local dns = require "org.conman.dns"


function dns_encode()
	
	if ngx.var.app == nil then
		ngx.exit(ngx.HTTP_SERVER_ERROR)
	end

	if ngx.var.group == nil then
		ngx.exit(ngx.HTTP_SERVER_ERROR)
	end

	if ngx.var.resolvedomain == nil then
		ngx.exit(ngx.HTTP_SERVER_ERROR)
	end

	domain = ''

	if ngx.var.portname == nil then
		domain = '_' .. 
			ngx.var.app .. '.' .. 
			ngx.var.group .. '._tcp.' .. 
			ngx.var.resolvedomain .. '.'
	else
		domain = '_' .. ngx.var.portname .. '.' .. 
			ngx.var.app .. '.' .. 
			ngx.var.group .. '._tcp.' .. 
			ngx.var.resolvedomain .. '.'
	end

	e,err = dns.encode {
	    id  = math.random(),
	    query = true,
	    rd = true,
	    opcode = 'query',
	    question = {
		name = domain,
		type = 'SRV',
		class = 'in'
	    }
	}

	if e == nil then
	    print('error: ', err)
	    ngx.exit(ngx.HTTP_SERVER_ERROR)
	end

	return e
end


function do_query(e)
	if ngx.var.dns == nil then
	    ngx.exit(ngx.HTTP_SERVER_ERROR)
	end

	r,err = dns.query(ngx.var.dns,e)
	
	if r == nil then
	    ngx.print(err)
	    ngx.exit(ngx.HTTP_SERVER_ERROR)
	end
	
	return r
end


function dns_decode(r)
	d = dns.decode(r)
	return d
end


resolved = do_query(dns_encode())
decoded = dns_decode(resolved)

ngx.var.upstr = decoded.answers[1].target .. ':' .. decoded.answers[1].port