Inital version of !time command

Syntax: !time [area]

Uses the google geocoding api to turn an area specification into a
lat/long coordinate pair, which is then used to get a timezone record to
determine the local time.

Usecase: when working in international groups it's convenient to know if
your co-worker is likely to be awake or asleep.

bot/bot.lua

@@ -1,4 +1,5 @@
   http = require("socket.http")
+  https = require("ssl.https")
   URL = require("socket.url")
   json = (loadfile "./bot/JSON.lua")()
 --  lrexlib = require("rex_pcre")

plugins/time.lua

@@ -0,0 +1,103 @@
+-- Implement a command !time [area] which uses
+-- 2 Google APIs to get the desired result:
+--   1. Geocoding to get from area to a lat/long pair
+--   2. Timezone to get the local time in that lat/long location
+
+-- Globals
+-- If you have a google api key for the geocoding/timezone api, you can fill it in here
+-- TODO: use bot config file
+api_key  = nil
+base_api = "https://maps.googleapis.com/maps/api"
+dateFormat = "%A %d %B - %H:%M:%S"
+
+-- Need the utc time for the google api
+function utctime()
+   return os.time(os.date("!*t"))
+end
+
+-- Use the geocoding api to get the lattitude and longitude with accuracy specifier
+-- CHECKME: this seems to work without a key??
+function get_latlong(area)
+   local api        = base_api .. "/geocode/json?"
+   local parameters = "address=".. (URL.escape(area) or "")
+   if api_key ~=nil then
+      parameters = parameters .. "&key="..api_key
+   end
+
+   -- Do the request
+   local res, code = https.request(api..parameters)
+   if code ~=200 then return nil  end
+   local data = json:decode(res)
+ 
+   if (data.status == "ZERO_RESULTS") then
+      return nil
+   end
+   if (data.status == "OK") then
+      -- Get the data
+      lat  = data.results[1].geometry.location.lat
+      lng  = data.results[1].geometry.location.lng
+      acc  = data.results[1].geometry.location_type
+      return lat,lng,acc
+   end
+end
+
+-- Use timezone api to get the time in the lat,
+-- Note: this needs an API key
+function get_time(lat,lng)
+   local api  = base_api .. "/timezone/json?"
+
+   -- Get a timestamp (server time is relevant here)
+   local timestamp = utctime()
+   local parameters = "location=" ..
+      URL.escape(lat) .. "," ..
+      URL.escape(lng) .. 
+      "&timestamp="..URL.escape(timestamp)
+   if api_key ~=nil then
+      parameters = parameters .. "&key="..api_key
+   end
+
+   local res,code = https.request(api..parameters)
+   if code ~= 200 then return nil end
+   local data = json:decode(res)
+   
+   if (data.status == "ZERO_RESULTS") then
+      return nil
+   end
+   if (data.status == "OK") then
+      -- Construct what we want
+      -- The local time in the location is:
+      -- timestamp + rawOffset + dstOffset
+      local localTime = timestamp + data.rawOffset + data.dstOffset
+      return localTime
+   end
+   return localTime
+end
+
+function getformattedLocalTime(area)
+   if area == nil then
+      return "The time in nowhere is never"
+   end
+
+   lat,lng,acc = get_latlong(area)
+   if lat == nil and lng==nil then
+      return "It seems that in '"..area.."' they do not have a concept of time."
+   end
+   local localTime = get_time(lat,lng)
+
+   return "The local time in '"..area..
+      "'\n(Loc: "..lat..", "..lng.." with '"..acc.."' accuracy is:\n" ..
+      os.date(dateFormat,localTime)
+end
+
+function run(msg, matches)
+   return getformattedLocalTime(matches[1])
+end
+
+return {
+    description = "Displays the local time in an area", 
+    usage = "!time [area]",
+    patterns = {"^!time (.*)$"}, 
+    run = run 
+}
+
+