#!/usr/bin/env lua
local json = require "cjson"
local tA = {...}

local mhwurl = tA[2] or "https://www.monsterhunter.com/world-iceborne/pc/assets/data/us/news.json"
local title = "Unofficial Monster Hunter World News"
local jsf = os.tmpname()
os.execute(string.format("curl -so '%s' '%s'",jsf,mhwurl))
local f = io.open(jsf,"rb")
if not f then error("unable to open file for reading: "..jsf) end
local c = f:read("*a")
f:close()
os.execute(string.format("rm '%s'",jsf))
local jt = json.decode(c)
local f = io.open(tA[1],"wb")
if not f then error("unable to open file for writing: "..tA[1]) end
f:write(string.format([[<?xml version="1.0" encoding="UTF-8" ?>
<rss version="2.0">
<channel>
 <title>%s</title>
 <link>https://www.monsterhunter.com/world-iceborne/pc/us/</link>
 <lastBuildDate>%s</lastBuildDate>
 <ttl>1440</ttl>
]], title, os.date("%a, %d %b %Y %H:%M:%S %z")))
for k,v in pairs(jt.topics) do
 if v.link:sub(1,8) ~= "https://" then
  v.link = "https://www.monsterhunter.com/" .. v.link
 end
 local p = io.popen(string.format("curl -sI '%s' | grep last-modified",v.link))
 local c = p:read("*a")
 p:close()
 mdate = c:match(": ([^\r\n]+)")
 if mdate then
 f:write(string.format([[ <item>
  <title>%s</title>
  <description><img src="https://www.monsterhunter.com/world-iceborne/pc/%s"></img></description>
  <link>%s</link>
  <guid>%s</guid>
  <pubDate>%s</pubDate>
 </item>
]], v.text, v.img, v.link, v.link, mdate))
 else
 f:write(string.format([[ <item>
  <title>%s</title>
  <description><img src="https://www.monsterhunter.com/world-iceborne/pc/%s"></img></description>
  <link>%s</link>
  <guid>%s</guid>
 </item>
]], v.text, v.img, v.link, v.link))
 end
end

f:write([[</channel>
</rss>]])
f:close()