using System.Reflection;

namespace NewLife.Reflection;

class OrcasNamer
{
    public static String? GetName(MemberInfo member)
    {
        using TextWriter writer = new StringWriter();
        switch (member.MemberType)
        {
            case MemberTypes.TypeInfo:
            case MemberTypes.NestedType:
                writer.Write("T:");
                if (member is Type type) WriteType(type, writer);
                break;
            case MemberTypes.Field:
                writer.Write("F:");
                if (member is FieldInfo field) WriteField(field, writer);
                break;
            case MemberTypes.Property:
                writer.Write("P:");
                if (member is PropertyInfo property) WriteProperty(property, writer);
                break;
            case MemberTypes.Method:
                writer.Write("M:");
                if (member is MethodInfo method) WriteMethod(method, writer);
                break;
            case MemberTypes.Constructor:
                writer.Write("M:");
                if (member is ConstructorInfo ctor)
                {
                    if (!ctor.IsStatic)
                        WriteConstructor(ctor, writer);
                    else
                        WriteStaticConstructor(ctor, writer);
                }
                break;
            case MemberTypes.Event:
                writer.Write("E:");
                if (member is EventInfo @event) WriteEvent(@event, writer);
                break;
        }

        return writer.ToString();
    }

    private static void WriteEvent(EventInfo trigger, TextWriter writer)
    {
        WriteType(trigger.DeclaringType, writer);

        //EventInfo eiiTrigger = null;
        //if (trigger.IsPrivate && trigger.IsVirtual)
        //{
        //    EventInfo[] eiiTriggers = ReflectionUtilities.GetImplementedEvents(trigger);
        //    if (eiiTriggers.Length > 0) eiiTrigger = eiiTriggers[0];
        //}

        //if (eiiTrigger != null)
        //{
        //    Type eiiType = eiiTrigger.DeclaringType;
        //    TextWriter eiiWriter = new StringWriter();

        //    if (eiiType != null && eiiType.Template != null)
        //    {
        //        writer.Write(".");
        //        WriteTemplate(eiiType, writer);
        //    }
        //    else
        //    {
        //        WriteType(eiiType, eiiWriter);
        //        writer.Write(".");
        //        writer.Write(eiiWriter.ToString().Replace('.', '#'));
        //    }

        //    writer.Write("#");
        //    writer.Write(eiiTrigger.Name);
        //}
        //else
        {
            writer.Write(".{0}", trigger.Name);
        }
    }

    private static void WriteField(FieldInfo field, TextWriter writer)
    {
        WriteType(field.DeclaringType, writer);
        writer.Write(".{0}", field.Name);
    }

    private static void WriteMethod(MethodInfo method, TextWriter writer)
    {
        var name = method.Name;
        WriteType(method.DeclaringType, writer);

        //MethodInfo eiiMethod = null;
        //if (method.IsPrivate && method.IsVirtual)
        //{
        //    MethodInfo[] eiiMethods = method.ImplementedInterfaceMethods;
        //    if (eiiMethods.Length > 0) eiiMethod = eiiMethods[0];
        //}
        //if (eiiMethod != null)
        //{ //explicitly implemented interface
        //    Type eiiType = eiiMethod.DeclaringType;
        //    TextWriter eiiWriter = new StringWriter();


        //    //we need to keep the param names instead of turning them into numbers
        //    //get the template to the right format
        //    if (eiiType != null && eiiType.Template != null)
        //    {
        //        writer.Write(".");
        //        WriteTemplate(eiiType, writer);
        //    }
        //    else //revert back to writing the type the old way if there is no template
        //    {
        //        WriteType(eiiType, eiiWriter);
        //        writer.Write(".");
        //        writer.Write(eiiWriter.ToString().Replace('.', '#'));
        //    }

        //    writer.Write("#");
        //    writer.Write(eiiMethod.Name);
        //}
        //else
        {
            writer.Write(".{0}", name);
        }
        if (method.IsGenericMethod)
        {
            var genericParameters = method.GetGenericArguments();
            if (genericParameters != null)
            {
                writer.Write("``{0}", genericParameters.Length);
            }
        }
        WriteParameters(method.GetParameters(), writer);
        // add ~ for conversion operators
        if (name is "op_Implicit" or "op_Explicit")
        {
            writer.Write("~");
            WriteType(method.ReturnType, writer);
        }
    }

    private static void WriteConstructor(ConstructorInfo constructor, TextWriter writer)
    {
        WriteType(constructor.DeclaringType, writer);
        writer.Write(".#ctor");
        WriteParameters(constructor.GetParameters(), writer);
    }

    private static void WriteStaticConstructor(ConstructorInfo constructor, TextWriter writer)
    {
        WriteType(constructor.DeclaringType, writer);
        writer.Write(".#cctor");
        WriteParameters(constructor.GetParameters(), writer);
    }

    private static void WriteProperty(PropertyInfo property, TextWriter writer)
    {
        WriteType(property.DeclaringType, writer);
        //Console.WriteLine( "{0}::{1}", property.DeclaringType.FullName, property.Name );

