#!/usr/bin/pypy

import argparse
import itertools
import os
import re
import py_compile
import subprocess
import sys


def abort(message):
    print >> sys.stderr, message
    sys.exit(1)


def package_modules(package):
    '''Iterate through all python modules in an installed Debian package'''
    p = subprocess.Popen(('dpkg', '-L', package), stdout=subprocess.PIPE,
                         stderr=subprocess.PIPE)
    files, stderr = p.communicate()
    if p.returncode != 0:
        abort('Unable to list files in %s. Is it installed?' % package)

    for fn in files.splitlines():
        if fn.endswith('.py'):
            if fn.startswith('/usr/share/doc/'):
                continue
            yield fn


def find_modules(root):
    '''Iterate through all python modules in directory tree root'''
    if os.path.isfile(root):
        yield root
        return

    for dirpath, dirnames, filenames in os.walk(root):
        for fn in filenames:
            if fn.endswith('.py'):
                yield os.path.join(dirpath, fn)


def generate_namespace_init(package, verbose):
    '''Iterate through a package's ns file.
    Create all necessary__init__.pys, and yield them.
    '''
    ns_file = os.path.join('/usr/share/pypy/ns', package)
    if not os.path.exists(ns_file):
        return
    with open(ns_file) as f:
        contents = f.read().decode('utf-8').strip()
        namespaces = [line.strip() for line in contents.splitlines()]

    for namespace in namespaces:
        init = os.path.join('/usr/lib/pypy/dist-packages',
                            namespace.replace('.', '/'),
                            '__init__.py')
        if verbose:
            print 'Ensuring %s exists' % init
        with open(init, 'w') as f:
            pass
        yield init


def main():
    parser = argparse.ArgumentParser(
        description='Byte-compile Python source files in a package, for PyPy')
    parser.add_argument('-p', '--package', metavar='PACKAGE',
                        action='append', default=[],
                        help='Debian package to byte-compile '
                             '(may be specified multiple times)')
    parser.add_argument('directory', nargs='*',
                        help='Directory tree (or file) to byte-compile')
    parser.add_argument('-X', '--exclude', metavar='REGEXPR',
                        action='append', default=[], type=re.compile,
                        help='Exclude items that match given REGEXPR '
                             '(may be specified multiple times)')
    parser.add_argument('-v', '--verbose', action='store_true',
                        help='Be more verbose')
    parser.add_argument('-q', '--quiet', action='store_true',
                        help='Be quiet')
    parser.add_argument('-V', metavar='VRANGE', dest='vrange',
                        help=argparse.SUPPRESS)
    parser.add_argument('-O', action='store_true', dest='pyo',
                        help=argparse.SUPPRESS)
    args = parser.parse_args()

    if not (args.package or args.directory):
        parser.error('Either a package or a directory must be specified')
    if args.quiet and args.verbose:
        parser.error('--quiet and --verbose cannot both be specified')

    if args.vrange:
        print >> sys.stderr, '-V is ignored in pypycompile'
    if args.pyo:
        print >> sys.stderr, '-O is ignored in pypycompile'

    modules_p = set(itertools.chain(*(
        package_modules(package) for package in args.package)))
    modules_d = set(itertools.chain(*(
        find_modules(dir_) for dir_ in args.directory)))

    if args.package and args.directory:
        modules = modules_d & modules_p
    else:
        modules = modules_d | modules_p

    for package in args.package:
        modules |= set(generate_namespace_init(package, verbose=args.verbose))

    modules = filter(lambda module: not any(pattern.match(module)
                                            for pattern in args.exclude),
                     modules)

    for module in modules:
        if args.verbose:
            print 'Byte-compiling %s' % module
        try:
            py_compile.compile(module, doraise=True)
        except py_compile.PyCompileError as e:
            if not args.quiet:
                print >> sys.stderr, ('Failed to byte-compile %s: %s'
                                      % (module, e.msg))

if __name__ == '__main__':
    main()

# vim: ft=python