using System;

namespace Ariadne.Generator
{
    /// <summary>
    /// Describes what an arc class gets written as plain data, which an incremental generator step can compare between
    /// runs.
    /// </summary>
    public sealed class ArcOutput : IEquatable<ArcOutput>
    {
        /// <summary>
        /// Holds the path of the script file the class's code-behind is written beside, or null if nothing is written
        /// for the class.
        /// </summary>
        public readonly string FilePath;

        public readonly string TypeName;

        /// <summary>
        /// Holds where the class is declared, which orders the classes of a file and places errors about the file.
        /// </summary>
        public readonly SourcePlace TypePlace;

        /// <summary>
        /// Holds the using directives the script file needs the code-behind to repeat.
        /// </summary>
        public readonly EquatableArray<string> FileUsings;

        /// <summary>
        /// Holds the class as the code-behind writes it, or null if nothing is written for it.
        /// </summary>
        public readonly string ClassText;

        /// <summary>
        /// Holds what is wrong with the class itself, which is reported whether or not its file is written.
        /// </summary>
        public readonly EquatableArray<DiagnosticData> ClassProblems;

        /// <summary>
        /// Holds what is wrong with the script's code, which is only reported if its file is written.
        /// </summary>
        public readonly EquatableArray<DiagnosticData> ScriptProblems;

        public ArcOutput(string filePath, string typeName, SourcePlace typePlace, EquatableArray<string> fileUsings,
            string classText, EquatableArray<DiagnosticData> classProblems,
            EquatableArray<DiagnosticData> scriptProblems)
        {
            FilePath = filePath;
            TypeName = typeName;
            TypePlace = typePlace;
            FileUsings = fileUsings;
            ClassText = classText;
            ClassProblems = classProblems;
            ScriptProblems = scriptProblems;
        }

        public bool Equals(ArcOutput other)
        {
            return other != null
                && FilePath == other.FilePath
                && TypeName == other.TypeName
                && TypePlace.Equals(other.TypePlace)
                && FileUsings.Equals(other.FileUsings)
                && ClassText == other.ClassText
                && ClassProblems.Equals(other.ClassProblems)
                && ScriptProblems.Equals(other.ScriptProblems);
        }

        public override bool Equals(object obj)
        {
            return Equals(obj as ArcOutput);
        }

        public override int GetHashCode()
        {
            int returnMe = TypeName.GetHashCode();
            if (ClassText != null)
            {
                returnMe = returnMe * 31 + ClassText.GetHashCode();
            }

            return returnMe;
        }
    }
}