/*
 * 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.
 */
package org.hibernate.dialect;

import java.sql.SQLException;
import java.sql.Types;

import org.hibernate.JDBCException;
import org.hibernate.dialect.function.AbstractAnsiTrimEmulationFunction;
import org.hibernate.dialect.function.NoArgSQLFunction;
import org.hibernate.dialect.function.SQLFunction;
import org.hibernate.dialect.function.SQLFunctionTemplate;
import org.hibernate.dialect.function.StandardSQLFunction;
import org.hibernate.dialect.function.VarArgsSQLFunction;
import org.hibernate.exception.ConstraintViolationException;
import org.hibernate.exception.DataException;
import org.hibernate.exception.GenericJDBCException;
import org.hibernate.exception.JDBCConnectionException;
import org.hibernate.exception.LockAcquisitionException;
import org.hibernate.exception.spi.SQLExceptionConverter;
import org.hibernate.exception.spi.TemplatedViolatedConstraintNameExtracter;
import org.hibernate.exception.spi.ViolatedConstraintNameExtracter;
import org.hibernate.internal.util.JdbcExceptionHelper;
import org.hibernate.type.StandardBasicTypes;

public class SQLiteDialect extends Dialect {

	public SQLiteDialect() {
		registerColumnType(Types.BIT, "boolean");
		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($p, $s)");
		registerColumnType(Types.DECIMAL, "decimal");
		registerColumnType(Types.CHAR, "char");
		registerColumnType(Types.VARCHAR, "varchar($l)");
		registerColumnType(Types.LONGVARCHAR, "longvarchar");
		registerColumnType(Types.DATE, "date");
		registerColumnType(Types.TIME, "time");
		registerColumnType(Types.TIMESTAMP, "datetime");
		registerColumnType(Types.BINARY, "blob");
		registerColumnType(Types.VARBINARY, "blob");
		registerColumnType(Types.LONGVARBINARY, "blob");
		registerColumnType(Types.BLOB, "blob");
		registerColumnType(Types.CLOB, "clob");
		registerColumnType(Types.BOOLEAN, "boolean");

		registerFunction("concat", new VarArgsSQLFunction(StandardBasicTypes.STRING, "", "||", ""));
		registerFunction("mod", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "?1 % ?2"));
		registerFunction("quote", new StandardSQLFunction("quote", StandardBasicTypes.STRING));
		registerFunction("random", new NoArgSQLFunction("random", StandardBasicTypes.INTEGER));
		registerFunction("round", new StandardSQLFunction("round"));
		registerFunction("substr", new StandardSQLFunction("substr", StandardBasicTypes.STRING));
		registerFunction("trim", new AbstractAnsiTrimEmulationFunction() {

			@Override
			protected SQLFunction resolveBothSpaceTrimFunction() {
				return new SQLFunctionTemplate(StandardBasicTypes.STRING, "trim(?1)");
			}

			@Override
			protected SQLFunction resolveBothSpaceTrimFromFunction() {
				return new SQLFunctionTemplate(StandardBasicTypes.STRING, "trim(?2)");
			}

			@Override
			protected SQLFunction resolveLeadingSpaceTrimFunction() {
				return new SQLFunctionTemplate(StandardBasicTypes.STRING, "ltrim(?1)");
			}

			@Override
			protected SQLFunction resolveTrailingSpaceTrimFunction() {
				return new SQLFunctionTemplate(StandardBasicTypes.STRING, "rtrim(?1)");
			}

			@Override
			protected SQLFunction resolveBothTrimFunction() {
				return new SQLFunctionTemplate(StandardBasicTypes.STRING, "trim(?1, ?2)");
			}

			@Override
			protected SQLFunction resolveLeadingTrimFunction() {
				return new SQLFunctionTemplate(StandardBasicTypes.STRING, "ltrim(?1, ?2)");
			}

			@Override
			protected SQLFunction resolveTrailingTrimFunction() {
				return new SQLFunctionTemplate(StandardBasicTypes.STRING, "rtrim(?1, ?2)");
			}
		});
	}





	/*
	 * @Override public boolean dropTemporaryTableAfterUse() { return true; // temporary tables are only dropped when the connection is
	 * closed. If the connection is pooled... }
	 */

	@Override
	public boolean supportsCurrentTimestampSelection() {
		return true;
	}

	@Override
	public boolean isCurrentTimestampSelectStringCallable() {
		return false;
	}

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

	private static final int SQLITE_BUSY = 5;
	private static final int SQLITE_LOCKED = 6;
	private static final int SQLITE_IOERR = 10;
	private static final int SQLITE_CORRUPT = 11;
	private static final int SQLITE_NOTFOUND = 12;
	private static final int SQLITE_FULL = 13;
	private static final int SQLITE_CANTOPEN = 14;
	private static final int SQLITE_PROTOCOL = 15;
	private static final int SQLITE_TOOBIG = 18;
	private static final int SQLITE_CONSTRAINT = 19;
	private static final int SQLITE_MISMATCH = 20;
	private static final int SQLITE_NOTADB = 26;

	@Override
	public SQLExceptionConverter buildSQLExceptionConverter() {
		return new SQLExceptionConverter() {

			@Override
			public JDBCException convert(final SQLException sqlException, final String message, final String sql) {
				final int errorCode = JdbcExceptionHelper.extractErrorCode(sqlException);
				if (errorCode == SQLITE_CONSTRAINT) {
					final String constraintName = EXTRACTER.extractConstraintName(sqlException);
					return new ConstraintViolationException(message, sqlException, sql, constraintName);
				} else if ((errorCode == SQLITE_TOOBIG) || (errorCode == SQLITE_MISMATCH)) return new DataException(message, sqlException, sql);
				else if ((errorCode == SQLITE_BUSY) || (errorCode == SQLITE_LOCKED)) return new LockAcquisitionException(message, sqlException, sql);
				else if (((errorCode >= SQLITE_IOERR) && (errorCode <= SQLITE_PROTOCOL)) || (errorCode == SQLITE_NOTADB))
					return new JDBCConnectionException(message, sqlException, sql);
				return new GenericJDBCException(message, sqlException, sql);
			}
		};
	}

	public static final ViolatedConstraintNameExtracter EXTRACTER = new TemplatedViolatedConstraintNameExtracter() {

		@Override
		protected String doExtractConstraintName(final SQLException e) throws NumberFormatException {
			return extractUsingTemplate("constraint ", " failed", e.getMessage());
		}
	};

	@Override
	public boolean supportsUnionAll() {
		return true;
	}

	@Override
	public boolean hasAlterTable() {
		return false; // As specified in NHibernate dialect
	}

	@Override
	public boolean dropConstraints() {
		return false;
	}

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

	@Override
	public String getForUpdateString() {
		return "";
	}

	@Override
	public boolean supportsOuterJoinForUpdate() {
		return false;
	}

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

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

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

	@Override
	public boolean supportsIfExistsBeforeTableName() {
		return true;
	}

	/*
	 * public boolean supportsCascadeDelete() { return true; }
	 */

	/*
	 * not case insensitive for unicode characters by default (ICU extension needed) public boolean supportsCaseInsensitiveLike() { return
	 * true; }
	 */

	@Override
	public boolean supportsTupleDistinctCounts() {
		return false;
	}

	@Override
	public String getSelectGUIDString() {
		return "select hex(randomblob(16))";
	}
}