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

-- Deeply inspired by MattJ's riddim bot

function xep.cmd (xepstr)

    if (xepstr) then

        xepstr = xepstr:gsub("[%s%?%.%!]+$", "")

        local n = xepstr:upper():match("^XEP[%-%s]?(%d+)$")

        if n then xepstr = n end

    end

    -- Check that xepnum is a valid number

    xepnum = tonumber(xepstr)

    if xepnum and (xepnum <= 0 or xepnum > 9999) then

        return nil, "What XEP?"

    end

    if not xepnum and not xepstr:match("^[%w%s%-_]+$") then

        return nil, "What XEP?  Please use a simple keyword..."

    end

    -- Download XEP list

    fetch_xeps()

    -- #1 The argument is a XEP number

    if xepnum then

        xepnum = tostring(xepnum)

        -- Expand to full 4 char number

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

        local 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

    -- #2 The argument is a keyword

    local r = ""

    xepstr = xepstr:lower()

    for n, xep in pairs(xeps) do

        if xep.name:lower():find(xepstr) then

            r = r.."XEP-"..xep.number..": "..xep.name.."\n"

        end

    end

    r = r:gsub("\n$", "")

    if r ~= "" then return r; end

    return nil, "Sorry, not matching XEP found"

end

mcbot_register_command("xep", xep)