# Copyright (C) 2015-2016 Red Hat, Inc. All rights reserved.
#
# This copyrighted material is made available to anyone wishing to use,
# modify, copy, or redistribute it subject to the terms and conditions
# of the GNU General Public License v.2.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import errno
from subprocess import Popen, PIPE
import select
import time
import threading
from itertools import chain
import collections
import traceback
import os

from lvmdbusd import cfg
from lvmdbusd.utils import pv_dest_ranges, log_debug, log_error, add_no_notify,\
							make_non_block, read_decoded
from lvmdbusd.lvm_shell_proxy import LVMShellProxy

try:
	import simplejson as json
except ImportError:
	import json


total_time = 0.0
total_count = 0

# We need to prevent different threads from using the same lvm shell
# at the same time.
cmd_lock = threading.RLock()


class LvmExecutionMeta(object):

	def __init__(self, start, ended, cmd, ec=-1000, stdout_txt=None, stderr_txt=None):
		self.lock = threading.RLock()
		self.start = start
		self.ended = ended
		self.cmd = cmd
		self.ec = ec
		self.stdout_txt = stdout_txt
		self.stderr_txt = stderr_txt

	def __str__(self):
		with self.lock:
			if self.ended == 0:
				ended_txt = "still running"
				self.ended = time.time()
			else:
				ended_txt = str(time.ctime(self.ended))

			return 'EC= %d for "%s"\n' \
				"STARTED: %s, ENDED: %s, DURATION: %f\n" \
				"STDOUT=%s\n" \
				"STDERR=%s\n" % \
				(self.ec, " ".join(self.cmd), time.ctime(self.start), ended_txt, float(self.ended) - self.start,
					self.stdout_txt,
					self.stderr_txt)

	def completed(self, end_time, ec, stdout_txt, stderr_txt):
		with self.lock:
			self.ended = end_time
			self.ec = ec
			self.stdout_txt = stdout_txt
			self.stderr_txt = stderr_txt


class LvmFlightRecorder(object):

	def __init__(self, size=16):
		self.queue = collections.deque(maxlen=size)
		self.lock = threading.RLock()

	def add(self, lvm_exec_meta):
		with self.lock:
			self.queue.append(lvm_exec_meta)

	def dump(self):
		with self.lock:
			if len(self.queue):
				log_error("LVM dbus flight recorder START (in order of newest to oldest)")
				for c in reversed(self.queue):
					log_error(str(c))
				log_error("LVM dbus flight recorder END")
				self.queue.clear()


cfg.flightrecorder = LvmFlightRecorder()


def _debug_c(cmd, exit_code, out):
	log_error('CMD= %s' % ' '.join(cmd))
	log_error(("EC= %d" % exit_code))
	log_error(("STDOUT=\n %s\n" % out[0]))
	log_error(("STDERR=\n %s\n" % out[1]))


def call_lvm(command, debug=False, line_cb=None,
			 cb_data=None):
	"""
	Call an executable and return a tuple of exitcode, stdout, stderr
	:param command: Command to execute
	:param debug:   Dump debug to stdout
	:param line_cb:	Call the supplied function for each line read from
					stdin, CALL MUST EXECUTE QUICKLY and not *block*
					otherwise call_lvm function will fail to read
					stdin/stdout.  Return value of call back is ignored
	:param cb_data: Supplied to callback to allow caller access to
								its own data

	# Callback signature
	def my_callback(my_context, line_read_stdin)
		pass
	"""
	# Prepend the full lvm executable so that we can run different versions
	# in different locations on the same box
	command.insert(0, cfg.LVM_CMD)
	command = add_no_notify(command)

	process = Popen(command, stdout=PIPE, stderr=PIPE, close_fds=True,
					env=os.environ)

	stdout_text = ""
	stderr_text = ""
	stdout_index = 0
	make_non_block(process.stdout)
	make_non_block(process.stderr)

	while True and cfg.run.value != 0:
		try:
			rd_fd = [process.stdout.fileno(), process.stderr.fileno()]
			ready = select.select(rd_fd, [], [], 2)

			for r in ready[0]:
				if r == process.stdout.fileno():
					stdout_text += read_decoded(process.stdout)
				elif r == process.stderr.fileno():
					stderr_text += read_decoded(process.stderr)

			if line_cb is not None:
				# Process the callback for each line read!
				while True:
					i = stdout_text.find("\n", stdout_index)
					if i != -1:
						try:
							line_cb(cb_data, stdout_text[stdout_index:i])
						except:
							st = traceback.format_exc()
							log_error("call_lvm: line_cb exception: \n %s" % st)
						stdout_index = i + 1
					else:
						break

