#!/usr/bin/env python
# vi: ft=python expandtab sts=4 sw=4
import os
import re
import subprocess
import sys
import urlparse

import curl


def get_release():
    proc = subprocess.Popen(['lsb_release', '-c'], stdout=subprocess.PIPE)
    out, _ = proc.communicate()
    release = out.split()[1]
    return release


def get_deb_line(client, url):
    content = client.get(url)
    # print content
    # look for "deb <a href="http://ppa.launchpad.net/bzr/ppa/ubuntu">http://ppa.launchpad.net/bzr/ppa/ubuntu</a> <span id="series-deb">jaunty</span> main"
    deb_regex = 'deb <[^>]*>([^<]*)</a> <span\n.*id="series-deb">[^<]*</span> (.*)\n'
    match = re.search(deb_regex, content)
    repo, component = match.groups()
    release = get_release()
    name = repo
    if name.startswith('http://ppa.launchpad.net/'):
        name = name.replace('http://ppa.launchpad.net/', '')
    name = name.replace('/ppa/', '/')
    name = name.replace('/', '-')
    archive_dep_regex = 'archive-dependencies(.*)archive-dependencies'
    content = content.replace('\n', ' ')
    match = re.search(archive_dep_regex, content)
    deps = []
    if match is not None:
        dep_content = match.groups()[0]
        # "<a href="/~subvertpy/+archive/ppa">"
        dep_regex = '<a href="(.*)">'
        for match in re.finditer(dep_regex, dep_content):
            depurl = urlparse.urljoin(url, match.groups()[0])
            deps.append(depurl)
    key_area_regex = 'signing-key(.*)signing-key'
    match = re.search(key_area_regex, content)
    key = None
    if match:
        key_regex = 'search=0x(.*)&'
        key = re.search(key_regex, match.groups()[0]).groups()[0]
    return "deb %s %s %s" % (repo, release, component), name , key, deps


def main(argv):
    """Enable a ppa."""
    if len(argv) != 2:
        sys.stderr.write("Usage: ppa-enable ppa-url\n")
        return 2
    print "Activating", argv[1]
    client = curl.Curl()
    needed = set()
    done = set([argv[1]])
    lines = set()
    keys = set()
    debline, name, key, deps = get_deb_line(client, argv[1])
    lines.add(debline)
    needed.update(deps)
    if key:
        keys.add(key)
    ppa_filename = "/etc/apt/sources.list.d/%s.list" % name
    while needed:
        url = needed.pop()
        if url in done:
            continue
        done.add(url)
        debline, _, key, deps = get_deb_line(client, url)
        lines.add(debline)
        needed.update(deps)
        if key:
            keys.add(key)
    # install keys
    print "Adding GPG keys for PPA"
    subprocess.call(
        ["sudo", "apt-key", "adv", "--recv-keys", "--keyserver",
         "keyserver.ubuntu.com"] + list(keys))
    print
    print "Adding deb lines for PPA to", ppa_filename
    proc = subprocess.Popen(["sudo", "tee", ppa_filename], stdin=subprocess.PIPE)
    proc.communicate(input='\n'.join(lines))
    print
    if 0 != os.WEXITSTATUS(proc.returncode):
        print "Failed to write PPA list file."
        return 2
    print "PPA Activated. Now update in synaptic."
    return 0


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