# hook.py - hook support for mercurial

#

# Copyright 2007 Matt Mackall <mpm@selenic.com>

#

# This software may be used and distributed according to the terms

# of the GNU General Public License, incorporated herein by reference.

from i18n import _

import util, os, sys

def _pythonhook(ui, repo, name, hname, funcname, args, throw):

    '''call python hook. hook is callable object, looked up as

    name in python module. if callable returns "true", hook

    fails, else passes. if hook raises exception, treated as

    hook failure. exception propagates if throw is "true".

    reason for "true" meaning "hook failed" is so that

    unmodified commands (e.g. mercurial.commands.update) can

    be run as hooks without wrappers to convert return values.'''

    ui.note(_("calling hook %s: %s\n") % (hname, funcname))

    obj = funcname

    if not callable(obj):

        d = funcname.rfind('.')

        if d == -1:

            raise util.Abort(_('%s hook is invalid ("%s" not in '

                               'a module)') % (hname, funcname))

        modname = funcname[:d]

        try:

            obj = __import__(modname)

        except ImportError:

            try:

                # extensions are loaded with hgext_ prefix

                obj = __import__("hgext_%s" % modname)

            except ImportError:

                raise util.Abort(_('%s hook is invalid '

                                   '(import of "%s" failed)') %

                                 (hname, modname))

        try:

            for p in funcname.split('.')[1:]:

                obj = getattr(obj, p)

        except AttributeError:

            raise util.Abort(_('%s hook is invalid '

                               '("%s" is not defined)') %

                             (hname, funcname))

        if not callable(obj):

            raise util.Abort(_('%s hook is invalid '

                               '("%s" is not callable)') %

                             (hname, funcname))

    try:

        r = obj(ui=ui, repo=repo, hooktype=name, **args)

    except KeyboardInterrupt:

        raise

    except Exception, exc:

        if isinstance(exc, util.Abort):

            ui.warn(_('error: %s hook failed: %s\n') %

                         (hname, exc.args[0]))

        else:

            ui.warn(_('error: %s hook raised an exception: '

                           '%s\n') % (hname, exc))

        if throw:

            raise

        ui.print_exc()

        return True

    if r:

        if throw:

            raise util.Abort(_('%s hook failed') % hname)

        ui.warn(_('warning: %s hook failed\n') % hname)

    return r

def _exthook(ui, repo, name, cmd, args, throw):

    ui.note(_("running hook %s: %s\n") % (name, cmd))

    env = {}

    for k, v in args.iteritems():

        if callable(v):

            v = v()

        env['HG_' + k.upper()] = v

    if repo:

        cwd = repo.root

    else:

        cwd = os.getcwd()

    r = util.system(cmd, environ=env, cwd=cwd)

    if r:

        desc, r = util.explain_exit(r)

        if throw:

            raise util.Abort(_('%s hook %s') % (name, desc))

        ui.warn(_('warning: %s hook %s\n') % (name, desc))

    return r

_redirect = False

def redirect(state):

    global _redirect

    _redirect = state

def hook(ui, repo, name, throw=False, **args):

    r = False

    if _redirect:

        # temporarily redirect stdout to stderr

        oldstdout = os.dup(sys.__stdout__.fileno())

        os.dup2(sys.__stderr__.fileno(), sys.__stdout__.fileno())

    try:

        for hname, cmd in util.sort(ui.configitems('hooks')):

            if hname.split('.')[0] != name or not cmd:

                continue

            if callable(cmd):

                r = _pythonhook(ui, repo, name, hname, cmd, args, throw) or r

            elif cmd.startswith('python:'):

                r = _pythonhook(ui, repo, name, hname, cmd[7:].strip(),

                                args, throw) or r

            else:

                r = _exthook(ui, repo, hname, cmd, args, throw) or r

    finally:

        if _redirect:

            os.dup2(oldstdout, sys.__stdout__.fileno())

            os.close(oldstdout)

    return r