module(..., package.seeall)

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

-- Set variables
local configfile = "/etc/dnsmasq.conf"
local processname = "dnsmasq"
local packagename = "dnsmasq"

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

local function update_file (file, search_name, value_in)
	if not file or not search_name or search_name == "" then
		return file, false
	end
	
	-- Since we clear out the value, this prevents us from changing parent's value
	local value = value_in
	if type(value_in) == "table" then
		value = {}
		for i,val in ipairs(value_in) do	
			value[#value + 1] = val
		end
	end

	local new_conf_file = {}
	local skip_lines = {}
	for l in string.gmatch(file, "([^\n]*)\n?") do
		if string.find ( l, "\\%s*$" ) then
			skip_lines[#skip_lines+1] = string.match(l, "^(.*)\\%s*$")
			l = nil
		else
			if #skip_lines then
				skip_lines[#skip_lines+1] = l
				l = table.concat(skip_lines, " ")
			end
			-- check if comment line
			if not string.find ( l, "^%s*#" ) then
				-- find name
				local a = string.match ( l, "^%s*([^=]*%S)%s*=" )
				if a and (search_name == a) then
					-- Figure out the value
					local b = string.match ( l, '=%s*(.*%S)%s*$' ) or ""
					-- remove comments from end of line
					if string.find ( b, '#' ) then
						b = string.match ( b, '^(.*%S)%s*#.*$' ) or ""
					end

					-- We found the name, change the value
					if not value then
						l = nil
					elseif type(value) == "string" then
						if value ~= b then
							l = search_name.."="..value
						end
						value = nil
					else
						local temp = l
						l = nil
						for i,val in ipairs(value) do
							if val == b then
								l = temp
								table.remove(value, i)
								break
							end
						end
					end
					skip_lines = {}	-- replacing line
				end
			end
			if #skip_lines > 0 then
				for i,line in ipairs(skip_lines) do
					new_conf_file[#new_conf_file + 1] = line
				end
				skip_lines = {}
				l = nil
			end
		end
		new_conf_file[#new_conf_file + 1] = l
	end

	if value then
		-- we didn't find the searchname, add it now
		if type(value) == "string" then
			new_conf_file[#new_conf_file + 1] = search_name.."="..value
		else
			for i,val in ipairs(value) do
				new_conf_file[#new_conf_file + 1] = search_name.."="..val
			end
		end
	end

	file = table.concat(new_conf_file, '\n')

	return file, true
end

-- Parse string for name=value pairs, returned in a table
local function parse_file (file)
	if not file or file == "" then
		return nil
	end
	local opts = nil
	local skip_lines = {}
	for l in string.gmatch(file, "([^\n]*)\n?") do
		if string.find ( l, "\\%s*$" ) then
			skip_lines[#skip_lines+1] = string.match(l, "^(.*)\\%s*$")
		else
			if #skip_lines then
				skip_lines[#skip_lines+1] = l
				l = table.concat(skip_lines, " ")
				skip_lines = {}
			end
			-- check if comment line
			if not string.find ( l, "^%s*#" ) then
				-- find name
				local a = string.match ( l, "^%s*([^=]*%S)%s*=" )
				if a then
					-- Figure out the value
					local b = string.match ( l, '=%s*(.*%S)%s*$' ) or ""
					-- remove comments from end of line
					if string.find ( b, '#' ) then
						b = string.match ( b, '^(.*%S)%s*#.*$' ) or ""
					end
					
					if not (opts) then opts = {} end
					if not opts[a] then
						opts[a] = {b}
					else
						table.insert(opts[a], b)
					end
				end
			end
		end
	end

	return opts
end

local function validateconfig(config)
	local success = true

	function testlist(param, test, errtxt)
		if #param.value > 0 then
			for i,val in ipairs(param.value) do	
				if test(val) then
					param.errtxt = errtxt
					success = false
					break
				end
			end
		end
	end
	
	testlist(config.value.domain, function(v) return string.find(v, "%s") end, "Cannot contain spaces")
	testlist(config.value.interface, function(v) return string.find(v, "%W") end, "Illegal character")
	testlist(config.value.listen_address, function(v) return not validator.is_ipv4(v) end, "Invalid IP Address")
	testlist(config.value.dhcp_range, function(v) return string.find(v, "%s") end, "Cannot contain spaces")
	testlist(config.value.no_dhcp_interface, function(v) return string.find(v, "%W") end, "Illegal character")
	testlist(config.value.dhcp_host, function(v) return string.find(v, "%s") end, "Cannot contain spaces")
	testlist(config.value.dhcp_option, function(v) return string.find(v, "%s") end, "Cannot contain spaces")
	testlist(config.value.mx_host, function(v) return string.find(v, "%s") end, "Cannot contain spaces")
	
	return success, config
end

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

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

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

function getconfig()
	local conf = parse_file(fs.read_file(configfile) or "") or {}

	local output = {}
	output.domain = cfe({ type="list", value=conf.domain or {}, label="Local Domain",
		descr="List of internal domain(s) for your LAN 'domain[,address_range]'.  Address range can be a single IP address, a range specified by 'IP,IP', or IP/netmask." })
	output.interface = cfe({ type="list", value=conf.interface or {}, label="Interface", descr="List of interfaces to listen on." })
	output.listen_address = cfe({ type="list", value=conf["listen-address"] or {}, label="List of IP addresses to listen on" })
	output.dhcp_range = cfe ({ type="list", value=conf["dhcp-range"] or {},	label="Range of DHCP IPs",
		descr="List of Start,End,Netmask,Time in seconds/minutes(m)/hours(h) ie. 169.254.0.10,169.254.0.100,255.255.255.0,12h" })
	output.no_dhcp_interface = cfe({ type="list", value=conf["no-dhcp-interface"] or {}, label="No DHCP Interface", descr="List of interfaces which should have DNS but not DHCP." })
	output.dhcp_host = cfe({ type="list", value=conf["dhcp-host"] or {}, label="DHCP Host Parameter", descr="List of per host parameters for the DHCP server. See dnsmasq documentation." })
	output.dhcp_option = cfe({ type="list", value=conf["dhcp-option"] or {}, label="DHCP Option", descr="List of different or extra options to DHCP clients. See dnsmasq documentation." })
	output.mx_host = cfe({ type="list", value=conf["mx-host"] or {}, label="MX Record", descr="List of MX records 'mx_name,hostname'." })
	 
	-- APP.logevent(html.cfe_unpack(output))
	
	return cfe({ type="group", value=output, label="DNS Masq Config" })
end

function setconfig(config)
	local success, config = validateconfig(config)

	if success then
		local file = fs.read_file(configfile)
		file = update_file(file,"domain",config.value.domain.value)
		file = update_file(file,"interface",config.value.interface.value)
		file = update_file(file,"listen-address",config.value.listen_address.value)
		file = update_file(file,"dhcp-range",config.value.dhcp_range.value)
		file = update_file(file,"no-dhcp-interface",config.value.no_dhcp_interface.value)
		file = update_file(file,"dhcp-host",config.value.dhcp_host.value)
		file = update_file(file,"dhcp-option",config.value.dhcp_option.value)
		file = update_file(file,"mx-host",config.value.mx_host.value)
		fs.write_file(configfile, file)	
	else
		config.errtxt = "Failed to set config"
	end

	return config
end

function getconfigfile()
	-- FIXME Validate
	return modelfunctions.getfiledetails(configfile)
end

function setconfigfile(filedetails)
	-- FIXME Validate
	return modelfunctions.setfiledetails(filedetails, {configfile})
end