using Discord;
using Discord.Commands;
using Discord.WebSocket;
using NadekoBot.Common;
using NadekoBot.Common.Collections;
using NadekoBot.Services;
using NadekoBot.Modules.Administration.Services;
using SixLabors.Fonts;
using SixLabors.ImageSharp;
using SixLabors.ImageSharp.Drawing;
using SixLabors.ImageSharp.Drawing.Processing;
using SixLabors.ImageSharp.Formats;
using SixLabors.ImageSharp.Formats.Png;
using SixLabors.ImageSharp.PixelFormats;
using SixLabors.ImageSharp.Processing;
using System.Globalization;
using System.IO;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Text.Json;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using NadekoBot.Common.Attributes;
using Color = Discord.Color;
using JsonSerializer = System.Text.Json.JsonSerializer;

namespace NadekoBot.Extensions;

public static class Extensions
{
    public static Regex UrlRegex = new Regex(@"^(https?|ftp)://(?<path>[^\s/$.?#].[^\s]*)$", RegexOptions.Compiled);

    public static TOut[] Map<TIn, TOut>(this TIn[] arr, Func<TIn, TOut> f)
        => Array.ConvertAll(arr, x => f(x));

    public static Task EditAsync(this IUserMessage msg, SmartText text)
        => text switch
        {
            SmartEmbedText set => msg.ModifyAsync(x =>
            {
                x.Embed = set.GetEmbed().Build();
                x.Content = set.PlainText?.SanitizeMentions() ?? "";
            }),
            SmartPlainText spt => msg.ModifyAsync(x =>
            {
                x.Content = spt.Text.SanitizeMentions();
                x.Embed = null;
            }),
            _ => throw new ArgumentOutOfRangeException(nameof(text))
        };
        
    public static Task<IUserMessage> SendAsync(this IMessageChannel channel, string plainText, Embed embed, bool sanitizeAll = false)
    {
        plainText = sanitizeAll
            ? plainText?.SanitizeAllMentions() ?? ""
            : plainText?.SanitizeMentions() ?? "";

        return channel.SendMessageAsync(plainText, embed: embed);
    }
        
    public static Task<IUserMessage> SendAsync(this IMessageChannel channel, SmartText text, bool sanitizeAll = false)
        => text switch
        {
            SmartEmbedText set => channel.SendAsync(set.PlainText, set.GetEmbed().Build(), sanitizeAll),
            SmartPlainText st => channel.SendAsync(st.Text, null, sanitizeAll),
            _ => throw new ArgumentOutOfRangeException(nameof(text))
        };

    public static List<ulong> GetGuildIds(this DiscordSocketClient client)
        => client.Guilds.Select(x => x.Id).ToList();

    /// <summary>
    /// Generates a string in the format HHH:mm if timespan is <= 2m.
    /// Generates a string in the format 00:mm:ss if timespan is less than 2m.
    /// </summary>
    /// <param name="span">Timespan to convert to string</param>
    /// <returns>Formatted duration string</returns>
    public static string ToPrettyStringHM(this TimeSpan span)
    {
        if (span < TimeSpan.FromMinutes(2))
            return $"{span:mm}m {span:ss}s";
        return $"{(int) span.TotalHours:D2}h {span:mm}m";
    }

    public static bool TryGetUrlPath(this string input, out string path)
    {
        var match = UrlRegex.Match(input);
        if (match.Success)
        {
            path = match.Groups["path"].Value;
            return true;
        }
        path = string.Empty;
        return false;
    }

    public static IEmote ToIEmote(this string emojiStr)
        => Emote.TryParse(emojiStr, out var maybeEmote)
            ? (IEmote)maybeEmote
            : new Emoji(emojiStr);

    // https://github.com/SixLabors/Samples/blob/master/ImageSharp/AvatarWithRoundedCorner/Program.cs
    public static IImageProcessingContext ApplyRoundedCorners(this IImageProcessingContext ctx, float cornerRadius)
    {
        Size size = ctx.GetCurrentSize();
        IPathCollection corners = BuildCorners(size.Width, size.Height, cornerRadius);

        ctx.SetGraphicsOptions(new GraphicsOptions()
        {
            Antialias = true,
            AlphaCompositionMode = PixelAlphaCompositionMode.DestOut // enforces that any part of this shape that has color is punched out of the background
        });

        foreach (var c in corners)
        {
            ctx = ctx.Fill(SixLabors.ImageSharp.Color.Red, c);
        }
        return ctx;
    }

    private static IPathCollection BuildCorners(int imageWidth, int imageHeight, float cornerRadius)
    {
        // first create a square
        var rect = new RectangularPolygon(-0.5f, -0.5f, cornerRadius, cornerRadius);

        // then cut out of the square a circle so we are left with a corner
        IPath cornerTopLeft = rect.Clip(new EllipsePolygon(cornerRadius - 0.5f, cornerRadius - 0.5f, cornerRadius));

