L_UPnPProxy1.lua

--
-- WeMo plugin
-- Copyright (C) 2013 Deborah Pickett
-- 
-- Version 0.0 2013-04-14 by Deborah Pickett
--

module ("L_UPnPProxy1", package.seeall)

local http = require("socket.http")
local ltn12 = require("ltn12")

local initScript = [=[#!/bin/sh /etc/rc.common
# Copyright (C) 2007 OpenWrt.org
START=80
PID_FILE=/var/run/upnp-event-proxy.pid
PROXY_DAEMON=/tmp/upnp-event-proxy.lua
start() {
	if [ -f "$PID_FILE" ]; then
		# May already be running.
		PID=$(cat "$PID_FILE")
		if [ -d "/proc/$PID" ]; then
			COMMAND=$(readlink "/proc/$PID/exe")
			if [ "$COMMAND" = "/usr/bin/lua" ]; then
				echo "Daemon is already running"
				return 1
			fi
		fi
	fi
	# Find and decompress the proxy daemon Lua source.
	if [ -f /etc/cmh-ludl/L_UPnPProxyDaemon.lua.lzo ]; then
		PROXY_DAEMON_LZO=/etc/cmh-ludl/L_UPnPProxyDaemon.lua.lzo
	elif [ -f /etc/cmh-lu/L_UPnPProxyDaemon.lua.lzo ]; then
		PROXY_DAEMON_LZO=/etc/cmh-lu/L_UPnPProxyDaemon.lua.lzo
	fi
	if [ -n "$PROXY_DAEMON_LZO" ]; then
		/usr/bin/pluto-lzo d "$PROXY_DAEMON_LZO" /tmp/upnp-event-proxy.lua
	fi
	# Close file descriptors.
	for fd in /proc/self/fd/*; do
		fd=${fd##*/}
		case $fd in
			0|1|2) ;;
			*) eval "exec $fd<&-"
		esac
	done
	# Run daemon.
	/usr/bin/lua "$PROXY_DAEMON" </dev/null >/dev/null 2>&1 &
	echo "$!" > "$PID_FILE"
}
stop() {
	if [ -f "$PID_FILE" ]; then
		PID=$(cat "$PID_FILE")
		if [ -d "/proc/$PID" ]; then
			COMMAND=$(readlink "/proc/$PID/exe")
			if [ "$COMMAND" = "/usr/bin/lua" ]; then
				/bin/kill -KILL "$PID" && /bin/rm "$PID_FILE"
				return 0
			fi
		fi
	fi
	echo "Daemon is not running"
	return 1
}
]=]

local initScriptPath = "/etc/init.d/upnp-proxy-daemon"

local ProxyServiceId = "urn:futzle-com:serviceId:UPnPProxy1"
local DeviceId
local taskHandle = -1

function task(message, mode)
	taskHandle = luup.task(message, mode, string.format("%s[%d]", luup.devices[DeviceId].description, DeviceId), taskHandle)
end

function createInitScript()
	task("Creating init script", 1)
	local f = io.open(initScriptPath, "w")
	f:write(initScript)
	f:close()
	task("Created init script", 4)
	task("Making init script executable", 1)
	os.execute("chmod +x " .. initScriptPath)
	task("Made init script executable", 4)
	task("Enabling init script", 1)
	os.execute(initScriptPath .. " enable")
	task("Enabled init script", 4)
	task("Starting init script", 1)
	os.execute(initScriptPath .. " start")
	task("Started init script", 4)
end

function updateProxyVersion()
	-- Get API version.
	task("Checking that proxy is running", 1)
	local ProxyApiVersion
	local t = {}
	local request, code = http.request({
		url = "http://localhost:2529/version",
		sink = ltn12.sink.table(t)
	})

	if (request == nil and code == "timeout") then
		task("Checking that proxy is running (retrying)", 1)
		luup.call_delay("updateProxyVersion", 5, "")
		return
	elseif (request == nil and code ~= "closed") then
		-- Proxy not running.
		task("Proxy is not running", 4)
		luup.variable_set(ProxyServiceId, "Status", 0, DeviceId)
		luup.variable_set(ProxyServiceId, "StatusText", "Not Running", DeviceId)
	else
		-- Proxy is running, note its version number.
		task("Proxy is running", 4)
		ProxyApiVersion = table.concat(t)
		luup.variable_set(ProxyServiceId, "Status", 1, DeviceId)
		luup.variable_set(ProxyServiceId, "StatusText", "Running", DeviceId)
		luup.variable_set(ProxyServiceId, "API", ProxyApiVersion, DeviceId)
	end

	-- Check again in a while.
	luup.call_delay("updateProxyVersion", 400, "")
end

function initialize(deviceId)
	DeviceId = deviceId
	-- Create the init script in /etc/init.d/upnp-proxy-daemon.
	local f = io.open(initScriptPath, "r")
	if (f) then
		-- File already exists.
		if (f:read("*a") == initScript) then
			luup.log("Init script unchanged.")
			f:close()
		else
			luup.log("Init script different; will be recreated.")
			f:close()
			task("Stopping init script", 1)
			os.execute(initScriptPath .. " stop")
			task("Stopped init script", 4)
			createInitScript()
			luup.call_delay("restartNeeded", 1, "Restart Luup engine to complete installation")
			return true
		end
	else
		luup.log("Init script absent; will be created.")
		createInitScript()
		luup.call_delay("restartNeeded", 1, "Restart Luup engine to complete installation")
		return true
	end

	-- Proxy should be running now.

	luup.call_delay("updateProxyVersion", 1, "")
	return true
end

function uninstall(deviceId)
	local f = io.open(initScriptPath, "r")
	if (f) then
		-- File exists.
		f:close()
		task("Stopping init script", 1)
		os.execute(initScriptPath .. " stop")
		task("Stopped init script", 4)
		task("Disabling init script", 1)
		os.execute(initScriptPath .. " disable")
		task("Disabling init script", 4)
		task("Removing init script", 1)
		os.execute("rm " .. initScriptPath)
		task("Removed init script", 4)
		task("Delete the UPnP Event Proxy device, then reload Luup engine.", 1)
	end
end

function restartNeeded(message)
	task(message, 2)
end