require "libs.shcmd"

-- The caching idea is borrowed from MattJ's riddim code,

-- and the function parse_xeps() as well.

local xeplisturl = "curl http://xmpp.org/extensions/xeps.xml"

local xeps = {}

-- parse_xep() from Matthew Wild (aka MattJ)

local function parse_xeps(t)

if not t or t == "" then return nil end

local currxep = {}

    for b in string.gmatch(t,"<xep>(.-)</xep>") do

        for k,v in string.gmatch(b,"<(%w+)>(.-)</%1>") do

            currxep[k] = v

        end

        xeps[currxep.number] = { }

        for k, v in pairs(currxep) do xeps[currxep.number][k] = v end

    end

    return true

end

local function fetch_xeps ()

    local now = os.time()

    if os.difftime(now, xeps_updated_at) < 43200 then return end

    -- Let's get some fresh data

    local xepdata = shcmd(xeplisturl)

    xeps_updated_at = now

    parse_xeps(xepdata)

end

-- Logics comes from MattJ's riddim bot

local function lookup_xep (xepnum)

    -- Check that xepnum is a valid number

    xepnum = tonumber(xepnum)

    if not xepnum or xepnum <= 0 or xepnum > 9999 then return nil, "What XEP?" end

    xepnum = tostring(xepnum)

    -- Download XEP list

    fetch_xeps()

    -- Expand to full 4 char number

    xepnum = string.rep("0", 4-xepnum:len())..xepnum

    xep = xeps[tostring(xepnum)]

    if not xep then return nil,"Sorry, XEP-"..xepnum.." not found" end

    return "XEP-"..xep.number.." is \""..xep.name.."\"\n"..

           -- xep.type..", "..xep.status..", last updated "..xep.updated.."\n"..

           "URL: <http://xmpp.org/extensions/xep-"..xep.number..".html>"

end

mcbot_register_command("xep", lookup_xep)