using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.Json.Serialization;
using System.Threading.Tasks;
using Avalonia.Controls;
using Avalonia.Media;
using Avalonia.Media.Imaging;
using Avalonia.Platform;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

namespace CrossLangDevStudio;

public static class CrossLangFileExtensions
{
    public static void Skip(this Stream strm, long bytes)
    {
        byte[] data = new byte[1024];
        if (strm.CanSeek)
            strm.Position += bytes;
        else
        {
            do
            {
                int read = strm.Read(data, 0, (int)Math.Min(bytes, data.LongLength));
                if (read == 0) return;
                bytes -= read;
            } while (bytes != 0);
        }
    }
}

public class CrossLangFile
{
    const string CROSSVM = "TCROSSVM";
    public void Load(string path)
    {
        if (File.Exists(path))
            using (var strm = File.OpenRead(path))
                Load(strm);
    }



    public void Load(Stream strm)
    {
        byte[] header = new byte[18];
        strm.ReadExactly(header);
        for (int i = 0; i < CROSSVM.Length; i++)
        {
            if (header[i] != (byte)CROSSVM[i]) throw new Exception("Invalid signature");
        }

        Version = new CrossLangVersion(header, 13);

        uint ReadInt()
        {
            strm.ReadExactly(header, 0, 4);

            if (BitConverter.IsLittleEndian)
                Array.Reverse(header, 0, 4);
            return BitConverter.ToUInt32(header, 0);
        }

        void ReadString()
        {
            uint length = ReadInt();
            byte[] data = new byte[length];
            strm.ReadExactly(data, 0, data.Length);
            Strings.Add(Encoding.UTF8.GetString(data));
        }
        string ReadSectionName()
        {
            strm.ReadExactly(header, 0, 4);
            return Encoding.UTF8.GetString(header, 0, 4);
        }

        string GetString()
        {
            uint index = ReadInt();
            return Strings[(int)index];
        }



        uint count = ReadInt();
        for (uint i = 0; i < count; i++)
        {
            string section = ReadSectionName();
            uint sectionSize = ReadInt();
            switch (section)
            {
                case "FUNS":
                    {
                        uint chks = ReadInt();
                        for (uint j = 0; j < chks; j++)
                        {
                            uint fnParts = ReadInt();

                            string[] parts = new string[fnParts];
                            for (uint k = 0; k < fnParts; k++)
                            {
                                parts[k] = GetString();
                            }
                            uint fid = ReadInt();
                            Functions.Add(new CrossLangFunction(parts, fid));
                        }
                    }
                    break;
                case "CHKS":
                    {
                        uint chks = ReadInt();
                        for (uint j = 0; j < chks; j++)
                        {
                            uint fnParts = ReadInt();

                            string[] parts = new string[fnParts];
                            for (uint k = 0; k < fnParts; k++)
                            {
                                parts[k] = GetString();
                            }

                            uint len = ReadInt();
                            strm.Skip(len);
                            Chunks.Add(parts);
                        }
                    }
                    break;
                case "STRS":
                    {
                        uint theCount = ReadInt();
                        for (uint j = 0; j < theCount; j++)
                        {
                            ReadString();
                        }
                    }
                    break;
                case "NAME":
                    Name = GetString();
                    break;
                case "INFO":
                    Info = GetString();
                    break;
                case "ICON":
                    Icon = (int)ReadInt();
                    break;
                case "RESO":
                    byte[] data = new byte[sectionSize];
                    strm.ReadExactly(data, 0, data.Length);
                    Resources.Add(data);
                    break;
                case "DEPS":
                    if (sectionSize == 9)
                    {
                        string name = GetString();
                        strm.ReadExactly(header, 0, 5);
                        var version = new CrossLangVersion(header);
                        Dependencies.Add(new CrossLangDependency() { Name = name, Version = version });
                    }
                    break;
                case "CLSS":
                    {
                        uint chks = ReadInt();
                        for (uint j = 0; j < chks; j++)
                        {
                            string docs = GetString();
                            uint namePartLen = ReadInt();
                            string[] nameParts = new string[namePartLen];
                            for (uint k = 0; k < namePartLen; k++)
                            {
                                nameParts[k] = GetString();
                            }
                            string name = string.Join(".", nameParts);
                            uint inhPartLen = ReadInt();
                            string[] inhParts = new string[inhPartLen];
                            for (uint k = 0; k < inhPartLen; k++)
                            {
                                inhParts[k] = GetString();
                            }
                            string inh = string.Join(".", inhParts);
                            uint entCount = ReadInt();
                            CrossLangClassEntry[] entries = new CrossLangClassEntry[entCount];
                            for (uint k = 0; k < entCount; k++)
                            {
                                /*
      Ensure(stream,main_header,1);
                      uint8_t sig = main_header[0];
                      ent.isAbstract = (sig & 0b00001000) != 0;
                      ent.isFunction = (sig & 0b00000100) == 0;
                      ent.modifier = (TClassModifier)(sig & 3);
                      ent.documentation = GetString(stream);
                      ent.name = GetString(stream);
                      uint32_t arglen = EnsureInt(stream);
                      for(uint32_t l = 0; l < arglen; l++)
                          ent.args.push_back(GetString(stream));
                      ent.chunkId = EnsureInt(stream);
                      cls.entry.push_back(ent);
  */
                                int sig = strm.ReadByte();

