function getBTCX(amount,currency)
   -- Do request on bitcoinaverage, the final / is critical!
   local res,code  = https.request("https://api.bitcoinaverage.com/ticker/global/"..currency.."/")
   
   if code~= 200 then return nil end
   local data = json:decode(res)

   -- Easy, it's right there
   text = "BTC/"..currency..'\n'..'Buy: '..data.ask..'\n'..'Sell: '..data.bid
   
   -- If we have a number as second parameter, calculate the bitcoin amount
   if amount~=nil then
      btc = tonumber(amount) / tonumber(data.ask)
      text = text.."\n "..currency .." "..amount.." = BTC "..btc
   end
   return text
end

function run(msg, matches)
   vardump(matches)
   local cur = 'EUR'
   local amt = nil
   -- Get the global match out of the way
   if matches[1] == "!btc" then  return getBTCX(amt,cur) end

   if matches[2]~=nil then
      -- There is a second match
      amt = matches[2]
      cur = string.upper(matches[1])
   else
      -- Just a EUR or USD param
      cur = string.upper(matches[1])
   end
   return getBTCX(amt,cur)
end

return {
   description = "Bitcoin global average market value (in EUR or USD)", 
   usage = "!btc [EUR|USD] [amount]",
   patterns = {
      "^!btc$",
      "^!btc ([Ee][Uu][Rr])$",
      "^!btc ([Uu][Ss][Dd])$",
      "^!btc (EUR) (%d+[%d%.]*)$",
      "^!btc (USD) (%d+[%d%.]*)$"
   }, 
   run = run 
}