// Copyright © Microsoft Corporation.
// This source file is subject to the Microsoft Permissive License.
// See http://www.microsoft.com/resources/sharedsource/licensingbasics/sharedsourcelicenses.mspx.
// All other rights reserved.

using System;
using System.Collections;
using System.Collections.Generic;

using System.Compiler;

using Microsoft.Ddue.Tools.Reflection;

namespace Microsoft.Ddue.Tools {

    public class MemberDictionary : ICollection < Member > {

        private Dictionary < string, List < Member > > index = new Dictionary < string, List < Member > >();

        private TypeNode type;

        // construct the dictionary

        public MemberDictionary(TypeNode type, ApiFilter filter) {

            this.type = type;

            bool isSealed = type.IsSealed;

            // add all member of the type that the filter allows
            MemberList members = type.Members;
            for (int i = 0; i < members.Count; i++) {
                Member member = members[i];

                // don't add nested types
                if (member is TypeNode) continue;

                // if our type is sealed, don't add protected members (is this check even necessary?)
                // if (isSealed && (member.IsFamily || member.IsFamilyAndAssembly)) continue;

                // don't add members that the filter rejects
                if (!filter.IsExposedMember(member)) continue;

                // okay, add the member
                AddMember(member);
            }

            // for enumerations, don't list inherited members
            if (type is EnumNode) return;

            // for interfaces, list members of inherited interfaces
            if (type is Interface) {

                InterfaceList contracts = type.Interfaces;
                for (int i = 0; i < contracts.Count; i++) {

                    Interface contract = contracts[i];

                    // members of hidden interfaces don't count
                    if (!filter.IsExposedType(contract)) continue;

                    // otherwise, add inherited interface members
                    MemberList contractMembers = contract.Members;
                    for (int j = 0; j < contractMembers.Count; j++) {
                        Member contractMember = contractMembers[j];

                        // check for exposure; this is necessary to remove accessor methods
                        if (!filter.IsExposedMember(contractMember)) continue;

                        AddMember(contractMember);
                    }


                }

                return;
            }

            // don't list inherited memers for static classes
            if (type.IsAbstract && type.IsSealed) return;

            // now interate up through the type hierarchy
            for (TypeNode parentType = type.BaseType; parentType != null; parentType = parentType.BaseType) {

                // iterate through the members of each type
                MemberList parentMembers = parentType.Members;
                for (int i = 0; i < parentMembers.Count; i++) {
                    Member parentMember = parentMembers[i];

                    // don't add constructors
                    if ((parentMember.NodeType == NodeType.InstanceInitializer) || (parentMember.NodeType == NodeType.StaticInitializer)) continue;

                    // don't add inherited static members
                    if (parentMember.IsStatic) continue;

                    // don't add nested types
                    if (parentMember is TypeNode) continue;

                    // if our type is sealed, don't add protected members
                    // if (isSealed && (parentMember.IsFamily || parentMember.IsFamilyAndAssembly)) continue;

                    // don't add members that the filter rejects
                    if (!filter.IsExposedMember(parentMember)) continue;

                    // don't add members we have overridden
                    if (this.Contains(parentMember)) continue;

                    // otherwise, add the member 
                    AddMember(parentMember);

                }

            }

        }

        public List < Member > AllMembers {
            get {
                List < Member > list = new List < Member >();
                foreach (List < Member > entries in index.Values) {
                    list.AddRange(entries);
                }
                return (list);
            }
        }

        public int Count {
            get {
                int count = 0;
                foreach (List < Member > entries in index.Values) {
                    count += entries.Count;
                }
                return (count);
            }
        }

        public IList < string > MemberNames {
            get {
                return (new List < string >(index.Keys));
            }
        }

        // access the data

        public TypeNode Type {
            get {
                return (type);
            }
        }

        bool ICollection < Member >.IsReadOnly {
            get {
                return (true);
            }
        }

        public List < Member > this[string name] {
            get {
                List < Member > members;
                index.TryGetValue(name, out members);
                return (members);
            }
        }

        public void Clear() {
            throw new InvalidOperationException();
        }

        public bool Contains(Member member) {

            // get candidate members with the same name
            List < Member > candidates;
            bool found = index.TryGetValue(member.Name.Name, out candidates);

            // if no candidates were found, we don't have the member
            if (!found) return (false);

            // iterate over the candidates, looking for one of the same type with the same parameters
            ParameterList parameters = GetParameters(member);
            foreach (Member candidate in candidates) {

                // candidates must be of the same type
                if (candidate.NodeType != member.NodeType) continue;

                // get candidate parameters
                ParameterList candidateParameters = GetParameters(candidate);

                // number of parameters must match
                if (parameters.Count != candidateParameters.Count) continue;

                // each parameter type must match
                bool parameterMismatch = false;
                for (int i = 0; i < parameters.Count; i++) {
                    if (parameters[i].Type != candidateParameters[i].Type) parameterMismatch = true;
                }
                // if the parameters match, we have the member
                if (!parameterMismatch) return (true);

            }

            // no candidates matched
            return (false);

        }

        // methods to complete ICollection<Member>

        public void CopyTo(Member[] array, int index) {
            throw new NotImplementedException();
        }

        void ICollection < Member >.Add(Member member) {
            throw new InvalidOperationException();
        }

        IEnumerator < Member > IEnumerable < Member >.GetEnumerator() {
            return (GetEnumerator());
        }

        IEnumerator IEnumerable.GetEnumerator() {
            return (GetEnumerator());
        }

        public bool Remove(Member member) {
            throw new InvalidOperationException();
        }

        private static ParameterList GetParameters(Member member) {

            // if the member is a method, get it's parameter list
            Method method = member as Method;
            if (method != null) {
                return (method.Parameters);
            }

            // if the member is a property, get it's parameter list
            Property property = member as Property;
            if (property != null) {
                return (property.Parameters);
            }

            // member is neither a method nor a property
            return (new ParameterList());
            //return(null);

        }

        private void AddMember(Member member) {

            // get the member name
            string name = member.Name.Name;

            // look up the member list for that name
            List < Member > members;
            if (!index.TryGetValue(name, out members)) {
                // if there isn't one already, make one
                members = new List < Member >();
                index.Add(name, members);
            }
            // add the member to the list
            members.Add(member);

        }

        // enumerator stuff

        private IEnumerator < Member > GetEnumerator() {
            return (AllMembers.GetEnumerator());
        }

    }

}