package br.usp.libras.util;

/*
 * The author disclaims copyright to this source code. In place of
 * a legal notice, here is a blessing:
 * 
 * May you do good and not evil.
 * May you find forgiveness for yourself and forgive others.
 * May you share freely, never taking more than you give.
 *
 */
import java.sql.Types;

import org.hibernate.dialect.Dialect;
import org.hibernate.dialect.function.StandardSQLFunction;
import org.hibernate.dialect.function.SQLFunctionTemplate;
import org.hibernate.dialect.function.VarArgsSQLFunction;
import org.hibernate.Hibernate;

public class SQLiteDialect extends Dialect {
	public SQLiteDialect() {
		super();
		registerColumnType(Types.BIT, "integer");
		registerColumnType(Types.TINYINT, "tinyint");
		registerColumnType(Types.SMALLINT, "smallint");
		registerColumnType(Types.INTEGER, "integer");
		registerColumnType(Types.BIGINT, "bigint");
		registerColumnType(Types.FLOAT, "float");
		registerColumnType(Types.REAL, "real");
		registerColumnType(Types.DOUBLE, "double");
		registerColumnType(Types.NUMERIC, "numeric");
		registerColumnType(Types.DECIMAL, "decimal");
		registerColumnType(Types.CHAR, "char");
		registerColumnType(Types.VARCHAR, "varchar");
		registerColumnType(Types.LONGVARCHAR, "longvarchar");
		registerColumnType(Types.DATE, "date");
		registerColumnType(Types.TIME, "time");
		registerColumnType(Types.TIMESTAMP, "timestamp");
		registerColumnType(Types.BINARY, "blob");
		registerColumnType(Types.VARBINARY, "blob");
		registerColumnType(Types.LONGVARBINARY, "blob");
		// registerColumnType(Types.NULL, "null");
		registerColumnType(Types.BLOB, "blob");
		registerColumnType(Types.CLOB, "clob");
		registerColumnType(Types.BOOLEAN, "integer");

		 registerFunction( "concat", new VarArgsSQLFunction(Hibernate.STRING, "", "||", "") );
		 registerFunction( "mod", new SQLFunctionTemplate( Hibernate.INTEGER, "?1 % ?2" ) );
		 registerFunction( "substr", new StandardSQLFunction("substr", Hibernate.STRING) );
		 registerFunction( "substring", new StandardSQLFunction( "substr", Hibernate.STRING ) );
	}

	public boolean supportsIdentityColumns() {
		return true;
	}

	/*
	 public boolean supportsInsertSelectIdentity() {
	 return true; // As specify in NHibernate dialect
	 }
	 */

	public boolean hasDataTypeInIdentityColumn() {
		return false; // As specify in NHibernate dialect
	}

	/*
	 public String appendIdentitySelectToInsert(String insertString) {
	 return new StringBuffer(insertString.length()+30). // As specify in NHibernate dialect
	 append(insertString).
	 append("; ").append(getIdentitySelectString()).
	 toString();
	 }
	 */

	public String getIdentityColumnString() {
		// return "integer primary key autoincrement";
		return "integer";
	}

	public String getIdentitySelectString() {
		return "select last_insert_rowid()";
	}

	public boolean supportsLimit() {
		return true;
	}

	public String getLimitString(String query, boolean hasOffset) {
		return new StringBuffer(query.length() + 20).append(query).append(
				hasOffset ? " limit ? offset ?" : " limit ?").toString();
	}

	public boolean supportsTemporaryTables() {
		return true;
	}

	public String getCreateTemporaryTableString() {
		return "create temporary table if not exists";
	}

	public boolean dropTemporaryTableAfterUse() {
		return false;
	}

	public boolean supportsCurrentTimestampSelection() {
		return true;
	}

	public boolean isCurrentTimestampSelectStringCallable() {
		return false;
	}

	public String getCurrentTimestampSelectString() {
		return "select current_timestamp";
	}

	public boolean supportsUnionAll() {
		return true;
	}

	public boolean hasAlterTable() {
		return false; // As specify in NHibernate dialect
	}

	public boolean dropConstraints() {
		return false;
	}

	public String getAddColumnString() {
		return "add column";
	}

	public String getForUpdateString() {
		return "";
	}

	public boolean supportsOuterJoinForUpdate() {
		return false;
	}

	public String getDropForeignKeyString() {
		throw new UnsupportedOperationException(
				"No drop foreign key syntax supported by SQLiteDialect");
	}

	public String getAddForeignKeyConstraintString(String constraintName,
			String[] foreignKey, String referencedTable, String[] primaryKey,
			boolean referencesPrimaryKey) {
		throw new UnsupportedOperationException(
				"No add foreign key syntax supported by SQLiteDialect");
	}

	public String getAddPrimaryKeyConstraintString(String constraintName) {
		throw new UnsupportedOperationException(
				"No add primary key syntax supported by SQLiteDialect");
	}

	public boolean supportsIfExistsBeforeTableName() {
		return true;
	}

	public boolean supportsCascadeDelete() {
		return false;
	}
}