        // corner is now a corner shape positions top left
        //lets make 3 more positioned correctly, we can do that by translating the original around the center of the image

        float rightPos = imageWidth - cornerTopLeft.Bounds.Width + 1;
        float bottomPos = imageHeight - cornerTopLeft.Bounds.Height + 1;

        // move it across the width of the image - the width of the shape
        IPath cornerTopRight = cornerTopLeft.RotateDegree(90).Translate(rightPos, 0);
        IPath cornerBottomLeft = cornerTopLeft.RotateDegree(-90).Translate(0, bottomPos);
        IPath cornerBottomRight = cornerTopLeft.RotateDegree(180).Translate(rightPos, bottomPos);

        return new PathCollection(cornerTopLeft, cornerBottomLeft, cornerTopRight, cornerBottomRight);
    }

    /// <summary>
    /// First 10 characters of teh bot token.
    /// </summary>
    public static string RedisKey(this IBotCredentials bc)
    {
        return bc.Token.Substring(0, 10);
    }

    public static async Task<string> ReplaceAsync(this Regex regex, string input, Func<Match, Task<string>> replacementFn)
    {
        var sb = new StringBuilder();
        var lastIndex = 0;

        foreach (Match match in regex.Matches(input))
        {
            sb.Append(input, lastIndex, match.Index - lastIndex)
                .Append(await replacementFn(match).ConfigureAwait(false));

            lastIndex = match.Index + match.Length;
        }

        sb.Append(input, lastIndex, input.Length - lastIndex);
        return sb.ToString();
    }

    public static void ThrowIfNull<T>(this T o, string name) where T : class
    {
        if (o is null)
            throw new ArgumentNullException(nameof(name));
    }

    public static bool IsAuthor(this IMessage msg, IDiscordClient client)
        => msg.Author?.Id == client.CurrentUser.Id;

    public static string RealSummary(this CommandInfo cmd, IBotStrings strings, ulong? guildId, string prefix)
        => string.Format(strings.GetCommandStrings(cmd.Name, guildId).Desc, prefix);

    public static string[] RealRemarksArr(this CommandInfo cmd, IBotStrings strings, ulong? guildId, string prefix)
        => Array.ConvertAll(strings.GetCommandStrings(cmd.MethodName(), guildId).Args,
            arg => GetFullUsage(cmd.Name, arg, prefix));

    public static string MethodName(this CommandInfo cmd)
        => ((NadekoCommandAttribute) cmd.Attributes.FirstOrDefault(x => x is NadekoCommandAttribute))?.MethodName
           ?? cmd.Name;
    // public static string RealRemarks(this CommandInfo cmd, IBotStrings strings, string prefix)
    //     => string.Join('\n', cmd.RealRemarksArr(strings, prefix));

    public static string GetFullUsage(string commandName, string args, string prefix)
        => $"{prefix}{commandName} {string.Format(args, prefix)}";

    public static IEmbedBuilder AddPaginatedFooter(this IEmbedBuilder embed, int curPage, int? lastPage)
    {
        if (lastPage != null)
            return embed.WithFooter($"{curPage + 1} / {lastPage + 1}");
        else
            return embed.WithFooter(curPage.ToString());
    }

    public static Color ToDiscordColor(this Rgba32 color)
        => new Color(color.R, color.G, color.B);
        
    public static IEmbedBuilder WithOkColor(this IEmbedBuilder eb) =>
        eb.WithColor(EmbedColor.Ok);

    public static IEmbedBuilder WithPendingColor(this IEmbedBuilder eb) =>
        eb.WithColor(EmbedColor.Pending);
        
    public static IEmbedBuilder WithErrorColor(this IEmbedBuilder eb) =>
        eb.WithColor(EmbedColor.Error);

    public static ReactionEventWrapper OnReaction(this IUserMessage msg, DiscordSocketClient client, Func<SocketReaction, Task> reactionAdded, Func<SocketReaction, Task> reactionRemoved = null)
    {
        if (reactionRemoved is null)
            reactionRemoved = _ => Task.CompletedTask;

        var wrap = new ReactionEventWrapper(client, msg);
        wrap.OnReactionAdded += (r) => { var _ = Task.Run(() => reactionAdded(r)); };
        wrap.OnReactionRemoved += (r) => { var _ = Task.Run(() => reactionRemoved(r)); };
        return wrap;
    }

    public static HttpClient AddFakeHeaders(this HttpClient http)
    {
        AddFakeHeaders(http.DefaultRequestHeaders);
        return http;
    }

    public static void AddFakeHeaders(this HttpHeaders dict)
    {
        dict.Clear();
        dict.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
        dict.Add("User-Agent", "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/14.0.835.202 Safari/535.1");
    }

    public static IMessage DeleteAfter(this IUserMessage msg, int seconds, ILogCommandService logService = null)
    {
        if (msg is null)
            return null;
            
