#!/usr/bin/lua

--[[

Luci statistics - collectd configuration generator
(c) 2008 Freifunk Leipzig / Jo-Philipp Wich <jow@openwrt.org>

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

		http://www.apache.org/licenses/LICENSE-2.0

$Id$

]]--


require("luci.model.uci")
require("luci.util")
require("luci.i18n")
require("luci.jsonc")
require("nixio.fs")

local uci = luci.model.uci.cursor()
local sections = uci:get_all( "luci_statistics" )


function print(...)
	nixio.stdout:write(...)
	nixio.stdout:write("\n")
end

function section( plugin )

	local config = sections[ "collectd_" .. plugin ] or sections["collectd"]

	if type(config) == "table" and ( plugin == "collectd" or config.enable == "1" ) then

		local params = ""

		if type( plugins[plugin] ) == "function" then
			params = plugins[plugin]( config )
		else
			params = config_generic( config, plugins[plugin][1], plugins[plugin][2], plugins[plugin][3], plugin == "collectd" )
		end


		if plugin ~= "collectd" then
			print( "LoadPlugin " .. plugin )

			if params:len() > 0 then
				print( "<Plugin " .. plugin .. ">\n" .. params .. "</Plugin>\n" )
			else
				print( "" )
			end
		else
			print( params .. "\n" )
		end
	end
end

function config_generic( c, singles, bools, lists, nopad )
	local str = ""

	if type(c) == "table" then

		if type(singles) == "table" then
			for i, key in ipairs( singles ) do
				if preprocess[key] then
					c[key] = preprocess[key](c[key])
				end

				str = str .. _string( c[key], key, nopad )
			end
		end

		if type(bools) == "table" then
			for i, key in ipairs( bools ) do
				if preprocess[key] then
					c[key] = preprocess[key](c[key])
				end

				str = str .. _bool( c[key], key, nopad )
			end
		end

		if type(lists) == "table" then
			str = str .. _list_expand( c, lists, nopad )
		end
	end

	return str
end

function config_exec( c )
	local str = ""

	for s in pairs(sections) do
		for key, type in pairs({ Exec="collectd_exec_input", NotificationExec="collectd_exec_notify" }) do
			if sections[s][".type"] == type then

				cmd = sections[s].cmdline

				if cmd then
					cmd   = cmd:gsub("^%s+", ""):gsub("%s+$", "")
					user  = sections[s].cmduser  or "nobody"
					group = sections[s].cmdgroup

					str = str .. "\t" .. key .. ' "' ..
						user .. ( group and ":" .. group or "" ) .. '" "' ..
						cmd:gsub('%s+', '" "') .. '"\n'
				end
			end
		end
	end

	return str
end

function config_curl( c )
	local str = ""

	for s in pairs(sections) do
		if sections[s][".type"] == "collectd_curl_page" then
			str = str .. "\t<Page \"" .. sections[s].name .. "\">\n" ..
						 "\t\tURL \"" .. sections[s].url .. "\"\n" ..
						 "\t\tMeasureResponseTime true\n" ..
						 "\t</Page>\n"
		end
	end

	return str
end

function config_iptables( c )
	local str = ""

	for id, s in pairs(sections) do
		if s[".type"] == "collectd_iptables_match" or s[".type"] == "collectd_iptables_match6" then
			local tname = s.table and tostring(s.table)
			local chain = s.chain and tostring(s.chain)

			if tname and tname:match("^%S+$") and chain and chain:match("^%S+$") then
				local line = { #s[".type"] > 23 and "\tChain6" or "\tChain", tname, chain }
				local rule = s.rule and tostring(s.rule)

				if rule and rule:match("^%S+$") then
					line[#line+1] = rule

					local name = s.name and tostring(s.name)
					if name and name:match("^%S+$") then
						line[#line+1] = name
					end
				end

				str = str .. table.concat(line, " ") .. "\n"
			end
		end
	end

	return str
end

function config_network( c )
	local str = ""

	for s in pairs(sections) do
		for key, type in pairs({ Listen="collectd_network_listen", Server="collectd_network_server" }) do
			if sections[s][".type"] == type then

				host = sections[s].host
				port = sections[s].port

				if host then
					if port then
						str = str .. "\t" .. key .. " \"" .. host .. "\" \"" .. port .. "\"\n"
					else
						str = str .. "\t" .. key .. " \"" .. host .. "\"\n"
					end
				end
						end
				end
		end

	return str .. _string( c["TimeToLive"], "TimeToLive" )
		   .. _string( c["CacheFlush"], "CacheFlush" )
		   .. _bool(   c["Forward"],    "Forward"    )
end


function _list_expand( c, l, nopad )
	local str = ""

	for i, n in ipairs(l) do
		if c[n] then
			if preprocess[n] then
				c[n] = preprocess[n](c[n])
			end

			if n:find("(%w+)ses") then
				k = n:gsub("(%w+)ses$", "%1s")
			else
				k = n:gsub("(%w+)s$", "%1")
			end

			str = str .. _expand( c[n], k, nopad )
		end
	end

	return str
end

function _expand( s, n, nopad )
	local str = ""

	if type(s) == "string" then
		for i, v in ipairs( luci.util.split( s, "%s+", nil, true ) ) do
			str = str .. _string( v, n, nopad )
		end
	elseif type(s) == "table" then
		for i, v in ipairs(s) do
			str = str .. _string( v, n, nopad )
		end
	end

	return str
end

function _bool( s, n, nopad )

	local str = ""
	local pad = ""
	if not nopad then pad = "\t" end

	if s and s == "1" then
		str = pad .. n .. " true"
	else
		str = pad .. n .. " false"
	end

	return str .. "\n"
end

function _string( s, n, nopad )

	local str = ""
	local pad = ""
	if not nopad then pad = "\t" end

	if s then
		if s:find("[^%d]") or n == "Port" then
			if not s:find("[^%w]") and n ~= "Port" then
				str = pad .. n .. " " .. luci.util.trim(s)
			else
				str = pad .. n .. ' "' .. luci.util.trim(s) .. '"'
			end
		else
			str = pad .. n .. " " .. luci.util.trim(s)
		end

		str = str .. "\n"
	end

	return str
end


plugins = {
	collectd = {
		{ "BaseDir", "Include", "PIDFile", "PluginDir", "TypesDB", "Interval", "ReadThreads", "Hostname" },
		{ },
		{ }
	},
	logfile	= {
		{ "LogLevel", "File" },
		{ "Timestamp" },
		{ }
	},
}

local plugin_dir = "/usr/share/luci/statistics/plugins/"
for filename in nixio.fs.dir(plugin_dir) do
	local name = filename:gsub("%.json", "")
	if (name == "exec") then
		plugins[name] = config_exec
	elseif (name == "iptables") then
		plugins[name] = config_iptables
	elseif (name == "curl") then
		plugins[name] = config_curl
	elseif (name == "network") then
		plugins[name] = config_network
	else
		local plugin_def = luci.jsonc.parse(nixio.fs.readfile(plugin_dir .. filename))
		if type(plugin_def) == "table" then
			plugins[name] = plugin_def.legend
		end
	end
end


preprocess = {
	RRATimespans = function(val)
		local rv = { }
		for time in val:gmatch("[^%s]+") do
			table.insert( rv, luci.util.parse_units(time) )
		end
		return table.concat(rv, " ")
	end
}


section("collectd")

section("logfile")

for plugin in pairs(plugins) do
	if (plugin ~= "collectd") and (plugin ~= "logfile") then
		section( plugin )
	end
end