using System;
using System.Collections.Generic;

namespace AspClassic.Parser;

/// <summary>
/// A parse tree for an If block.
/// </summary>
public sealed class IfBlockStatement : BlockStatement
{
	private readonly Expression _Expression;

	private readonly Location _ThenLocation;

	private readonly StatementCollection _ElseIfBlockStatements;

	private readonly ElseBlockStatement _ElseBlockStatement;

	private readonly EndBlockStatement _EndStatement;

	/// <summary>
	/// The conditional expression.
	/// </summary>
	public Expression Expression => _Expression;

	/// <summary>
	/// The location of the 'Then', if any.
	/// </summary>
	public Location ThenLocation => _ThenLocation;

	/// <summary>
	/// The Else If statements.
	/// </summary>
	public StatementCollection ElseIfBlockStatements => _ElseIfBlockStatements;

	/// <summary>
	/// The Else statement, if any.
	/// </summary>
	public ElseBlockStatement ElseBlockStatement => _ElseBlockStatement;

	/// <summary>
	/// The End If statement, if any.
	/// </summary>
	public EndBlockStatement EndStatement => _EndStatement;

	/// <summary>
	/// Constructs a new parse tree for a If statement.
	/// </summary>
	/// <param name="expression">The conditional expression.</param>
	/// <param name="thenLocation">The location of the 'Then', if any.</param>
	/// <param name="statements">The statements in the If block.</param>
	/// <param name="elseIfBlockStatements">The Else If statements.</param>
	/// <param name="elseBlockStatement">The Else statement, if any.</param>
	/// <param name="endStatement">The End If statement, if any.</param>
	/// <param name="span">The location of the parse tree.</param>
	/// <param name="comments">The comments for the parse tree.</param>
	public IfBlockStatement(Expression expression, Location thenLocation, StatementCollection statements, StatementCollection elseIfBlockStatements, ElseBlockStatement elseBlockStatement, EndBlockStatement endStatement, Span span, IList<Comment> comments)
		: base(TreeType.IfBlockStatement, statements, span, comments)
	{
		if (expression == null)
		{
			throw new ArgumentNullException("expression");
		}
		SetParent(expression);
		SetParent(elseIfBlockStatements);
		SetParent(elseBlockStatement);
		SetParent(endStatement);
		_Expression = expression;
		_ThenLocation = thenLocation;
		_ElseIfBlockStatements = elseIfBlockStatements;
		_ElseBlockStatement = elseBlockStatement;
		_EndStatement = endStatement;
	}

	protected override void GetChildTrees(IList<Tree> childList)
	{
		Tree.AddChild(childList, Expression);
		base.GetChildTrees(childList);
		Tree.AddChild(childList, ElseIfBlockStatements);
		Tree.AddChild(childList, ElseBlockStatement);
		Tree.AddChild(childList, EndStatement);
	}
}