                                if (sig == -1) throw new EndOfStreamException("Could not read flags byte");

                                bool isAbstract = ((byte)sig & 0b00001000) != 0;
                                bool isFunction = ((byte)sig & 0b00000100) == 0;
                                CrossLangClassEntryModifier modifier = (CrossLangClassEntryModifier)(sig & 3);
                                string ent_doc = GetString();
                                string ent_name = GetString();
                                uint arglen = ReadInt();
                                string[] ent_args = new string[arglen];
                                for (uint l = 0; l < arglen; l++)
                                {
                                    ent_args[l] = GetString();
                                }
                                uint chunkId = ReadInt();

                                entries[k] = new CrossLangClassEntry(isAbstract, isFunction, modifier, ent_doc, ent_name, ent_args, chunkId);
                            }
                            Classes.Add(new CrossLangClass(docs, nameParts, name, inhParts, inh, entries));
                        }
                    }
                    break;
                default:
                    strm.Skip(sectionSize);
                    break;
            }
        }

    }
    public string Name { get; private set; } = "";
    public CrossLangVersion Version { get; private set; }

    public string Info { get; private set; } = "";

    public int Icon { get; private set; } = -1;

    public CrossLangInfo InfoObject => JsonConvert.DeserializeObject<CrossLangInfo>(Info) ?? new CrossLangInfo();

    public Bitmap GetIcon(int height = 128)
    {
        using (Stream strm = (Icon > -1 && Icon < Resources.Count) ? new MemoryStream(Resources[Icon], false) : AssetLoader.Open(new Uri("avares://CrossLangDevStudio/Assets/crosslang.png")))
        {
            return Bitmap.DecodeToHeight(strm, height);
        }
    }

    internal string GetPrettyName()
    {
        var info = InfoObject;
        if (info is not null)
        {
            if (!string.IsNullOrWhiteSpace(info.ShortNamePretty)) return info.ShortNamePretty;
            if (!string.IsNullOrWhiteSpace(info.ShortName)) return info.ShortName;
        }
        return this.Name;
    }

    public List<string> Strings { get; } = new List<string>();

    public List<byte[]> Resources { get; } = new List<byte[]>();

    public List<CrossLangDependency> Dependencies { get; } = new List<CrossLangDependency>();

    public List<CrossLangFunction> Functions { get; } = new List<CrossLangFunction>();
    public List<CrossLangClass> Classes { get; } = new List<CrossLangClass>();
    public List<string[]> Chunks { get; } = new List<string[]>();
    
}
public class CrossLangClass(string doc, string[] nameParts, string name, string[] inhParts, string inh, CrossLangClassEntry[] ents)
{
    public string Documentation => doc;

    public string[] NameParts => nameParts;
    public string Name => name;

    public string[] InheritParts => inhParts;

    public string Inherit => inh;

    public CrossLangClassEntry[] Entries => ents;
}
public enum CrossLangClassEntryModifier
{
    Private,
    Protected,
    Public,
    Static
}
public class CrossLangClassEntry(bool isAbstract, bool isFunction, CrossLangClassEntryModifier modifier, string documentation, string name, string[] args, uint chunkId)
{
    public bool IsAbstract => isAbstract;

    public bool IsFunction => isFunction;

    public CrossLangClassEntryModifier Modifier => modifier;

    public string Documentation => documentation;
    public string Name => name;

    public string[] Arguments => args;

    public uint ChunkId => chunkId;


