using System.Collections.Concurrent;
using System.Text.Json;
using SkyBot.Helpers;
using SkyBot.Models;
using Valour.Sdk.Models;
using Valour.Shared.Models;

namespace SkyBot.Commands
{
    public class Happy : ICommand
    {
        public string Name => "happy";
        public string[] Aliases => Array.Empty<string>();
        public string Description => "Express happiness with a random gif.";
        public string Section => "RP";
        public string Usage => "happy [@user]";

        private static readonly HttpClient _http = new()
        {
            DefaultRequestHeaders = { { "User-Agent", "SkyBot/1.0 (https://skyjoshua.xyz, https://valour.gg)" } }
        };

        public async Task Execute(CommandContext ctx)
        {
            ConcurrentDictionary<long, Channel> channelCache = ctx.ChannelCache;
            long channelId = ctx.ChannelId;

            if (!channelCache.TryGetValue(channelId, out var channel)) return;

            await channel.SendIsTyping();

            string json;
            try
            {
                json = await _http.GetStringAsync("https://nekos.best/api/v2/happy");
            }
            catch
            {
                await MessageHelper.ReplyAsync(ctx, channel, "Could not fetch a happy gif. Try again later.");
                return;
            }

            using var doc = JsonDocument.Parse(json);
            var results = doc.RootElement.GetProperty("results");
            string gifUrl = results[0].GetProperty("url").GetString()!;

            byte[] gifBytes;
            try
            {
                gifBytes = await _http.GetByteArrayAsync(gifUrl);
            }
            catch
            {
                await MessageHelper.ReplyAsync(ctx, channel, "Could not download the happy gif. Try again later.");
                return;
            }

            int width = 0, height = 0;
            if (gifBytes.Length >= 10)
            {
                width  = gifBytes[6] | (gifBytes[7] << 8);
                height = gifBytes[8] | (gifBytes[9] << 8);
            }

            string cdnUrl;
            try
            {
                using var form = new MultipartFormDataContent();
                using var fileContent = new ByteArrayContent(gifBytes);
                fileContent.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("image/gif");
                form.Add(fileContent, "file", "happy.gif");

                var uploadResult = await ctx.Planet.Node.PostMultipartDataWithResponse<string>("upload/image", form);
                if (!uploadResult.Success)
                {
                    await MessageHelper.ReplyAsync(ctx, channel, "Could not upload the happy gif. Try again later.");
                    return;
                }
                cdnUrl = uploadResult.Data!;
            }
            catch
            {
                await MessageHelper.ReplyAsync(ctx, channel, "Could not upload the happy gif. Try again later.");
                return;
            }

            string? target = null;
            if (ctx.Message.ReplyToId is not null)
            {
                var replied = await ctx.Message.FetchReplyMessageAsync();
                if (replied is not null)
                {
                    var author = await replied.FetchAuthorAsync();
                    if (author is not null)
                        target = author.Name;
                }
            }
            if (target is null && ctx.Args.Length > 0)
                target = string.Join(" ", ctx.Args);

            string sender = ctx.Member.Nickname ?? ctx.Member.User?.Name ?? "Unknown";
            string text = target is not null
                ? $"{sender} is happy with {target}!"
                : $"{sender} is happy!";

            var attachment = new MessageAttachment(MessageAttachmentType.Image)
            {
                Location = cdnUrl,
                MimeType = "image/gif",
                FileName = "happy.gif",
                Width = width,
                Height = height
            };

            await MessageHelper.ReplyAsync(ctx, channel, text, [attachment]);
        }
    }
}