			# Check to see if process has terminated, None when running
			if process.poll() is not None:
				break
		except IOError as ioe:
			log_debug("call_lvm:" + str(ioe))
			break

	if process.returncode is not None:
		if debug or process.returncode != 0:
			_debug_c(command, process.returncode, (stdout_text, stderr_text))

		return process.returncode, stdout_text, stderr_text
	else:
		if cfg.run.value == 0:
			raise Exception("Daemon is exiting!")
		# We can bail out before the lvm command finished when we get a signal
		# which is requesting we exit
		return -errno.EINTR, "", "operation interrupted"


# The actual method which gets called to invoke the lvm command, can vary
# from forking a new process to using lvm shell
_t_call = call_lvm


def _shell_cfg():
	global _t_call
	# noinspection PyBroadException
	try:
		lvm_shell = LVMShellProxy()
		_t_call = lvm_shell.call_lvm
		cfg.SHELL_IN_USE = lvm_shell
		return True
	except Exception:
		_t_call = call_lvm
		cfg.SHELL_IN_USE = None
		log_error(traceback.format_exc())
		log_error("Unable to utilize lvm shell, dropping back to fork & exec")
		return False


def set_execution(shell):
	global _t_call
	with cmd_lock:
		# If the user requested lvm shell and we are currently setup that
		# way, just return
		if cfg.SHELL_IN_USE and shell:
			return True
		else:
			if not shell and cfg.SHELL_IN_USE:
				cfg.SHELL_IN_USE.exit_shell()
				cfg.SHELL_IN_USE = None

		_t_call = call_lvm
		if shell:
			if cfg.args.use_json:
				return _shell_cfg()
			else:
				return False
		return True


def time_wrapper(command, debug=False):
	global total_time
	global total_count

	with cmd_lock:
		start = time.time()
		meta = LvmExecutionMeta(start, 0, command)
		# Add the partial metadata to flight recorder, so if the command hangs
		# we will see what it was.
		cfg.flightrecorder.add(meta)
		results = _t_call(command, debug)
		ended = time.time()
		total_time += (ended - start)
		total_count += 1
		meta.completed(ended, *results)
	return results


call = time_wrapper


# Default cmd
# Place default arguments for every command here.
def _dc(cmd, args):
	c = [cmd, '--nosuffix', '--unbuffered', '--units', 'b']
	c.extend(args)
	return c


def options_to_cli_args(options):
	rc = []
	for k, v in list(dict(options).items()):
		if k.startswith("-"):
			rc.append(k)
		else:
			rc.append("--%s" % k)
		if v != "":
			if isinstance(v, int):
				rc.append(str(int(v)))
			else:
				rc.append(str(v))
	return rc


def pv_remove(device, remove_options):
	cmd = ['pvremove']
	cmd.extend(options_to_cli_args(remove_options))
	cmd.append(device)
	return call(cmd)


def _qt(tag_name):
	return '@%s' % tag_name


def _tag(operation, what, add, rm, tag_options):
	cmd = [operation]
	cmd.extend(options_to_cli_args(tag_options))

	if isinstance(what, list):
		cmd.extend(what)
	else:
		cmd.append(what)

	if add:
		cmd.extend(list(chain.from_iterable(
			('--addtag', _qt(x)) for x in add)))
	if rm:
		cmd.extend(list(chain.from_iterable(
			('--deltag', _qt(x)) for x in rm)))

	return call(cmd, False)


def pv_tag(pv_devices, add, rm, tag_options):
	return _tag('pvchange', pv_devices, add, rm, tag_options)


def vg_tag(vg_name, add, rm, tag_options):
	return _tag('vgchange', vg_name, add, rm, tag_options)


