# extensions.py - extension handling for mercurial

#

# Copyright 2005-2007 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.

import imp, os

import util, cmdutil, help, error

from i18n import _, gettext

_extensions = {}

_order = []

def extensions():

    for name in _order:

        module = _extensions[name]

        if module:

            yield name, module

def find(name):

    '''return module with given extension name'''

    try:

        return _extensions[name]

    except KeyError:

        for k, v in _extensions.iteritems():

            if k.endswith('.' + name) or k.endswith('/' + name):

                return v

        raise KeyError(name)

def loadpath(path, module_name):

    module_name = module_name.replace('.', '_')

    path = util.expandpath(path)

    if os.path.isdir(path):

        # module/__init__.py style

        d, f = os.path.split(path.rstrip('/'))

        fd, fpath, desc = imp.find_module(f, [d])

        return imp.load_module(module_name, fd, fpath, desc)

    else:

        return imp.load_source(module_name, path)

def load(ui, name, path):

    # unused ui argument kept for backwards compatibility

    if name.startswith('hgext.') or name.startswith('hgext/'):

        shortname = name[6:]

    else:

        shortname = name

    if shortname in _extensions:

        return _extensions[shortname]

    _extensions[shortname] = None

    if path:

        # the module will be loaded in sys.modules

        # choose an unique name so that it doesn't

        # conflicts with other modules

        mod = loadpath(path, 'hgext.%s' % name)

    else:

        def importh(name):

            mod = __import__(name)

            components = name.split('.')

            for comp in components[1:]:

                mod = getattr(mod, comp)

            return mod

        try:

            mod = importh("hgext.%s" % name)

        except ImportError:

            mod = importh(name)

    _extensions[shortname] = mod

    _order.append(shortname)

    return mod

def loadall(ui):

    result = ui.configitems("extensions")

    newindex = len(_order)

    for (name, path) in result:

        if path:

            if path[0] == '!':

                continue

        try:

            load(ui, name, path)

        except KeyboardInterrupt:

            raise

        except Exception, inst:

            if path:

                ui.warn(_("*** failed to import extension %s from %s: %s\n")

                        % (name, path, inst))

            else:

                ui.warn(_("*** failed to import extension %s: %s\n")

                        % (name, inst))

            if ui.traceback():

                return 1

    for name in _order[newindex:]:

        uisetup = getattr(_extensions[name], 'uisetup', None)

        if uisetup:

            uisetup(ui)

    for name in _order[newindex:]:

        extsetup = getattr(_extensions[name], 'extsetup', None)

        if extsetup:

            try:

                extsetup(ui)

            except TypeError:

                if extsetup.func_code.co_argcount != 0:

                    raise

                extsetup() # old extsetup with no ui argument

def wrapcommand(table, command, wrapper):

    '''Wrap the command named `command' in table

    Replace command in the command table with wrapper. The wrapped command will

    be inserted into the command table specified by the table argument.

    The wrapper will be called like

      wrapper(orig, *args, **kwargs)

    where orig is the original (wrapped) function, and *args, **kwargs

    are the arguments passed to it.

    '''

    assert hasattr(wrapper, '__call__')

    aliases, entry = cmdutil.findcmd(command, table)

    for alias, e in table.iteritems():

        if e is entry:

            key = alias

            break

    origfn = entry[0]

    def wrap(*args, **kwargs):

        return util.checksignature(wrapper)(

            util.checksignature(origfn), *args, **kwargs)

    wrap.__doc__ = getattr(origfn, '__doc__')

    wrap.__module__ = getattr(origfn, '__module__')

    newentry = list(entry)

    newentry[0] = wrap

    table[key] = tuple(newentry)

    return entry

def wrapfunction(container, funcname, wrapper):

    '''Wrap the function named funcname in container

    Replace the funcname member in the given container with the specified

    wrapper. The container is typically a module, class, or instance.

    The wrapper will be called like

      wrapper(orig, *args, **kwargs)

    where orig is the original (wrapped) function, and *args, **kwargs

    are the arguments passed to it.

