import os
import os.path
import platform
import re
import runpy
import subprocess
import sys
import time
import traceback
from os.path import dirname, expanduser, join
from subprocess import PIPE, CalledProcessError, Popen


class MakeCertPem:
    """ create openssl cert bundle from system certificates """

    def __init__(self, openssl):
        self.openssl = openssl

    def is_valid_cert(self, cert):
        """ check if cert is valid according to openssl"""
        cmd = [self.openssl, "x509", "-inform", "pem", "-checkend", "0", "-noout"]
        # print("D: is_valid_cert %r" % cmd)
        proc = Popen(cmd, stdin=PIPE, stdout=PIPE, stderr=PIPE)
        stdout, stderr = proc.communicate(cert)
        # print("out: %s; err:%s; ret:%i" % (stdout, stderr, proc.returncode))
        return proc.returncode == 0

    def get_certs(self):
        """ extract System's certificates then filter them by validity
            and return a list of text of valid certs
        """
        cmd = ["security", "find-certificate", "-a", "-p",
               "/System/Library/Keychains/SystemRootCertificates.keychain"]
        cert_re = re.compile(b"^-----BEGIN CERTIFICATE-----$" +
                             b".+?" +
                             b"^-----END CERTIFICATE-----$", re.M | re.S)
        try:
            certs_str = subprocess.check_output(cmd)
            all_certs = cert_re.findall(certs_str)
            print("I: extracted %i certificates" % len(all_certs))
            valid_certs = [cert for cert in all_certs
                           if self.is_valid_cert(cert)]
            print("I: of which %i are valid certificates" % len(valid_certs))
            return valid_certs
        except OSError:
            print("E: extracting certificates using %r" % cmd)
            traceback.print_exc()
        except CalledProcessError as err:
            print(("E: extracting certificates using %r, exit=%i" %
                  (cmd, err.returncode)))

    @staticmethod
    def write_certs(certs, dest):
        """ write concatenated certs to dest """
        with open(dest, "wb") as output:
            output.write(b"\n".join(certs))

    def regen(self, dest):
        """ main program """
        print("I: make_cert_pem %s %s" % (self.openssl, dest))
        certs = self.get_certs()
        if certs is None:
            print("E: no certificate extracted")
            return -1
        else:
            self.write_certs(certs, dest)
            print("I: updated %s with %i certificates" % (dest, len(certs)))
            return 0


# print("launcher.py sys.argv=", sys.argv)
bundlepath = sys.argv.pop(0)
app = os.path.basename(sys.argv[0])

bundle_contents = join(bundlepath, 'Contents')
bundle_res = join(bundle_contents, 'Resources')

bundle_lib = join(bundle_res, 'lib')
bundle_bin = join(bundle_res, 'bin')
bundle_data = join(bundle_res, 'share')
bundle_etc = join(bundle_res, 'etc')

os.environ['CHARSETALIASDIR'] = bundle_lib
os.environ['DYLD_LIBRARY_PATH'] = bundle_lib
os.environ['GTK_DATA_PREFIX'] = bundle_res
os.environ['GTK_EXE_PREFIX'] = bundle_res
os.environ['GTK_PATH'] = bundle_res
os.environ['LD_LIBRARY_PATH'] = bundle_lib
os.environ['XDG_CONFIG_DIRS'] = bundle_etc
os.environ['XDG_DATA_DIRS'] = bundle_data

os.environ['PANGO_LIBDIR'] = bundle_lib
os.environ['PANGO_RC_FILE'] = join(bundle_etc, 'pango', 'pangorc')
os.environ['PANGO_SYSCONFDIR'] = bundle_etc
os.environ['GDK_PIXBUF_MODULE_FILE'] = join(bundle_lib, 'gdk-pixbuf-2.0',
                                            '2.10.0', 'loaders.cache')
if int(platform.release().split('.')[0]) > 10:
    os.environ['GTK_IM_MODULE_FILE'] = join(bundle_etc, 'gtk-3.0',
                                            'gtk.immodules')

os.environ['GI_TYPELIB_PATH'] = join(bundle_lib, 'girepository-1.0')

# for forked python
os.environ['PYTHONHOME'] = bundle_res
# Set $PYTHON to point inside the bundle
PYVER = 'python3.8'
sys.path.append(bundle_res)
print('System Path:\n', '\n'.join(sys.path))

# see https://gpodder.github.io/docs/user-manual.html#gpodder-home-folder-and-download-location
# To override gPodder home and/or download directory:
# 1. uncomment (remove the pound sign and space) at the begining of the relevant line
# 2. replace ~/gPodderData or ~/gPodderDownloads with the path you want for your gPodder home
#    (you can move the original folder in the Finder first,
#     then drag and drop to the launcher.py in TextEdit to ensure the correct path is set)
# uncomment the following line to override gPodder home
# os.environ['GPODDER_HOME'] = expanduser('~/gPodderData')
# uncomment the following line to override gPodder download directory
# os.environ['GPODDER_DOWNLOAD_DIR'] = expanduser('~/gPodderDownloads')

for k, v in os.environ.items():
    print("%s=%s" % (k, v))


def gpodder_home():
    # don't inadvertently create the new gPodder home,
    # it would be prefered to the old one
    default_path = join(os.environ['HOME'], 'Library', 'Application Support', 'gPodder')
    cands = [
        os.environ.get('GPODDER_HOME'),
        default_path,
        join(os.environ['HOME'], 'gPodder'),
    ]
    for cand in cands:
        if cand and os.path.exists(cand):
            return cand
    return default_path


gphome = gpodder_home()
os.makedirs(join(gphome, 'openssl'), exist_ok=True)
# generate cert.extracted.pem
cert_gen = join(gphome, 'openssl', 'cert.extracted.pem')
cert_pem = join(gphome, 'openssl', 'cert.pem')
regen = False
if not os.path.isfile(cert_gen):
    regen = True
else:
    last_modified = os.stat(cert_gen).st_mtime
    regen = last_modified < time.time() - 3600 * 7

if regen:
    print('(Re)generating', cert_pem)
    openssl = join(bundle_bin, 'openssl')
    MakeCertPem(openssl).regen(cert_gen)
else:
    print('No regenerating', cert_gen, 'it\'s fresh enough')

# and link to it by default. Users may want to point cert.pem to MacPorts
# /opt/local/etc/openssl/cert.pem, for instance.
if not os.path.exists(cert_pem):
    os.symlink(os.path.basename(cert_gen), cert_pem)
# Set path to CA files
os.environ['SSL_CERT_FILE'] = cert_pem

if app == 'run-python':
    python_exe = join(bundle_contents, 'MacOS', 'python3')
    # executable is repeated as argv[0].
    # Old sys.argv[0] points to Contents/MacOS so must be removed
    args = [python_exe] + sys.argv[1:]
    # print("running", args)
    os.execv(python_exe, args)
elif app == 'run-pip':
    python_exe = join(bundle_contents, 'MacOS', 'python3')
    pip = join(bundle_contents, 'Resources', 'bin', 'pip3')
    # executable is repeated as argv[0].
    # Old sys.argv[0] points to Contents/MacOS so must be removed
    args = [python_exe, pip] + sys.argv[1:]
    # print("running", args)
    os.execv(python_exe, args)
else:
    import runpy
    runpy.run_path(join(bundle_bin, app), run_name='__main__')
