#!/usr/bin/env python

"""
Script to parse GtkBuilder XML file for signal handler references and list
them in a linker file for which symbols to dynamically export.
"""

import optparse
import os
import re
import sys
from xml.etree import ElementTree as ET

def find_handlers(xml_filename, excludes=[]):
    def is_excluded(name, excludes):
        for exclude in excludes:
            m = re.match(exclude, name)
            if m:
                return True
        return False

    tree = ET.parse(xml_filename)
    root = tree.getroot()
    handlers = []
    signals = root.findall(".//signal")

    for signal in signals:
        handler = signal.attrib["handler"]
        if not is_excluded(handler, excludes):
            handlers.append(handler)

    return sorted(handlers)

def write_dynamic_list(handlers, output_file):
    output_file.write("""\
/* This file was auto-generated by the `%s' script, do not edit. */
{
""" % os.path.basename(__file__))
    for handler in handlers:
        output_file.write("\t%s;\n" % handler)
    output_file.write("};\n")

def main(args):
    p = optparse.OptionParser(usage="%prog [-o FILE] XMLFILE")
    p.add_option("-o", "--output", metavar="FILE", dest="output_file",
        default="-", help="write the output to this file (default `-' for stdin)")

    opts, args = p.parse_args(args)

    output_file = None
    try:
        if opts.output_file == "-":
            output_file = sys.stdout
        else:
            output_file = open(opts.output_file, 'w')

        args = args[1:]
        if len(args) == 0:
            p.error("invalid XMLFILE argument, expecting a filename, got none")
        elif len(args) > 1:
            p.error("too many XMLFILE arguments, expecting a single filename")

        handlers = find_handlers(args[0], ["gtk_.+"])
        write_dynamic_list(handlers, output_file)

    finally:
        if output_file is not None and output_file is not sys.stdout:
            output_file.close()

    return 0

if __name__ == "__main__":
    sys.exit(main(sys.argv))