? await PostWithFilesAsync(webhookUrl, content, payload, attachments, embedImageUrl)
					: await PostJsonAsync(webhookUrl, content, payload, embedImageUrl);

				if (!response.IsSuccessStatusCode)
				{
					var errorBody = await response.Content.ReadAsStringAsync();
				}
			}
			catch (Exception)
			{
			}
		});
	}

	private static async Task<HttpResponseMessage> PostJsonAsync(string url, string content, DiscordPayload payload, string? embedImageUrl)
	{
		var body = DiscordPayloadJson.Build(payload, content, embedImageUrl);
		using var request = new HttpRequestMessage(HttpMethod.Post, url);
		request.Content = new StringContent(body, Encoding.UTF8, "application/json");
		return await Http.SendAsync(request);
	}

	private static async Task<HttpResponseMessage> PostWithFilesAsync(string url, string content, DiscordPayload payload,
		IReadOnlyList<DiscordAttachment> attachments, string? embedImageUrl)
	{
		var json = DiscordPayloadJson.Build(payload, content, embedImageUrl);
		using var form = new MultipartFormDataContent();
		form.Add(new StringContent(json, Encoding.UTF8, "application/json"), "payload_json");
		for (int i = 0; i < attachments.Count; i++)
		{
			var file = new ByteArrayContent(attachments[i].Data);
			file.Headers.ContentType = new MediaTypeHeaderValue(attachments[i].MimeType);
			form.Add(file, $"files[{i}]", attachments[i].Filename);
		}
		return await Http.PostAsync(url, form);
	}

	private static string Truncate(string value, int max)
	{
		if (string.IsNullOrEmpty(value)) return "";
		if (value.Length <= max) return value;
		var cut = max;
		if (char.IsHighSurrogate(value[cut - 1]) && cut < value.Length && char.IsLowSurrogate(value[cut]))
			cut--;
		return value[..cut];
	}
}