        Task.Run(async () =>
        {
            await Task.Delay(seconds * 1000).ConfigureAwait(false);
            if(logService != null)
            {
                logService.AddDeleteIgnore(msg.Id);
            }
            try { await msg.DeleteAsync().ConfigureAwait(false); }
            catch { }
        });
        return msg;
    }

    public static ModuleInfo GetTopLevelModule(this ModuleInfo module)
    {
        while (module.Parent != null)
        {
            module = module.Parent;
        }
        return module;
    }

    public static void AddRange<T>(this HashSet<T> target, IEnumerable<T> elements) where T : class
    {
        foreach (var item in elements)
        {
            target.Add(item);
        }
    }

    public static void AddRange<T>(this ConcurrentHashSet<T> target, IEnumerable<T> elements) where T : class
    {
        foreach (var item in elements)
        {
            target.Add(item);
        }
    }

    public static double UnixTimestamp(this DateTime dt) 
        => dt.ToUniversalTime().Subtract(new DateTime(1970, 1, 1, 0, 0, 0)).TotalSeconds;

    public static async Task<IEnumerable<IGuildUser>> GetMembersAsync(this IRole role) =>
        (await role.Guild.GetUsersAsync(CacheMode.CacheOnly).ConfigureAwait(false)).Where(u => u.RoleIds.Contains(role.Id)) ?? Enumerable.Empty<IGuildUser>();

    public static string ToJson<T>(this T any, JsonSerializerOptions options = null) =>
        JsonSerializer.Serialize(any, options);

    /// <summary>
    /// Adds fallback fonts to <see cref="TextOptions"/>
    /// </summary>
    /// <param name="opts"><see cref="TextOptions"/> to which fallback fonts will be added to</param>
    /// <param name="fallback">List of fallback Font Families to add</param>
    /// <returns>The same <see cref="TextOptions"/> to allow chaining</returns>
    public static TextOptions WithFallbackFonts(this TextOptions opts, List<FontFamily> fallback)
    {
        foreach (var ff in fallback)
        {
            opts.FallbackFonts.Add(ff);
        }
        return opts;
    }

    /// <summary>
    /// Adds fallback fonts to <see cref="TextGraphicsOptions"/>
    /// </summary>
    /// <param name="opts"><see cref="TextGraphicsOptions"/> to which fallback fonts will be added to</param>
    /// <param name="fallback">List of fallback Font Families to add</param>
    /// <returns>The same <see cref="TextGraphicsOptions"/> to allow chaining</returns>
    public static TextGraphicsOptions WithFallbackFonts(this TextGraphicsOptions opts, List<FontFamily> fallback)
    {
        opts.TextOptions.WithFallbackFonts(fallback);
        return opts;
    }

    public static MemoryStream ToStream(this Image<Rgba32> img, IImageFormat format = null)
    {
        var imageStream = new MemoryStream();
        if (format?.Name == "GIF")
        {
            img.SaveAsGif(imageStream);
        }
        else
        {
            img.SaveAsPng(imageStream, new PngEncoder()
            {
                ColorType = PngColorType.RgbWithAlpha,
                CompressionLevel = PngCompressionLevel.BestCompression
            });
        }
        imageStream.Position = 0;
        return imageStream;
    }

    public static Stream ToStream(this IEnumerable<byte> bytes, bool canWrite = false)
    {
        var ms = new MemoryStream(bytes as byte[] ?? bytes.ToArray(), canWrite);
        ms.Seek(0, SeekOrigin.Begin);
        return ms;
    }

    public static IEnumerable<IRole> GetRoles(this IGuildUser user) =>
        user.RoleIds.Select(r => user.Guild.GetRole(r)).Where(r => r != null);

    public static async Task<IMessage> SendMessageToOwnerAsync(this IGuild guild, string message)
    {
        var ownerPrivate = await (await guild.GetOwnerAsync().ConfigureAwait(false)).GetOrCreateDMChannelAsync()
            .ConfigureAwait(false);

        return await ownerPrivate.SendMessageAsync(message).ConfigureAwait(false);
    }

    public static bool IsImage(this HttpResponseMessage msg) => IsImage(msg, out _);

    public static bool IsImage(this HttpResponseMessage msg, out string mimeType)
    {
        mimeType = msg.Content.Headers.ContentType?.MediaType;
        if (mimeType == "image/png"
            || mimeType == "image/jpeg"
            || mimeType == "image/gif")
        {
            return true;
        }
        return false;
    }

    public static long? GetImageSize(this HttpResponseMessage msg)
    {
        if (msg.Content.Headers.ContentLength is null)
        {
            return null;
        }

        return msg.Content.Headers.ContentLength / 1.MB();
    }

    public static string GetText(this IBotStrings strings, in LocStr str, ulong? guildId = null)
        => strings.GetText(str.Key, guildId, str.Params);
        
    public static string GetText(this IBotStrings strings, in LocStr str, CultureInfo culture)
        => strings.GetText(str.Key, culture, str.Params);
}