using Canon.Core.CodeGenerators;
using Canon.Core.Enums;
using Canon.Core.LexicalParser;

namespace Canon.Core.SyntaxNodes;

public class SubprogramHead : NonTerminatedSyntaxNode
{
    public override NonTerminatorType Type => NonTerminatorType.SubprogramHead;

    public bool IsProcedure { get; private init; }

    /// <summary>
    /// 子程序的名称
    /// </summary>
    public IdentifierSemanticToken SubprogramName =>
        (IdentifierSemanticToken)Children[1].Convert<TerminatedSyntaxNode>().Token;

    /// <summary>
    /// 子程序的参数
    /// </summary>
    public IEnumerable<Parameter> Parameters => Children[2].Convert<FormalParameter>().Parameters;

    public static SubprogramHead Create(List<SyntaxNodeBase> children)
    {
        bool isProcedure;

        TerminatedSyntaxNode node = children[0].Convert<TerminatedSyntaxNode>();
        KeywordSemanticToken token = (KeywordSemanticToken)node.Token;

        if (token.KeywordType == KeywordType.Procedure)
        {
            isProcedure = true;
        }
        else if (token.KeywordType == KeywordType.Function)
        {
            isProcedure = false;
        }
        else
        {
            throw new InvalidOperationException();
        }

        return new SubprogramHead { Children = children, IsProcedure = isProcedure };
    }

    public override void GenerateCCode(CCodeBuilder builder)
    {
        //可能要用到符号表
        if (IsProcedure)
        {
            builder.AddString("void ");
        }
        else
        {
            //返回类型暂时未知
            builder.AddString("int ");
        }

        builder.AddString(SubprogramName.LiteralValue);

        builder.AddString("(");
        foreach (var param in Parameters)
        {

        }

        builder.AddString(")");
    }
}