module (..., package.seeall)

require ("modelfunctions")
require ("posix")
require ("format")
require ("fs")
require ("processinfo")
require ("validator")
require ("date")

local processname = "openvpn"
local packagename = "openvpn"
local baseurl = "/etc/openvpn/"

-- ################################################################################
-- LOCAL FUNCTIONS

local function config_content( f )
	local config = {}
	local lines = format.parse_linesandwords(fs.read_file(f) or "", "[#;]")
	-- there can be multiple entries
	for i,linetable in ipairs(lines) do
		if config[linetable[1]] then
			config[linetable[1]] = config[linetable[1]] .. "\n" .. (table.concat(linetable, " ", 2) or "")
		else
			config[linetable[1]] = table.concat(linetable, " ", 2) or ""
		end
	end

	config.name = f
	if config.remote then
		config.remoteport = string.match ( config.remote, "^%S+%s+(%S*)" )
	end
	if not ( config.log ) then
		config.log = config["log-append"]
	end
	if not ( config["max-clients"] ) then
		config["max-clients"] = "Unlimited"
	end
	if not ( config["local"] ) then
		config["local"] = "0.0.0.0"
	end
	return config
end


local is_running = function( process, parameters )
	local retval = "Stopped"
	for i,v in ipairs(processinfo.pidof(process) or {}) do
		local path = string.gsub("/proc/".. v .. "/cmdline", "%s", "")
		local f = io.open(path,r)
		local file_resultx = f:read("*a")
		local file_result = string.match(file_resultx, parameters)
		f:close()
		if ( file_result ) then
			retval = "Running"
		end
	end
	return retval
end

local function check_valid_config (config)
	config.errtxt = nil
	if not (config.client) or not (config.ca) or not (config.cert) or not (config.key) or not (config.dev) or not (config.proto) or not (config.remote) then
		config.errtxt = ""
		if not (config.ca) then
			config.errtxt = config.errtxt .. "Check CA; "
		end
		if not (config.cert) then
			config.errtxt = config.errtxt .. "Check CERT; "
		end
		if not (config.key) then
			config.errtxt = config.errtxt .. "Check KEY; "
		end
		if not (config.dev) then
			config.errtxt = config.errtxt .. "Check DEV; "
		end
		if not (config.proto) then
			config.errtxt = config.errtxt .. "Check PROTO; "
		end
		if (config.client) or not (config.ca) or not (config.cert) or not (config.key) or not (config.dev) or not (config.proto) or not (config.port) then
			config.type = nil
		else
			config.type = "server"
			config.errtxt = nil
		end
	else
		config.type = "client"
		config.errtxt = nil
	end
	if not (config.type) then config.type = "unknown" end
	return config.type, config.errtxt
end

local function list_conffiles()
	local configfiles = {}
	for file in fs.find(".*conf", baseurl) do
		if fs.is_file(file) then
			configfiles[#configfiles+1] = file
		end
	end
	return configfiles
end

local function clientlist( statusfile )
	local clientlist = {}
	local routinglist = {}
	local datechange = {}
	local list = {}
	if (statusfile) then
		local f = fs.read_file_as_array( statusfile )
		local clientlst = false
		local routinglst = false
		if ( f ) then
			for k,v in ipairs(f) do
				local col = format.string_to_table(v, ",")
				if ( col[1] == "ROUTING TABLE" ) or ( col[1] == "GLOBAL STATS" ) then
					clientlst = false
					routinglst = false
				end
				if ( clientlst ) then
					table.insert(clientlist, { CN=col[1],
						REALADDR=col[2],
						BYTESRCV=col[3],
						BYTESSND=col[4],
						CONN=col[5] } )
				end
				if ( routinglst ) then
					table.insert(routinglist, { VIRTADDR=col[1],
						CN=col[2],
						REALADDR=col[3],
						LAST=col[4] } )
					if (col[4]) then
						local month,day,hour,min,sec,year = string.match(col[4],"^%S+%s+(%S+)%s+(%S+)%s+(%d%d):(%d%d):(%d%d)%s+(%S+)")
						table.insert(datechange, { year=year,
							month=date.abr_month_num(month),
							day=day,
							hour=hour,
							min=min,
							sec=sec } )
					end
				end
				if ( col[1] == "Virtual Address" ) then
					routinglst = true
				end
				if ( col[1] == "Common Name" ) then
					clientlst = true
				end

