package SQLite;

/**
 * Class to represent compiled SQLite3 statement.
 *
 * Note, that all native methods of this class are
 * not synchronized, i.e. it is up to the caller
 * to ensure that only one thread is in these
 * methods at any one time.
 */

public class Stmt {

    /**
     * Internal handle for the SQLite3 statement.
     */

    private long handle = 0;

    /**
     * Internal last error code for prepare()/step() methods.
     */

    protected int error_code = 0;

    /**
     * Prepare the next SQL statement for the Stmt instance.
     * @return true when the next piece of the SQL statement sequence
     * has been prepared, false on end of statement sequence.
     */

    public native boolean prepare() throws SQLite.Exception;

    /**
     * Perform one step of compiled SQLite3 statement.
     *
     * Example:<BR>
     * <PRE>
     *   ...
     *   try {
     *     Stmt s = db.prepare("select * from x; select * from y;");
     *     s.bind(...);
     *     ...
     *     s.bind(...);
     *     while (s.step(cb)) {
     *       Object o = s.value(...);
     *       ...
     *     }
     *     // s.reset() for re-execution or
     *     // s.prepare() for the next piece of SQL
     *     while (s.prepare()) {
     *       s.bind(...);
     *       ...
     *       s.bind(...);
     *       while (s.step(cb)) {
     *         Object o = s.value(...);
     *         ...
     *       }
     *     }
     *   } catch (SQLite.Exception e) {
     *     s.close();
     *   }
     * </PRE>
     *
     * @return true when row data is available, false on end
     * of result set.
     */

    public native boolean step() throws SQLite.Exception;

    /**
     * Close the compiled SQLite3 statement.
     */

    public native void close() throws SQLite.Exception;

    /**
     * Reset the compiled SQLite3 statement without
     * clearing parameter bindings.
     */

    public native void reset() throws SQLite.Exception;

    /**
     * Clear all bound parameters of the compiled SQLite3 statement.
     */

    public native void clear_bindings() throws SQLite.Exception;

    /**
     * Bind positional integer value to compiled SQLite3 statement.
     * @param pos parameter index, 1-based
     * @param value value of parameter
     */

    public native void bind(int pos, int value) throws SQLite.Exception;

    /**
     * Bind positional long value to compiled SQLite3 statement.
     * @param pos parameter index, 1-based
     * @param value value of parameter
     */

    public native void bind(int pos, long value) throws SQLite.Exception;

    /**
     * Bind positional double value to compiled SQLite3 statement.
     * @param pos parameter index, 1-based
     * @param value value of parameter
     */

    public native void bind(int pos, double value) throws SQLite.Exception;

    /**
     * Bind positional byte array to compiled SQLite3 statement.
     * @param pos parameter index, 1-based
     * @param value value of parameter, may be null
     */

    public native void bind(int pos, byte[] value) throws SQLite.Exception;

    /**
     * Bind positional String to compiled SQLite3 statement.
     * @param pos parameter index, 1-based
     * @param value value of parameter, may be null
     */

    public native void bind(int pos, String value) throws SQLite.Exception;

    /**
     * Bind positional SQL null to compiled SQLite3 statement.
     * @param pos parameter index, 1-based
     */

    public native void bind(int pos) throws SQLite.Exception;

    /**
     * Bind positional zero'ed blob to compiled SQLite3 statement.
     * @param pos parameter index, 1-based
     * @param length byte size of zero blob
     */

    public native void bind_zeroblob(int pos, int length)
	throws SQLite.Exception;

    /**
     * Return number of parameters in compiled SQLite3 statement.
     * @return int number of parameters
     */

    public native int bind_parameter_count() throws SQLite.Exception;

    /**
     * Return name of parameter in compiled SQLite3 statement.
     * @param pos parameter index, 1-based
     * @return String parameter name
     */

    public native String bind_parameter_name(int pos) throws SQLite.Exception;

    /**
     * Return index of named parameter in compiled SQLite3 statement.
     * @param name of parameter
     * @return int index of parameter, 1-based
     */

    public native int bind_parameter_index(String name)
	throws SQLite.Exception;


    /**
     * Retrieve integer column from exec'ed SQLite3 statement.
     * @param col column number, 0-based
     * @return int column value
     */

    public native int column_int(int col) throws SQLite.Exception;

    /**
     * Retrieve long column from exec'ed SQLite3 statement.
     * @param col column number, 0-based
     * @return long column value
     */
    public native long column_long(int col) throws SQLite.Exception;

    /**
     * Retrieve double column from exec'ed SQLite3 statement.
     * @param col column number, 0-based
     * @return double column value
     */
    public native double column_double(int col) throws SQLite.Exception;

    /**
     * Retrieve blob column from exec'ed SQLite3 statement.
     * @param col column number, 0-based
     * @return byte[] column value
     */
    public native byte[] column_bytes(int col) throws SQLite.Exception;

    /**
     * Retrieve string column from exec'ed SQLite3 statement.
     * @param col column number, 0-based
     * @return String column value
     */
    public native String column_string(int col) throws SQLite.Exception;

    /**
     * Retrieve column type from exec'ed SQLite3 statement.
     * @param col column number, 0-based
     * @return column type code, e.g. SQLite.Constants.SQLITE_INTEGER
     */
    public native int column_type(int col) throws SQLite.Exception;

    /**
     * Retrieve number of columns of exec'ed SQLite3 statement.
     * @return int number of columns
     */

    public native int column_count() throws SQLite.Exception;

    /**
     * Retrieve column data as object from exec'ed SQLite3 statement.
     * @param col column number, 0-based
     * @return Object or null
     */

    public Object column(int col) throws SQLite.Exception {
	switch (column_type(col)) {
	case Constants.SQLITE_INTEGER:
	    return new Long(column_long(col));
	case Constants.SQLITE_FLOAT:
	    return new Double(column_double(col));
	case Constants.SQLITE_BLOB:
	    return column_bytes(col);
	case Constants.SQLITE3_TEXT:
	    return column_string(col);
	}
	return null;
    }

    /**
     * Return table name of column of SQLite3 statement.
     * @param col column number, 0-based
     * @return String or null
     */

    public native String column_table_name(int col) throws SQLite.Exception;

    /**
     * Return database name of column of SQLite3 statement.
     * @param col column number, 0-based
     * @return String or null
     */

    public native String column_database_name(int col) throws SQLite.Exception;

    /**
     * Return declared column type of SQLite3 statement.
     * @param col column number, 0-based
     * @return String or null
     */

    public native String column_decltype(int col) throws SQLite.Exception;

    /**
     * Return origin column name of column of SQLite3 statement.
     * @param col column number, 0-based
     * @return String or null
     */

    public native String column_origin_name(int col) throws SQLite.Exception;

    /**
     * Return statement status information.
     * @param op which counter to report
     * @param flg reset flag
     * @return counter
     */

    public native int status(int op, boolean flg);

    /**
     * Destructor for object.
     */

    protected native void finalize();

    /**
     * Internal native initializer.
     */

    private static native void internal_init();

    static {
	internal_init();
    }
}