def lv_tag(lv_name, add, rm, tag_options):
	return _tag('lvchange', lv_name, add, rm, tag_options)


def vg_rename(vg_uuid, new_name, rename_options):
	cmd = ['vgrename']
	cmd.extend(options_to_cli_args(rename_options))
	cmd.extend([vg_uuid, new_name])
	return call(cmd)


def vg_remove(vg_name, remove_options):
	cmd = ['vgremove']
	cmd.extend(options_to_cli_args(remove_options))
	cmd.extend(['-f', vg_name])
	return call(cmd)


def vg_lv_create(vg_name, create_options, name, size_bytes, pv_dests):
	cmd = ['lvcreate']
	cmd.extend(options_to_cli_args(create_options))
	cmd.extend(['--size', '%dB' % size_bytes])
	cmd.extend(['--name', name, vg_name, '--yes'])
	pv_dest_ranges(cmd, pv_dests)
	return call(cmd)


def vg_lv_snapshot(vg_name, snapshot_options, name, size_bytes):
	cmd = ['lvcreate']
	cmd.extend(options_to_cli_args(snapshot_options))
	cmd.extend(["-s"])

	if size_bytes != 0:
		cmd.extend(['--size', '%dB' % size_bytes])

	cmd.extend(['--name', name, vg_name])
	return call(cmd)


def _vg_lv_create_common_cmd(create_options, size_bytes, thin_pool):
	cmd = ['lvcreate']
	cmd.extend(options_to_cli_args(create_options))

	if not thin_pool:
		cmd.extend(['--size', '%dB' % size_bytes])
	else:
		cmd.extend(['--thin', '--size', '%dB' % size_bytes])

	cmd.extend(['--yes'])
	return cmd


def vg_lv_create_linear(vg_name, create_options, name, size_bytes, thin_pool):
	cmd = _vg_lv_create_common_cmd(create_options, size_bytes, thin_pool)
	cmd.extend(['--name', name, vg_name])
	return call(cmd)


def vg_lv_create_striped(vg_name, create_options, name, size_bytes,
							num_stripes, stripe_size_kb, thin_pool):
	cmd = _vg_lv_create_common_cmd(create_options, size_bytes, thin_pool)
	cmd.extend(['--stripes', str(int(num_stripes))])

	if stripe_size_kb != 0:
		cmd.extend(['--stripesize', str(int(stripe_size_kb))])

	cmd.extend(['--name', name, vg_name])
	return call(cmd)


def _vg_lv_create_raid(vg_name, create_options, name, raid_type, size_bytes,
						num_stripes, stripe_size_kb):
	cmd = ['lvcreate']

	cmd.extend(options_to_cli_args(create_options))

	cmd.extend(['--type', raid_type])
	cmd.extend(['--size', '%dB' % size_bytes])

	if num_stripes != 0:
		cmd.extend(['--stripes', str(int(num_stripes))])

	if stripe_size_kb != 0:
		cmd.extend(['--stripesize', str(int(stripe_size_kb))])

	cmd.extend(['--name', name, vg_name, '--yes'])
	return call(cmd)


def vg_lv_create_raid(vg_name, create_options, name, raid_type, size_bytes,
						num_stripes, stripe_size_kb):
	cmd = ['lvcreate']
	cmd.extend(options_to_cli_args(create_options))

	return _vg_lv_create_raid(vg_name, create_options, name, raid_type,
								size_bytes, num_stripes, stripe_size_kb)


def vg_lv_create_mirror(
		vg_name, create_options, name, size_bytes, num_copies):
	cmd = ['lvcreate']
	cmd.extend(options_to_cli_args(create_options))

	cmd.extend(['--type', 'mirror'])
	cmd.extend(['--mirrors', str(int(num_copies))])
	cmd.extend(['--size', '%dB' % size_bytes])
	cmd.extend(['--name', name, vg_name, '--yes'])
	return call(cmd)


def vg_create_cache_pool(md_full_name, data_full_name, create_options):
	cmd = ['lvconvert']
	cmd.extend(options_to_cli_args(create_options))
	cmd.extend(['--type', 'cache-pool', '--force', '-y',
				'--poolmetadata', md_full_name, data_full_name])
	return call(cmd)


