# 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 __future__ import absolute_import

import contextlib

import os

import sys

from .i18n import _

from .pycompat import getattr

from . import (

    demandimport,

    encoding,

    error,

    extensions,

    pycompat,

    util,

)

from .utils import (

    procutil,

    resourceutil,

    stringutil,

)

def pythonhook(ui, repo, htype, 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.'''

    if callable(funcname):

        obj = funcname

        funcname = pycompat.sysbytes(obj.__module__ + "." + obj.__name__)

    else:

        d = funcname.rfind(b'.')

        if d == -1:

            raise error.HookLoadError(

                _(b'%s hook is invalid: "%s" not in a module')

                % (hname, funcname)

            )

        modname = funcname[:d]

        oldpaths = sys.path

        if resourceutil.mainfrozen():

            # binary installs require sys.path manipulation

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

            if modpath and modfile:

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

                modname = modfile

        with demandimport.deactivated():

            try:

                obj = __import__(pycompat.sysstr(modname))

            except (ImportError, SyntaxError):

                e1 = sys.exc_info()

                try:

                    # extensions are loaded with hgext_ prefix

                    obj = __import__("hgext_%s" % pycompat.sysstr(modname))

                except (ImportError, SyntaxError):

                    e2 = sys.exc_info()

                    if ui.tracebackflag:

                        ui.warn(

                            _(

                                b'exception from first failed import '

                                b'attempt:\n'

                            )

                        )

                    ui.traceback(e1)

                    if ui.tracebackflag:

                        ui.warn(

                            _(

                                b'exception from second failed import '

                                b'attempt:\n'

                            )

                        )

                    ui.traceback(e2)

                    if not ui.tracebackflag:

                        tracebackhint = _(

                            b'run with --traceback for stack trace'

                        )

                    else:

                        tracebackhint = None

                    raise error.HookLoadError(

                        _(b'%s hook is invalid: import of "%s" failed')

                        % (hname, modname),

                        hint=tracebackhint,

                    )

        sys.path = oldpaths

        try:

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

                obj = getattr(obj, p)

        except AttributeError:

            raise error.HookLoadError(

                _(b'%s hook is invalid: "%s" is not defined')

                % (hname, funcname)

            )

        if not callable(obj):

            raise error.HookLoadError(

                _(b'%s hook is invalid: "%s" is not callable')

                % (hname, funcname)

            )

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

    starttime = util.timer()

    try:

        r = obj(ui=ui, repo=repo, hooktype=htype, **pycompat.strkwargs(args))

    except Exception as exc:

        if isinstance(exc, error.Abort):

            ui.warn(_(b'error: %s hook failed: %s\n') % (hname, exc.args[0]))

        else:

            ui.warn(

                _(b'error: %s hook raised an exception: %s\n')

                % (hname, stringutil.forcebytestr(exc))

            )

        if throw:

            raise

        if not ui.tracebackflag:

            ui.warn(_(b'(run with --traceback for stack trace)\n'))

        ui.traceback()

        return True, True

    finally:

        duration = util.timer() - starttime

        ui.log(

            b'pythonhook',

            b'pythonhook-%s: %s finished in %0.2f seconds\n',

            htype,

            funcname,

            duration,

        )

    if r:

        if throw:

            raise error.HookAbort(_(b'%s hook failed') % hname)

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

    return r, False

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

    starttime = util.timer()

    env = {}

    # make in-memory changes visible to external process

    if repo is not None:

        tr = repo.currenttransaction()

        repo.dirstate.write(tr)

        if tr and tr.writepending():

            env[b'HG_PENDING'] = repo.root

    env[b'HG_HOOKTYPE'] = htype

    env[b'HG_HOOKNAME'] = name

    for k, v in pycompat.iteritems(args):

        # transaction changes can accumulate MBs of data, so skip it

        # for external hooks

        if k == b'changes':

            continue

        if callable(v):

            v = v()

        if isinstance(v, (dict, list)):

            v = stringutil.pprint(v)

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

    if ui.configbool(b'hooks', b'tonative.%s' % name, False):

        oldcmd = cmd

        cmd = procutil.shelltonative(cmd, env)

        if cmd != oldcmd:

            ui.note(_(b'converting hook "%s" to native\n') % name)

