Accessing Assembly Metadata with Reflection or Mono Cecil (Part 6)

// The Nova Project by Ken Beckett.
// Copyright (C) 2007-2012 Inevitable Software, all rights reserved.
// Released under the Common Development and Distribution License, CDDL-1.0: http://opensource.org/licenses/cddl1.php

using Nova.Parsing;
using Nova.Rendering;

namespace Nova.CodeDOM
{
    /// <summary>
    /// Represents a generated message associated with a <see cref="CodeObject"/> (error, warning, suggestion, or hint).
    /// </summary>
    public class Message : Annotation
    {
        #region /* FIELDS */

        protected string _text;
        protected MessageSeverity _severity;
        protected MessageSource _source;

        #endregion

        #region /* CONSTRUCTORS */

        /// <summary>
        /// Create a <see cref="Message"/> with the specified text, severity, and source.
        /// </summary>
        public Message(string text, MessageSeverity severity, MessageSource source)
        {
            _text = text;
            _severity = severity;
            _source = source;
        }

        #endregion

        #region /* PROPERTIES */

        /// <summary>
        /// The text of the <see cref="Message"/>.
        /// </summary>
        public override string Text
        {
            get { return _text; }
            set { _text = value; }
        }

        /// <summary>
        /// The <see cref="MessageSeverity"/> of the message.
        /// </summary>
        public MessageSeverity Severity
        {
            get { return _severity; }
        }

        /// <summary>
        /// The <see cref="MessageSource"/> of the message.
        /// </summary>
        public MessageSource Source
        {
            get { return _source; }
        }

        /// <summary>
        /// The line number associated with the Parent <see cref="CodeObject"/> of the <see cref="Message"/> (if any, 0 if none).
        /// </summary>
        /// <remarks>
        /// The line number will match the input file when the object is parsed, but may differ if the code tree is modified.
        /// Parsing messages that relate to a <see cref="Token"/> will use <see cref="TokenMessage"/>, in which case the line
        /// number will be that of the related <see cref="Token"/>.
        /// </remarks>
        public override int LineNumber
        {
            get { return (_parent != null ? _parent.LineNumber : 0); }
        }

        /// <summary>
        /// The column number associated with the Parent <see cref="CodeObject"/> of the <see cref="Message"/> (if any, 0 if none).
        /// </summary>
        /// <remarks>
        /// The line number will match the input file when the object is parsed, but may differ if the code tree is modified.
        /// Parsing messages that relate to a <see cref="Token"/> will use <see cref="TokenMessage"/>, in which case the column
        /// will be that of the related <see cref="Token"/>.
        /// </remarks>
        public override int ColumnNumber
        {
            get { return _parent.ColumnNumber; }
        }

        /// <summary>
        /// The category of the message.
        /// </summary>
        public string Category
        {
            get
            {
                switch (_severity)
                {
                    case MessageSeverity.Error:
                        return "ERROR";
                    case MessageSeverity.Warning:
                        return "Warning";
                    case MessageSeverity.Suggestion:
                        return "Suggestion";
                    case MessageSeverity.Hint:
                        return "Hint";
                    case MessageSeverity.Information:
                        return "Information";
                }
                return null;
            }
        }

        /// <summary>
        /// Always <c>true</c> for <see cref="Message"/> annotations.
        /// </summary>
        public override bool IsListed
        {
            get { return true; }
        }

        #endregion

        #region /* RENDERING */

        public override void AsText(CodeWriter writer, RenderFlags flags)
        {
            if (!flags.HasFlag(RenderFlags.SuppressNewLine))
                writer.WriteLine();
            writer.Write(Category + ": " + _text);
        }

        #endregion
    }

    /// <summary>
    /// Represents a <see cref="Message"/> associated with a parse <see cref="Token"/>.
    /// </summary>
    /// <remarks>
    /// A <see cref="TokenMessage"/> will still be associated with a Parent <see cref="CodeObject"/> like any
    /// other <see cref="Message"/>, but it also contains the specific <see cref="Token"/> related to the message
    /// generated by the parser.  The <see cref="LineNumber"/> and <see cref="ColumnNumber"/> properties will return
    /// the information from the <see cref="Token"/> instead of the Parent <see cref="CodeObject"/>.
    /// </remarks>
    public class TokenMessage : Message
    {
        #region /* FIELDS */

        protected Token _token;

        #endregion

        #region /* CONSTRUCTORS */

        /// <summary>
        /// Create a parse error <see cref="Message"/> with the specified text, in connection with the specified <see cref="Token"/>.
        /// </summary>
        protected internal TokenMessage(string text, Token token)
            : base(text, token.InDocComment ? MessageSeverity.Warning : MessageSeverity.Error, MessageSource.Parse)
        {
            _token = token;
        }

        #endregion

        #region /* PROPERTIES */

        /// <summary>
        /// The <see cref="Token"/> that the message is associated with.
        /// </summary>
        public Token Token
        {
            get { return _token; }
        }

        /// <summary>
        /// The line number associated with the related <see cref="Token"/> (if any, 0 if none).
        /// </summary>
        /// <remarks>
        /// The line number will match the input file from when the object was parsed.
        /// </remarks>
        public override int LineNumber
        {
            get { return _token.LineNumber; }
        }

        /// <summary>
        /// The column number associated with the related <see cref="Token"/> (if any, 0 if none).
        /// </summary>
        /// <remarks>
        /// The column will match the input file from when the object was parsed.
        /// </remarks>
        public override int ColumnNumber
        {
            get { return _token.ColumnNumber; }
        }

        #endregion
    }


    #region /* ENUMS */

    /// <summary>
    /// The severity of a message.
    /// </summary>
    public enum MessageSeverity : byte
    {
        Unspecified,
        Error,
        Warning,
        Suggestion,
        Hint,
        Information
    }

    /// <summary>
    /// The source of a message.
    /// </summary>
    public enum MessageSource : byte
    {
        Unspecified,
        Load,
        Parse,
        Resolve,
        Save
    }

    #endregion
}