Wiping previous installs plus confirmation

assets/install.ps1

@@ -5,6 +5,7 @@ import json
 import urllib
 import tempfile
 import tarfile
+import shutil
 from subprocess import Popen
 from _winreg import OpenKey, CloseKey, QueryValueEx, SetValueEx, \
                    HKEY_CURRENT_USER, KEY_ALL_ACCESS, REG_EXPAND_SZ
@@ -22,94 +23,111 @@ LRESULT = LPARAM
 HWND_BROADCAST = 0xFFFF
 WM_SETTINGCHANGE = 0x1A
 
+
+def get_confirmation():
+    while 1:
+        input = raw_input('Continue? [Yn] ').lower().strip()
+        if input in ('', 'y'):
+            break
+        elif input == 'n':
+            print
+            print 'Aborted!'
+            sys.exit()
+
 def find_location():
-   install_dir = os.path.join(APPDATA, APP)
-   if os.path.exists(install_dir) and os.path.isdir(install_dir):
-       return None, None
-   return install_dir, os.path.join(install_dir, LIB)
+    install_dir = os.path.join(APPDATA, APP)
+    return install_dir, os.path.join(install_dir, LIB)
+
+def wipe_installation(install_dir):
+    shutil.rmtree(install_dir, ignore_errors=True)
+
+def check_installation(install_dir):
+    if os.path.exists(install_dir):
+        print '   Lektor seems to be installed already.'
+        print '   Continuing will wipe %s' % install_dir
+        print
+        get_confirmation()
+        print
+        wipe_installation(install_dir)
 
 def fail(message):
-   print 'Error: %s' % message
-   sys.exit(1)
+    print 'Error: %s' % message
+    sys.exit(1)
 
 def add_to_path(location):
-   reg_key = OpenKey(ROOT_KEY, SUB_KEY, 0, KEY_ALL_ACCESS)
+    reg_key = OpenKey(ROOT_KEY, SUB_KEY, 0, KEY_ALL_ACCESS)
 
-   try:
-       path_value, _ = QueryValueEx(reg_key, 'Path')
-   except WindowsError:
-       path_value = ''
+    try:
+        path_value, _ = QueryValueEx(reg_key, 'Path')
+    except WindowsError:
+        path_value = ''
 
-   paths = path_value.split(';')
-   if location not in paths:
-       paths.append(location)
-       path_value = ';'.join(paths)
-       SetValueEx(reg_key, 'Path', 0, REG_EXPAND_SZ, path_value)
+    paths = path_value.split(';')
+    if location not in paths:
+        paths.append(location)
+        path_value = ';'.join(paths)
+        SetValueEx(reg_key, 'Path', 0, REG_EXPAND_SZ, path_value)
 
-   SendMessage = ctypes.windll.user32.SendMessageW
-   SendMessage.argtypes = HWND, UINT, WPARAM, LPVOID
-   SendMessage.restype = LRESULT
-   SendMessage(HWND_BROADCAST, WM_SETTINGCHANGE, 0, u'Environment')
+    SendMessage = ctypes.windll.user32.SendMessageW
+    SendMessage.argtypes = HWND, UINT, WPARAM, LPVOID
+    SendMessage.restype = LRESULT
+    SendMessage(HWND_BROADCAST, WM_SETTINGCHANGE, 0, u'Environment')
 
 def install(virtualenv_url, virtualenv_filename, install_dir, lib_dir):
-   t = tempfile.mkdtemp()
-   with open(os.path.join(t, 'virtualenv.tar.gz'), 'wb') as f:
-       download = urllib.urlopen(virtualenv_url)
-       f.write(download.read())
-       download.close()
-   with tarfile.open(os.path.join(t, 'virtualenv.tar.gz'), 'r:gz') as tar:
-       tar.extractall(path=t)
+    t = tempfile.mkdtemp()
+    with open(os.path.join(t, 'virtualenv.tar.gz'), 'wb') as f:
+        download = urllib.urlopen(virtualenv_url)
+        f.write(download.read())
+        download.close()
+    with tarfile.open(os.path.join(t, 'virtualenv.tar.gz'), 'r:gz') as tar:
+        tar.extractall(path=t)
 
-   os.makedirs(install_dir)
-   os.makedirs(lib_dir)
+    os.makedirs(install_dir)
+    os.makedirs(lib_dir)
 
-   Popen(['python', 'virtualenv.py', lib_dir],
+    Popen(['python', 'virtualenv.py', lib_dir],
            cwd=os.path.join(t, virtualenv_filename)).wait()
-   scripts = os.path.join(lib_dir, 'Scripts')
-   #just using pip.exe and cwd will still install globally
-   Popen([os.path.join(scripts, 'pip.exe'),
+
+    scripts = os.path.join(lib_dir, 'Scripts')
+    Popen([os.path.join(scripts, 'pip.exe'),
            'install', '--upgrade', 'Lektor'],
            cwd=scripts).wait()
 
-   with open(os.path.join(install_dir, 'lektor.cmd'), 'w') as link_file:
-       link_file.write('@echo off\n')
-       link_file.write('\"' + os.path.join(scripts, 'lektor.exe') + '\"' + ' %*')
+    with open(os.path.join(install_dir, 'lektor.cmd'), 'w') as link_file:
+        link_file.write('@echo off\n')
+        link_file.write('\"' + os.path.join(scripts, 'lektor.exe') + '\"' + ' %*')
 
-   add_to_path(install_dir)
+    add_to_path(install_dir)
 
 
 def main():
-   print 'Welcome to Lektor'
-   print
-   print 'This script will install Lektor on your computer.'
-   print
+    print
+    print 'Welcome to Lektor'
+    print
+    print 'This script will install Lektor on your computer.'
+    print
 
-   install_dir, lib_dir = find_location()
-   if install_dir == None:
-       fail('Lektor seems to be installed already.')
+    install_dir, lib_dir = find_location()
 
-   print '   Installing at: %s' % install_dir
-   while 1:
-       input = raw_input('Continue? [Yn] ').lower().strip()
-       if input in ('', 'y'):
-           break
-       elif input == 'n':
-           print 'Aborted!'
-           sys.exit()
+    check_installation(install_dir)
 
-   for url in json.load(urllib.urlopen(VENV_URL))['urls']:
-       if url['python_version'] == 'source':
-           virtualenv_url = url['url']
-           #stripping '.tar.gz'
-           virtualenv_filename = url['filename'][:-7]
-           break
-   else:
-       fail('Could not find virtualenv')
+    print '   Installing at: %s' % install_dir
+    print
+    get_confirmation()
 
-   install(virtualenv_url, virtualenv_filename, install_dir, lib_dir)
+    for url in json.load(urllib.urlopen(VENV_URL))['urls']:
+        if url['python_version'] == 'source':
+            virtualenv_url = url['url']
+            #stripping '.tar.gz'
+            virtualenv_filename = url['filename'][:-7]
+            break
+    else:
+        fail('Could not find virtualenv')
 
-   print
-   print 'All done!'
+    install(virtualenv_url, virtualenv_filename, install_dir, lib_dir)
+
+    print
+    print 'All done!'
 
 main()
 "@