Add features and fix some bugs in remind.coffee

- Adds support for "remind me on <date/time> to <action>"
- Requires new npm packages:
  - moment, for duration/time formatting
  - lodash, for utility functions
  - chrono-node, for parsing natural language type dates (e.g. next Tuesday, Tomorrow at 3:00pm, etc.)

src/scripts/remind.coffee

@@ -1,99 +1,157 @@
 # Description:
-#   Forgetful? Add reminders
+#   Forgetful? Add reminders!
 #
 # Dependencies:
-#   None
+#   "chrono-node": "^0.1.10"
+#   "moment": "^2.8.1"
+#   "lodash": "^2.4.1"
 #
 # Configuration:
 #   None
 #
 # Commands:
-#   hubot remind me in <time> to <action> - Set a reminder in <time> to do an <action> <time> is in the format 1 day, 2 hours, 5 minutes etc. Time segments are optional, as are commas
+#   hubot remind me (on <date>|in <time>) to <action> - Set a reminder in <time> to do an <action> <time> is in the format 1 day, 2 hours, 5 minutes etc. Time segments are optional, as are commas
+#   hubot delete reminder <action> - Delete reminder matching <action> (exact match required)
+#   hubot show reminders
 #
 # Author:
 #   whitman
+#   jtwalters
+
+_ = require('lodash')
+moment = require('moment')
+chrono = require('chrono-node')
+timeoutIds = {}
 
 class Reminders
   constructor: (@robot) ->
     @cache = []
-    @current_timeout = null
+    @currentTimeout = null
 
-    @robot.brain.on 'loaded', =>
+    # Load reminders from brain, on loaded event
+    @robot.brain.on('loaded', =>
       if @robot.brain.data.reminders
-        @cache = @robot.brain.data.reminders
+        @cache = _.map(@robot.brain.data.reminders, (item) ->
+          new Reminder(item)
+        )
+        console.log("loaded #{@cache.length} reminders")
         @queue()
+    )
+
+    # Persist reminders to the brain, on save event
+    @robot.brain.on('save', =>
+      @robot.brain.data.reminders = @cache
+    )
 
   add: (reminder) ->
-    @cache.push reminder
-    @cache.sort (a, b) -> a.due - b.due
-    @robot.brain.data.reminders = @cache
+    @cache.push(reminder)
+    @cache.sort((a, b) -> a.due - b.due)
     @queue()
 
   removeFirst: ->
     reminder = @cache.shift()
-    @robot.brain.data.reminders = @cache
     return reminder
 
   queue: ->
-    clearTimeout @current_timeout if @current_timeout
-    if @cache.length > 0
-      now = new Date().getTime()
-      @removeFirst() until @cache.length is 0 or @cache[0].due > now
-      if @cache.length > 0
-        trigger = =>
-          reminder = @removeFirst()
-          @robot.reply reminder.msg_envelope, 'you asked me to remind you to ' + reminder.action
-          @queue()
-        # setTimeout uses a 32-bit INT
-        extendTimeout = (timeout, callback) ->
-          if timeout > 0x7FFFFFFF
-            @current_timeout = setTimeout ->
-              extendTimeout (timeout - 0x7FFFFFFF), callback
-            , 0x7FFFFFFF
-          else
-            @current_timeout = setTimeout callback, timeout
-        extendTimeout @cache[0].due - now, trigger
+    return if @cache.length is 0
+    now = (new Date).getTime()
+    trigger = =>
+      reminder = @removeFirst()
+      @robot.reply(reminder.msg_envelope, 'you asked me to remind you to ' + reminder.action)
+      @queue()
+    # setTimeout uses a 32-bit INT
+    extendTimeout = (timeout, callback) ->
+      if timeout > 0x7FFFFFFF
+        setTimeout(->
+          extendTimeout(timeout - 0x7FFFFFFF, callback)
+        , 0x7FFFFFFF)
+      else
+        setTimeout(callback, timeout)
+    reminder = @cache[0]
+    duration = reminder.due - now
+    duration = 0 if duration < 0
+    clearTimeout(timeoutIds[reminder])
+    timeoutIds[reminder] = extendTimeout(reminder.due - now, trigger)
+    console.log("reminder set with duration of #{duration}")
 
