using Convention.RScript.Parser;
using System.Collections;
using System.Diagnostics.CodeAnalysis;

namespace Convention.RScript
{
    public class BreakpointRunner : IRSentenceRunner
    {
        public void Compile(ExpressionParser parser, RScriptSentence sentence, RScriptContext context)
        {
            parser.Compile<bool>(sentence.content);
        }

        [return: MaybeNull]
        public object Run(ExpressionParser parser, RScriptSentence sentence, RScriptContext context)
        {
            // 检查并跳转到当前命名空间的结束位置
            if (parser.Evaluate<bool>(sentence.content))
            {
                if (context.RuntimePointerStack.Count == 0)
                {
                    context.CurrentRuntimePointer = context.Sentences.Length;
                }
                else if (context.NamespaceLayer.TryGetValue(context.RuntimePointerStack.Peek(), out var exitPointer))
                {
                    context.CurrentRuntimePointer = exitPointer;
                    return context.SentenceRunners[RScriptSentence.Mode.ExitNamespace].Run(parser, context.CurrentSentence, context);
                }
                else
                {
                    throw new RScriptRuntimeException($"No namespace to break.", context.CurrentRuntimePointer);
                }
            }
            return null;
        }

        [return: MaybeNull]
        public IEnumerator RunAsync(ExpressionParser parser, RScriptSentence sentence, RScriptContext context)
        {
            // 检查并跳转到当前命名空间的结束位置
            if (parser.Evaluate<bool>(sentence.content))
            {
                if (context.RuntimePointerStack.Count == 0)
                {
                    context.CurrentRuntimePointer = context.Sentences.Length;
                }
                else if (context.NamespaceLayer.TryGetValue(context.RuntimePointerStack.Peek(), out var exitPointer))
                {
                    context.CurrentRuntimePointer = exitPointer;
                    yield return context.SentenceRunners[RScriptSentence.Mode.ExitNamespace].RunAsync(parser, context.CurrentSentence, context);
                }
                else
                {
                    throw new RScriptRuntimeException($"No namespace to break.", context.CurrentRuntimePointer);
                }
            }
        }
    }
}