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
@@ -22,12 +23,33 @@ 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)
 
+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)
@@ -65,8 +87,8 @@ def install(virtualenv_url, virtualenv_filename, install_dir, 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'),
            'install', '--upgrade', 'Lektor'],
            cwd=scripts).wait()
@@ -79,23 +101,19 @@ def install(virtualenv_url, virtualenv_filename, install_dir, lib_dir):
 
 
 def main():
+    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.')
+
+    check_installation(install_dir)
 
     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()
+    print
+    get_confirmation()
 
     for url in json.load(urllib.urlopen(VENV_URL))['urls']:
         if url['python_version'] == 'source':