    /*
        Ensure(stream,main_header,1);
                        uint8_t sig = main_header[0];
                        ent.isAbstract = (sig & 0b00001000) != 0;
                        ent.isFunction = (sig & 0b00000100) == 0;
                        ent.modifier = (TClassModifier)(sig & 3);
                        ent.documentation = GetString(stream);
                        ent.name = GetString(stream);
                        uint32_t arglen = EnsureInt(stream);
                        for(uint32_t l = 0; l < arglen; l++)
                            ent.args.push_back(GetString(stream));
                        ent.chunkId = EnsureInt(stream);
                        cls.entry.push_back(ent);
    */
}

public class CrossLangFunction(string[] nameParts, uint chunkId)
{
    public string[] NameParts => nameParts;
    public uint ChunkId => chunkId;
}

public class CrossLangConfig
{
    [JsonProperty("name")]
    public string? Name { get; set; }

    [JsonProperty("version")]
    public CrossLangVersion Version { get; set; }

    [JsonProperty("dependencies")]
    public List<CrossLangDependency> Dependencies { get; set; } = new List<CrossLangDependency>();

    [JsonProperty("info")]
    public CrossLangInfo Info { get; set; } = new CrossLangInfo();

    [JsonProperty("project_dependencies")]
    public List<string> ProjectDependencies { get; set; } = new List<string>();

    [JsonProperty("icon")]
    public string? Icon { get; set; }
}


public class CrossLangInfo
{
    [JsonProperty("maintainer")]
    public string? Maintainer { get; set; } //Not checked when building project
    [JsonProperty("type")]
    public string? Type { get; set; } //gets checked whether it is compile_tool by build tool, possible values are in file: project_types.txt
    [JsonProperty("repo")]
    public string? Repoository { get; set; } //optional, is the place where the code is stored
    [JsonProperty("homepage")]
    public string? HomePage { get; set; } //optional, is the website for the project
    [JsonProperty("license")]
    public string? License { get; set; } //optional, but recommended to tell people what the license is
    [JsonProperty("description")]
    public string? Description { get; set; } //optional but tells people about the package

    [JsonProperty("short_name")]
    public string? ShortName { get; set; }

    public string? ToolName { get; set; }

    [JsonProperty("short_name_pretty")]
    public string? ShortNamePretty { get; set; }

    [JsonProperty("template_project_dependencies")]
    public JToken? TemplateDependencies { get; set; }

    [JsonProperty("template_info")]
    public JToken? TemplateInfo { get; set; }
    [JsonProperty("template_extra_text_ftles")]
    public JToken? TemplateExtraTextFiles { get; set; }
    [JsonProperty("template_ignored_files")]
    public JToken? TemplateIgnoredFiles { get; set; }
}

public class CrossLangDependency
{
    [JsonProperty("name")]
    public string Name { get; set; } = "";
    [JsonProperty("version")]
    public CrossLangVersion Version { get; set; }

}

public enum CrossLangVersionStage
{
    Development = 0,
    Alpha = 1,
    Beta = 2,
    Production = 3
}
public class CrossLangVersionConverter : Newtonsoft.Json.JsonConverter<CrossLangVersion>
{
    public override CrossLangVersion ReadJson(JsonReader reader, Type objectType, CrossLangVersion existingValue, bool hasExistingValue, JsonSerializer serializer)
    {
        string? s = reader.Value as string;
        if (!string.IsNullOrWhiteSpace(s))
        {

            if (CrossLangVersion.TryParse(s, out var version)) return version;

