#!/usr/bin/env python
# Copyright (C) 2015 OpenStack, LLC.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

# Manage Jenkins plugin module registry.

import logging
import operator
import pkg_resources
import re
import types

from jenkins_jobs.errors import JenkinsJobsException
from jenkins_jobs.formatter import deep_format
from jenkins_jobs.local_yaml import Jinja2Loader

__all__ = ["ModuleRegistry"]

logger = logging.getLogger(__name__)


class ModuleRegistry(object):
    _entry_points_cache = {}
    _component_type_cache = {}

    def __init__(self, jjb_config, plugins_list=None):
        self.modules = []
        self.modules_by_component_type = {}
        self.handlers = {}
        self.jjb_config = jjb_config
        self.masked_warned = {}

        if plugins_list is None:
            self.plugins_dict = {}
        else:
            self.plugins_dict = self._get_plugins_info_dict(plugins_list)

        for entrypoint in pkg_resources.iter_entry_points(group="jenkins_jobs.modules"):
            Mod = entrypoint.load()
            mod = Mod(self)
            self.modules.append(mod)
            self.modules.sort(key=operator.attrgetter("sequence"))
            if mod.component_type is not None:
                self.modules_by_component_type[mod.component_type] = entrypoint

    @staticmethod
    def _get_plugins_info_dict(plugins_list):
        def mutate_plugin_info(plugin_info):
            """
            We perform mutations on a single member of plugin_info here, then
            return a dictionary with the longName and shortName of the plugin
            mapped to its plugin info dictionary.
            """
            version = plugin_info.get("version", "0")
            plugin_info["version"] = re.sub(
                r"(.*)-(?:SNAPSHOT|BETA).*", r"\g<1>.preview", version
            )

            aliases = []
            for key in ["longName", "shortName"]:
                value = plugin_info.get(key, None)
                if value is not None:
                    aliases.append(value)

            plugin_info_dict = {}
            for name in aliases:
                plugin_info_dict[name] = plugin_info

            return plugin_info_dict

        list_of_dicts = [mutate_plugin_info(v) for v in plugins_list]

        plugins_info_dict = {}
        for d in list_of_dicts:
            plugins_info_dict.update(d)

        return plugins_info_dict

    def get_plugin_info(self, plugin_name):
        """ This method is intended to provide information about plugins within
        a given module's implementation of Base.gen_xml. The return value is a
        dictionary with data obtained directly from a running Jenkins instance.
        This allows module authors to differentiate generated XML output based
        on information such as specific plugin versions.

        :arg str plugin_name: Either the shortName or longName of a plugin
          as see in a query that looks like:
          ``http://<jenkins-hostname>/pluginManager/api/json?pretty&depth=2``

        During a 'test' run, it is possible to override JJB's query to a live
        Jenkins instance by passing it a path to a file containing a YAML list
        of dictionaries that mimics the plugin properties you want your test
        output to reflect::

          jenkins-jobs test -p /path/to/plugins-info.yaml

        Below is example YAML that might be included in
        /path/to/plugins-info.yaml.

        .. literalinclude:: /../../tests/cmd/fixtures/plugins-info.yaml

        """
        return self.plugins_dict.get(plugin_name, {})

    def registerHandler(self, category, name, method):
        cat_dict = self.handlers.get(category, {})
        if not cat_dict:
            self.handlers[category] = cat_dict
        cat_dict[name] = method

    def getHandler(self, category, name):
        return self.handlers[category][name]

    @property
    def parser_data(self):
        return self.__parser_data

    def set_parser_data(self, parser_data):
        self.__parser_data = parser_data

    def get_component_list_type(self, entry_point):
        if entry_point in self._component_type_cache:
            return self._component_type_cache[entry_point]

        # pkg_resources.EntryPoint.load() is costly, cache it.
        component_list_type = entry_point.load().component_list_type
        logging.info("Caching type %s of %s", component_list_type, entry_point)
        self._component_type_cache[entry_point] = component_list_type

        return component_list_type

    def dispatch(self, component_type, xml_parent, component, template_data={}):
        """This is a method that you can call from your implementation of
        Base.gen_xml or component.  It allows modules to define a type
        of component, and benefit from extensibility via Python
        entry points and Jenkins Job Builder :ref:`Macros <macro>`.

