using System.Collections.Generic;
using System.Linq;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.CSharp.Syntax;

namespace Cfa;

internal static class MemberSyntax
{
    public static IEnumerable<SyntaxNode> ExecutionRoots(ISymbol member, SyntaxNode declaration)
    {
        if (
            member is not IMethodSymbol { MethodKind: MethodKind.Constructor }
            || declaration is not TypeDeclarationSyntax type
        )
        {
            yield return declaration;
            yield break;
        }

        if (type.BaseList is { } bases)
        {
            foreach (var initializer in bases.Types.OfType<PrimaryConstructorBaseTypeSyntax>())
            {
                yield return initializer;
            }
        }
        foreach (var child in type.Members)
        {
            switch (child)
            {
                case BaseFieldDeclarationSyntax field
                    when !field.Modifiers.Any(SyntaxKind.StaticKeyword)
                        && !field.Modifiers.Any(SyntaxKind.ConstKeyword):
                    foreach (var variable in field.Declaration.Variables)
                    {
                        if (variable.Initializer is { } initializer)
                        {
                            yield return initializer;
                        }
                    }
                    break;
                case PropertyDeclarationSyntax { Initializer: { } initializer } property
                    when !property.Modifiers.Any(SyntaxKind.StaticKeyword):
                    yield return initializer;
                    break;
            }
        }
    }
}