reactor.py

#   -*- coding: utf-8 -*-
#
#   This file is part of PyBuilder
#
#   Copyright 2011-2015 PyBuilder Team
#
#   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.

"""
    The PyBuilder reactor module.
    Operates a build process by instrumenting an ExecutionManager from the
    execution module.
"""

import imp

import os.path

from pybuilder.core import (TASK_ATTRIBUTE, DEPENDS_ATTRIBUTE,
                            DESCRIPTION_ATTRIBUTE, AFTER_ATTRIBUTE,
                            BEFORE_ATTRIBUTE, INITIALIZER_ATTRIBUTE,
                            ACTION_ATTRIBUTE, ONLY_ONCE_ATTRIBUTE, TEARDOWN_ATTRIBUTE,
                            Project, NAME_ATTRIBUTE, ENVIRONMENTS_ATTRIBUTE)
from pybuilder.errors import PyBuilderException, ProjectValidationFailedException
from pybuilder.pluginloader import (BuiltinPluginLoader,
                                    DispatchingPluginLoader,
                                    ThirdPartyPluginLoader,
                                    DownloadingPluginLoader)
from pybuilder.utils import as_list
from pybuilder.execution import Action, Initializer, Task


class BuildSummary(object):
    def __init__(self, project, task_execution_summaries):
        self.project = project
        self.task_summaries = task_execution_summaries


class Reactor(object):
    _current_instance = None

    @staticmethod
    def current_instance():
        return Reactor._current_instance

    def __init__(self, logger, execution_manager, plugin_loader=None):
        self.logger = logger
        self.execution_manager = execution_manager
        if not plugin_loader:
            builtin_plugin_loader = BuiltinPluginLoader(self.logger)
            installed_thirdparty_plugin_loader = ThirdPartyPluginLoader(self.logger)
            downloading_thirdparty_plugin_loader = DownloadingPluginLoader(self.logger)
            self.plugin_loader = DispatchingPluginLoader(
                self.logger, builtin_plugin_loader, installed_thirdparty_plugin_loader,
                downloading_thirdparty_plugin_loader)
        else:
            self.plugin_loader = plugin_loader
        self._plugins = []
        self.project = None

    def require_plugin(self, plugin):
        if plugin not in self._plugins:
            try:
                self._plugins.append(plugin)
                self.import_plugin(plugin)
            except:  # NOQA
                self._plugins.remove(plugin)
                raise

    def get_plugins(self):
        return self._plugins

    def get_tasks(self):
        return self.execution_manager.tasks

    def validate_project(self):
        validation_messages = self.project.validate()
        if len(validation_messages) > 0:
            raise ProjectValidationFailedException(validation_messages)

    def prepare_build(self,
                      property_overrides=None,
                      project_directory=".",
                      project_descriptor="build.py"):
        if not property_overrides:
            property_overrides = {}
        Reactor._current_instance = self

        project_directory, project_descriptor = self.verify_project_directory(
            project_directory, project_descriptor)

        self.logger.debug("Loading project module from %s", project_descriptor)

        self.project = Project(basedir=project_directory)

        self.project_module = self.load_project_module(project_descriptor)

        self.apply_project_attributes()
        self.override_properties(property_overrides)

        self.logger.debug("Have loaded plugins %s", ", ".join(self._plugins))

        self.collect_tasks_and_actions_and_initializers(self.project_module)

        self.execution_manager.resolve_dependencies()

    def build(self, tasks=None, environments=None):
        if not tasks:
            tasks = []
        if not environments:
            environments = []
        Reactor._current_instance = self

        if environments:
            self.logger.info(
                "Activated environments: %s", ", ".join(environments))

        self.execution_manager.execute_initializers(
            environments, logger=self.logger, project=self.project)

        self.log_project_properties()

        self.validate_project()

        tasks = as_list(tasks)

        if not len(tasks):
            if self.project.default_task:
                tasks += as_list(self.project.default_task)
            else:
                raise PyBuilderException("No default task given.")

        execution_plan = self.execution_manager.build_execution_plan(tasks)
        self.logger.debug("Execution plan is %s", ", ".join(
            [task.name for task in execution_plan]))

        self.logger.info(
            "Building %s version %s", self.project.name, self.project.version)
        self.logger.info("Executing build in %s", self.project.basedir)

        if len(tasks) == 1:
            self.logger.info("Going to execute task %s", tasks[0])
        else:
            list_of_tasks = ", ".join(tasks)
            self.logger.info("Going to execute tasks: %s", list_of_tasks)

        task_execution_summaries = self.execution_manager.execute_execution_plan(
            execution_plan,
            logger=self.logger,
            project=self.project,
            reactor=self)

        return BuildSummary(self.project, task_execution_summaries)

    def execute_task(self, task_name):
        execution_plan = self.execution_manager.build_execution_plan(task_name)

