/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.boot.model.naming;

import java.util.Locale;

import org.hibernate.dialect.Dialect;
import org.hibernate.internal.util.StringHelper;

Models an identifier (name), which may or may not be quoted.
Author:
Steve Ebersole/**
 * Models an identifier (name), which may or may not be quoted.
 *
 * @author Steve Ebersole
 */
public class Identifier implements Comparable<Identifier> {
	private final String text;
	private final boolean isQuoted;

	
Means to generate an Identifier instance from its simple text form. 
 If passed text is null, null is returned. 

If passed text is surrounded in quote markers, the generated Identifier
is considered quoted.  Quote markers include back-ticks (`), and
double-quotes (").
Params:
text – The text form
Returns:
The identifier form, or null if text was null/**
	 * Means to generate an {@link Identifier} instance from its simple text form.
	 * <p/>
	 * If passed text is {@code null}, {@code null} is returned.
	 * <p/>
	 * If passed text is surrounded in quote markers, the generated Identifier
	 * is considered quoted.  Quote markers include back-ticks (`), and
	 * double-quotes (").
	 *
	 * @param text The text form
	 *
	 * @return The identifier form, or {@code null} if text was {@code null}
	 */
	public static Identifier toIdentifier(String text) {
		if ( StringHelper.isEmpty( text ) ) {
			return null;
		}
		final String trimmedText = text.trim();
		if ( isQuoted( trimmedText ) ) {
			final String bareName = trimmedText.substring( 1, trimmedText.length() - 1 );
			return new Identifier( bareName, true );
		}
		else {
			return new Identifier( trimmedText, false );
		}
	}

	
Means to generate an Identifier instance from its simple text form. 
 If passed text is null, null is returned. 

If passed text is surrounded in quote markers, the generated Identifier
is considered quoted.  Quote markers include back-ticks (`), and
double-quotes (").
Params:
text – The text form
quote – Whether to quote unquoted text forms
Returns:
The identifier form, or null if text was null/**
	 * Means to generate an {@link Identifier} instance from its simple text form.
	 * <p/>
	 * If passed text is {@code null}, {@code null} is returned.
	 * <p/>
	 * If passed text is surrounded in quote markers, the generated Identifier
	 * is considered quoted.  Quote markers include back-ticks (`), and
	 * double-quotes (").
	 *
	 * @param text The text form
	 * @param quote Whether to quote unquoted text forms
	 *
	 * @return The identifier form, or {@code null} if text was {@code null}
	 */
	public static Identifier toIdentifier(String text, boolean quote) {
		if ( StringHelper.isEmpty( text ) ) {
			return null;
		}
		final String trimmedText = text.trim();
		if ( isQuoted( trimmedText ) ) {
			final String bareName = trimmedText.substring( 1, trimmedText.length() - 1 );
			return new Identifier( bareName, true );
		}
		else {
			return new Identifier( trimmedText, quote );
		}
	}

	
Is the given identifier text considered quoted.  The following patterns are
recognized as quoted:

    
`name`
    
[name]
    
"name"


That final form using double-quote (") is the JPA-defined quoting pattern.  Although
it is the standard, it makes for ugly declarations.
Params:
name – 
Returns:
/**
	 * Is the given identifier text considered quoted.  The following patterns are
	 * recognized as quoted:<ul>
	 *     <li>{@code `name`}</li>
	 *     <li>{@code [name]}</li>
	 *     <li>{@code "name"}</li>
	 * </ul>
	 * <p/>
	 * That final form using double-quote (") is the JPA-defined quoting pattern.  Although
	 * it is the standard, it makes for ugly declarations.
	 *
	 * @param name
	 *
	 * @return
	 */
	public static boolean isQuoted(String name) {
		return ( name.startsWith( "`" ) && name.endsWith( "`" ) )
				|| ( name.startsWith( "[" ) && name.endsWith( "]" ) )
				|| ( name.startsWith( "\"" ) && name.endsWith( "\"" ) );
	}

	
Constructs an identifier instance.
Params:
text – The identifier text.
quoted – Is this a quoted identifier?/**
	 * Constructs an identifier instance.
	 *
	 * @param text The identifier text.
	 * @param quoted Is this a quoted identifier?
	 */
	public Identifier(String text, boolean quoted) {
		if ( StringHelper.isEmpty( text ) ) {
			throw new IllegalIdentifierException( "Identifier text cannot be null" );
		}
		if ( isQuoted( text ) ) {
			throw new IllegalIdentifierException( "Identifier text should not contain quote markers (` or \")" );
		}
		this.text = text;
		this.isQuoted = quoted;
	}

	
Constructs an unquoted identifier instance.
Params:
text – The identifier text./**
	 * Constructs an unquoted identifier instance.
	 *
	 * @param text The identifier text.
	 */
	protected Identifier(String text) {
		this.text = text;
		this.isQuoted = false;
	}

	
Get the identifiers name (text)
Returns:
The name/**
	 * Get the identifiers name (text)
	 *
	 * @return The name
	 */
	public String getText() {
		return text;
	}

	
Is this a quoted identifier>
Returns:
True if this is a quote identifier; false otherwise./**
	 * Is this a quoted identifier>
	 *
	 * @return True if this is a quote identifier; false otherwise.
	 */
	public boolean isQuoted() {
		return isQuoted;
	}

	
If this is a quoted identifier, then return the identifier name
enclosed in dialect-specific open- and end-quotes; otherwise,
simply return the unquoted identifier.
Params:
dialect – The dialect whose dialect-specific quoting should be used.
Returns:
if quoted, identifier name enclosed in dialect-specific open- and
end-quotes; otherwise, the unquoted identifier./**
	 * If this is a quoted identifier, then return the identifier name
	 * enclosed in dialect-specific open- and end-quotes; otherwise,
	 * simply return the unquoted identifier.
	 *
	 * @param dialect The dialect whose dialect-specific quoting should be used.
	 *
	 * @return if quoted, identifier name enclosed in dialect-specific open- and
	 * end-quotes; otherwise, the unquoted identifier.
	 */
	public String render(Dialect dialect) {
		return isQuoted
				? String.valueOf( dialect.openQuote() ) + getText() + dialect.closeQuote()
				: getText();
	}

	public String render() {
		return isQuoted
				? '`' + getText() + '`'
				: getText();
	}

	public String getCanonicalName() {
		return isQuoted ? text : text.toLowerCase( Locale.ENGLISH );
	}

	@Override
	public String toString() {
		return render();
	}

	@Override
	public boolean equals(Object o) {
		if ( !(o instanceof Identifier) ) {
			return false;
		}

		final Identifier that = (Identifier) o;
		return getCanonicalName().equals( that.getCanonicalName() );
	}

	@Override
	public int hashCode() {
		return isQuoted ? text.hashCode() : text.toLowerCase( Locale.ENGLISH ).hashCode();
	}

	public static boolean areEqual(Identifier id1, Identifier id2) {
		if ( id1 == null ) {
			return id2 == null;
		}
		else {
			return id1.equals( id2 );
		}
	}

	public static Identifier quote(Identifier identifier) {
		return identifier.isQuoted()
				? identifier
				: Identifier.toIdentifier( identifier.getText(), true );
	}

	@Override
	public int compareTo(Identifier o) {
		return getCanonicalName().compareTo( o.getCanonicalName() );
	}
}