// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System.Collections.Generic;
using System.Runtime.CompilerServices;
using System.Runtime.Serialization;

namespace System.Reflection
{
    public abstract partial class Module : ICustomAttributeProvider, ISerializable
    {
        protected Module() { }

        public virtual Assembly Assembly => throw NotImplemented.ByDesign;
        public virtual string FullyQualifiedName => throw NotImplemented.ByDesign;
        public virtual string Name => throw NotImplemented.ByDesign;

        public virtual int MDStreamVersion => throw NotImplemented.ByDesign;
        public virtual Guid ModuleVersionId => throw NotImplemented.ByDesign;
        public virtual string ScopeName => throw NotImplemented.ByDesign;
        public ModuleHandle ModuleHandle => GetModuleHandleImpl();
        protected virtual ModuleHandle GetModuleHandleImpl() => ModuleHandle.EmptyHandle; // Not an api but declared protected because of Reflection.Core/Corelib divide (when built by CoreRt)
        public virtual void GetPEKind(out PortableExecutableKinds peKind, out ImageFileMachine machine) { throw NotImplemented.ByDesign; }
        public virtual bool IsResource() { throw NotImplemented.ByDesign; }

        public virtual bool IsDefined(Type attributeType, bool inherit) { throw NotImplemented.ByDesign; }
        public virtual IEnumerable<CustomAttributeData> CustomAttributes => GetCustomAttributesData();
        public virtual IList<CustomAttributeData> GetCustomAttributesData() { throw NotImplemented.ByDesign; }
        public virtual object[] GetCustomAttributes(bool inherit) { throw NotImplemented.ByDesign; }
        public virtual object[] GetCustomAttributes(Type attributeType, bool inherit) { throw NotImplemented.ByDesign; }

        public MethodInfo? GetMethod(string name)
        {
            if (name == null)
                throw new ArgumentNullException(nameof(name));

            return GetMethodImpl(name, Module.DefaultLookup, null, CallingConventions.Any, null, null);
        }

        public MethodInfo? GetMethod(string name, Type[] types) => GetMethod(name, Module.DefaultLookup, null, CallingConventions.Any, types, null);
        public MethodInfo? GetMethod(string name, BindingFlags bindingAttr, Binder? binder, CallingConventions callConvention, Type[] types, ParameterModifier[]? modifiers)
        {
            if (name == null)
                throw new ArgumentNullException(nameof(name));
            if (types == null)
                throw new ArgumentNullException(nameof(types));
            for (int i = 0; i < types.Length; i++)
            {
                if (types[i] == null)
                    throw new ArgumentNullException(nameof(types));
            }
            return GetMethodImpl(name, bindingAttr, binder, callConvention, types, modifiers);
        }

        protected virtual MethodInfo? GetMethodImpl(string name, BindingFlags bindingAttr, Binder? binder, CallingConventions callConvention, Type[]? types, ParameterModifier[]? modifiers) { throw NotImplemented.ByDesign; }

        public MethodInfo[] GetMethods() => GetMethods(Module.DefaultLookup);
        public virtual MethodInfo[] GetMethods(BindingFlags bindingFlags) { throw NotImplemented.ByDesign; }

        public FieldInfo? GetField(string name) => GetField(name, Module.DefaultLookup);
        public virtual FieldInfo? GetField(string name, BindingFlags bindingAttr) { throw NotImplemented.ByDesign; }

        public FieldInfo[] GetFields() => GetFields(Module.DefaultLookup);
        public virtual FieldInfo[] GetFields(BindingFlags bindingFlags) { throw NotImplemented.ByDesign; }

        public virtual Type[] GetTypes() { throw NotImplemented.ByDesign; }

        public virtual Type? GetType(string className) => GetType(className, throwOnError: false, ignoreCase: false);
        public virtual Type? GetType(string className, bool ignoreCase) => GetType(className, throwOnError: false, ignoreCase: ignoreCase);
        public virtual Type? GetType(string className, bool throwOnError, bool ignoreCase) { throw NotImplemented.ByDesign; }

        public virtual Type[] FindTypes(TypeFilter? filter, object? filterCriteria)
        {
            Type[] c = GetTypes();
            int cnt = 0;
            for (int i = 0; i < c.Length; i++)
            {
                if (filter != null && !filter(c[i], filterCriteria))
                    c[i] = null!;
                else
                    cnt++;
            }
            if (cnt == c.Length)
                return c;