        self.execution_manager.execute_execution_plan(execution_plan,
                                                      logger=self.logger,
                                                      project=self.project,
                                                      reactor=self)

    def execute_task_shortest_plan(self, task_name):
        execution_plan = self.execution_manager.build_shortest_execution_plan(task_name)

        self.execution_manager.execute_execution_plan(execution_plan,
                                                      logger=self.logger,
                                                      project=self.project,
                                                      reactor=self)

    def override_properties(self, property_overrides):
        for property_override in property_overrides:
            self.project.set_property(
                property_override, property_overrides[property_override])

    def log_project_properties(self):
        formatted = ""
        for key in sorted(self.project.properties):
            formatted += "\n%40s : %s" % (key, self.project.get_property(key))
        self.logger.debug("Project properties: %s", formatted)

    def import_plugin(self, plugin):
        self.logger.debug("Loading plugin '%s'", plugin)
        plugin_module = self.plugin_loader.load_plugin(self.project, plugin)
        self.collect_tasks_and_actions_and_initializers(plugin_module)

    def collect_tasks_and_actions_and_initializers(self, project_module):
        for name in dir(project_module):
            candidate = getattr(project_module, name)

            if hasattr(candidate, NAME_ATTRIBUTE):
                name = getattr(candidate, NAME_ATTRIBUTE)
            elif hasattr(candidate, "__name__"):
                name = candidate.__name__
            description = getattr(candidate, DESCRIPTION_ATTRIBUTE) if hasattr(
                candidate, DESCRIPTION_ATTRIBUTE) else ""

            if hasattr(candidate, TASK_ATTRIBUTE) and getattr(candidate, TASK_ATTRIBUTE):
                dependencies = getattr(candidate, DEPENDS_ATTRIBUTE) if hasattr(
                    candidate, DEPENDS_ATTRIBUTE) else None

                self.logger.debug("Found task %s", name)
                self.execution_manager.register_task(
                    Task(name, candidate, dependencies, description))

            elif hasattr(candidate, ACTION_ATTRIBUTE) and getattr(candidate, ACTION_ATTRIBUTE):
                before = getattr(candidate, BEFORE_ATTRIBUTE) if hasattr(
                    candidate, BEFORE_ATTRIBUTE) else None
                after = getattr(candidate, AFTER_ATTRIBUTE) if hasattr(
                    candidate, AFTER_ATTRIBUTE) else None

                only_once = False
                if hasattr(candidate, ONLY_ONCE_ATTRIBUTE):
                    only_once = getattr(candidate, ONLY_ONCE_ATTRIBUTE)
                teardown = False
                if hasattr(candidate, TEARDOWN_ATTRIBUTE):
                    teardown = getattr(candidate, TEARDOWN_ATTRIBUTE)

                self.logger.debug("Found action %s", name)
                self.execution_manager.register_action(
                    Action(name, candidate, before, after, description, only_once, teardown))

            elif hasattr(candidate, INITIALIZER_ATTRIBUTE) and getattr(candidate, INITIALIZER_ATTRIBUTE):
                environments = []
                if hasattr(candidate, ENVIRONMENTS_ATTRIBUTE):
                    environments = getattr(candidate, ENVIRONMENTS_ATTRIBUTE)

                self.execution_manager.register_initializer(
                    Initializer(name, candidate, environments, description))

    def apply_project_attributes(self):
        self.propagate_property("name")
        self.propagate_property("version")
        self.propagate_property("default_task")
        self.propagate_property("summary")
        self.propagate_property("home_page")
        self.propagate_property("description")
        self.propagate_property("authors")
        self.propagate_property("license")
        self.propagate_property("url")

    def propagate_property(self, property):
        if hasattr(self.project_module, property):
            value = getattr(self.project_module, property)
            setattr(self.project, property, value)

    @staticmethod
    def load_project_module(project_descriptor):
        try:
            return imp.load_source("build", project_descriptor)
        except ImportError as e:
            raise PyBuilderException(
                "Error importing project descriptor %s: %s" % (project_descriptor, e))

    @staticmethod
    def verify_project_directory(project_directory, project_descriptor):
        project_directory = os.path.abspath(project_directory)

        if not os.path.exists(project_directory):
            raise PyBuilderException(
                "Project directory does not exist: %s", project_directory)

        if not os.path.isdir(project_directory):
            raise PyBuilderException(
                "Project directory is not a directory: %s", project_directory)

        project_descriptor_full_path = os.path.join(
            project_directory, project_descriptor)

        if not os.path.exists(project_descriptor_full_path):
            raise PyBuilderException(
                "Project directory does not contain descriptor file: %s",
                project_descriptor_full_path)

        if not os.path.isfile(project_descriptor_full_path):
            raise PyBuilderException(
                "Project descriptor is not a file: %s", project_descriptor_full_path)

        return project_directory, project_descriptor_full_path