using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using CommandLine;
using YamlDotNet.Core;
using YamlDotNet.Serialization;

namespace ArcToolkitCLI.Commands.Converters
{
    [Verb("mate", HelpText = "Convert MATE files into YAML and back")]
    public class MateConverter : BaseConverter
    {
        private const string MATE_TAG = "CM3D2_MATERIAL";

        private readonly Dictionary<string, Type> mappingTypes;

        public MateConverter()
        {
            Converters = new Dictionary<string, Func<string, int>>
            {
                [".mate"] = MateToYaml,
                [".yaml"] = YamlToMate
            };

            mappingTypes = GetType().GetNestedTypes(BindingFlags.NonPublic).Select(t => new
                {
                    type = t,
                    attrs = t.GetCustomAttributes(typeof(TagAttribute), true).Cast<TagAttribute>().ToArray()
                })
                .Where(d => d.attrs.Length != 0)
                .ToDictionary(d => $"!{d.attrs.First().Tag}", d => d.type);
        }

        private int YamlToMate(string file)
        {
            var fileName = Path.GetFileNameWithoutExtension(file);

            if (!fileName.ToLowerInvariant().EndsWith(".mate"))
            {
                Console.WriteLine($"Filename of {file} must have .mate.yaml extension! Skipping...");
                return 0;
            }

            var db = new DeserializerBuilder();

            foreach (var kv in mappingTypes)
                db.WithTagMapping(kv.Key, kv.Value);

            var deserializer = db.Build();

            MateFile data;
            try
            {
                data = deserializer.Deserialize<MateFile>(new StreamReader(file, Encoding.UTF8));
            }
            catch (YamlException e)
            {
                Console.WriteLine($"Failed to read YAML file because {e.Message}: {e.InnerException?.Message}");
                return 1;
            }

            using var bw =
                new BinaryWriter(File.Create(Path.Combine(Output, fileName)),
                    Encoding.UTF8);

            data.Serialize(bw);

            return 0;
        }

        private int MateToYaml(string file)
        {
            using var br = new BinaryReader(File.OpenRead(file), Encoding.UTF8);
            var tag = br.ReadString();
            if (tag != MATE_TAG)
            {
                Console.WriteLine("Provided file is not a valid MATE file!");
                return 1;
            }

            var mateFile = new MateFile
            {
                Version = br.ReadInt32(),
                Path = br.ReadString(),
                Name = br.ReadString(),
                ShaderName = br.ReadString(),
                DefMaterial = br.ReadString(),
                ShaderProperties = new List<ShaderVariable>()
            };

            while (true)
            {
                var prop = br.ReadString();

                if (prop == "end")
                {
                    mateFile.ShaderProperties.Add(new EndTag());
                    break;
                }
                
                // TODO: Clean up

                var paramName = br.ReadString();
                ShaderVariable sVar;
                switch (prop)
                {
                    case "tex":
                        var texType = br.ReadString();
                        sVar = texType switch
                        {
                            "null" => new TexNullVar(),
                            "tex2d" => new Tex2DVar
                            {
                                TextureName = br.ReadString(),
                                Path = br.ReadString(),
                                Offset = new Vec2
                                {
                                    X = br.ReadSingle(),
                                    Y = br.ReadSingle()
                                },
                                Scale = new Vec2
                                {
                                    X = br.ReadSingle(),
                                    Y = br.ReadSingle()
                                }
                            },
                            "texRT" => new TexRTVar
                            {
                                TextureName = br.ReadString(),
                                Path = br.ReadString()
                            },
                            _ => throw new Exception($"Invalid prop {texType} in file {file}")
                        };
                        break;
                    case "col":
                        sVar = new ColVar
                        {
                            Red = br.ReadSingle(),
                            Green = br.ReadSingle(),
                            Blue = br.ReadSingle(),
                            Alpha = br.ReadSingle()
                        };
                        break;
                    case "vec":
                        sVar = new Vec4Var
                        {
                            X = br.ReadSingle(),
                            Y = br.ReadSingle(),
                            Z = br.ReadSingle(),
                            W = br.ReadSingle()
                        };
                        break;
                    case "f":
                        sVar = new FloatVar
                        {
                            Value = br.ReadSingle()
                        };
                        break;
                    default:
                        Console.WriteLine($"Invalid prop {prop} in file {file}");
                        return 1;
                }

                sVar.ShaderProperty = paramName;
                mateFile.ShaderProperties.Add(sVar);
            }

            var sb = new SerializerBuilder();
            sb.ConfigureDefaultValuesHandling(DefaultValuesHandling.OmitNull);
            foreach (var kv in mappingTypes)
                sb.WithTagMapping(kv.Key, kv.Value);
            var serializer = sb.Build();

            var yaml = serializer.Serialize(mateFile);
            File.WriteAllText(Path.Combine(Output, $"{Path.GetFileName(file)}.yaml"), yaml);
            return 0;
        }