			end
		end
	end
	-- JOIN 'CLIENT_LIST' and 'ROUTING_LIST' TABLES INTO ONE TABLE AND LATER ON PRESENT THIS TABLE
	for k,v in ipairs(clientlist) do
		for kk,vv in ipairs(routinglist) do
			if ( v.CN == vv.CN ) then
				table.insert(list, { CN=v.CN, REALADDR=v.REALADDR, BYTESRCV=v.BYTESRCV, BYTESSND=v.BYTESSND, VIRTADDR=vv.VIRTADDR, CONN=v.CONN, LAST = LAST } )
			end
		end
	end
	local lastdatechangetxt, lastdatechangediff
	if ( #clientlist > 0 ) then
		local lastdatechange = date.date_to_seconds(datechange)
		lastdatechangetxt = os.date("%c", lastdatechange[#lastdatechange])
		lastdatechangediff = os.time() - os.date(lastdatechange[table.maxn(lastdatechange)])
		if (lastdatechangediff > 60) then
			lastdatechangediff = math.modf(lastdatechangediff / 60) .. " min"
		else
			lastdatechangediff = lastdatechangediff  .. " sec"
		end
	end
	return list, #clientlist, lastdatechangetxt, lastdatechangediff
end

-- ################################################################################
-- PUBLIC FUNCTIONS

function getstatus()
	local status = modelfunctions.getstatus(processname, packagename, "OpenVPN Status")
	status.value.autostart = nil
	status.value.status = nil
	return status
end

function getclientinfo(f)
	local config = config_content(f)
	return cfe({ type="structure", value=clientlist(config.status), label="Client info" })
end

function get_config(f)
	local config = config_content(f)
	check_valid_config(config)
	if config.type == "server" then
		local clientlist, client_count, client_lastupdate, client_lastdatechangediff = clientlist(config.status)
		config["client_lastupdate"] = client_lastupdate or "?"
		config["client_lastdatechangediff"] = client_lastdatechangediff or "? min"
		config["client_count"] = client_count or 0
	end
	config["status_isrunning"] = is_running ("openvpn", basename(f))
	return cfe({ type="structure", value=config, label="OpenVPN Config" })
end

function get_logfile(f)
	local config = config_content(f)
	return cfe({ value=config.log or "", label="Config file" })
end

function get_conflist ()
	local configlist = {}
	for i,file in ipairs(list_conffiles()) do
		config = config_content ( file )
		local conf_type, errtxt = check_valid_config(config)
		local isrunning = is_running ("openvpn", basename(file))
		local clientlist, connclients = clientlist (config.status)
		table.insert ( configlist, { name = file, type = conf_type, errtxt = errtxt, status = isrunning, clients = connclients } )
	end
	return cfe({ type="structure", value=configlist, label="Configuration List" })
end

function get_filecontent(f)
	--FIXME validate
	return modelfunctions.getfiledetails(f, list_conffiles())
end

function update_filecontent(filedetails)
	--FIXME validate
	return modelfunctions.setfiledetails(filedetails, list_conffiles())
end

function create_new_config()
	config = {
		name = cfe({ label="File Name", descr="File name should end with \".conf\"" }),
	}

	return cfe({ type="group", value=config, label="Config" })
end

function create_config(config)
	local success = true
	local path = config.value.name.value
	if not string.find(path, "/") then
		path = baseurl .. path
	end

	if not validator.is_valid_filename(path, baseurl) then
		success = false
		config.value.name.errtxt = "Invalid path"
	elseif posix.stat(path) then
		success = false
		config.value.name.errtxt = "File already exists"
	elseif not string.match(path,".*%.conf") then
		success = false
		config.value.name.errtxt = "Filename must end with '.conf'"
	end

	if success then
		fs.create_file(path)
	else
		config.errtxt = "Failed to create config"
	end

	return config
end

function delete_config(name)
	local cmdresult = cfe({ label="Delete config result", errtxt="Failed to delete config - not found" })
	
	if validator.is_valid_filename(name, baseurl) and fs.is_file(name) then
		os.remove(name)
		cmdresult.value = "Config Deleted"
		cmdresult.errtxt = nil
	end

	return cmdresult
end

function startstop_service(action,service)
	if (service ~= "openvpn") then
		if ( fs.is_file(baseurl .. service .. ".conf") ) then
			service = "openvpn." .. tostring(service)
			if not ( fs.is_file("/etc/init.d/" .. service ) ) then
				-- Create missing symlinks
				posix.link("/etc/init.d/openvpn","/etc/init.d/" .. service, true)
			end
		else
			return nil
		end
	end
	return modelfunctions.startstop_service(service, action)
end