using System;
using System.Collections.Generic;

namespace AspClassic.Parser;

/// <summary>
/// A parse tree for an End declaration.
/// </summary>
public sealed class EndBlockDeclaration : Declaration
{
	private readonly BlockType _EndType;

	private readonly Location _EndArgumentLocation;

	/// <summary>
	/// The type of block the declaration ends.
	/// </summary>
	public BlockType EndType => _EndType;

	/// <summary>
	/// The location of the end block argument.
	/// </summary>
	public Location EndArgumentLocation => _EndArgumentLocation;

	/// <summary>
	/// Creates a new parse tree for an End block declaration.
	/// </summary>
	/// <param name="endType">The type of the block the statement ends.</param>
	/// <param name="endArgumentLocation">The location of the end block argument.</param>
	/// <param name="span">The location of the parse tree.</param>
	/// <param name="comments">The comments for the parse tree.</param>
	public EndBlockDeclaration(BlockType endType, Location endArgumentLocation, Span span, IList<Comment> comments)
		: base(TreeType.EndBlockDeclaration, span, comments)
	{
		if (endType < BlockType.Sub && endType > BlockType.Namespace)
		{
			throw new ArgumentOutOfRangeException("endType");
		}
		_EndType = endType;
		_EndArgumentLocation = endArgumentLocation;
	}

	internal EndBlockDeclaration(EndBlockStatement endBlockStatement)
		: base(TreeType.EndBlockDeclaration, endBlockStatement.Span, endBlockStatement.Comments)
	{
		BlockType endType = endBlockStatement.EndType;
		if ((uint)(endType - 10) <= 2u || (uint)(endType - 14) <= 4u)
		{
			_EndType = endBlockStatement.EndType;
			_EndArgumentLocation = endBlockStatement.EndArgumentLocation;
			return;
		}
		throw new ArgumentException("Invalid EndBlockStatement type.");
	}
}