#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# AWL simulator - LinuxCNC HAL module
#
# Copyright 2013-2020 Michael Buesch <m@bues.ch>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#

from __future__ import division, absolute_import, print_function, unicode_literals

import sys
import os
import getopt

from awlsim_loader.common import *
from awlsim_loader.core import *
from awlsim_loader.coreserver import *
from awlsim_loader.coreclient import *

from awlsim.common.monotonic import monotonic_time


class LinuxCNC_NotRunning(Exception):
	pass

def linuxCNCTriggerEStop():
	# Try to trigger LinuxCNC emergency stop.
	global linuxcnc_mod
	if linuxcnc_mod is not None:
		try:
			cmd = linuxcnc_mod.command()
			cmd.state(linuxcnc_mod.STATE_ESTOP)
			cmd.wait_complete()
		except Exception as e:
			print("ERROR: Failed to trigger LinuxCNC E-Stop: %s" % str(e),
			      file=sys.stderr)
		else:
			print("Triggered LinuxCNC E-Stop")

# Check presence of LinuxCNC.
# Returns normally, if LinuxCNC is detected.
# Raises LinuxCNC_NotRunning, if LinuxCNC is not detected.
def watchdogHook(_unused = None):
	# Check whether LinuxCNC is running.
	for lockname in ("/tmp/linuxcnc.lock", "/tmp/emc.lock"):
		if os.path.exists(lockname):
			return True
	if not opt_watchdog:
		# The check is disabled. Return success.
		return True
	printError("LinuxCNC doesn't seem to be running. "\
		   "(Use '--watchdog off' to disable this check.)")
	raise LinuxCNC_NotRunning()

def usage():
	print("awlsim-linuxcnc-hal version %s" % VERSION_STRING)
	print("")
	print("Usage: awlsim-linuxcnc-hal [OPTIONS] PROJECT.awlpro")
	print("")
	print("Options:")
	print(" -w|--rw-project         Enable project file writing after download of new program.")
	print("                         Default: Do not write to the project file.")
	print("")
	print(" -i|--input-size SIZE    The input area size, in bytes.")
	print("                         Overrides input-size from project file.")
	print(" -I|--input-base BASE    The AWL/STL input address base.")
	print("                         Overrides input-base from project file.")
	print(" -o|--output-size SIZE   The output area size, in bytes.")
	print("                         Overrides output-size from project file.")
	print(" -O|--output-base BASE   The AWL/STL output address base.")
	print("                         Overrides output-base from project file.")
	print("")
	print(" -l|--listen HOST:PORT   Set the address and port where the")
	print("                         awlsim core server should listen on.")
	print("                         Defaults to %s:%d" %\
		  (AwlSimServer.DEFAULT_HOST, AwlSimServer.DEFAULT_PORT))
	print("")
	print(" -L|--loglevel LVL       Set the log level:")
	print("                         0: Log nothing")
	print("                         1: Log errors")
	print("                         2: Log errors and warnings")
	print("                         3: Log errors, warnings and info messages (default)")
	print("                         4: Verbose logging")
	print("                         5: Extremely verbose logging")
	print(" -N|--nice NICE          Renice the process. -20 <= NICE <= 19.")
	print("                         Default: Do not renice")
	print("")
	print("Debugging options:")
	print(" -W|--watchdog 1/0       Enable/disable LinuxCNC runtime watchdog.")
	print("                         Default: on")
	print(" -M|--max-runtime SEC    Module will be stopped after SEC seconds.")
	print("                         Default: No timeout")
	print(" -x|--extended-insns     Force-enable extended instructions")
	print("")
	print("For an example LinuxCNC HAL configuration see:")
	print("  examples/linuxcnc-demo/linuxcnc-demo.hal")

def main():
	global linuxcnc_mod
	linuxcnc_mod = None

	global opt_inputSize
	global opt_inputBase
	global opt_outputSize
	global opt_outputBase
	global opt_listen
	global opt_loglevel
	global opt_nice
	global opt_watchdog
	global opt_maxRuntime
	global opt_extInsns
	global opt_rwProject

