#!/usr/bin/env python -tt
#
# Copyright (c) 2011 Intel, Inc.
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the Free
# Software Foundation; version 2 of the License
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
# for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc., 59
# Temple Place - Suite 330, Boston, MA 02111-1307, USA.

import os
import logging

from importlib.machinery import SourceFileLoader

from wic import pluginbase, WicError
from wic.utils.misc import get_bitbake_var

PLUGIN_TYPES = ["imager", "source"]

SCRIPTS_PLUGIN_DIR = "scripts/lib/wic/plugins"

logger = logging.getLogger('wic')

class PluginMgr:
    _plugin_dirs = []
    _loaded = []

    @classmethod
    def get_plugins(cls, ptype):
        """Get dictionary of <plugin_name>:<class> pairs."""
        if ptype not in PLUGIN_TYPES:
            raise WicError('%s is not valid plugin type' % ptype)

        # collect plugin directories
        if not cls._plugin_dirs:
            cls._plugin_dirs = [os.path.join(os.path.dirname(__file__), 'plugins')]
            layers = get_bitbake_var("BBLAYERS") or ''
            for layer_path in layers.split():
                path = os.path.join(layer_path, SCRIPTS_PLUGIN_DIR)
                path = os.path.abspath(os.path.expanduser(path))
                if path not in cls._plugin_dirs and os.path.isdir(path):
                    cls._plugin_dirs.insert(0, path)

        # load plugins
        for pdir in cls._plugin_dirs:
            ppath = os.path.join(pdir, ptype)
            if ppath not in cls._loaded:
                if os.path.isdir(ppath):
                    for fname in os.listdir(ppath):
                        if fname.endswith('.py'):
                            mname = fname[:-3]
                            mpath = os.path.join(ppath, fname)
                            SourceFileLoader(mname, mpath).load_module()
                cls._loaded.append(ppath)

        return pluginbase.get_plugins(ptype)