# -*- coding: utf-8 -*-
from __future__ import unicode_literals
import importlib
import pathlib
import logging
from typing import OrderedDict

from django.apps import AppConfig, apps
from django.conf import settings
from django.db.utils import OperationalError, ProgrammingError

try:
    from importlib import metadata
except:
    import importlib_metadata as metadata

from plugin import plugins as inventree_plugins
from plugin.integration import IntegrationPluginBase

logger = logging.getLogger('inventree')


class PluginAppConfig(AppConfig):
    name = 'plugin'

    def ready(self):
        self.collect_plugins()

        try:
            # we are using the db from here - so for migrations etc we need to try this block
            self.init_plugins()
            self.activate_integration()
        except (OperationalError, ProgrammingError):
            # Exception if the database has not been migrated yet
            pass

    def collect_plugins(self):
        """collect integration plugins from all possible ways of loading"""
        # Collect plugins from paths
        for plugin in settings.PLUGIN_DIRS:
            modules = inventree_plugins.get_plugins(importlib.import_module(plugin), IntegrationPluginBase, True)
            if modules:
                [settings.PLUGINS.append(item) for item in modules]

        if (not settings.PLUGIN_TESTING) or (settings.PLUGIN_TESTING and settings.PLUGIN_TESTING_SETUP):
            # Collect plugins from setup entry points
            for entry in metadata.entry_points().get('inventree_plugins', []):
                plugin = entry.load()
                plugin.is_package = True
                settings.PLUGINS.append(plugin)

        # Log found plugins
        logger.info(f'Found {len(settings.PLUGINS)} plugins!')
        logger.info(", ".join([a.__module__ for a in settings.PLUGINS]))

    def init_plugins(self):
        """initialise all found plugins"""
        from plugin.models import PluginConfig

        logger.info('Starting plugin initialisation')
        # Initialize integration plugins
        for plugin in inventree_plugins.load_integration_plugins():
            # check if package
            was_packaged = getattr(plugin, 'is_package', False)

            # check if activated
            # these checks only use attributes - never use plugin supplied functions -> that would lead to arbitrary code execution!!
            plug_name = plugin.PLUGIN_NAME
            plug_key = plugin.PLUGIN_SLUG if getattr(plugin, 'PLUGIN_SLUG', None) else plug_name
            try:
                plugin_db_setting, _ = PluginConfig.objects.get_or_create(key=plug_key, name=plug_name)
            except (OperationalError, ProgrammingError) as error:
                # Exception if the database has not been migrated yet - check if test are running - raise if not
                if not settings.PLUGIN_TESTING:
                    raise error
                plugin_db_setting = None

            # always activate if testing
            if settings.PLUGIN_TESTING or (plugin_db_setting and plugin_db_setting.active):
                # init package
                # now we can be sure that an admin has activated the plugin -> as of Nov 2021 there are not many checks in place
                # but we could enhance those to check signatures, run the plugin against a whitelist etc.
                logger.info(f'Loading integration plugin {plugin.PLUGIN_NAME}')
                plugin = plugin()
                logger.info(f'Loaded integration plugin {plugin.slug}')
                plugin.is_package = was_packaged
                if plugin_db_setting:
                    plugin.pk = plugin_db_setting.pk

                # safe reference
                settings.INTEGRATION_PLUGINS[plugin.slug] = plugin
            else:
                # save for later reference
                settings.INTEGRATION_PLUGINS_INACTIVE[plug_key] = plugin_db_setting

    def activate_integration(self):
        """fullfill integrations for all activated plugins"""
        # activate integrations
        plugins = settings.INTEGRATION_PLUGINS.items()
        logger.info(f'Found {len(plugins)} active plugins')

        # if plugin settings are enabled enhance the settings
        self.activate_integration_globalsettings(plugins)

        # if plugin apps are enabled
        self.activate_integration_app(plugins)

    def activate_integration_globalsettings(self, plugins):
        from common.models import InvenTreeSetting

        if settings.PLUGIN_TESTING or InvenTreeSetting.get_setting('ENABLE_PLUGINS_GLOBALSETTING'):
            logger.info('Registering IntegrationPlugin global settings')
            for slug, plugin in plugins:
                if plugin.mixin_enabled('globalsettings'):
                    plugin_setting = plugin.globalsettingspatterns
                    settings.INTEGRATION_PLUGIN_GLOBALSETTING[slug] = plugin_setting

                    # Add to settings dir
                    InvenTreeSetting.GLOBAL_SETTINGS.update(plugin_setting)

    def activate_integration_app(self, plugins):
        from common.models import InvenTreeSetting

        if settings.PLUGIN_TESTING or ((not settings.INTEGRATION_APPS_LOADED) and InvenTreeSetting.get_setting('ENABLE_PLUGINS_APP')):
            logger.info('Registering IntegrationPlugin apps')
            settings.INTEGRATION_APPS_LOADED = True  # ensure this section will not run again
            apps_changed = False

            # add them to the INSTALLED_APPS
            for slug, plugin in plugins:
                if plugin.mixin_enabled('app'):
                    try:
                        # for local path plugins
                        plugin_path = '.'.join(pathlib.Path(plugin.path).relative_to(settings.BASE_DIR).parts)
                    except ValueError:
                        # plugin is shipped as package
                        plugin_path = plugin.PLUGIN_NAME
                    if plugin_path not in settings.INSTALLED_APPS:
                        settings.INSTALLED_APPS += [plugin_path]
                        apps_changed = True

            # if apps were changed reload
            # TODO this is a bit jankey to be honest
            if apps_changed:
                apps.app_configs = OrderedDict()
                apps.apps_ready = apps.models_ready = apps.loading = apps.ready = False
                apps.clear_cache()
                apps.populate(settings.INSTALLED_APPS)