/*
 * Copyright Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags and
 * the COPYRIGHT.txt file distributed with this work.
 *
 * 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 org.teiid.query.sql.symbol;

import org.teiid.core.util.EquivalenceUtil;
import org.teiid.core.util.HashCodeUtil;
import org.teiid.query.QueryPlugin;
import org.teiid.query.metadata.TempMetadataAdapter;
import org.teiid.query.metadata.TempMetadataID;
import org.teiid.query.sql.LanguageVisitor;

/**
 * <p>This is the server's representation of a metadata group symbol.  The group
 * symbol has a name, an optional definition, and a reference to a real
 * metadata ID.  Typically, a GroupSymbol will be created only from a name and
 * possibly a definition if the group has an alias.  The metadata ID is
 * discovered only when resolving the query.</p>
 *
 * <p>For example, if the original string contained a FROM clause such as
 * "FROM Group1 AS G, Group2", there would be two GroupSymbols created.  The
 * first would have name=G, definition=Group1 and the second would have
 * name=Group2, definition=null.</p>
 */
public class GroupSymbol extends Symbol implements Comparable<GroupSymbol> {
	
    public static final String TEMP_GROUP_PREFIX = "#"; //$NON-NLS-1$

	/** Definition of the symbol, may be null */
	private String definition;

	/** Actual metadata ID */
	private Object metadataID;
    
    private boolean isTempTable;
    private boolean isGlobalTable;
    private boolean isProcedure;
    
    private String outputDefinition;
    //possible qualifier, not included with the short name
    //due do legacy choice this is ambiguous with schema and may be part of the name
    //TODO: refactor to be a proper schema reference
    private String qualifier; 
    
    private Object checkMatViewStatus;
    
	/**
	 * Construct a symbol with a name.
	 * @param name Name of the symbol
	 * @throws IllegalArgumentException If name is null
	 */
	public GroupSymbol(String name) {
		super(name);
	}

	/**
	 * Construct a symbol with a name.
	 * @param name Name of the symbol
	 * @param definition Definition of the symbol, may be null
	 * @throws IllegalArgumentException If name is null
	 */
	public GroupSymbol(String name, String definition) {
		super(name);
		setDefinition(definition);
	}
	
	private GroupSymbol(String schema, String shortName, String definition) {
		this.qualifier = schema;
		this.setShortName(shortName);
		this.setDefinition(definition);
	}
	
	public Object getModelMetadataId() {
		if (getMetadataID() instanceof TempMetadataID) {
			return ((TempMetadataID)getMetadataID()).getTableData().getModel();
		}
		return null;
	}
	
	public String getNonCorrelationName() {
	    if (this.definition == null) {
	        return this.getName();
	    }
	    return this.getDefinition();
	}

	/**
	 * Get the definition for the group symbol, which may be null
	 * @return Group definition, may be null
	 */
	public String getDefinition() {
		return definition;
	}

	/**
	 * Set the definition for the group symbol, which may be null
	 * @param definition Definition
	 */
	public void setDefinition(String definition) {
		this.definition = definition;
        this.outputDefinition = definition;
	}

	/**
	 * Get the metadata ID that this group symbol resolves to.  If
	 * the group symbol has not been resolved yet, this will be null.
	 * If the symbol has been resolved, this will never be null.
	 * @return Metadata ID object
	 */
	public Object getMetadataID() {
		return metadataID;
	}

    public void acceptVisitor(LanguageVisitor visitor) {
        visitor.visit(this);
    }

	/**
	 * Set the metadata ID that this group symbol resolves to.  It cannot
	 * be null.
	 * @param metadataID Metadata ID object
	 * @throws IllegalArgumentException If metadataID is null
	 */
	public void setMetadataID(Object metadataID) {
		if(metadataID == null) {
            throw new IllegalArgumentException(QueryPlugin.Util.getString("ERR.015.010.0016")); //$NON-NLS-1$
		}
		if (this.isImplicitTempGroupSymbol()) {
			this.isTempTable = true;
		}
		this.metadataID = metadataID;
	}

	/**
	 * Returns true if this symbol has been completely resolved with respect
	 * to actual runtime metadata.  A resolved symbol has been validated that
	 * it refers to actual metadata and will have references to the real metadata
	 * IDs if necessary.  Different types of symbols determine their resolution
	 * in different ways, so this method is abstract and must be implemented
	 * by subclasses.
	 * @return True if resolved with runtime metadata
	 */
	public boolean isResolved() {
		return (metadataID != null);
	}
    
