/**
 * Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright ownership. Apereo
 * 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 the
 * following location:
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0
 *
 * <p>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 org.apereo.portal.rendering.xslt;

import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apereo.portal.spring.spel.IPortalSpELService;
import org.apereo.portal.utils.cache.CacheKey;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.expression.Expression;
import org.springframework.web.context.request.ServletWebRequest;

/**
 */
public class StaticTransformerConfigurationSource implements TransformerConfigurationSource {
    protected final Logger logger = LoggerFactory.getLogger(this.getClass());

    private Properties outputProperties;
    private LinkedHashMap<String, Object> parameters;
    private IPortalSpELService portalSpELService;
    private Map<String, Expression> parameterExpressions;
    private Set<String> cacheKeyExcludedParameters = Collections.emptySet();

    @Autowired
    public void setPortalSpELService(IPortalSpELService portalSpELService) {
        this.portalSpELService = portalSpELService;
    }

    public void setProperties(Properties transformerOutputProperties) {
        this.outputProperties = transformerOutputProperties;
    }

    public void setParameters(Map<String, Object> transformerParameters) {
        this.parameters = new LinkedHashMap<String, Object>(transformerParameters);
    }

    public void setParameterExpressions(Map<String, String> parameterExpressions) {
        final Map<String, Expression> parameterExpressionsBuilder =
                new LinkedHashMap<String, Expression>();

        for (final Map.Entry<String, String> expressionEntry : parameterExpressions.entrySet()) {
            final String string = expressionEntry.getValue();
            final Expression expression = this.portalSpELService.parseExpression(string);
            parameterExpressionsBuilder.put(expressionEntry.getKey(), expression);
        }

        this.parameterExpressions = parameterExpressionsBuilder;
    }

    /** Parameter keys to exclude from the cache key. */
    public void setCacheKeyExcludedParameters(Set<String> cacheKeyExcludedParameters) {
        this.cacheKeyExcludedParameters = cacheKeyExcludedParameters;
    }

    @Override
    public CacheKey getCacheKey(HttpServletRequest request, HttpServletResponse response) {
        final LinkedHashMap<String, Object> transformerParameters =
                this.getParameters(request, response);
        transformerParameters.keySet().removeAll(this.cacheKeyExcludedParameters);
        return CacheKey.build(
                this.getClass().getName(), this.outputProperties, transformerParameters);
    }

    @Override
    public Properties getOutputProperties(
            HttpServletRequest request, HttpServletResponse response) {
        this.logger.debug("Returning output properties: {}", this.outputProperties);
        return this.outputProperties;
    }

    @Override
    public LinkedHashMap<String, Object> getParameters(
            HttpServletRequest request, HttpServletResponse response) {
        final ServletWebRequest webRequest = new ServletWebRequest(request, response);

        //Clone the static parameter map
        final LinkedHashMap<String, Object> parameters =
                new LinkedHashMap<String, Object>(this.parameters);

        //Add in any SpEL based parameters
        if (this.parameterExpressions != null) {
            for (final Map.Entry<String, Expression> expressionEntry :
                    this.parameterExpressions.entrySet()) {
                final Expression expression = expressionEntry.getValue();
                final Object value = this.portalSpELService.getValue(expression, webRequest);

                if (value != null) {
                    parameters.put(expressionEntry.getKey(), value);
                }
            }
        }

        this.logger.debug("Returning transformer parameters: {}", parameters);

        return parameters;
    }
}