module (..., package.seeall)

-- Load libraries
require("modelfunctions")
require("fs")
require("format")

-- Set variables
local configfile = "/etc/ntpd.conf"
local confdfile = "/etc/conf.d/ntpd"
local packagename = "openntpd"
local processname = "ntpd"

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

local function last_time_change()
	local cmdoutput = {}
	local cmd, error = io.popen("cat /var/log/messages | grep ntpd | grep adjusting | tail -1" ,r)
	local cmdoutput1,cmdoutput2 = string.match(cmd:read("*a"), "^%s*(%S+%s+%S+%s+%S+%s+).*: (.*)$")
	cmd:close()
	cmdoutput1 = cmdoutput1 or "(Have no data on updates)"
	cmdoutput2 = cmdoutput2 or ""
	return cmdoutput1 .. cmdoutput2
end

local function validate_config(config)
	local success = true

	-- Three of the fields are just lists of IP addresses / hostnames
	local tags = {"server", "servers", "listen"}
	for i,tag in ipairs(tags) do
		local field = config.value[tag]
		for j,entry in ipairs(field.value) do
			if string.find(entry, "[^%w.-]") then
				if not (tag=="listen" and entry=="*") then
					field.errtxt = "Invalid IP address/hostname"
					success = false
					break
				end
			end
		end
	end

	return success, config
end

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

function startstop_service(action)
	return modelfunctions.startstop_service(processname, action)
end

function getstatus()
	return modelfunctions.getstatus(processname, packagename, "OpenNTPD Status")
end

function getstatusdetails()
	local status = {}

	status.timechanged = cfe({ value=last_time_change(), label="Previous time adjustment" })
	status.date = cfe({ value=os.date(), label="Current time" })

	return cfe({ type="group", value=status, label="OpenNTPD Detailed Status" })
end

function read_config ()
	local config = {}
	config.server = cfe({ type="list", value={}, label="Single servers", descr="List of server IP addresses/hostnames.  OpenNTPD will attempt to synchronize to one resolved address for each hostname entry." })
	config.servers = cfe({ type="list", value={}, label="Multiple servers", descr="List of server IP addresses/hostnames.  OpenNTPD will attempt to synchronize to all resolved addresses for each hostname entry." })
	config.listen = cfe({ type="list", value={}, label="Addresses to listen on", descr="List of IP addresses/hostnames to listen on.  '*' means listen on all local addresses." })
	config.setstimeonstartup = cfe({ type="boolean", value=false, label="Set time on startup" })

	local conf = format.parse_linesandwords(fs.read_file(configfile) or "")
	for i,line in ipairs(conf) do
		if line[1] == "server" then
			table.insert(config.server.value, line[2])
		elseif line[1] == "servers" then
			table.insert(config.servers.value, line[2])
		elseif line[1] == "listen" and line[2] == "on" then
			table.insert(config.listen.value, line[3])
		end
	end

	local opts = string.sub(format.parse_ini_file(fs.read_file(confdfile) or "", "", "NTPD_OPTS") or "", 2, -2)
	if format.opts_to_table(opts, "-s") then
		config.setstimeonstartup.value = true
	end

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

function update_config(config)
	local success, config = validate_config(config)

	if success then
		local reverseserver = {} for i,val in ipairs(config.value.server.value) do reverseserver[val] = i end
		local reverseservers = {} for i,val in ipairs(config.value.servers.value) do reverseservers[val] = i end
		local reverselisten = {} for i,val in ipairs(config.value.listen.value) do reverselisten[val] = i end

		local configcontent = string.gsub(fs.read_file(configfile) or "", "\n+$", "")
		local configlines = format.parse_linesandwords(configcontent)
		for i=#configlines,1,-1 do
			if configlines[i][1] == "server" then
				if reverseserver[configlines[i][2]] then
					reverseserver[configlines[i][2]] = nil
				else
					configcontent = format.replace_line(configcontent, configlines[i].linenum)
				end
			elseif configlines[i][1] == "servers" then
				if reverseservers[configlines[i][2]] then
					reverseservers[configlines[i][2]] = nil
				else
					configcontent = format.replace_line(configcontent, configlines[i].linenum)
				end
			elseif configlines[i][1] == "listen" and configlines[i][2] == "on" then
				if reverselisten[configlines[i][3]] then
					reverselisten[configlines[i][3]] = nil
				else
					configcontent = format.replace_line(configcontent, configlines[i].linenum)
				end
			end
		end
		-- Then add the missing ones
		lines = {configcontent}
		for entry in pairs(reverselisten) do
			lines[#lines+1] = "listen on "..entry
		end
		for entry in pairs(reverseserver) do
			lines[#lines+1] = "server "..entry
		end
		for entry in pairs(reverseservers) do
			lines[#lines+1] = "servers "..entry
		end
		fs.write_file(configfile, table.concat(lines, "\n"))

		-- Finally, handle setstimeonstartup
		local opts = {}
		if config.value.setstimeonstartup.value then opts["-s"] = "" end
		fs.write_file(confdfile, format.update_ini_file(fs.read_file(confdfile) or "", "", "NTPD_OPTS", '"'..format.table_to_opts(opts)..'"'))
	else
		config.errtxt = "Failed to save config"
	end

	return config
end

function get_filedetails()
	return modelfunctions.getfiledetails(configfile)
end

function update_filedetails(filedetails)
	return modelfunctions.setfiledetails(filedetails, {configfile})
end