def validate_options(options):
    """Validates options."""
    kwcase = options.get('keyword_case')
    if kwcase not in [None, 'upper', 'lower', 'capitalize']:
        raise SQLParseError('Invalid value for keyword_case: '
                            '{0!r}'.format(kwcase))

    idcase = options.get('identifier_case')
    if idcase not in [None, 'upper', 'lower', 'capitalize']:
        raise SQLParseError('Invalid value for identifier_case: '
                            '{0!r}'.format(idcase))

    ofrmt = options.get('output_format')
    if ofrmt not in [None, 'sql', 'python', 'php']:
        raise SQLParseError('Unknown output format: '
                            '{0!r}'.format(ofrmt))

    strip_comments = options.get('strip_comments', False)
    if strip_comments not in [True, False]:
        raise SQLParseError('Invalid value for strip_comments: '
                            '{0!r}'.format(strip_comments))

    space_around_operators = options.get('use_space_around_operators', False)
    if space_around_operators not in [True, False]:
        raise SQLParseError('Invalid value for use_space_around_operators: '
                            '{0!r}'.format(space_around_operators))

    strip_ws = options.get('strip_whitespace', False)
    if strip_ws not in [True, False]:
        raise SQLParseError('Invalid value for strip_whitespace: '
                            '{0!r}'.format(strip_ws))

    truncate_strings = options.get('truncate_strings')
    if truncate_strings is not None:
        try:
            truncate_strings = int(truncate_strings)
        except (ValueError, TypeError):
            raise SQLParseError('Invalid value for truncate_strings: '
                                '{0!r}'.format(truncate_strings))
        if truncate_strings <= 1:
            raise SQLParseError('Invalid value for truncate_strings: '
                                '{0!r}'.format(truncate_strings))
        options['truncate_strings'] = truncate_strings
        options['truncate_char'] = options.get('truncate_char', '[...]')

    indent_columns = options.get('indent_columns', False)
    if indent_columns not in [True, False]:
        raise SQLParseError('Invalid value for indent_columns: '
                            '{0!r}'.format(indent_columns))
    elif indent_columns:
        options['reindent'] = True  # enforce reindent
    options['indent_columns'] = indent_columns

    reindent = options.get('reindent', False)
    if reindent not in [True, False]:
        raise SQLParseError('Invalid value for reindent: '
                            '{0!r}'.format(reindent))
    elif reindent:
        options['strip_whitespace'] = True

    reindent_aligned = options.get('reindent_aligned', False)
    if reindent_aligned not in [True, False]:
        raise SQLParseError('Invalid value for reindent_aligned: '
                            '{0!r}'.format(reindent))
    elif reindent_aligned:
        options['strip_whitespace'] = True

    indent_after_first = options.get('indent_after_first', False)
    if indent_after_first not in [True, False]:
        raise SQLParseError('Invalid value for indent_after_first: '
                            '{0!r}'.format(indent_after_first))
    options['indent_after_first'] = indent_after_first

    indent_tabs = options.get('indent_tabs', False)
    if indent_tabs not in [True, False]:
        raise SQLParseError('Invalid value for indent_tabs: '
                            '{0!r}'.format(indent_tabs))
    elif indent_tabs:
        options['indent_char'] = '\t'
    else:
        options['indent_char'] = ' '

    indent_width = options.get('indent_width', 2)
    try:
        indent_width = int(indent_width)
    except (TypeError, ValueError):
        raise SQLParseError('indent_width requires an integer')
    if indent_width < 1:
        raise SQLParseError('indent_width requires a positive integer')
    options['indent_width'] = indent_width

    wrap_after = options.get('wrap_after', 0)
    try:
        wrap_after = int(wrap_after)
    except (TypeError, ValueError):
        raise SQLParseError('wrap_after requires an integer')
    if wrap_after < 0:
        raise SQLParseError('wrap_after requires a positive integer')
    options['wrap_after'] = wrap_after

    comma_first = options.get('comma_first', False)
    if comma_first not in [True, False]:
        raise SQLParseError('comma_first requires a boolean value')
    options['comma_first'] = comma_first

    right_margin = options.get('right_margin')
    if right_margin is not None:
        try:
            right_margin = int(right_margin)
        except (TypeError, ValueError):
            raise SQLParseError('right_margin requires an integer')
        if right_margin < 10:
            raise SQLParseError('right_margin requires an integer > 10')
    options['right_margin'] = right_margin

    return options