/*
 * Copyright (c) 2018 - 2023, Entgra (Pvt) Ltd. (http://www.entgra.io) All Rights Reserved.
 *
 * Entgra (Pvt) Ltd. licenses this file to you 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 io.entgra.device.mgt.plugins.extension.siddhi.execution.json;

import org.json.JSONException;
import org.json.JSONObject;
import org.wso2.siddhi.core.config.ExecutionPlanContext;
import org.wso2.siddhi.core.exception.ExecutionPlanRuntimeException;
import org.wso2.siddhi.core.executor.ExpressionExecutor;
import org.wso2.siddhi.core.executor.function.FunctionExecutor;
import org.wso2.siddhi.query.api.definition.Attribute;
import org.wso2.siddhi.query.api.exception.ExecutionPlanValidationException;

/**
 * getProperty(json , propertyName)
 * Returns the vale of the property from the given json json
 * Accept Type(s): (STRING, STRING)
 * Return Type(s): (STRING|INT|DOUBLE|FLOAT|OBJECT)
 */
public class GetPropertyFunctionExtension extends FunctionExecutor {

    private Attribute.Type returnType = Attribute.Type.STRING;

    @Override
    protected void init(ExpressionExecutor[] attributeExpressionExecutors,
            ExecutionPlanContext executionPlanContext) {
        if (attributeExpressionExecutors.length != 2) {
            throw new ExecutionPlanValidationException(
                    "Invalid no of arguments passed to json:getProperty() function," + " required 2, but found "
                            + attributeExpressionExecutors.length);
        }
        if (attributeExpressionExecutors[0].getReturnType() != Attribute.Type.STRING) {
            throw new ExecutionPlanValidationException(
                    "Invalid parameter type found for the first argument of json:getProperty() function, required "
                            + Attribute.Type.STRING + ", but found " + attributeExpressionExecutors[0].getReturnType()
                            .toString());
        }
        if (attributeExpressionExecutors[1].getReturnType() != Attribute.Type.STRING) {
            throw new ExecutionPlanValidationException(
                    "Invalid parameter type found for the second argument of json:getProperty() function, required "
                            + Attribute.Type.STRING + ", but found "
                            + attributeExpressionExecutors[1].getReturnType().toString());
        }
    }

    @Override
    protected Object execute(Object[] data) {
        if (data[0] == null) {
            throw new ExecutionPlanRuntimeException("Invalid input given to json:getProperty() function." +
                    " First argument cannot be null");
        }
        if (data[1] == null) {
            throw new ExecutionPlanRuntimeException("Invalid input given to json:getProperty() function. " +
                    "Second argument cannot be null");
        }
        String jsonString = (String) data[0];
        String property = (String) data[1];
        Object jsonObject;
        try {
            jsonObject = new JSONObject(jsonString).get(property);
            return jsonObject == null ? null : jsonObject.toString();
        } catch (JSONException e) {
            throw new ExecutionPlanRuntimeException("Cannot parse JSON String in json:getPeroperty() function. " + e);
        }
    }

    @Override
    protected Object execute(Object data) {
        return null;  //Since the getProperty function takes in 2 parameters, this method does not get called.
                     // Hence,not implemented.
    }

    @Override
    public void start() {
        //Nothing to start
    }

    @Override
    public void stop() {
        //Nothing to stop
    }

    @Override
    public Attribute.Type getReturnType() {
        return returnType;
    }

    @Override
    public Object[] currentState() {
        return null;    //No need to maintain a state.
    }

    @Override
    public void restoreState(Object[] state) {
        //Since there's no need to maintain a state, nothing needs to be done here.
    }
}


