--print("DEBUG: got message:", msg)

--ipcmsg = require("json")
ipcmsg = require("cmsgpack")
ipcmsg.encode = ipcmsg.pack
ipcmsg.decode = ipcmsg.unpack

ml =  require("ml")

modules_path = "../modules/"

mods = {}

local function ret_error(errmsg)
	io.stderr:write("ERROR: "..tostring(errmsg).."\n")
	return ipcmsg.encode{ status = false, errmsg = errmsg}
end

local function ret_success(...)
	return ipcmsg.encode{ status = true, errmsg = "success",
		result = {...} }
end

reqhandler = {}
function reqhandler.load(req)
	-- make sure we dont have any path elements in modname so we cannot pass
	-- modnames like '../myevilmod'
	local file = modules_path..string.gsub(req.modname, ".*/", "")..".lua"
	mods[req.modidx] = dofile(file)
	if mods[req.modidx] == nil then
		return ret_error(file)
	end
	return true
end

function reqhandler.call(req)
	if req.modidx == nil or req.func == nil then
		return ret_error("failed to call function "..tostring(req.func))
	end
	local m = mods[req.modidx]
	-- check that the func we want exists
	if type(m[req.func]) ~= "function" then
		ret_error(func..": not a function in '".. mfile .."'")
	end

	-- TODO: check permissions here
--	print("DEBUG: Calling mods["..req.modidx.."]."..req.func)

	-- execute the func and pack the return values into a table
	return m[req.func](unpack(req.args))
end

function handler(msg)
	local req = ipcmsg.decode(msg)
--	print("DEBUG: req="..ml.tstring(req))
	if type(req.type) ~= "string" then
		return ret_error("request type missing")
	end
	if type(reqhandler[req.type]) == "function" then
		return ret_success(reqhandler[req.type](req))
	end
	return ret_error("no handler for request type "..req.type)
end