/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/**
 * ExprParser
 * This class is used to parse XSL Expressions
 * @see ExprLexer
 **/

#ifndef MITREXSL_EXPRPARSER_H
#define MITREXSL_EXPRPARSER_H

#include "txCore.h"
#include "mozilla/UniquePtr.h"
#include "nsString.h"

class Expr;
class txExprLexer;
class FunctionCall;
class LocationStep;
class nsAtom;
class PredicateList;
class Token;
class txIParseContext;
class txNodeTest;

class txExprParser {
 public:
  static nsresult createExpr(const nsAString& aExpression,
                             txIParseContext* aContext, Expr** aExpr) {
    return createExprInternal(aExpression, 0, aContext, aExpr);
  }

  /**
   * Creates an Attribute Value Template using the given value
   */
  static nsresult createAVT(const nsAString& aAttrValue,
                            txIParseContext* aContext, Expr** aResult);

 protected:
  static nsresult createExprInternal(const nsAString& aExpression,
                                     uint32_t aSubStringPos,
                                     txIParseContext* aContext, Expr** aExpr);
  /**
   * Using nsAutoPtr& to optimize passing the ownership to the
   * created binary expression objects.
   */
  static nsresult createBinaryExpr(mozilla::UniquePtr<Expr>& left,
                                   mozilla::UniquePtr<Expr>& right, Token* op,
                                   Expr** aResult);
  static nsresult createExpr(txExprLexer& lexer, txIParseContext* aContext,
                             Expr** aResult);
  static nsresult createFilterOrStep(txExprLexer& lexer,
                                     txIParseContext* aContext, Expr** aResult);
  static nsresult createFunctionCall(txExprLexer& lexer,
                                     txIParseContext* aContext, Expr** aResult);
  static nsresult createLocationStep(txExprLexer& lexer,
                                     txIParseContext* aContext, Expr** aResult);
  static nsresult createNodeTypeTest(txExprLexer& lexer, txNodeTest** aResult);
  static nsresult createPathExpr(txExprLexer& lexer, txIParseContext* aContext,
                                 Expr** aResult);
  static nsresult createUnionExpr(txExprLexer& lexer, txIParseContext* aContext,
                                  Expr** aResult);

  static bool isLocationStepToken(Token* aToken);

  static short precedence(Token* aToken);

  /**
   * Resolve a QName, given the mContext parse context.
   * Returns prefix and localName as well as namespace ID
   */
  static nsresult resolveQName(const nsAString& aQName, nsAtom** aPrefix,
                               txIParseContext* aContext, nsAtom** aLocalName,
                               int32_t& aNamespace, bool aIsNameTest = false);

  /**
   * Using the given lexer, parses the tokens if they represent a
   * predicate list
   * If an error occurs a non-zero String pointer will be returned
   * containing the error message.
   * @param predicateList, the PredicateList to add predicate expressions to
   * @param lexer the ExprLexer to use for parsing tokens
   * @return 0 if successful, or a String pointer to the error message
   */
  static nsresult parsePredicates(PredicateList* aPredicateList,
                                  txExprLexer& lexer,
                                  txIParseContext* aContext);
  static nsresult parseParameters(FunctionCall* aFnCall, txExprLexer& lexer,
                                  txIParseContext* aContext);
};

#endif