def vg_create_thin_pool(md_full_name, data_full_name, create_options):
	cmd = ['lvconvert']
	cmd.extend(options_to_cli_args(create_options))
	cmd.extend(['--type', 'thin-pool', '--force', '-y',
				'--poolmetadata', md_full_name, data_full_name])
	return call(cmd)


def vg_create_vdo_pool_lv_and_lv(vg_name, pool_name, lv_name, data_size,
									virtual_size, create_options):
	cmd = ['lvcreate']
	cmd.extend(options_to_cli_args(create_options))
	cmd.extend(['-y', '--type', 'vdo', '-n', lv_name,
				'-L', '%dB' % data_size, '-V', '%dB' % virtual_size,
				"%s/%s" % (vg_name, pool_name)])
	return call(cmd)


def vg_create_vdo_pool(pool_full_name, lv_name, virtual_size, create_options):
	cmd = ['lvconvert']
	cmd.extend(options_to_cli_args(create_options))
	cmd.extend(['--type', 'vdo-pool', '-n', lv_name, '--force', '-y',
				'-V', '%dB' % virtual_size, pool_full_name])
	return call(cmd)


def lv_remove(lv_path, remove_options):
	cmd = ['lvremove']
	cmd.extend(options_to_cli_args(remove_options))
	cmd.extend(['-f', lv_path])
	return call(cmd)


def lv_rename(lv_path, new_name, rename_options):
	cmd = ['lvrename']
	cmd.extend(options_to_cli_args(rename_options))
	cmd.extend([lv_path, new_name])
	return call(cmd)


def lv_resize(lv_full_name, size_change, pv_dests,
				resize_options):
	cmd = ['lvresize', '--force']

	cmd.extend(options_to_cli_args(resize_options))

	if size_change < 0:
		cmd.append("-L-%dB" % (-size_change))
	else:
		cmd.append("-L+%dB" % (size_change))

	cmd.append(lv_full_name)
	pv_dest_ranges(cmd, pv_dests)
	return call(cmd)


def lv_lv_create(lv_full_name, create_options, name, size_bytes):
	cmd = ['lvcreate']
	cmd.extend(options_to_cli_args(create_options))
	cmd.extend(['--virtualsize', '%dB' % size_bytes, '-T'])
	cmd.extend(['--name', name, lv_full_name, '--yes'])
	return call(cmd)


def lv_cache_lv(cache_pool_full_name, lv_full_name, cache_options):
	# lvconvert --type cache --cachepool VG/CachePoolLV VG/OriginLV
	cmd = ['lvconvert']
	cmd.extend(options_to_cli_args(cache_options))
	cmd.extend(['-y', '--type', 'cache', '--cachepool',
				cache_pool_full_name, lv_full_name])
	return call(cmd)


def lv_writecache_lv(cache_lv_full_name, lv_full_name, cache_options):
	# lvconvert --type writecache --cachevol VG/CacheLV VG/OriginLV
	cmd = ['lvconvert']
	cmd.extend(options_to_cli_args(cache_options))
	cmd.extend(['-y', '--type', 'writecache', '--cachevol',
				cache_lv_full_name, lv_full_name])
	return call(cmd)


def lv_detach_cache(lv_full_name, detach_options, destroy_cache):
	cmd = ['lvconvert']
	if destroy_cache:
		option = '--uncache'
	else:
		# Currently fairly dangerous
		# see: https://bugzilla.redhat.com/show_bug.cgi?id=1248972
		option = '--splitcache'
	cmd.extend(options_to_cli_args(detach_options))
	# needed to prevent interactive questions
	cmd.extend(["--yes", "--force"])
	cmd.extend([option, lv_full_name])
	return call(cmd)


def lv_vdo_compression(lv_path, enable, comp_options):
	cmd = ['lvchange', '--compression']
	if enable:
		cmd.append('y')
	else:
		cmd.append('n')
	cmd.extend(options_to_cli_args(comp_options))
	cmd.append(lv_path)
	return call(cmd)


def lv_vdo_deduplication(lv_path, enable, dedup_options):
	cmd = ['lvchange', '--deduplication']
	if enable:
		cmd.append('y')
	else:
		cmd.append('n')
	cmd.extend(options_to_cli_args(dedup_options))
	cmd.append(lv_path)
	return call(cmd)


