/*
 * 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 java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.teiid.core.TeiidProcessingException;
import org.teiid.core.types.DataTypeManager;
import org.teiid.core.util.EquivalenceUtil;
import org.teiid.core.util.HashCodeUtil;
import org.teiid.core.util.StringUtil;
import org.teiid.query.QueryPlugin;
import org.teiid.query.sql.LanguageObject;
import org.teiid.query.sql.LanguageVisitor;
import org.teiid.query.sql.visitor.SQLStringVisitor;

/**
 * Represents the only allowable expression for the textagg aggregate.
 * This is a Teiid specific construct.
 */
public class TextLine implements Expression {
	public static final String nl = System.getProperty("line.separator"); //$NON-NLS-1$
	public static final char NO_QUOTE_CHAR = 0;
	
	private Character delimiter;
	private Character quote;
	private boolean includeHeader;
	private List<DerivedColumn> expressions;
	private String encoding;
	private String lineEnding = nl;
	
	public Character getDelimiter() {
		return delimiter;
	}

	public void setDelimiter(Character delimiter) {
		this.delimiter = delimiter;
	}
	
	public String getEncoding() {
		return encoding;
	}
	
	public void setEncoding(String encoding) {
		this.encoding = encoding;
	}

	public Character getQuote() {
		return quote;
	}

	public void setQuote(Character quote) {
		this.quote = quote;
	}

	public boolean isIncludeHeader() {
		return includeHeader;
	}

	public void setIncludeHeader(boolean includeHeader) {
		this.includeHeader = includeHeader;
	}

	public List<DerivedColumn> getExpressions() {
		return expressions;
	}

	public void setExpressions(List<DerivedColumn> expressions) {
		this.expressions = expressions;
	}	
	
	public String getLineEnding() {
		return lineEnding;
	}
	
	public void setLineEnding(String lineEnding) {
		this.lineEnding = lineEnding;
	}
	
	@Override
	public Class<?> getType() {
		return String[].class;
	}

	@Override
	public void acceptVisitor(LanguageVisitor visitor) {
		visitor.visit(this);
	}
	
	@Override
	public TextLine clone() {
		TextLine clone = new TextLine();
		clone.expressions = LanguageObject.Util.deepClone(this.expressions, DerivedColumn.class);
		clone.delimiter = this.delimiter;
		clone.quote = this.quote;
		clone.includeHeader = this.includeHeader;
		clone.encoding = this.encoding;
		return clone;
	}

	@Override
	public boolean equals(Object obj) {
		if (obj == this) {
			return true;
		}
		if (!(obj instanceof TextLine)) {
			return false;
		}
		TextLine other = (TextLine)obj;
		return EquivalenceUtil.areEqual(this.expressions, other.expressions)
			  && EquivalenceUtil.areEqual(this.delimiter, other.delimiter)
			  && EquivalenceUtil.areEqual(this.quote, other.quote)
			  && this.includeHeader == other.includeHeader
			  && EquivalenceUtil.areEqual(this.encoding, other.encoding);
	}

	@Override
	public int hashCode() {
		return HashCodeUtil.expHashCode(0, this.expressions);
	}	
	
	@Override
	public String toString() {
		return SQLStringVisitor.getSQLString(this);
	}	
	
	public static interface ValueExtractor<T> {
		Object getValue(T t);
	}
	
	public static <T> String[] evaluate(final List<T> values, ValueExtractor<T> valueExtractor, TextLine textLine) throws TeiidProcessingException {
		Character delimeter = textLine.getDelimiter();
		if (delimeter == null) {
			delimeter = Character.valueOf(',');
		}
		String delim = String.valueOf(delimeter.charValue());
		Character quote = textLine.getQuote();
		String quoteStr = null;		
		if (quote == null) {
			quoteStr = "\""; //$NON-NLS-1$
		} else if (quote.charValue() != NO_QUOTE_CHAR) {
			quoteStr = String.valueOf(quote);
		}
		String doubleQuote = null;
		if (quoteStr != null) {
			doubleQuote = quoteStr + quoteStr;
		}
		ArrayList<String> result = new ArrayList<String>();
		for (Iterator<T> iterator = values.iterator(); iterator.hasNext();) {
			T t = iterator.next();
			String text = (String)DataTypeManager.transformValue(valueExtractor.getValue(t), DataTypeManager.DefaultDataClasses.STRING);
			if (text != null) {
				if (quoteStr != null) {
					result.add(quoteStr);
					result.add(StringUtil.replaceAll(text, quoteStr, doubleQuote));
					result.add(quoteStr);
				} else {
					if (text.indexOf(delimeter) > -1 || text.indexOf(textLine.getLineEnding()) > -1) {
						throw new TeiidProcessingException(QueryPlugin.Event.TEIID31201, QueryPlugin.Util.gs(QueryPlugin.Event.TEIID31201, text));
					}
					result.add(text);
				}
			}
			if (iterator.hasNext()) {
				result.add(delim);
			}			
		}
		result.add(textLine.getLineEnding());
		return result.toArray(new String[result.size()]);
	}
	
}