 class Reminder
-  constructor: (@msg_envelope, @time, @action) ->
-    @time.replace(/^\s+|\s+$/g, '')
-
-    periods =
-      weeks:
-        value: 0
-        regex: "weeks?"
-      days:
-        value: 0
-        regex: "days?"
-      hours:
-        value: 0
-        regex: "hours?|hrs?"
-      minutes:
-        value: 0
-        regex: "minutes?|mins?"
-      seconds:
-        value: 0
-        regex: "seconds?|secs?"
-
-    for period of periods
-      pattern = new RegExp('^.*?([\\d\\.]+)\\s*(?:(?:' + periods[period].regex + ')).*$', 'i')
-      matches = pattern.exec(@time)
-      periods[period].value = parseInt(matches[1]) if matches
-
-    @due = new Date().getTime()
-    @due += ((periods.weeks.value * 604800) + (periods.days.value * 86400) + (periods.hours.value * 3600) + (periods.minutes.value * 60) + periods.seconds.value) * 1000
-
-  dueDate: ->
-    dueDate = new Date @due
-    dueDate.toLocaleString()
+  constructor: (data) ->
+    {@msg_envelope, @action, @time, @due} = data
+
+    if @time and !@due
+      @time.replace(/^\s+|\s+$/g, '')
+
+      periods =
+        weeks:
+          value: 0
+          regex: "weeks?"
+        days:
+          value: 0
+          regex: "days?"
+        hours:
+          value: 0
+          regex: "hours?|hrs?"
+        minutes:
+          value: 0
+          regex: "minutes?|mins?"
+        seconds:
+          value: 0
+          regex: "seconds?|secs?"
+
+      for period of periods
+        pattern = new RegExp('^.*?([\\d\\.]+)\\s*(?:(?:' + periods[period].regex + ')).*$', 'i')
+        matches = pattern.exec(@time)
+        periods[period].value = parseInt(matches[1]) if matches
+
+      @due = (new Date).getTime()
+      @due += (
+        (periods.weeks.value * 604800) +
+        (periods.days.value * 86400) +
+        (periods.hours.value * 3600) +
+        (periods.minutes.value * 60) +
+        periods.seconds.value
+      ) * 1000
+
+  formatDue: ->
+    dueDate = new Date(@due)
+    duration = dueDate - new Date
+    if duration > 0 and duration < 86400000
+      'in ' + moment.duration(duration).humanize()
+    else
+      'on ' + moment(dueDate).format("dddd, MMMM Do YYYY, h:mm:ss a")
 
 module.exports = (robot) ->
+  reminders = new Reminders(robot)
+
+  robot.respond(/show reminders$/i, (msg) ->
+    text = ''
+    for reminder in reminders.cache
+      text += "#{reminder.action} #{reminder.formatDue()}\n"
+    msg.send(text)
+  )
 
-  reminders = new Reminders robot
+  robot.respond(/delete reminder (.+)$/i, (msg) ->
+    query = msg.match[1]
+    prevLength = reminders.cache.length
+    reminders.cache = _.reject(reminders.cache, {action: query})
+    reminders.queue()
+    msg.send("Deleted reminder #{query}") if reminders.cache.length isnt prevLength
+  )
 
-  robot.respond /remind me in ((?:(?:\d+) (?:weeks?|days?|hours?|hrs?|minutes?|mins?|seconds?|secs?)[ ,]*(?:and)? +)+)to (.*)/i, (msg) ->
-    time = msg.match[1]
-    action = msg.match[2]
-    reminder = new Reminder msg.envelope, time, action
-    reminders.add reminder
-    msg.send 'I\'ll remind you to ' + action + ' on ' + reminder.dueDate()
+  robot.respond(/remind me (in|on) (.+?) to (.*)/i, (msg) ->
+    type = msg.match[1]
+    time = msg.match[2]
+    action = msg.match[3]
+    options =
+      msg_envelope: msg.envelope,
+      action: action
+      time: time
+    if type is 'on'
+      # parse the date (convert to timestamp)
+      due = chrono.parseDate(time).getTime()
+      if due.toString() isnt 'Invalid Date'
+        options.due = due
+    reminder = new Reminder(options)
+    reminders.add(reminder)
+    msg.send "I'll remind you to #{action} #{reminder.formatDue()}"
+  )