        :arg str component_type: the name of the component
          (e.g., `builder`)
        :arg YAMLParser parser: the global YAML Parser
        :arg Element xml_parent: the parent XML element
        :arg dict template_data: values that should be interpolated into
          the component definition

        See :py:class:`jenkins_jobs.modules.base.Base` for how to register
        components of a module.

        See the Publishers module for a simple example of how to use
        this method.
        """

        if component_type not in self.modules_by_component_type:
            raise JenkinsJobsException(
                "Unknown component type: " "'{0}'.".format(component_type)
            )

        entry_point = self.modules_by_component_type[component_type]
        component_list_type = self.get_component_list_type(entry_point)

        if isinstance(component, dict):
            # The component is a singleton dictionary of name: dict(args)
            name, component_data = next(iter(component.items()))
            if template_data or isinstance(component_data, Jinja2Loader):
                # Template data contains values that should be interpolated
                # into the component definition.  To handle Jinja2 templates
                # that don't contain any variables, we also deep format those.
                try:
                    component_data = deep_format(
                        component_data,
                        template_data,
                        self.jjb_config.yamlparser["allow_empty_variables"],
                    )
                except Exception:
                    logging.error(
                        "Failure formatting component ('%s') data '%s'",
                        name,
                        component_data,
                    )
                    raise
        else:
            # The component is a simple string name, eg "run-tests"
            name = component
            component_data = {}

        # Look for a component function defined in an entry point
        eps = self._entry_points_cache.get(component_list_type)
        if eps is None:
            logging.debug("Caching entrypoints for %s" % component_list_type)
            module_eps = []
            # auto build entry points by inferring from base component_types
            mod = pkg_resources.EntryPoint(
                "__all__", entry_point.module_name, dist=entry_point.dist
            )

            Mod = mod.load()
            func_eps = [
                Mod.__dict__.get(a)
                for a in dir(Mod)
                if isinstance(Mod.__dict__.get(a), types.FunctionType)
            ]
            for func_ep in func_eps:
                try:
                    # extract entry point based on docstring
                    name_line = func_ep.__doc__.split("\n")
                    if not name_line[0].startswith("yaml:"):
                        logger.debug("Ignoring '%s' as an entry point" % name_line)
                        continue
                    ep_name = name_line[0].split(" ")[1]
                except (AttributeError, IndexError):
                    # AttributeError by docstring not being defined as
                    # a string to have split called on it.
                    # IndexError raised by name_line not containing anything
                    # after the 'yaml:' string.
                    logger.debug(
                        "Not including func '%s' as an entry point" % func_ep.__name__
                    )
                    continue

                module_eps.append(
                    pkg_resources.EntryPoint(
                        ep_name,
                        entry_point.module_name,
                        dist=entry_point.dist,
                        attrs=(func_ep.__name__,),
                    )
                )
                logger.debug(
                    "Adding auto EP '%s=%s:%s'"
                    % (ep_name, entry_point.module_name, func_ep.__name__)
                )

            # load from explicitly defined entry points
            module_eps.extend(
                list(
                    pkg_resources.iter_entry_points(
                        group="jenkins_jobs.{0}".format(component_list_type)
                    )
                )
            )

            eps = {}
            for module_ep in module_eps:
                if module_ep.name in eps:
                    raise JenkinsJobsException(
                        "Duplicate entry point found for component type: "
                        "'{0}', '{0}',"
                        "name: '{1}'".format(component_type, name)
                    )

                eps[module_ep.name] = module_ep.load()

            # cache both sets of entry points
            self._entry_points_cache[component_list_type] = eps
            logger.debug("Cached entry point group %s = %s", component_list_type, eps)

        # check for macro first
        component = self.parser_data.get(component_type, {}).get(name)
        if component:
            if name in eps and name not in self.masked_warned:
                self.masked_warned[name] = True
                logger.warning(
                    "You have a macro ('%s') defined for '%s' "
                    "component type that is masking an inbuilt "
                    "definition" % (name, component_type)
                )

            for b in component[component_list_type]:
                # Pass component_data in as template data to this function
                # so that if the macro is invoked with arguments,
                # the arguments are interpolated into the real defn.
                self.dispatch(component_type, xml_parent, b, component_data)
        elif name in eps:
            func = eps[name]
            func(self, xml_parent, component_data)
        else:
            raise JenkinsJobsException(
                "Unknown entry point or macro '{0}' "
                "for component type: '{1}'.".format(name, component_type)
            )