def supports_json():
	cmd = ['help']
	rc, out, err = call(cmd)
	if rc == 0:
		if cfg.SHELL_IN_USE:
			return True
		else:
			if 'fullreport' in err:
				return True
	return False


def supports_vdo():
	cmd = ['segtypes']
	rc, out, err = call(cmd)
	if rc == 0:
		if "vdo" in out:
			log_debug("We have VDO support")
			return True
	return False


def lvm_full_report_json():
	pv_columns = ['pv_name', 'pv_uuid', 'pv_fmt', 'pv_size', 'pv_free',
					'pv_used', 'dev_size', 'pv_mda_size', 'pv_mda_free',
					'pv_ba_start', 'pv_ba_size', 'pe_start', 'pv_pe_count',
					'pv_pe_alloc_count', 'pv_attr', 'pv_tags', 'vg_name',
					'vg_uuid', 'pv_missing']

	pv_seg_columns = ['pvseg_start', 'pvseg_size', 'segtype',
						'pv_uuid', 'lv_uuid', 'pv_name']

	vg_columns = ['vg_name', 'vg_uuid', 'vg_fmt', 'vg_size', 'vg_free',
					'vg_sysid', 'vg_extent_size', 'vg_extent_count',
					'vg_free_count', 'vg_profile', 'max_lv', 'max_pv',
					'pv_count', 'lv_count', 'snap_count', 'vg_seqno',
					'vg_mda_count', 'vg_mda_free', 'vg_mda_size',
					'vg_mda_used_count', 'vg_attr', 'vg_tags']

	lv_columns = ['lv_uuid', 'lv_name', 'lv_path', 'lv_size',
				'vg_name', 'pool_lv_uuid', 'pool_lv', 'origin_uuid',
				'origin', 'data_percent',
				'lv_attr', 'lv_tags', 'vg_uuid', 'lv_active', 'data_lv',
				'metadata_lv', 'lv_parent', 'lv_role', 'lv_layout',
				'snap_percent', 'metadata_percent', 'copy_percent',
				'sync_percent', 'lv_metadata_size', 'move_pv', 'move_pv_uuid']

	lv_seg_columns = ['seg_pe_ranges', 'segtype', 'lv_uuid']

	if cfg.vdo_support:
		lv_columns.extend(
			['vdo_operating_mode', 'vdo_compression_state', 'vdo_index_state',
				'vdo_used_size', 'vdo_saving_percent']
		)

		lv_seg_columns.extend(
			['vdo_compression', 'vdo_deduplication',
				'vdo_use_metadata_hints', 'vdo_minimum_io_size',
				'vdo_block_map_cache_size', 'vdo_block_map_era_length',
				'vdo_use_sparse_index', 'vdo_index_memory_size',
				'vdo_slab_size', 'vdo_ack_threads', 'vdo_bio_threads',
				'vdo_bio_rotation', 'vdo_cpu_threads', 'vdo_hash_zone_threads',
				'vdo_logical_threads', 'vdo_physical_threads',
				'vdo_max_discard', 'vdo_write_policy', 'vdo_header_size'])

	cmd = _dc('fullreport', [
		'-a',		# Need hidden too
		'--configreport', 'pv', '-o', ','.join(pv_columns),
		'--configreport', 'vg', '-o', ','.join(vg_columns),
		'--configreport', 'lv', '-o', ','.join(lv_columns),
		'--configreport', 'seg', '-o', ','.join(lv_seg_columns),
		'--configreport', 'pvseg', '-o', ','.join(pv_seg_columns),
		'--reportformat', 'json'
	])

	rc, out, err = call(cmd)
	# When we have an exported vg the exit code of lvs or fullreport will be 5
	if rc == 0 or rc == 5:
		# With the current implementation, if we are using the shell then we
		# are using JSON and JSON is returned back to us as it was parsed to
		# figure out if we completed OK or not
		if cfg.SHELL_IN_USE:
			assert(type(out) == dict)
			return out
		else:
			try:
				return json.loads(out)
			except json.decoder.JSONDecodeError as joe:
				log_error("JSONDecodeError %s, \n JSON=\n%s\n" %
							(str(joe), out))
				raise joe