        //Property eiiProperty = null;
        //if (property.IsPrivate && property.IsVirtual)
        //{
        //    Property[] eiiProperties = ReflectionUtilities.GetImplementedProperties(property);
        //    if (eiiProperties.Length > 0) eiiProperty = eiiProperties[0];
        //}



        //if (eiiProperty != null)
        //{
        //    TypeNode eiiType = eiiProperty.DeclaringType;
        //    TextWriter eiiWriter = new StringWriter();


        //    if (eiiType != null && eiiType.Template != null)
        //    {
        //        writer.Write(".");
        //        WriteTemplate(eiiType, writer);
        //    }
        //    else
        //    {
        //        WriteType(eiiType, eiiWriter);
        //        writer.Write(".");
        //        writer.Write(eiiWriter.ToString().Replace('.', '#'));
        //    }

        //    writer.Write("#");
        //    writer.Write(eiiProperty.Name.Name);
        //}
        //else
        {
            writer.Write(".{0}", property.Name);
        }
        WriteParameters(property.GetIndexParameters(), writer);
    }

    private static void WriteParameters(ParameterInfo[] parameters, TextWriter writer)
    {
        if (parameters == null || parameters.Length == 0) return;
        writer.Write("(");
        for (var i = 0; i < parameters.Length; i++)
        {
            if (i > 0) writer.Write(",");
            WriteType(parameters[i].ParameterType, writer);
        }
        writer.Write(")");
    }

    private static void WriteType(Type? type, TextWriter writer)
    {
        if (type == null) return;

        if (type.IsArray)
        {
            WriteType(type.GetElementType(), writer);
            writer.Write("[");
            if (type.GetArrayRank() > 1)
            {
                for (var i = 0; i < type.GetArrayRank(); i++)
                {
                    if (i > 0) writer.Write(",");
                    writer.Write("0:");
                }
            }
            writer.Write("]");
        }
        else if (type.IsByRef)
        {
            WriteType(type.GetElementType(), writer);
            writer.Write("@");
        }
        else if (type.IsPointer)
        {
            WriteType(type.GetElementType(), writer);
            writer.Write("*");
        }
        //case MemberTypes.OptionalModifier:
        //    TypeModifier optionalModifierClause = type as TypeModifier;
        //    WriteType(optionalModifierClause.ModifiedType, writer);
        //    writer.Write("!");
        //    WriteType(optionalModifierClause.Modifier, writer);
        //    break;
        //case MemberTypes.RequiredModifier:
        //    TypeModifier requiredModifierClause = type as TypeModifier;
        //    WriteType(requiredModifierClause.ModifiedType, writer);
        //    writer.Write("|");
        //    WriteType(requiredModifierClause.Modifier, writer);
        //    break;
        else
        {
            if (type.IsGenericParameter)
            {
                if (type.DeclaringMethod != null)
                    writer.Write("``");
                else if (type.DeclaringType != null)
                    writer.Write("`");
                else
                    throw new InvalidOperationException("Generic parameter not on type or method.");
                writer.Write(type.GenericParameterPosition);
            }
            else
            {
                // namespace
                var declaringType = type.DeclaringType;
                if (declaringType != null)
                {
                    // names of nested types begin with outer type name
                    WriteType(declaringType, writer);
                    writer.Write(".");
                }
                else
                {
                    // otherwise just prepend the namespace
                    //Identifier space = type.Namespace;
                    if (!String.IsNullOrEmpty(type.Namespace))
                    {
                        writer.Write(type.Namespace);
                        writer.Write(".");
                    }
                }
                // name
                //writer.Write(type.GetUnmangledNameWithoutTypeParameters());
                var typeName = type.Name;
                var p = typeName.IndexOf('`');
                if (p >= 0)
                    writer.Write(typeName[..p]);
                else
                    writer.Write(typeName);
                // generic parameters
                if (type.IsGenericType)
                {
                    if (type.IsGenericTypeDefinition)
                    {
                        // number of parameters
                        var parameters = type.GetGenericArguments();
                        if (parameters != null)
                        {
                            writer.Write("`{0}", parameters.Length);
                        }
                    }
                    else
                    {
                        // arguments
                        var arguments = type.GetGenericArguments();
                        if (arguments != null && arguments.Length > 0)
                        {
                            writer.Write("{");
                            for (var i = 0; i < arguments.Length; i++)
                            {
                                //TypeNode argument = arguments[i];
                                if (i > 0) writer.Write(",");
                                WriteType(arguments[i], writer);
                            }
                            writer.Write("}");
                        }
                    }
                }
            }
        }
    }
}