#!/usr/bin/python

'''A script to buildMoonshot  potentially using a schroot for install testing.
'''

from contextlib import contextmanager
import os, subprocess, exceptions
import re
import sys
from optparse import OptionParser
from shutil import copy



# These variables can be overridden by options. If packages is not
# set, then it is read from the rpm_packages file
packages = []  # Set of packages to build
tar_file = None

class CommandError(exceptions.StandardError):
    pass

def is_tarball(name):
    return re.match('^.*\\.tar\\.gz', name)

def trim_tarball(t):
    match = re.match('([^/-]*/)?([^-/]+)', t)
    return match.group(2)

@contextmanager
def current_directory(dir):
    "Change the current directory as a context manager; when the context exits, return."
    cwd = os.getcwd()
    os.chdir(dir)
    yield
    os.chdir(cwd)


def run_cmd(args, **kwords):
    rcode =  subprocess.call( args, **kwords)
    if rcode <> 0:
        raise CommandError(args)

def command_output(args) :
    p = subprocess.Popen(args, stdout=subprocess.PIPE)
    output = p.communicate()
    output = output[0]
    if p.returncode != 0:
        raise CommandError(args)
    return output.strip()

def build(package):
    run_cmd(['rpmbuild', '-ta', package])



def read_packages():
    '''Read in the packages file from rpm_packages
    '''
    try: pf = file("rpm_packages")
    except IOError:
        print "Error: rpm_packages file not found"
        exit(1)
    def is_comment(line):
        if re.match("^\\s*#", line): return False
        if "#" in line: raise ValueError(
            "Source package line contains a comment but not at beginning")
        return True
    return map(lambda(x): x.rstrip(),
        filter(is_comment, pf.readlines()))


# main program
opt = OptionParser()
opt.usage = "%prog [options] distributions_dir [packages]"
opt.add_option('--tar-file',
               dest='tar_file',
               help = 'Tar up resulting packages in given tar file',
               default = None)
(options, args) = opt.parse_args()
tar_file = options.tar_file
if tar_file is not None:
    tar_file = os.path.join(os.getcwd(), tar_file)
if len(args) == 0:
    print "Distributions directory required"
    exit(1)
dist_dir = args[0]
packages = args[1:]

if len(packages) == 0: packages = read_packages()
package_order = {}
count = 0
tarballs = filter(is_tarball, os.listdir(dist_dir))
for t in packages:
    package_order[trim_tarball(t)] = count
    count += 1
    

os.umask(022)

try:
    run_cmd([ 'rm', '-rf',
              os.path.expanduser("~/rpmbuild")])
    rum_cmd([ 'rpmdev-setuptree'])
    with current_directory(dist_dir):
        tarballs.sort (key = lambda x: package_order[trim_tarball(x)])
        for t in tarballs:
            build(t)
    if tar_file is not None:
        with current_directory(os.path.expanduser("~/rpmbuild")):
            run_cmd(['tar', '-cf', tar_file,
                     './RPMS', './SRPMS'])

except CommandError as c:
    print "Error:" + str(c.args)
    exit(1)