        [AttributeUsage(AttributeTargets.Class, Inherited = false)]
        private class TagAttribute : Attribute
        {
            public TagAttribute(string Tag)
            {
                this.Tag = Tag;
            }

            public string Tag { get; }

            public bool WriteShaderProp { get; set; } = true;
        }

        private class ShaderVariable
        {
            [YamlMember(Alias = "property")] public string ShaderProperty { get; set; }

            public virtual void Serialize(BinaryWriter bw)
            {
                var tagAttribute = GetType().GetCustomAttributes(typeof(TagAttribute), true).Cast<TagAttribute>()
                    .FirstOrDefault();

                if (tagAttribute == null)
                    return;

                bw.Write(tagAttribute.Tag);

                if (tagAttribute.WriteShaderProp)
                    bw.Write(ShaderProperty);
            }
        }

        [Tag("end", WriteShaderProp = false)]
        private class EndTag : ShaderVariable
        {
        }

        private class TexVar : ShaderVariable
        {
            public override void Serialize(BinaryWriter bw)
            {
                var tagAttribute = GetType().GetCustomAttributes(typeof(TagAttribute), true).Cast<TagAttribute>()
                    .FirstOrDefault();
                if (tagAttribute == null)
                    return;

                bw.Write("tex");
                bw.Write(ShaderProperty);
                bw.Write(tagAttribute.Tag);
            }
        }

        [Tag("tex_null")]
        private class TexNullVar : TexVar
        {
            public override void Serialize(BinaryWriter bw)
            {
                bw.Write("tex");
                bw.Write(ShaderProperty);
                bw.Write("null");
            }
        }

        [Tag("tex2d")]
        private class Tex2DVar : TexVar
        {
            [YamlMember(Alias = "texname")] public string TextureName { get; set; }

            [YamlMember(Alias = "path")] public string Path { get; set; }

            [YamlMember(Alias = "offset")] public Vec2 Offset { get; set; }

            [YamlMember(Alias = "scale")] public Vec2 Scale { get; set; }

            public override void Serialize(BinaryWriter bw)
            {
                base.Serialize(bw);
                bw.Write(TextureName);
                bw.Write(Path);
                bw.Write(Offset.X);
                bw.Write(Offset.Y);
                bw.Write(Scale.X);
                bw.Write(Scale.Y);
            }
        }

        [Tag("texRT")]
        private class TexRTVar : TexVar
        {
            [YamlMember(Alias = "texname")] public string TextureName { get; set; }

            [YamlMember(Alias = "path")] public string Path { get; set; }

            public override void Serialize(BinaryWriter bw)
            {
                base.Serialize(bw);
                bw.Write(Path);
                bw.Write(TextureName);
            }
        }

        [Tag("col")]
        private class ColVar : ShaderVariable
        {
            [YamlMember(Alias = "r")] public float Red { get; set; }

            [YamlMember(Alias = "g")] public float Green { get; set; }

            [YamlMember(Alias = "b")] public float Blue { get; set; }

            [YamlMember(Alias = "a")] public float Alpha { get; set; }

            public override void Serialize(BinaryWriter bw)
            {
                base.Serialize(bw);
                bw.Write(Red);
                bw.Write(Green);
                bw.Write(Blue);
                bw.Write(Alpha);
            }
        }

        [Tag("vec")]
        private class Vec4Var : ShaderVariable
        {
            [YamlMember(Alias = "x")] public float X { get; set; }

            [YamlMember(Alias = "y")] public float Y { get; set; }

            [YamlMember(Alias = "z")] public float Z { get; set; }

            [YamlMember(Alias = "w")] public float W { get; set; }

            public override void Serialize(BinaryWriter bw)
            {
                base.Serialize(bw);
                bw.Write(X);
                bw.Write(Y);
                bw.Write(Z);
                bw.Write(W);
            }
        }

        [Tag("f")]
        private class FloatVar : ShaderVariable
        {
            [YamlMember(Alias = "value")] public float Value { get; set; }

            public override void Serialize(BinaryWriter bw)
            {
                base.Serialize(bw);
                bw.Write(Value);
            }
        }

        private class Vec2
        {
            [YamlMember(Alias = "x")] public float X { get; set; }

            [YamlMember(Alias = "y")] public float Y { get; set; }
        }

        private class MateFile
        {
            [YamlMember(Alias = "version")] public int Version { get; set; }

            [YamlMember(Alias = "path")] public string Path { get; set; }

            [YamlMember(Alias = "name")] public string Name { get; set; }

            [YamlMember(Alias = "shader")] public string ShaderName { get; set; }

            [YamlMember(Alias = "def_material")] public string DefMaterial { get; set; }

            [YamlMember(Alias = "shader_props")] public List<ShaderVariable> ShaderProperties { get; set; }

            public void Serialize(BinaryWriter bw)
            {
                bw.Write(MATE_TAG);
                bw.Write(Version);
                bw.Write(Path);
                bw.Write(Name);
                bw.Write(ShaderName);
                bw.Write(DefMaterial);

                foreach (var shaderProperty in ShaderProperties)
                    shaderProperty.Serialize(bw);
            }
        }
    }
}