Using: host/gift/yourname

annual_gift_lottery.lua

#!/usr/bin/lua
-- Using:
-- Deploy this file to openresty
-- and visit host/gift/yourname.
-- E.g http://192.168.18.22/gift/zengrong
-- Will get a gift object for zengrong.

function in_table(t, v)
	for key,value in pairs(t) do
		if type(value) == 'table' then
			if v == value[1] then
				return value
			end
		else
			if v == value then
				return key
			end
		end
	end
	return nil
end

function split(str)
	local list = {}
	for k in string.gmatch(str, '[^,]+') do
		if string.find(k, ':') then
			local list = {}
			for v in string.gmatch(k, '[^:]+') do
				table.insert(list, v)
			end
			k = list
		end
		table.insert(list, k)
	end
	return list
end

function print_table(t)
	for key,value in pairs(t) do
		if type(value) == 'table' then
			ngx.say(key,' ', table.concat(value, ':'))
		else
			ngx.say(key, ' ', value)
		end
	end
end

function print_pool(pool)
	local num = #pool
	if num == 0 then
		ngx.say(string.format('The GIFT LOTTERY is over, enjoy it!'))
	else
		ngx.say(string.format('There are %d stuff(s) in the POOL.', num))
	end
end

function init_pool(t, name)
	local pool = ngx.shared.lottery:get(name)
	if not pool then
		pool = {}
		for k,v in pairs(t) do
			table.insert(pool, v)
		end
		ngx.shared.lottery:set(name, table.concat(pool, ','))
	else
		pool = split(pool)
	end
	return pool
end

function init_names()
	local names = ngx.shared.lottery:get('names')
	if not names then
		names = {
			'chentao', 
			'sunminghong',
			'yueli',
			'zengrong',
			'xukun',
			'xiefei',
			'zhangming',
			'qiaoyan',
			'zhulan',
			'lizequn',
			'wanglong',
			'zhangjiawen',
		}
		ngx.shared.lottery:set('names', table.concat(names, ','))
	else
		names = split(names)
	end
	return names
end

function init_done()
	local done = ngx.shared.lottery:get('done')
	if not done then
		done = {}
	else
		done = split(done)
	end
	return done
end

math.randomseed(os.time())

local no_restrict_ip = false
local admin_ip = '192.168.18.22'
local uri = ngx.var.uri
local ip = ngx.var.remote_addr
local lottery = ngx.shared.lottery

local names = init_names()
local done = init_done()
local sele = init_pool(names, 'sele')
local pool = init_pool(names, 'pool')

local name = string.sub(uri, 7)
ngx.say('Your name: '..name)

-- For administrator
if ip == admin_ip then
	if name == 'allmatching' then
		ngx.say('\n----DONE----')
		print_table(done)
		ngx.say('\n----POOL----')
		print_table(pool)
		ngx.say('\n----SELE----')
		print_table(sele)
		ngx.say('\n----NAMES----')
		print_table(names)
		return
	end

	if name == 'clearall' then
		lottery:set('done', '')
		lottery:set('pool', table.concat(names, ','))
		lottery:set('sele', table.concat(names, ','))
		return
	end
end

local is_staff = in_table(names, name)

if not is_staff then
	ngx.say('You are NOT our friend! GET OUT!')
	return
end

local idx = in_table(sele, name)

if not idx then
	local fmt = 'You have already got a object. He/She is -- %s.'
	local obj = in_table(done, name)
	if not obj then
		ngx.say('You are neither in the SELE list nor the DONE list. Please contact administrator.')
		return
	end
	if no_restrict_ip or obj[3] == ip then
		ngx.say(string.format(fmt, obj[2]))
	else
		ngx.say(string.format(fmt, '******'))
	end
	print_pool(pool)
	return
end

--[[
ngx.say(math.random(#names))
ngx.say(math.random(#names))
ngx.say(math.random(#names))
ngx.say(math.random(#names))
]]

while true do
	local rnd = math.random(#pool)
	obj = pool[rnd]
	if #pool == 2 then
		local obj2 = nil
		rnd2idx = (rnd == 1 and 2) or 1
		name2idx = (idx == 1 and 2) or 1

		if sele[name2idx] == pool[rnd2idx] then
			rnd = rnd2idx
			obj = pool[rnd]
		end
	end
	if obj ~= name then
		table.remove(sele, idx)
		table.remove(pool, rnd)
		break
	end
end
lottery:set('pool', table.concat(pool, ','))
lottery:set('sele', table.concat(sele, ','))

table.insert(done, {name, obj, ip})
local donestr = {}

for k,v in pairs(done) do
	table.insert(donestr, table.concat(v, ':'))
end
lottery:set('done', table.concat(donestr, ','))

ngx.say('Your gift object is '.. obj .. '.')
print_pool(pool)

test.sh

#!/bin/bash

testonce()
{
	curl 192.168.18.22/gift/clearall

	for name in chentao sunminghong yueli zengrong xukun xiefei zhangming qiaoyan zhulan lizequn wanglong zhangjiawen; do
		curl 192.168.18.22/gift/$name
	done
}

testonce
testonce
testonce
testonce
testonce
testonce
testonce
testonce
testonce
testonce
testonce
testonce