# 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 version 2 or any later version.

from i18n import _

import os, sys

import extensions, util

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 hasattr(obj, '__call__'):

        d = funcname.rfind('.')

        if d == -1:

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

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

        modname = funcname[:d]

        oldpaths = sys.path

        if hasattr(sys, "frozen"):

            # binary installs require sys.path manipulation

            modpath, modfile = os.path.split(modname)

            if modpath and modfile:

                sys.path = sys.path[:] + [modpath]

                modname = modfile

        try:

            obj = __import__(modname)

        except ImportError:

            e1 = sys.exc_type, sys.exc_value, sys.exc_traceback

            try:

                # extensions are loaded with hgext_ prefix

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

            except ImportError:

                e2 = sys.exc_type, sys.exc_value, sys.exc_traceback

                if ui.tracebackflag:

                    ui.warn(_('exception from first failed import attempt:\n'))

                ui.traceback(e1)

                if ui.tracebackflag:

                    ui.warn(_('exception from second failed import attempt:\n'))

                ui.traceback(e2)

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

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

                                 (hname, modname))

        sys.path = oldpaths

        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 hasattr(obj, '__call__'):

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

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

                             (hname, funcname))

    try:

            raise

    finally:

        sys.stdout, sys.stderr, sys.stdin = old

    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 hasattr(v, '__call__'):

            v = v()

        if isinstance(v, dict):

            # make the dictionary element order stable across Python

            # implementations

            v = ('{' +

                 ', '.join('%r: %r' % i for i in sorted(v.iteritems())) +

                 '}')

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

    if repo:

        cwd = repo.root

    else:

        cwd = os.getcwd()

    if 'HG_URL' in env and env['HG_URL'].startswith('remote:http'):

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

    else:

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

    if r:

        desc, r = util.explainexit(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

    oldstdout = -1

    if _redirect:

        stdoutno = sys.__stdout__.fileno()

        stderrno = sys.__stderr__.fileno()

        # temporarily redirect stdout to stderr, if possible

        if stdoutno >= 0 and stderrno >= 0:

            oldstdout = os.dup(stdoutno)

            os.dup2(stderrno, stdoutno)

    try:

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

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

                continue

            if hasattr(cmd, '__call__'):

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

            elif cmd.startswith('python:'):

                if cmd.count(':') >= 2:

                    path, cmd = cmd[7:].rsplit(':', 1)

                    path = util.expandpath(path)

                    if repo:

                        path = os.path.join(repo.root, path)

                    mod = extensions.loadpath(path, 'hghook.%s' % hname)

                    hookfn = getattr(mod, cmd)

                else:

                    hookfn = cmd[7:].strip()

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

            else:

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

    finally:

        if _redirect and oldstdout >= 0:

            os.dup2(oldstdout, stdoutno)

            os.close(oldstdout)

    return r