DotDevTools/EfDbCommentGenerator/Core/XmlDocFinder.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Xml.Linq;
using System.Xml.XPath;

namespace EfDbCommentGenerator.Core
{
    internal class XmlDocFinder
    {
        private readonly Dictionary<string, XDocument> _dicXml;

        public XmlDocFinder()
        {
            _dicXml = new Dictionary<string, XDocument>();
        }

        private XDocument GetXml(Assembly assembly)
        {
            var xmlFilePath = Path.ChangeExtension(assembly.Location, "xml");
            if (_dicXml.ContainsKey(xmlFilePath)) return _dicXml[xmlFilePath];

            XDocument load = null;

            try
            {
                load = XDocument.Load(xmlFilePath);
            }
            catch (Exception ex)
            {
                Debug.Print(ex.ToString());
            }

            return _dicXml[xmlFilePath] = load;
        }

        public string FindDoc(MemberInfo member)
        {
            var xml = GetXml(member.Module.Assembly);
            if (xml == null) return null;

            Type identityType;
            switch (member.MemberType)
            {
                case MemberTypes.TypeInfo:
                case MemberTypes.NestedType:
                    return xml.XPathSelectElement($"/doc/members/member[@name=\"T:{((Type)member).FullName.Replace("+", ".")}\"]/summary")?.Value.Trim();

                case MemberTypes.Field:
                    var fi = (FieldInfo)member;
                    identityType = fi.ReflectedType;
                    if (identityType != null && identityType.IsGenericType && false == identityType.IsGenericTypeDefinition)
                    {
                        identityType = identityType.GetGenericTypeDefinition();
                    }

                    Debug.Assert(identityType != null, "t != null");

                    return xml.XPathSelectElement($"/doc/members/member[@name=\"F:{identityType.FullName.Replace("+", ".")}.{fi.Name}\"]/summary")?.Value.Trim();
                case MemberTypes.Property:
                    var pi = (PropertyInfo)member;
                    if (pi.ReflectedType != pi.DeclaringType && pi.DeclaringType != null)
                    {
                        var findDoc = FindDoc(pi.DeclaringType.GetProperty(pi.Name));
                        return findDoc;
                    }

                    string additionalComment = null;
                    if (pi.PropertyType.IsEnum)
                    {
                        additionalComment += FindDoc(pi.PropertyType)
                            + "("
                            + string.Join(",", Enum.GetValues(pi.PropertyType).Cast<object>().Select(p => pi.PropertyType.GetField(p.ToString())).Select(p => Convert.ToInt64(p.GetRawConstantValue()) + ":" + FindDoc(p)))
                            + ")";
                    }

                    identityType = pi.ReflectedType;
                    if (identityType != null && identityType.IsGenericType && false == identityType.IsGenericTypeDefinition)
                    {
                        identityType = identityType.GetGenericTypeDefinition();
                    }

                    Debug.Assert(identityType != null, "t != null");

                    return xml.XPathSelectElement($"/doc/members/member[@name=\"P:{identityType.FullName.Replace("+", ".")}.{pi.Name}\"]/summary")?.Value.Trim()
                        + additionalComment;

                case MemberTypes.Constructor:
                case MemberTypes.Event:
                case MemberTypes.Method:
                case MemberTypes.Custom:
                case MemberTypes.All:
                default:
                    return null;
            }
        }
    }
}