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

    if repo:

        cwd = repo.root

    else:

        cwd = encoding.getcwd()

    r = ui.system(cmd, environ=env, cwd=cwd, blockedtag=b'exthook-%s' % (name,))

    duration = util.timer() - starttime

    ui.log(

        b'exthook',

        b'exthook-%s: %s finished in %0.2f seconds\n',

        name,

        cmd,

        duration,

    )

    if r:

        desc = procutil.explainexit(r)

        if throw:

            raise error.HookAbort(_(b'%s hook %s') % (name, desc))

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

    return r

# represent an untrusted hook command

_fromuntrusted = object()

def _allhooks(ui):

    """return a list of (hook-id, cmd) pairs sorted by priority"""

    hooks = _hookitems(ui)

    # Be careful in this section, propagating the real commands from untrusted

    # sources would create a security vulnerability, make sure anything altered

    # in that section uses "_fromuntrusted" as its command.

    untrustedhooks = _hookitems(ui, _untrusted=True)

    for name, value in untrustedhooks.items():

        trustedvalue = hooks.get(name, ((), (), name, _fromuntrusted))

        if value != trustedvalue:

            (lp, lo, lk, lv) = trustedvalue

            hooks[name] = (lp, lo, lk, _fromuntrusted)

    # (end of the security sensitive section)

    return [(k, v) for p, o, k, v in sorted(hooks.values())]

def _hookitems(ui, _untrusted=False):

    """return all hooks items ready to be sorted"""

    hooks = {}

    for name, cmd in ui.configitems(b'hooks', untrusted=_untrusted):

        if name.startswith(b'priority.') or name.startswith(b'tonative.'):

            continue

        priority = ui.configint(b'hooks', b'priority.%s' % name, 0)

        hooks[name] = ((-priority,), (len(hooks),), name, cmd)

    return hooks

_redirect = False

def redirect(state):

    global _redirect

    _redirect = state

def hashook(ui, htype):

    """return True if a hook is configured for 'htype'"""

    if not ui.callhooks:

        return False

    for hname, cmd in _allhooks(ui):

        if hname.split(b'.')[0] == htype and cmd:

            return True

    return False

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

    if not ui.callhooks:

        return False

    hooks = []

    for hname, cmd in _allhooks(ui):

        if hname.split(b'.')[0] == htype and cmd:

            hooks.append((hname, cmd))

    res = runhooks(ui, repo, htype, hooks, throw=throw, **args)

    r = False

    for hname, cmd in hooks:

        r = res[hname][0] or r

    return r

@contextlib.contextmanager

def redirect_stdio():

    """Redirects stdout to stderr, if possible."""

    oldstdout = -1

    try:

        if _redirect:

            try:

                stdoutno = procutil.stdout.fileno()

                stderrno = procutil.stderr.fileno()

                # temporarily redirect stdout to stderr, if possible

                if stdoutno >= 0 and stderrno >= 0:

                    procutil.stdout.flush()

                    oldstdout = os.dup(stdoutno)

                    os.dup2(stderrno, stdoutno)

            except (OSError, AttributeError):

                # files seem to be bogus, give up on redirecting (WSGI, etc)

                pass

        yield

    finally:

        # The stderr is fully buffered on Windows when connected to a pipe.

        # A forcible flush is required to make small stderr data in the

        # remote side available to the client immediately.

        procutil.stderr.flush()

        if _redirect and oldstdout >= 0:

            procutil.stdout.flush()  # write hook output to stderr fd

            os.dup2(oldstdout, stdoutno)

            os.close(oldstdout)

def runhooks(ui, repo, htype, hooks, throw=False, **args):

    args = pycompat.byteskwargs(args)

    res = {}

    with redirect_stdio():

        for hname, cmd in hooks:

            if cmd is _fromuntrusted:

                if throw:

                    raise error.HookAbort(

                        _(b'untrusted hook %s not executed') % hname,

                        hint=_(b"see 'hg help config.trusted'"),

                    )

                ui.warn(_(b'warning: untrusted hook %s not executed\n') % hname)

                r = 1

                raised = False

            elif callable(cmd):

                r, raised = pythonhook(ui, repo, htype, hname, cmd, args, throw)

            elif cmd.startswith(b'python:'):

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

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

                    path = util.expandpath(path)

                    if repo:

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

                    try:

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

                    except Exception:

                        ui.write(_(b"loading %s hook failed:\n") % hname)

                        raise

                    hookfn = getattr(mod, cmd)

                else:

                    hookfn = cmd[7:].strip()

                r, raised = pythonhook(

                    ui, repo, htype, hname, hookfn, args, throw

                )

            else:

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

                raised = False

            res[hname] = r, raised

    return res