	opt_inputSize = None
	opt_inputBase = None
	opt_outputSize = None
	opt_outputBase = None
	opt_listen = (AwlSimServer.DEFAULT_HOST, AwlSimServer.DEFAULT_PORT)
	opt_loglevel = Logging.LOG_INFO
	opt_nice = None
	opt_watchdog = True
	opt_maxRuntime = None
	opt_extInsns = None
	opt_rwProject = False

	try:
		(opts, args) = getopt.getopt(sys.argv[1:],
			"hi:I:o:O:l:L:N:W:M:xw",
			[ "help", "input-size=", "input-base=",
			  "output-size=", "output-base=",
			  "listen=",
			  "loglevel=", "nice=",
			  "watchdog=", "max-runtime=", "extended-insns",
			  "rw-project", ])
	except getopt.GetoptError as e:
		printError(str(e))
		usage()
		return 1
	for (o, v) in opts:
		if o in ("-h", "--help"):
			usage()
			return 0
		if o in ("-i", "--input-size"):
			try:
				opt_inputSize = int(v)
			except ValueError:
				printError("-i|--input-size: Invalid argument")
				return 1
		if o in ("-I", "--input-base"):
			try:
				opt_inputBase = int(v)
			except ValueError:
				printError("-I|--input-base: Invalid argument")
				return 1
		if o in ("-o", "--output-size"):
			try:
				opt_outputSize = int(v)
			except ValueError:
				printError("-o|--output-size: Invalid argument")
				return 1
		if o in ("-O", "--output-base"):
			try:
				opt_outputBase = int(v)
			except ValueError:
				printError("-O|--output-base: Invalid argument")
				return 1
		if o in ("-l", "--listen"):
			try:
				host, port = parseNetAddress(v)
				if not host.strip() or\
				   host in {"any", "all"}:
					host = ""
				if port is None:
					port = AwlSimServer.DEFAULT_PORT
				opt_listen = (host, port)
			except AwlSimError as e:
				printError("-l|--listen: Invalid host/port")
				return 1
		if o in ("-L", "--loglevel"):
			try:
				opt_loglevel = int(v)
			except ValueError:
				printError("-L|--loglevel: Invalid log level")
				return 1
		if o in ("-N", "--nice"):
			try:
				opt_nice = int(v)
				if opt_nice < -20 or opt_nice > 19:
					raise ValueError
			except ValueError:
				printError("-N|--nice: Invalid niceness level")
				return 1
		if o in ("-W", "--watchdog"):
			opt_watchdog = str2bool(v)
		if o in ("-M", "--max-runtime"):
			try:
				opt_maxRuntime = float(v)
			except ValueError:
				printError("-M|--max-runtime: Invalid time format")
				return 1
		if o in ("-x", "--extended-insns"):
			opt_extInsns = True
		if o in ("-w", "--rw-project"):
			opt_rwProject = True
	if len(args) != 1:
		usage()
		return 1
	projectFile = args[0]

	result = ExitCodes.EXIT_OK
	server = None
	try:
		Logging.setPrefix("awlsim-linuxcnc: ")
		Logging.setLoglevel(opt_loglevel)

		# Adjust process priority
		if opt_nice is not None:
			try:
				os.nice(opt_nice)
			except OSError as e:
				printError("Failed to renice process to "
					   "%d: %s" % (opt_nice, str(e)))
				return 1

		# Try to import the LinuxCNC HAL module
		try:
			import hal as LinuxCNC_HAL
		except ImportError as e:
			printError("Failed to import LinuxCNC HAL "
				   "module: %s" % str(e))
			return 1
		try:
			import linuxcnc as linuxcnc_mod
		except ImportError as e:
			printError("Failed to import LinuxCNC "
				   "module: %s" % str(e))
			return 1

		# Create the LinuxCNC HAL component.
		halComponent = LinuxCNC_HAL.component("awlsim")

		# Read the project.
		project = Project.fromProjectOrRawAwlFile(projectFile)
		hwmodSettings = project.getHwmodSettings()

