from base import Task
from common import phases
from common.tasks import apt


class AddManifestPackages(Task):
	description = 'Adding packages from the manifest'
	phase = phases.preparation
	predecessors = [apt.AddDefaultSources]

	@classmethod
	def run(cls, info):
		import re
		remote = re.compile('^(?P<name>[^/]+)(/(?P<target>[^/]+))?$')
		for package in info.manifest.packages['install']:
			match = remote.match(package)
			if match is not None:
				info.packages.add(match.group('name'), match.group('target'))
			else:
				info.packages.add_local(package)


class InstallPackages(Task):
	description = 'Installing packages'
	phase = phases.package_installation
	predecessors = [apt.AptUpgrade]

	@classmethod
	def run(cls, info):
		batch = []
		actions = {info.packages.Remote: cls.install_remote,
		           info.packages.Local: cls.install_local}
		for i, package in enumerate(info.packages.install):
			batch.append(package)
			next_package = info.packages.install[i + 1] if i + 1 < len(info.packages.install) else None
			if next_package is None or package.__class__ is not next_package.__class__:
				actions[package.__class__](info, batch)
				batch = []

	@classmethod
	def install_remote(cls, info, remote_packages):
		import os
		from common.tools import log_check_call
		from subprocess import CalledProcessError
		try:
			env = os.environ.copy()
			env['DEBIAN_FRONTEND'] = 'noninteractive'
			log_check_call(['chroot', info.root,
			                'apt-get', 'install',
			                           '--no-install-recommends',
			                           '--assume-yes']
			               + map(str, remote_packages),
			               env=env)
		except CalledProcessError as e:
			import logging
			disk_stat = os.statvfs(info.root)
			root_free_mb = disk_stat.f_bsize * disk_stat.f_bavail / 1024 / 1024
			disk_stat = os.statvfs(os.path.join(info.root, 'boot'))
			boot_free_mb = disk_stat.f_bsize * disk_stat.f_bavail / 1024 / 1024
			free_mb = min(root_free_mb, boot_free_mb)
			if free_mb < 50:
				msg = ('apt exited with a non-zero status, '
				       'this may be because\nthe image volume is '
				       'running out of disk space ({free}MB left)').format(free=free_mb)
				logging.getLogger(__name__).warn(msg)
			else:
				if e.returncode == 100:
					msg = ('apt exited with status code 100. '
					       'This can sometimes occur when package retrieval times out or a package extraction failed. '
					       'apt might succeed if you try bootstrapping again.')
					logging.getLogger(__name__).warn(msg)
			raise e

	@classmethod
	def install_local(cls, info, local_packages):
		from shutil import copy
		from common.tools import log_check_call
		import os

		absolute_package_paths = []
		chrooted_package_paths = []
		for package_src in local_packages:
			pkg_name = os.path.basename(package_src.path)
			package_rel_dst = os.path.join('tmp', pkg_name)
			package_dst = os.path.join(info.root, package_rel_dst)
			copy(package_src.path, package_dst)
			absolute_package_paths.append(package_dst)
			package_path = os.path.join('/', package_rel_dst)
			chrooted_package_paths.append(package_path)

		env = os.environ.copy()
		env['DEBIAN_FRONTEND'] = 'noninteractive'
		log_check_call(['chroot', info.root,
		                'dpkg', '--install']
		               + chrooted_package_paths,
		               env=env)

		for path in absolute_package_paths:
			os.remove(path)


class AddTaskselStandardPackages(Task):
	description = 'Adding standard packages from tasksel'
	phase = phases.package_installation
	predecessors = [apt.AptUpdate]
	successors = [InstallPackages]

	@classmethod
	def run(cls, info):
		import subprocess
		tasksel_packages = subprocess.check_output(['chroot', info.root,
		                                         'tasksel', '--task-packages',
		                                         'standard']).strip().split('\n')
		for pkg in tasksel_packages:
			info.packages.add(pkg)