#!/usr/bin/python

import os
import sys
import getopt
import socket
import subprocess
import yaml

data_path = os.path.expanduser("~") + "/.config/host-control.yaml"

class host_control():
	host = None
	verbose = False
	shell = False

	usage = "Usage: host-control [options] [action]\n" \
		"\n" \
		"Options:\n" \
		"  -h [host]:			specify host\n" \
		"  -v:				tell more details\n" \
		"  -s:				produce minimal shell output\n" \
		"\n" \
		"Actions:\n" \
		"  system-info			show kernel info\n" \
		"  system-shell			access system shell\n" \
		"  system-ping			ping host system\n" \
		"  system-update			update system\n" \
		"  system-restart		restart system\n" \
		"  system-daemon-status		show systemd status\n" \
		"  system-daemon-log		show systemd log\n" \
		"  system-daemon-reload		reload systemd units\n" \
		"  system-docker-status		show docker status\n" \
		"  config-list			list host config items\n" \
		"  config-update [config]	update host config\n" \
		"  unit-list			list host units\n" \
		"  unit-status [unit]		show unit status\n" \
		"  unit-start [unit]		start unit\n" \
		"  unit-stop [unit]		stop unit\n" \
		"  unit-restart [unit]		restart unit\n" \
		"  unit-log [unit]		show unit log\n" \
		"  unit-update [unit]		update unit"

	# trace

	def print_message(self, message):
		if not self.shell:
			print(message)

	def print_command(self, command):
		if self.verbose:
			print("Running: " + " ".join(command))

	# ssh

	def ssh_address(self, host):
		address = ""

		if "user" in host:
			address += host["user"]+"@"

		address += self.host_address(host)

		return address

	def ssh_command(self, address, arguments):
		return [ "ssh", address ] + arguments

	# host

	def host_address(self, host):
		if "address" in host:
			return host["address"]
		else:
			return host["name"]

	def host_lookup(self, name):
		for h in self.hosts:
			if not "name" in h:
				continue

			if h["name"] == name:
				return h

		return None

	# config

	def config_path(self):
		return self.config["path"]

	def config_lookup(self, host, name):
		if not "config" in host:
			self.print_message("No config in host: " + self.host)
			return 1

		for c in host["config"]:
			if not "name" in c:
				continue
			elif not "files" in c:
				continue

			if c["name"] == name:
				return c

		return None

	def config_copy(self, host, source, sink):
		source_path = os.path.join(self.config_path(), source)

		if self.host_address(host) == self.hostname:
			self.print_message("Copy " + source + " to " + sink)

			command = [ "cp", source_path, sink ]
		else:
			sink_address = self.ssh_address(host) + ":" + sink
			self.print_message("Copy " + source + " to " + sink_address)

			command = [ "scp", source_path, sink_address ]


		self.print_command(command)
		subprocess.call(command)

	def config_update(self, host, name):
		config = self.config_lookup(host, name)
		if config is None:
			self.print_message("No config for " + name + " in host: " + self.host)
			return 1

		if not self.shell:
			self.print_message("Updating host " + self.host + " config: " + name)

		for f in config["files"]:
			source = f.split(":")[0]
			sink = f.split(":")[1]

			self.config_copy(host, source, sink)

		return 0

	def config_list(self, host):
		if not "config" in host:
			self.print_message("No config in host: " + self.host)
			return 1

		self.print_message("Host " + self.host + " config:")

		for c in host["config"]:
			if not "name" in c:
				continue
			elif not "files" in c:
				continue

			if not self.shell:
				print("- " + c["name"])
			else:
				print(c["name"])

		return 0

	# unit

	def unit_lookup(self, host, name):
		if not "units" in host:
			self.print_message("No units in host: " + self.host)
			return 1

		for u in host["units"]:
			if not "name" in u:
				continue

			if u["name"] == name:
				return u

		return None

	def unit_systemctl(self, host, name, option):
		address = self.ssh_address(host)

		unit = self.unit_lookup(host, name)
		if unit is None:
			self.print_message("No " + name + " unit in host: " + self.host)
			return 1

		if not "systemd-unit" in unit:
			return 1

		command = self.ssh_command(address, [ "SYSTEMD_COLORS=1", "systemctl", option, unit["systemd-unit"] ])

		self.print_command(command)
		subprocess.call(command)

		return 0

	def unit_status(self, host, name):
		return self.unit_systemctl(host, name, "status")

	def unit_start(self, host, name):
		self.print_message("Starting unit: " + name)
		return self.unit_systemctl(host, name, "start")

	def unit_stop(self, host, name):
		self.print_message("Stopping unit: " + name)
		return self.unit_systemctl(host, name, "stop")

	def unit_restart(self, host, name):
		self.print_message("Restarting unit: " + name)
		return self.unit_systemctl(host, name, "restart")

	def unit_log(self, host, name):
		address = self.ssh_address(host)

		unit = self.unit_lookup(host, name)
		if unit is None:
			self.print_message("No " + name + " unit in host: " + self.host)
			return 1

		if not "systemd-unit" in unit:
			return 1

		if "log-path" in unit:
			arguments = [ "tail", "-n", "50", "-f", unit["log-path"] ]
		else:
			arguments = [ "SYSTEMD_COLORS=1", "journalctl", "-n", "50", "-fu", unit["systemd-unit"] ]

		command = self.ssh_command(address, arguments)

		self.print_command(command)
		subprocess.call(command)