    /**
     * Returns true if this is a symbol for a temporary (implicit or explicit) group
     * May return false for explicit temp tables prior to resolving.
     * see {@link #isTempTable()}
     * @return
     * @since 5.5
     */
    public boolean isTempGroupSymbol() {
        return isTempTable || (metadataID == null && isImplicitTempGroupSymbol());
    }
    
    public boolean isImplicitTempGroupSymbol() {
        return isTempGroupName(getNonCorrelationName());
    }

	/**
	 * Compare two groups and give an ordering.
	 * @param o Other group
	 * @return -1, 0, or 1 depending on how this compares to group
	 */
    public int compareTo(GroupSymbol o) {
    	return getName().compareTo(o.getName());
	}

	/**
	 * Return a deep copy of this object.
	 * @return Deep copy of the object
	 */
	public GroupSymbol clone() {
		GroupSymbol copy = new GroupSymbol(qualifier, getShortName(), getDefinition());
		copy.metadataID = this.metadataID;
        copy.setIsTempTable(isTempTable);
        copy.setProcedure(isProcedure);
        copy.outputDefinition = this.outputDefinition;
        copy.outputName = this.outputName;
        copy.isGlobalTable = isGlobalTable;
        copy.checkMatViewStatus = checkMatViewStatus;
		return copy;
	}

	/**
	 * Compare group symbols
	 * @param obj Other object to compare
	 * @return True if equivalent
	 */
	public boolean equals(Object obj) {
		if(this == obj) {
			return true;
		}

		if(!(obj instanceof GroupSymbol)) {
			return false;
		}
		GroupSymbol other = (GroupSymbol) obj;

		if (this.qualifier == null || other.qualifier == null) {
			return this.getName().equals(other.getName());
		}
		return EquivalenceUtil.areEqual(this.qualifier, other.qualifier) && this.getShortName().equals(other.getShortName());
	}
    
    public boolean hasAlias() {
        return getDefinition() != null;
    }
    
    public void setIsTempTable(boolean isTempTable) {
        this.isTempTable = isTempTable;
    }
    
    public static boolean isTempGroupName(String name) {
        if (name == null) 
            return false;
        return name.startsWith(TEMP_GROUP_PREFIX);
    }

    /**
     * Returns if this is a Temp Table 
     * Set after resolving.
     * @return
     */
    public boolean isTempTable() {
        return this.isTempTable;
    }
    
    /**
     * Returns if this is a pushed Common Table 
     * Set after resolving and initial common table planning
     * @return
     */
    public boolean isPushedCommonTable() {
        return isTempTable && TempMetadataAdapter.getActualMetadataId(metadataID) == metadataID;
    }

    public boolean isProcedure() {
        return this.isProcedure;
    }

    public void setProcedure(boolean isProcedure) {
        this.isProcedure = isProcedure;
    }
    
    public String getOutputDefinition() {
        return this.outputDefinition == null?this.getDefinition():this.outputDefinition;
    }

    public void setOutputDefinition(String outputDefinition) {
        this.outputDefinition = outputDefinition;
    }
    
    public boolean isGlobalTable() {
		return isGlobalTable;
	}
    
    public void setGlobalTable(boolean isGlobalTable) {
		this.isGlobalTable = isGlobalTable;
	}
    
    @Override
    public String getName() {
    	if (this.qualifier != null) {
    		return this.qualifier + Symbol.SEPARATOR + this.getShortName();
    	}
    	return super.getName();
    }
    
    @Override
    public int hashCode() {
    	if (this.qualifier != null) {
    		return HashCodeUtil.hashCode(this.qualifier.hashCode(), this.getShortName().hashCode());
    	}
    	return super.hashCode();
    }
    
    public void setName(String name) {
    	int index = name.indexOf('.');
    	if (index > 0) {
    		this.qualifier = new String(name.substring(0, index));
    		name = new String(name.substring(index + 1));
    	} else {
    		this.qualifier = null;
    	}
    	super.setShortName(name);
    }

    public void setCheckMatStatus(Object viewMatadataId) {
        this.checkMatViewStatus = viewMatadataId;
    }
    
    public Object getCheckMatViewStatus() {
        return this.checkMatViewStatus;
    }
}
