# 
# 
import os, sys
import py
from distutils import sysconfig

class Win32PathHandling:
    """ a helper to remove things added to system PATHs in previous installations. """
    _winreg = None
    def __init__(self):
        if sys.platform == 'win32':
            try:
                import _winreg  
            except ImportError:
                print sys.stderr, "huh could not import _winreg on windows, ignoring"
            else:
                self._winreg = _winreg

    def remove_pylib_path(self):
        reg = self._winreg.ConnectRegistry(
		  None, self._winreg.HKEY_LOCAL_MACHINE)
        key = r"SYSTEM\CurrentControlSet\Control\Session Manager\Environment"
        path = self.get_registry_value(reg, key, "Path")
        newpath = self.prunepath(path)
        if newpath != path:
            print "PATH contains old py/bin/win32 scripts:", path
            print "pruning and setting a new PATH:", newpath
            self.set_registry_value(reg, key, "Path", newpath)
        # Propagate changes to current command prompt
        os.system("set PATH=%s" % path)
        self.try_propagate_system()

    def prunepath(self, path):
        basename = os.path.basename
        dirname = os.path.dirname
        l = []
        for p in path.split(';'):
            if basename(p) == "win32" and basename(dirname(p)) == "bin" \
               and basename(dirname(dirname(p))) == "py":
               continue # prune this path 
            l.append(p)
        return ";".join(l)

    def try_propagate_system(self):
        try:
            import win32gui, win32con
        except ImportError:
            return
        # Propagate changes throughout the system
        win32gui.SendMessageTimeout(win32con.HWND_BROADCAST,
            win32con.WM_SETTINGCHANGE, 0, "Environment",
            win32con.SMTO_ABORTIFHUNG, 5000)
    
    def get_registry_value(self, reg, key, value_name):
        k = self._winreg.OpenKey(reg, key)
        value = self._winreg.QueryValueEx(k, value_name)[0]
        self._winreg.CloseKey(k)
        return value
      
    def set_registry_value(self, reg, key, value_name, value):
        k = self._winreg.OpenKey(reg, key, 0, self._winreg.KEY_WRITE)
        value_type = self._winreg.REG_SZ
        # if we handle the Path value, then set its type to REG_EXPAND_SZ
        # so that things like %SystemRoot% get automatically expanded by the
        # command prompt
        if value_name == "Path":
            value_type = self._winreg.REG_EXPAND_SZ
        self._winreg.SetValueEx(k, value_name, 0, value_type, value)
        self._winreg.CloseKey(k)

def remove_scripts():
    sitepackages = py.path.local(sysconfig.get_python_lib())
    scripts = sitepackages.dirpath().dirpath().join("scripts")
    if not scripts.check():
        print "could not find script dir in", scripts
        raise SystemExit, 1
    for name in ("py.test", "py.lookup", "py.cleanup", "py.rest", 
        "py.which", "py.countloc", '_update_website.py', 
        '_makepyrelease.py', '_findpy.py', 'pytest.cmd',):
        p = scripts.join(name)
        if p.check():
            print "removing", p
            p.remove()
        p = scripts.join(name.replace(".", "_"))
        if p.check():
            print "removing", p
            p.remove()
        p = scripts.join(name + ".cmd")
        if p.check():
            print "removing", p
            p.remove()

if __name__ == "__main__":
    w32path = Win32PathHandling()
    w32path.remove_pylib_path()
    remove_scripts()