Source code for cpenv.hooks

# -*- coding: utf-8 -*-
from __future__ import absolute_import, print_function

# Standard library imports
import os
from types import ModuleType

# Local imports
from . import paths


class HookFinder(object):
    """Find python hooks by name in the provided path.

    usage::

        >>> hook_finder = HookFinder('~/.cpenv/hooks')
        >>> hook = hook_finder('precreate')
        >>> hook.run(env=VirtualEnvironment('path/to/env'))
    """

    def __init__(self, *hook_paths):
        self.hook_paths = hook_paths

    def _find_pyfile(self, hook_name):
        for path in self.hook_paths:
            hook_path = paths.normalize(path, hook_name + ".py")
            if os.path.exists(hook_path):
                return hook_path

    def find(self, hook_name):

        hook_path = self._find_pyfile(hook_name)

        if not hook_path:
            return

        try:
            with open(hook_path, "r") as f:
                code = compile(f.read(), "", "exec")
        except SyntaxError as e:
            print("SyntaxError compiling hook: {}".format(e))
            raise

        hook = ModuleType(hook_name)
        hook.__file__ = hook_path

        try:
            exec(code, hook.__dict__)
            return hook
        except Exception:
            print("Error executing hook: {}".format(hook_path))
            raise

    __call__ = find


def get_global_hook_path():
    """Returns the global hook path"""

    from .api import get_home_path

    return paths.normalize(get_home_path(), "hooks")


def run_global_hook(hook_name, *args):
    """Attempt to run a global hook by name with args"""

    hook_finder = HookFinder(get_global_hook_path())
    hook = hook_finder(hook_name)
    if hook:
        hook.run(*args)