    Wrapping methods of the repository object is not recommended since

    it conflicts with extensions that extend the repository by

    subclassing. All extensions that need to extend methods of

    localrepository should use this subclassing trick: namely,

    reposetup() should look like

      def reposetup(ui, repo):

          class myrepo(repo.__class__):

              def whatever(self, *args, **kwargs):

                  [...extension stuff...]

                  super(myrepo, self).whatever(*args, **kwargs)

                  [...extension stuff...]

          repo.__class__ = myrepo

    In general, combining wrapfunction() with subclassing does not

    work. Since you cannot control what other extensions are loaded by

    your end users, you should play nicely with others by using the

    subclass trick.

    '''

    assert hasattr(wrapper, '__call__')

    def wrap(*args, **kwargs):

        return wrapper(origfn, *args, **kwargs)

    origfn = getattr(container, funcname)

    assert hasattr(origfn, '__call__')

    setattr(container, funcname, wrap)

    return origfn

def _disabledpaths(strip_init=False):

    '''find paths of disabled extensions. returns a dict of {name: path}

    removes /__init__.py from packages if strip_init is True'''

    import hgext

    extpath = os.path.dirname(os.path.abspath(hgext.__file__))

    try: # might not be a filesystem path

        files = os.listdir(extpath)

    except OSError:

        return {}

    exts = {}

    for e in files:

        if e.endswith('.py'):

            name = e.rsplit('.', 1)[0]

            path = os.path.join(extpath, e)

        else:

            name = e

            path = os.path.join(extpath, e, '__init__.py')

            if not os.path.exists(path):

                continue

            if strip_init:

                path = os.path.dirname(path)

        if name in exts or name in _order or name == '__init__':

            continue

        exts[name] = path

    return exts

def _disabledhelp(path):

    '''retrieve help synopsis of a disabled extension (without importing)'''

    try:

        file = open(path)

    except IOError:

        return

    else:

        doc = help.moduledoc(file)

        file.close()

    if doc: # extracting localized synopsis

        return gettext(doc).splitlines()[0]

    else:

        return _('(no help text available)')

def disabled():

    '''find disabled extensions from hgext

    returns a dict of {name: desc}, and the max name length'''

    paths = _disabledpaths()

    if not paths:

        return None, 0

    exts = {}

    maxlength = 0

    for name, path in paths.iteritems():

        doc = _disabledhelp(path)

        if not doc:

            continue

        exts[name] = doc

        if len(name) > maxlength:

            maxlength = len(name)

    return exts, maxlength

def disabledext(name):

    '''find a specific disabled extension from hgext. returns desc'''

    paths = _disabledpaths()

    if name in paths:

        return _disabledhelp(paths[name])

def disabledcmd(cmd, strict=False):

    '''import disabled extensions until cmd is found.

    returns (cmdname, extname, doc)'''

    paths = _disabledpaths(strip_init=True)

    if not paths:

        raise error.UnknownCommand(cmd)

    def findcmd(cmd, name, path):

        try:

            mod = loadpath(path, 'hgext.%s' % name)

        except Exception:

            return

        try:

            aliases, entry = cmdutil.findcmd(cmd,

                getattr(mod, 'cmdtable', {}), strict)

        except (error.AmbiguousCommand, error.UnknownCommand):

            return

        for c in aliases:

            if c.startswith(cmd):

                cmd = c

                break

        else:

            cmd = aliases[0]

        return (cmd, name, mod)

    # first, search for an extension with the same name as the command

    path = paths.pop(cmd, None)

    if path:

        ext = findcmd(cmd, cmd, path)

        if ext:

            return ext

    # otherwise, interrogate each extension until there's a match

    for name, path in paths.iteritems():

        ext = findcmd(cmd, name, path)

        if ext:

            return ext

    raise error.UnknownCommand(cmd)

def enabled():

    '''return a dict of {name: desc} of extensions, and the max name length'''

    exts = {}

    maxlength = 0

    for ename, ext in extensions():

        doc = (gettext(ext.__doc__) or _('(no help text available)'))

        ename = ename.split('.')[-1]

        maxlength = max(len(ename), maxlength)

        exts[ename] = doc.splitlines()[0].strip()

    return exts, maxlength