		# Get the 'linuxcnc' hardware module descriptor.
		linuxcncHwmodDesc = None
		for modDesc in hwmodSettings.getLoadedModules():
			if modDesc.getModuleName() == "linuxcnc":
				if linuxcncHwmodDesc:
					printError("ERROR: More than one 'linuxcnc' hardware "
						   "module found in the project file. Only "
						   "one 'linuxcnc' module is supported.")
				linuxcncHwmodDesc = modDesc
		if not linuxcncHwmodDesc:
			if opt_inputBase is None and\
			   opt_outputBase is None and\
			   opt_inputSize is None and\
			   opt_outputSize is None:
				printWarning("Warning: Hardware module 'linuxcnc' not "
					     "included in project file. "
					     "Loading module nevertheless.")
			modDesc = HwmodDescriptor(moduleName = "linuxcnc",
						  parameters = {
				"inputAddressBase"	: "0",
				"outputAddressBase"	: "0",
				"inputSize"		: "32",
				"outputSize"		: "32",
			})
			hwmodSettings.addLoadedModule(modDesc)
			linuxcncHwmodDesc = modDesc
		# Override hardware module parameters, if required.
		if opt_inputBase is not None:
			linuxcncHwmodDesc.setParameterValue("inputAddressBase",
							    str(opt_inputBase))
		if opt_inputSize is not None:
			linuxcncHwmodDesc.setParameterValue("inputSize",
							    str(opt_inputSize))
		if opt_outputBase is not None:
			linuxcncHwmodDesc.setParameterValue("outputAddressBase",
							    str(opt_outputBase))
		if opt_outputSize is not None:
			linuxcncHwmodDesc.setParameterValue("outputSize",
							    str(opt_outputSize))

		# Override CPUConf, if required.
		conf = project.getCpuConf()
		if opt_maxRuntime is not None:
			conf.setRunTimeLimitUs(int(round(opt_maxRuntime * 1000000.0)))
		if opt_extInsns is not None:
			conf.setExtInsnsEn(opt_extInsns)

		# Pass the hal component singleton to the Awlsim hw module.
		loader = HwModLoader.loadModule("linuxcnc")
		mod = loader.getModule()
		mod.setLinuxCNCHalComponentSingleton(LinuxCNC_HAL, halComponent)

		server = AwlSimServer()
		server.setCycleExitHook(watchdogHook)
		printInfo("Starting core server...")
		server.startup(host=opt_listen[0],
			       port=opt_listen[1],
			       project=project,
			       projectWriteBack=opt_rwProject,
			       raiseExceptionsFromRun=True,
			       handleMaintenanceServerside=True)
		try:
			server.setRunState(server.STATE_RUN)
		except AwlSimError as e:
			printError("Failed to go to RUN state.")
			# Continue to main loop.
		lastExceptionTime = monotonic_time() - 1.0
		exceptionCount = 0
		while True:
			try:
				server.run()
			except (AwlParserError, AwlSimError) as e:
				linuxCNCTriggerEStop()
				now = monotonic_time()
				if now - lastExceptionTime < 1.0:
					# The last fault is less than one second ago.
					exceptionCount += 1
				else:
					exceptionCount = 0
				lastExceptionTime = now
				if exceptionCount >= 10:
					# Many exceptions happened in a row.
					# Raise a fatal exception.
					printError("Fatal fault detected")
					raise e
				else:
					# Non-fatal fault.
					# Ensure the CPU is stopped and enter
					# the run loop again.
					printError(e.getReport())
					printError("CPU stopped due to fault")
					server.setRunState(server.STATE_STOP)
					continue
			# Run loop exited normally. Bail out.
			break
	except LinuxCNC_NotRunning as e:
		result = ExitCodes.EXIT_ERR_OTHER
	except KeyboardInterrupt as e:
		result = ExitCodes.EXIT_ERR_OTHER
	except (AwlParserError, AwlSimError) as e:
		printError(e.getReport())
		result = ExitCodes.EXIT_ERR_SIM
	except MaintenanceRequest as e:
		if e.requestType in (MaintenanceRequest.TYPE_SHUTDOWN,
				     MaintenanceRequest.TYPE_STOP,
				     MaintenanceRequest.TYPE_RTTIMEOUT):
			result = ExitCodes.EXIT_OK
		else:
			printError("Received invalid maintenance request %d" %\
				   e.requestType)
			result = ExitCodes.EXIT_ERR_SIM
	finally:
		linuxCNCTriggerEStop()
		if server:
			server.shutdown()
	printInfo("LinuxCNC HAL module shutdown.")

	return result

if __name__ == "__main__":
	sys.exit(main())