/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 * 
 * The Original Code is TransforMiiX XSLT processor.
 * 
 * The Initial Developer of the Original Code is The MITRE Corporation.
 * Portions created by MITRE are Copyright (C) 1999 The MITRE Corporation.
 *
 * Portions created by Keith Visco as a Non MITRE employee,
 * (C) 1999 Keith Visco. All Rights Reserved.
 * 
 * Contributor(s): 
 * Keith Visco, kvisco@ziplink.net
 *   -- original author.
 * 
 */

#include "Expr.h"

/**
 * This class represents a FunctionCall as defined by the XSL Working Draft
**/

const String FunctionCall::INVALID_PARAM_COUNT =
        "invalid number of parameters for function: ";

const String FunctionCall::INVALID_PARAM_VALUE =
        "invalid parameter value for function: ";

//- Constructors -/

/**
 * Creates a new FunctionCall
**/
FunctionCall::FunctionCall() {
    this->name = "void";
} //-- FunctionCall

/**
 * Creates a new FunctionCall with the given function
 * Note: The object references in parameters will be deleted when this
 * FunctionCall gets destroyed.
**/
FunctionCall::FunctionCall(const String& name)
{
    //-- copy name
    this->name = name;
} //-- FunctionCall

/**
 * Destructor
**/
FunctionCall::~FunctionCall()
{
    ListIterator* iter = params.iterator();
    while (iter->hasNext()) {
        iter->next();
        Expr* expr = (Expr*) iter->remove();
        delete expr;
    }
    delete iter;
} //-- ~FunctionCall

  //------------------/
 //- Public Methods -/
//------------------/

/**
 * Adds the given parameter to this FunctionCall's parameter list
 * @param expr the Expr to add to this FunctionCall's parameter list
**/
void FunctionCall::addParam(Expr* expr)
{
    if (expr)
      params.add(expr);
} //-- addParam

/**
 * Returns the default priority of this Expr based on the given Node,
 * context Node, and ContextState.
**/
double FunctionCall::getDefaultPriority(Node* node,
                                        Node* context,
                                        ContextState* cs)
{
    return 0.5;
} //-- getDefaultPriority

/**
 * Determines whether this Expr matches the given node within
 * the given context
**/
MBool FunctionCall::matches(Node* node, Node* context, ContextState* cs)
{
    MBool result = MB_FALSE;
    ExprResult* exprResult = evaluate(node, cs);
    if (exprResult->getResultType() == ExprResult::NODESET) {
        NodeSet* nodes = (NodeSet*)exprResult;
        result = (nodes->contains(node));
    }
    delete exprResult;
    return result;
} //-- matches

/*
 * Evaluates the given Expression and converts its result to a String.
 * The value is appended to the given destination String
 */
void FunctionCall::evaluateToString(Expr* aExpr,
                                    Node* aContext, 
                                    ContextState* aCs,
                                    String& aDest)
{
    NS_ASSERTION(aExpr, "missing expression");
    ExprResult* exprResult = aExpr->evaluate(aContext, aCs);
    if (!exprResult)
        return;

    exprResult->stringValue(aDest);
    delete exprResult;
}

/*
 * Evaluates the given Expression and converts its result to a number.
 */
double FunctionCall::evaluateToNumber(Expr* aExpr,
                                      Node* aContext,
                                      ContextState* aCs)
{
    NS_ASSERTION(aExpr, "missing expression");
    ExprResult* exprResult = aExpr->evaluate(aContext, aCs);
    if (!exprResult)
        return Double::NaN;

    double result = exprResult->numberValue();
    delete exprResult;
    return result;
}

/*
 * Evaluates the given Expression and converts its result to a boolean.
 */
MBool FunctionCall::evaluateToBoolean(Expr* aExpr,
                                      Node* aContext,
                                      ContextState* aCs)
{
    NS_ASSERTION(aExpr, "missing expression");
    ExprResult* exprResult = aExpr->evaluate(aContext, aCs);
    if (!exprResult)
        return MB_FALSE;

    MBool result = exprResult->booleanValue();
    delete exprResult;
    return result;
}

/*
 * Evaluates the given Expression and converts its result to a NodeSet.
 * If the result is not a NodeSet NULL is returned.
 */
NodeSet* FunctionCall::evaluateToNodeSet(Expr* aExpr,
                                         Node* aContext,
                                         ContextState* aCs)
{
    NS_ASSERTION(aExpr, "Missing expression to evaluate");
    ExprResult* exprResult = aExpr->evaluate(aContext, aCs);
    if (!exprResult)
        return 0;

    if (exprResult->getResultType() != ExprResult::NODESET) {
        String err("NodeSet expected as argument");
        aCs->recieveError(err);
        delete exprResult;
        return 0;
    }

    return (NodeSet*)exprResult;
}

/**
 * Called to check number of parameters
**/
MBool FunctionCall::requireParams (int paramCountMin,
                                   int paramCountMax,
                                   ContextState* cs)
{
    int argc = params.getLength();
    if ((argc < paramCountMin) || (argc > paramCountMax)) {
        String err(INVALID_PARAM_COUNT);
        toString(err);
        cs->recieveError(err);
        return MB_FALSE;
    }
    return MB_TRUE;
} //-- requireParams

/**
 * Called to check number of parameters
**/
MBool FunctionCall::requireParams(int paramCountMin, ContextState* cs)
{
    int argc = params.getLength();
    if (argc < paramCountMin) {
        String err(INVALID_PARAM_COUNT);
        toString(err);
        cs->recieveError(err);
        return MB_FALSE;
    }
    return MB_TRUE;
} //-- requireParams

/**
 * Returns the String representation of this NodeExpr.
 * @param dest the String to use when creating the String
 * representation. The String representation will be appended to
 * any data in the destination String, to allow cascading calls to
 * other #toString() methods for Expressions.
 * @return the String representation of this NodeExpr.
**/
void FunctionCall::toString(String& dest)
{
    dest.append(this->name);
    dest.append('(');
    //-- add parameters
    ListIterator* iterator = params.iterator();
    int argc = 0;
    while (iterator->hasNext()) {
        if (argc > 0)
            dest.append(',');
        Expr* expr = (Expr*)iterator->next();
        expr->toString(dest);
        ++argc;
    }
    delete iterator;
    dest.append(')');
} //-- toString