        }

        if (hasExistingValue)
            return existingValue;
        return new CrossLangVersion();
    }

    public override void WriteJson(JsonWriter writer, CrossLangVersion value, JsonSerializer serializer)
    {
        writer.WriteValue(value.ToString());
    }
}
[Newtonsoft.Json.JsonConverter(typeof(CrossLangVersionConverter))]
public struct CrossLangVersion : IComparable<CrossLangVersion>, IComparable
{
    public void CopyTo(byte[] data, int offset = 0)
    {
        if (offset + 5 > data.Length) throw new IndexOutOfRangeException("Cannot write outside of array");
        data[offset + 0] = Major;
        data[offset + 1] = Minor;
        data[offset + 2] = Patch;
        data[offset + 3] = (byte)(BuildAndStage >> 8);
        data[offset + 4] = (byte)(BuildAndStage & 0xFF);
    }
    public byte[] ToArray()
    {
        byte[] data = new byte[5];
        CopyTo(data);
        return data;
    }
    public static bool TryParse(string str, out CrossLangVersion version)
    {
        var dashPart = str.Split(new char[] { '-' }, 2, StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries);
        byte major = 1;
        byte minor = 0;
        byte patch = 0;
        ushort build = 0;
        CrossLangVersionStage stage = CrossLangVersionStage.Development;
        if (dashPart.Length >= 1)
        {

            var dotPart = dashPart[0].Split(new char[] { '.' }, 4, StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries);
            if (dotPart.Length > 0)
            {
                if (!byte.TryParse(dotPart[0], out major))
                {
                    version = new CrossLangVersion();
                    return false;
                }
                if (dotPart.Length > 1 && !byte.TryParse(dotPart[1], out minor))
                {
                    version = new CrossLangVersion();
                    return false;
                }
                if (dotPart.Length > 2 && !byte.TryParse(dotPart[2], out patch))
                {
                    version = new CrossLangVersion();
                    return false;
                }
                if (dotPart.Length > 3 && !ushort.TryParse(dotPart[3], out build))
                {
                    version = new CrossLangVersion();
                    return false;
                }
                if (dashPart.Length == 2)
                {
                    switch (dashPart[1])
                    {
                        case "dev":
                            stage = CrossLangVersionStage.Development;
                            break;
                        case "alpha":
                            stage = CrossLangVersionStage.Alpha;
                            break;
                        case "beta":
                            stage = CrossLangVersionStage.Beta;
                            break;
                        case "prod":
                            stage = CrossLangVersionStage.Production;
                            break;
                        default:
                            version = new CrossLangVersion();
                            return false;
                    }
                }

                version = new CrossLangVersion(major, minor, patch, build, stage);
                return true;
            }




        }

        version = new CrossLangVersion();

        return false;



    }
    public CrossLangVersion()
    {

    }
    public CrossLangVersion(byte major, byte minor, byte patch, ushort build, CrossLangVersionStage stage)
    {
        Major = major;
        Minor = minor;
        Patch = patch;
        Build = build;
        Stage = stage;
    }
    public CrossLangVersion(byte[] data, int offset = 0)
    {
        if (offset + 5 > data.Length) return;

        Major = data[offset + 0];
        Minor = data[offset + 1];
        Patch = data[offset + 2];
        ushort build = (ushort)(data[offset + 3] << 8 | data[offset + 4]);
        Build = (ushort)(build >> 2);
        Stage = (CrossLangVersionStage)(build & 3);
    }
    public byte Major { get; set; } = 1;
    public byte Minor { get; set; } = 0;
    public byte Patch { get; set; } = 0;

    public ushort Build { get; set; } = 0;

    public static CrossLangVersion OnePointZeroProd => new CrossLangVersion() { Major = 1, Minor = 0, Patch = 0, Build = 0, Stage = CrossLangVersionStage.Production };

    public CrossLangVersionStage Stage { get; set; } = CrossLangVersionStage.Development;

    public ushort BuildAndStage => (ushort)(Build << 2 | (ushort)Stage);

    public ulong AsInteger => (ulong)((ulong)Major << 32 | (ulong)Minor << 24 | (ulong)Patch << 16 | (ulong)BuildAndStage);

    public int CompareTo(CrossLangVersion other)
    {
        return AsInteger.CompareTo(other.AsInteger);
    }

    public int CompareTo(object? obj)
    {
        if (obj is CrossLangVersion oth)
            return CompareTo(oth);

        return 1;
    }

    public override string ToString()
    {
        string stage = "dev";
        switch (Stage)
        {
            case CrossLangVersionStage.Development:
                stage = "dev";
                break;
            case CrossLangVersionStage.Alpha:
                stage = "alpha";
                break;
            case CrossLangVersionStage.Beta:
                stage = "beta";
                break;
            case CrossLangVersionStage.Production:
                stage = "prod";
                break;
        }
        return $"{Major}.{Minor}.{Patch}.{Build}-{stage}";
    }
}