	def unit_update(self, host, name):
		daemon_reload = False

		unit = self.unit_lookup(host, name)
		if unit is None:
			self.print_message("No " + name + " unit in host: " + self.host)
			return 1

		if not "config" in unit:
			return 1

		self.print_message("Updating unit: " + name)

		if isinstance(unit["config"], list):
			for c in unit["config"]:
				self.config_update(host, c)

				if c.startswith("systemd"):
					daemon_reload = True
		else:
			self.config_update(host, unit["config"])
			if unit["config"].startswith("systemd"):
				daemon_reload = True

		if daemon_reload:
			self.system_daemon_reload(host)

		self.unit_restart(host, name)

		return 0

	def unit_list(self, host):
		if not "units" in host:
			self.print_message("No units in host: " + self.host)
			return 1

		self.print_message("Host " + self.host + " units:")

		for u in host["units"]:
			if not "name" in u:
				continue

			if not self.shell:
				print("- " + u["name"])
			else:
				print(u["name"])

	# system

	def system_info(self, host):
		address = self.ssh_address(host)
		arguments = [ "uname", "-a" ]
		command = self.ssh_command(address, arguments)

		self.print_command(command)
		subprocess.call(command)

	def system_shell(self, host):
		address = self.ssh_address(host)
		command = self.ssh_command(address, [])

		self.print_command(command)
		subprocess.call(command)

	def system_ping(self, host):
		address = self.host_address(host)
		command = [ "ping", address ]

		self.print_command(command)
		subprocess.call(command)

	def system_update(self, host):
		address = self.ssh_address(host)
		# TODO: Move update command in config.
		arguments = [ "apt", "update", "&&", "apt", "upgrade" ]

		command = self.ssh_command(address, arguments)

		self.print_command(command)
		subprocess.call(command)

	def system_restart(self, host):
		address = self.ssh_address(host)
		arguments = [ "reboot" ]

		command = self.ssh_command(address, arguments)

		self.print_command(command)
		subprocess.call(command)

	def system_daemon_status(self, host):
		address = self.ssh_address(host)
		arguments = [ "SYSTEMD_COLORS=1", "systemctl", "status" ]
		command = self.ssh_command(address, arguments)

		self.print_command(command)
		subprocess.call(command)

	def system_daemon_log(self, host):
		address = self.ssh_address(host)
		arguments = [ "SYSTEMD_COLORS=1", "journalctl", "-n", "50", "-fb" ]
		command = self.ssh_command(address, arguments)

		self.print_command(command)
		subprocess.call(command)

	def system_daemon_reload(self, host):
		address = self.ssh_address(host)
		arguments = [ "SYSTEMD_COLORS=1", "systemctl", "daemon-reload" ]

		command = self.ssh_command(address, arguments)

		self.print_command(command)
		subprocess.call(command)

	def system_docker_status(self, host):
		address = self.ssh_address(host)
		arguments = [ "docker", "ps" ]

		command = self.ssh_command(address, arguments)

		self.print_command(command)
		subprocess.call(command)

	# main

	def data_load(self):
		s = open(data_path, "r")
		y = yaml.load(s, Loader = yaml.SafeLoader)
		s.close()

		self.hostname = socket.gethostname()
		self.config = y["config"]
		self.hosts = y["hosts"]

	def main(self):
		action = None
		self.data_load()

		try:
			options, arguments = getopt.getopt(sys.argv[1:], "h:vs")
		except getopt.GetoptError:
			self.print_message(self.usage)
			return 1

		for key, value in options:
			if key == "-h":
				self.host = value
			elif key == "-v":
				self.verbose = True
			elif key == "-s":
				self.shell = True

		if len(arguments) < 1:
			self.print_message(self.usage)
			return 1

		if self.host is None:
			self.host = self.hostname

		host = self.host_lookup(self.host)
		if host is None:
			self.print_message("Unknown host: " + self.host)
			return 1

		self.print_message("Target host: " + self.host)

		action = arguments[0]

		if action == "system-info":
			return self.system_info(host)
		elif action == "system-shell":
			return self.system_shell(host)
		elif action == "system-ping":
			return self.system_ping(host)
		elif action == "system-update":
			return self.system_update(host)
		elif action == "system-restart":
			return self.system_restart(host)
		elif action == "system-daemon-status":
			return self.system_daemon_status(host)
		elif action == "system-daemon-log":
			return self.system_daemon_log(host)
		elif action == "system-daemon-reload":
			return self.system_daemon_reload(host)
		elif action == "system-docker-status":
			return self.system_docker_status(host)
		elif action == "config-list":
			return self.config_list(host)
		elif action == "unit-list":
			return self.unit_list(host)

		if len(arguments) < 2:
			self.print_message(self.usage)
			return 1

		if action == "config-update":
			return self.config_update(host, arguments[1])
		elif action == "unit-status":
			return self.unit_status(host, arguments[1])
		elif action == "unit-start":
			return self.unit_start(host, arguments[1])
		elif action == "unit-stop":
			return self.unit_stop(host, arguments[1])
		elif action == "unit-restart":
			return self.unit_restart(host, arguments[1])
		elif action == "unit-log":
			return self.unit_log(host, arguments[1])
		elif action == "unit-update":
			return self.unit_update(host, arguments[1])
		else:
			self.print_message("Unknown action: " + action)
			return 1

		return 0

if __name__ == "__main__":
	host_control().main()