            Type[] ret = new Type[cnt];
            cnt = 0;
            for (int i = 0; i < c.Length; i++)
            {
                if (c[i] != null)
                    ret[cnt++] = c[i];
            }
            return ret;
        }

        public virtual int MetadataToken => throw NotImplemented.ByDesign;

        public FieldInfo? ResolveField(int metadataToken) => ResolveField(metadataToken, null, null);
        public virtual FieldInfo? ResolveField(int metadataToken, Type[]? genericTypeArguments, Type[]? genericMethodArguments) { throw NotImplemented.ByDesign; }

        public MemberInfo? ResolveMember(int metadataToken) => ResolveMember(metadataToken, null, null);
        public virtual MemberInfo? ResolveMember(int metadataToken, Type[]? genericTypeArguments, Type[]? genericMethodArguments) { throw NotImplemented.ByDesign; }

        public MethodBase? ResolveMethod(int metadataToken) => ResolveMethod(metadataToken, null, null);
        public virtual MethodBase? ResolveMethod(int metadataToken, Type[]? genericTypeArguments, Type[]? genericMethodArguments) { throw NotImplemented.ByDesign; }

        public virtual byte[] ResolveSignature(int metadataToken) { throw NotImplemented.ByDesign; }
        public virtual string ResolveString(int metadataToken) { throw NotImplemented.ByDesign; }

        public Type ResolveType(int metadataToken) => ResolveType(metadataToken, null, null);
        public virtual Type ResolveType(int metadataToken, Type[]? genericTypeArguments, Type[]? genericMethodArguments) { throw NotImplemented.ByDesign; }

        public virtual void GetObjectData(SerializationInfo info, StreamingContext context) { throw NotImplemented.ByDesign; }

        public override bool Equals(object? o) => base.Equals(o);
        public override int GetHashCode() => base.GetHashCode();

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static bool operator ==(Module? left, Module? right)
        {
            // Test "right" first to allow branch elimination when inlined for null checks (== null)
            // so it can become a simple test
            if (right is null)
            {
                // return true/false not the test result https://github.com/dotnet/coreclr/issues/914
                return (left is null) ? true : false;
            }

            // Try fast reference equality and opposite null check prior to calling the slower virtual Equals
            if ((object?)left == (object)right)
            {
                return true;
            }

            return (left is null) ? false : left.Equals(right);
        }

        public static bool operator !=(Module? left, Module? right) => !(left == right);

        public override string ToString() => ScopeName;

        public static readonly TypeFilter FilterTypeName = (m, c) => FilterTypeNameImpl(m, c!, StringComparison.Ordinal);
        public static readonly TypeFilter FilterTypeNameIgnoreCase = (m, c) => FilterTypeNameImpl(m, c!, StringComparison.OrdinalIgnoreCase);

        private const BindingFlags DefaultLookup = BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public;

        // FilterTypeName
        // This method will filter the class based upon the name.  It supports
        //    a trailing wild card.
        private static bool FilterTypeNameImpl(Type cls, object filterCriteria, StringComparison comparison)
        {
            // Check that the criteria object is a String object
            if (!(filterCriteria is string str))
            {
                throw new InvalidFilterCriteriaException(SR.InvalidFilterCriteriaException_CritString);
            }
            // Check to see if this is a prefix or exact match requirement
            if (str.Length > 0 && str[^1] == '*')
            {
                ReadOnlySpan<char> slice = str.AsSpan(0, str.Length - 1);
                return cls.Name.AsSpan().StartsWith(slice, comparison);
            }

            return cls.Name.Equals(str, comparison);
        }
    }
}