import os
from subprocess import PIPE, Popen
import ctypes
import ssl
import urllib2
import time

# ------------------------------------------------------------
# Disable WOW64 filesystem redirection
# ------------------------------------------------------------
class disable_file_system_redirection:
    _disable = ctypes.windll.kernel32.Wow64DisableWow64FsRedirection
    _revert = ctypes.windll.kernel32.Wow64RevertWow64FsRedirection
    def __enter__(self):
        self.old_value = ctypes.c_long()
        self.success = self._disable(ctypes.byref(self.old_value))
    def __exit__(self, type, value, traceback):
        if self.success:
            self._revert(self.old_value)

# ------------------------------------------------------------
# Download details
# ------------------------------------------------------------
url = "https://cdn-patchportal-one.comodo.com/portal/packages/spm/Dell%20Command%20Update/x64/Dell-5.7.0.EXE"
Down_path = os.environ['TEMP']
fileName = url.split('/')[-1]
DownTo = os.path.join(Down_path, fileName)

# ------------------------------------------------------------
# Execute command
# ------------------------------------------------------------
def ecmd(command):
    with disable_file_system_redirection():
        obj = Popen(command, shell=True, stdout=PIPE, stderr=PIPE)
    obj.communicate()
    return obj.returncode

# ------------------------------------------------------------
# Download installer
# ------------------------------------------------------------
def downloadFile(DownTo, fromURL):
    headers = {'User-Agent': 'Mozilla/5.0'}
    context = ssl._create_unverified_context()
    request = urllib2.Request(fromURL, headers=headers)
    req = urllib2.urlopen(request, context=context)

    with open(DownTo, 'wb') as f:
        while True:
            chunk = req.read(1024 * 1024)
            if not chunk:
                break
            f.write(chunk)

    return os.path.isfile(DownTo)

# ------------------------------------------------------------
# Check if any Dell product exists (after DCU removal)
# ------------------------------------------------------------
def dell_products_exist():
    cmd = (
        'wmic product where '
        '"name like \'Dell %%\'" '
        'get name'
    )
    output = os.popen(cmd).read()
    lines = [l.strip() for l in output.splitlines()
             if l.strip() and 'Name' not in l and 'Dell Core Services' not in l]
    return len(lines) > 0

# ------------------------------------------------------------
# Uninstall Dell Core Services ONLY if no Dell products exist
# ------------------------------------------------------------
def uninstall_dell_core_services():
    if dell_products_exist():
        print("Dell products still present. Dell Core Services will NOT be removed.")
        return

    print("No Dell products found. Uninstalling Dell Core Services.")
    ecmd(
        'wmic product where "name=\'Dell Core Services\'" '
        'call uninstall /nointeractive'
    )

# ------------------------------------------------------------
# Install
# ------------------------------------------------------------
def spm_install(dir, args):
    with disable_file_system_redirection():
        if downloadFile(DownTo, url):
            ecmd('"%s" /s' % DownTo)
            time.sleep(10)
            if os.path.exists(DownTo):
                os.remove(DownTo)

# ------------------------------------------------------------
# Uninstall (Correct Order)
# ------------------------------------------------------------
def spm_uninstall(dir, args):
    with disable_file_system_redirection():
        # 1. Remove Dell Command | Update first
        ecmd(
            'wmic product where '
            '"name like \'Dell Command | Update%%\'" '
            'call uninstall /nointeractive'
        )

        time.sleep(15)

        # 2. Decide about Dell Core Services
        uninstall_dell_core_services()

# ------------------------------------------------------------
# Update
# ------------------------------------------------------------
def spm_update(dir, args):
    with disable_file_system_redirection():
        spm_uninstall(None, None)
        time.sleep(20)
        spm_install(None, None)