using NubLang.Tokenization;

namespace NubLang.Parsing.Syntax;

public abstract record StatementSyntax(IEnumerable<Token> Tokens) : SyntaxNode(Tokens);

public record StatementExpressionSyntax(IEnumerable<Token> Tokens, ExpressionSyntax Expression) : StatementSyntax(Tokens)
{
    public override IEnumerable<SyntaxNode> GetChildren()
    {
        yield return Expression;
    }
}

public record ReturnSyntax(IEnumerable<Token> Tokens, Optional<ExpressionSyntax> Value) : StatementSyntax(Tokens)
{
    public override IEnumerable<SyntaxNode> GetChildren()
    {
        if (Value.HasValue)
        {
            yield return Value.Value;
        }
    }
}

public record AssignmentSyntax(IEnumerable<Token> Tokens, ExpressionSyntax Target, ExpressionSyntax Value) : StatementSyntax(Tokens)
{
    public override IEnumerable<SyntaxNode> GetChildren()
    {
        yield return Target;
        yield return Value;
    }
}

public record IfSyntax(IEnumerable<Token> Tokens, ExpressionSyntax Condition, BlockSyntax Body, Optional<Variant<IfSyntax, BlockSyntax>> Else) : StatementSyntax(Tokens)
{
    public override IEnumerable<SyntaxNode> GetChildren()
    {
        yield return Condition;
        yield return Body;
        if (Else.HasValue)
        {
            if (Else.Value.IsCase1(out var elseIf))
            {
                yield return elseIf;
            }
            else if (Else.Value.IsCase2(out var @else))
            {
                yield return @else;
            }
        }
    }
}

public record VariableDeclarationSyntax(IEnumerable<Token> Tokens, string Name, Optional<TypeSyntax> ExplicitType, Optional<ExpressionSyntax> Assignment) : StatementSyntax(Tokens)
{
    public override IEnumerable<SyntaxNode> GetChildren()
    {
        if (ExplicitType.HasValue)
        {
            yield return ExplicitType.Value;
        }

        if (Assignment.HasValue)
        {
            yield return Assignment.Value;
        }
    }
}

public record ContinueSyntax(IEnumerable<Token> Tokens) : StatementSyntax(Tokens)
{
    public override IEnumerable<SyntaxNode> GetChildren() => [];
}

public record BreakSyntax(IEnumerable<Token> Tokens) : StatementSyntax(Tokens)
{
    public override IEnumerable<SyntaxNode> GetChildren() => [];
}

public record WhileSyntax(IEnumerable<Token> Tokens, ExpressionSyntax Condition, BlockSyntax Body) : StatementSyntax(Tokens)
{
    public override IEnumerable<SyntaxNode> GetChildren() => [];
}