using System.Collections.Generic;
using System.Linq;

namespace Rokojori;

public class PrecedenceLevel
{
  public bool fromLeft = true;
  public List<ExpressionOperator> operators = [];

  public bool Process( ASTNode parent )
  {
    SearchExpressionForOperators( parent );      

    if ( _operatorIndex == -1 )
    {
      return false;
    }

    var currentOperator = operators[ _operatorIndex ];
    
    var changed = currentOperator.ProcessStartNode( parent, _expressionIndex );

    if ( changed )
    {
      //console.log( "Processed", className( currentOperator ), currentOperator.tokenType, currentOperator.tokenValue );    
    }

    return changed;
  }


  public bool HasHigherPrecedence( int i, int e )
  {
    return fromLeft ? i < e : i > e;
  }

  int _expressionIndex = -1;
  int _operatorIndex = -1;

  
  public void SearchExpressionForOperators( ASTNode parent )
  {
    _expressionIndex = fromLeft ? parent.children.Count : -1;
    _operatorIndex   = -1;

    for ( int i = 0; i < operators.Count; i++ )
    {
      var index = operators[ i ].FindStartNodeIndex( parent );

      if ( index == -1 )
      {
        continue;
      }

      if ( ! HasHigherPrecedence( index, this._expressionIndex ) )
      {
        continue;
      }

      _expressionIndex = index;
      _operatorIndex = i;
      
    }
  
  }
}