	return None


def pv_resize(device, size_bytes, create_options):
	cmd = ['pvresize']

	cmd.extend(options_to_cli_args(create_options))

	if size_bytes != 0:
		cmd.extend(['--yes', '--setphysicalvolumesize', '%dB' % size_bytes])

	cmd.extend([device])
	return call(cmd)


def pv_create(create_options, devices):
	cmd = ['pvcreate', '-ff']
	cmd.extend(options_to_cli_args(create_options))
	cmd.extend(devices)
	return call(cmd)


def pv_allocatable(device, yes, allocation_options):
	yn = 'n'

	if yes:
		yn = 'y'

	cmd = ['pvchange']
	cmd.extend(options_to_cli_args(allocation_options))
	cmd.extend(['-x', yn, device])
	return call(cmd)


def pv_scan(activate, cache, device_paths, major_minors, scan_options):
	cmd = ['pvscan']
	cmd.extend(options_to_cli_args(scan_options))

	if activate:
		cmd.extend(['--activate', "ay"])

	if cache:
		cmd.append('--cache')

		if len(device_paths) > 0:
			for d in device_paths:
				cmd.append(d)

		if len(major_minors) > 0:
			for mm in major_minors:
				cmd.append("%s:%s" % (mm))

	return call(cmd)


def vg_create(create_options, pv_devices, name):
	cmd = ['vgcreate']
	cmd.extend(options_to_cli_args(create_options))
	cmd.append(name)
	cmd.extend(pv_devices)
	return call(cmd)


def vg_change(change_options, name):
	cmd = ['vgchange']
	cmd.extend(options_to_cli_args(change_options))
	cmd.append(name)
	return call(cmd)


def vg_reduce(vg_name, missing, pv_devices, reduce_options):
	cmd = ['vgreduce']
	cmd.extend(options_to_cli_args(reduce_options))

	if missing:
		cmd.append('--removemissing')
	elif len(pv_devices) == 0:
		cmd.append('--all')

	cmd.append(vg_name)
	cmd.extend(pv_devices)
	return call(cmd)


def vg_extend(vg_name, extend_devices, extend_options):
	cmd = ['vgextend']
	cmd.extend(options_to_cli_args(extend_options))
	cmd.append(vg_name)
	cmd.extend(extend_devices)
	return call(cmd)


def _vg_value_set(name, arguments, options):
	cmd = ['vgchange']
	cmd.extend(options_to_cli_args(options))
	cmd.append(name)
	cmd.extend(arguments)
	return call(cmd)


def vg_allocation_policy(vg_name, policy, policy_options):
	return _vg_value_set(vg_name, ['--alloc', policy], policy_options)


def vg_max_pv(vg_name, number, max_options):
	return _vg_value_set(vg_name, ['--maxphysicalvolumes', str(int(number))],
							max_options)


def vg_max_lv(vg_name, number, max_options):
	return _vg_value_set(vg_name, ['-l', str(int(number))], max_options)


def vg_uuid_gen(vg_name, ignore, options):
	assert ignore is None
	return _vg_value_set(vg_name, ['--uuid'], options)


def activate_deactivate(op, name, activate, control_flags, options):
	cmd = [op]
	cmd.extend(options_to_cli_args(options))

	op = '-a'

	if control_flags:
		# Autoactivation
		if (1 << 0) & control_flags:
			op += 'a'
		# Exclusive locking (Cluster)
		if (1 << 1) & control_flags:
			op += 'e'

		# Local node activation
		if (1 << 2) & control_flags:
			op += 'l'

		# Activation modes
		if (1 << 3) & control_flags:
			cmd.extend(['--activationmode', 'complete'])
		elif (1 << 4) & control_flags:
			cmd.extend(['--activationmode', 'partial'])

		# Ignore activation skip
		if (1 << 5) & control_flags:
			cmd.append('--ignoreactivationskip')

	if activate:
		op += 'y'
	else:
		op += 'n'

	cmd.append(op)
	cmd.append("-y")
	cmd.append(name)
	return call(cmd)


if __name__ == '__main__':
	# Leave this for future debug as needed
	pass