/*
 * JBoss, Home of Professional Open Source.
 * See the COPYRIGHT.txt file distributed with this work for information
 * regarding copyright ownership.  Some portions may be licensed
 * to Red Hat, Inc. under one or more contributor license agreements.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA.
 */

package org.teiid.dqp.internal.process;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.teiid.adminapi.impl.ModelMetaData;
import org.teiid.adminapi.impl.VDBMetaData;
import org.teiid.core.CoreConstants;
import org.teiid.core.TeiidComponentException;
import org.teiid.core.TeiidException;
import org.teiid.core.TeiidRuntimeException;
import org.teiid.dqp.internal.datamgr.ConnectorManager;
import org.teiid.dqp.internal.datamgr.ConnectorManagerRepository;
import org.teiid.logging.LogConstants;
import org.teiid.logging.LogManager;
import org.teiid.query.QueryPlugin;
import org.teiid.query.optimizer.capabilities.BasicSourceCapabilities;
import org.teiid.query.optimizer.capabilities.CapabilitiesFinder;
import org.teiid.query.optimizer.capabilities.SourceCapabilities;
import org.teiid.query.optimizer.capabilities.SourceCapabilities.Capability;
import org.teiid.translator.SourceSystemFunctions;


/**
 */
public class CachedFinder implements CapabilitiesFinder {

	static BasicSourceCapabilities INVALID_CAPS = new BasicSourceCapabilities();
	private static BasicSourceCapabilities SYSTEM_CAPS = new BasicSourceCapabilities();
	static {
		SYSTEM_CAPS.setCapabilitySupport(Capability.CRITERIA_IN, true);
		SYSTEM_CAPS.setCapabilitySupport(Capability.CRITERIA_COMPARE_EQ, true);
		SYSTEM_CAPS.setCapabilitySupport(Capability.CRITERIA_COMPARE_ORDERED, true);
		SYSTEM_CAPS.setCapabilitySupport(Capability.CRITERIA_ONLY_LITERAL_COMPARE, true);
		SYSTEM_CAPS.setCapabilitySupport(Capability.CRITERIA_LIKE, true);
		SYSTEM_CAPS.setCapabilitySupport(Capability.CRITERIA_LIKE_ESCAPE, true);
		SYSTEM_CAPS.setCapabilitySupport(Capability.CRITERIA_LIKE_REGEX, true);
		SYSTEM_CAPS.setCapabilitySupport(Capability.CRITERIA_SIMILAR, true);
		SYSTEM_CAPS.setFunctionSupport(SourceSystemFunctions.UCASE, true);
		SYSTEM_CAPS.setSourceProperty(Capability.MAX_IN_CRITERIA_SIZE, 100000);
		SYSTEM_CAPS.setSourceProperty(Capability.MAX_DEPENDENT_PREDICATES, 1);
	}
	
    private ConnectorManagerRepository connectorRepo;
    private VDBMetaData vdb;
    
    private Map<String, SourceCapabilities> userCache = new HashMap<String, SourceCapabilities>();
    
    /**
     * Construct a CacheFinder that wraps another finder
     * @param internalFinder Finder to wrap
     */
    public CachedFinder(ConnectorManagerRepository repo, VDBMetaData vdb) {
        this.connectorRepo = repo;
        this.vdb = vdb;
    	userCache.put(CoreConstants.SYSTEM_MODEL, SYSTEM_CAPS);
    	userCache.put(CoreConstants.ODBC_MODEL, SYSTEM_CAPS);
    	userCache.put(CoreConstants.SYSTEM_ADMIN_MODEL, SYSTEM_CAPS);
    }

    /**
     * Find capabilities used the cache if possible, otherwise do the lookup.
     */
    public SourceCapabilities findCapabilities(String modelName) throws TeiidComponentException {
    	SourceCapabilities caps = userCache.get(modelName);
        if(caps != null) {
            return caps;
        }
        ModelMetaData model = vdb.getModel(modelName);
        List<String> sourceNames = model.getSourceNames();
        if (sourceNames.isEmpty()) {
        	throw new TeiidRuntimeException(QueryPlugin.Event.TEIID30499, QueryPlugin.Util.gs(QueryPlugin.Event.TEIID30499, modelName));
        }
        for (String sourceName:sourceNames) {
        	//TOOD: in multi-source mode it may be necessary to compute minimal capabilities across the sources
        	ConnectorManager mgr = this.connectorRepo.getConnectorManager(sourceName);
    		if (mgr == null) {
    			throw new TeiidComponentException(QueryPlugin.Event.TEIID30497, QueryPlugin.Util.gs(QueryPlugin.Event.TEIID30497, sourceName, modelName, sourceName));
    		}
        	try {
        		caps = mgr.getCapabilities();
        		break;
            } catch(TeiidException e) {
            	LogManager.logDetail(LogConstants.CTX_DQP, e, "Could not obtain capabilities for" + sourceName); //$NON-NLS-1$
            }
        }

        if (caps == null) {
        	caps = INVALID_CAPS;
        }
        
        userCache.put(modelName, caps);
        return caps;
    }
    
    public void addCapabilities(String connBinding, SourceCapabilities sourceCaps) {
    	userCache.put(connBinding, sourceCaps);
    }
    
    public boolean isValid(String modelName) {
    	return userCache.get(modelName) != INVALID_CAPS;
    }
        
}
