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Port of jsonata.js to Java to enable rules for JSON content
/**
* (c) Copyright 2018, 2019 IBM Corporation
* 1 New Orchard Road,
* Armonk, New York, 10504-1722
* United States
* +1 914 499 1900
* support: Nathaniel Mills [email protected]
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package com.api.jsonata4java.expressions.functions;
import com.api.jsonata4java.expressions.EvaluateRuntimeException;
import com.api.jsonata4java.expressions.ExpressionsVisitor;
import com.api.jsonata4java.expressions.generated.MappingExpressionParser;
import com.api.jsonata4java.expressions.generated.MappingExpressionParser.ExprContext;
import com.api.jsonata4java.expressions.generated.MappingExpressionParser.ExprValuesContext;
import com.api.jsonata4java.expressions.generated.MappingExpressionParser.Function_callContext;
import com.api.jsonata4java.expressions.utils.ArrayUtils;
import com.api.jsonata4java.expressions.utils.Constants;
import com.api.jsonata4java.expressions.utils.FunctionUtils;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.JsonNodeFactory;
public class SortFunction extends FunctionBase implements Function {
public static String ERR_BAD_CONTEXT = String.format(Constants.ERR_MSG_BAD_CONTEXT, Constants.FUNCTION_SORT);
public static String ERR_ARG1BADTYPE = String.format(Constants.ERR_MSG_ARG1_BAD_TYPE, Constants.FUNCTION_SORT);
public static String ERR_ARG2BADTYPE = String.format(Constants.ERR_MSG_ARG2_BAD_TYPE, Constants.FUNCTION_SORT);
public static String ERR_FCTNOTFOUND = String.format(Constants.ERR_MSG_FCT_NOT_FOUND, Constants.FUNCTION_SORT);
public static String ERR_ARG1BADARRAYTYPE = String.format(Constants.ERR_MSG_ARG1_MUST_BE_ARRAY,
Constants.FUNCTION_SORT);
public JsonNode invoke(ExpressionsVisitor expressionVisitor, Function_callContext ctx) {
ArrayNode result = JsonNodeFactory.instance.arrayNode();
// Retrieve the number of arguments
JsonNode arg = JsonNodeFactory.instance.nullNode();
boolean useContext = FunctionUtils.useContextVariable(ctx, getSignature());
int argCount = getArgumentCount(ctx);
if (useContext) {
arg = FunctionUtils.getContextVariable(expressionVisitor);
argCount++;
}
// Make sure that we have the right number of arguments
if (argCount == 1) {
if (!useContext) {
// use the default comparator
arg = expressionVisitor.visit(ctx.exprValues().exprList().expr(0));
}
// if arg is an array, return its length. Any other type of input
// returns 1.
if (arg == null) {
return null; // throw new EvaluateRuntimeException(ERR_ARG1BADTYPE);
} else if (arg.isArray()) {
ArrayNode array = (ArrayNode) arg;
for (int i = 0; i < array.size(); i++) {
result.add(array.get(i));
}
msort(result, null, expressionVisitor, ctx);
} else {
// allow to work with any input
result.add(arg);
return result;
}
} else if (argCount == 2) {
// use the defined function comparator
DeclaredFunction fct = null;
if (!useContext) {
// use the default comparator
arg = expressionVisitor.visit(ctx.exprValues().exprList().expr(0));
}
// if arg is an array, return its length. Any other type of input
// returns 1.
if (arg == null) {
throw new EvaluateRuntimeException(ERR_ARG1BADTYPE);
}
ExprContext fctCtx = ctx.exprValues().exprList().expr(useContext ? 0 : 1);
if (fctCtx == null) {
throw new EvaluateRuntimeException(ERR_ARG2BADTYPE);
}
if (!(fctCtx instanceof MappingExpressionParser.Function_declContext)) {
if (!(fctCtx instanceof MappingExpressionParser.Var_recallContext)) {
throw new EvaluateRuntimeException("Expected an function declaration reference but got "
+ fctCtx.getText() + " that is an " + fctCtx.getClass().getName());
}
String varID = ((MappingExpressionParser.Var_recallContext) fctCtx).VAR_ID().getText();
fct = expressionVisitor.getFunctionMap().get(varID);
if (fct == null) {
throw new EvaluateRuntimeException(
String.format(Constants.ERR_MSG_VARIABLE_FCT_NOT_FOUND, varID, Constants.FUNCTION_SORT));
}
} else {
MappingExpressionParser.Function_declContext fctDeclCtx = (MappingExpressionParser.Function_declContext) fctCtx;
MappingExpressionParser.VarListContext varList = fctDeclCtx.varList();
MappingExpressionParser.ExprListContext exprList = fctDeclCtx.exprList();
try {
fct = new DeclaredFunction(varList, exprList);
} catch (EvaluateRuntimeException e) {
throw new EvaluateRuntimeException(ERR_FCTNOTFOUND);
}
}
// if arg is an array, return its length. Any other type of input
// returns 1.
if (arg.isArray()) {
ArrayNode array = (ArrayNode) arg;
for (int i = 0; i < array.size(); i++) {
result.add(array.get(i));
}
msort(result, fct, expressionVisitor, ctx);
} else {
result.add(arg);
}
} else {
throw new EvaluateRuntimeException(argCount == 0 ? ERR_ARG1BADTYPE : ERR_ARG2BADTYPE);
}
return result;
}
@Override
public String getSignature() {
// accepts an array (or context variable), an optional function, returns an
// array
return "";
}
void msort(ArrayNode array, DeclaredFunction fct, ExpressionsVisitor exprVisitor, Function_callContext ctx) {
int n = array.size();
if (array == null || n < 2) {
return;
}
int middle = (int) Math.floor(n / 2);
ArrayNode left = ArrayUtils.slice(array, 0, middle);
ArrayNode right = ArrayUtils.slice(array, middle);
msort(left, fct, exprVisitor, ctx);
msort(right, fct, exprVisitor, ctx);
merge(array, left, right, fct, exprVisitor, ctx);
}
void merge(ArrayNode array, ArrayNode left, ArrayNode right, DeclaredFunction fct, ExpressionsVisitor exprVisitor,
Function_callContext ctx) {
int lSize = left.size();
int rSize = right.size();
int i = 0, j = 0, k = 0;
if (fct == null) {
while (i < lSize && j < rSize) {
if (ArrayUtils.compare(left.get(i), right.get(j))) {
array.set(k++, right.get(j++));
} else {
array.set(k++, left.get(i++));
}
}
while (i < lSize) {
array.set(k++, left.get(i++));
}
while (j < rSize) {
array.set(k++, right.get(j++));
}
} else {
while (i < lSize && j < rSize) {
// set up the variables for the function then call it
ExprValuesContext evc = new ExprValuesContext(ctx.getParent(), ctx.invokingState);
evc = FunctionUtils.fillExprVarContext(ctx, left.get(i), right.get(j));
JsonNode comp = fct.invoke(exprVisitor, evc);
if (comp != null && comp.asBoolean()) {
array.set(k++, right.get(j++));
} else {
array.set(k++, left.get(i++));
}
}
while (i < lSize) {
array.set(k++, left.get(i++));
}
while (j < rSize) {
array.set(k++, right.get(j++));
}
}
}
}