Set/unset alarms (configurable)

README.md

@@ -8,6 +8,8 @@ filtering options (looking at your Google Calendar)?
 Use ical-filter-proxy to (you guessed it) proxy and filter your iCal feed. Define your source
 calendar and filtering options in `config.yml` and you're good to go.
 
+In addition, display alarms can be created or cleared.
+
 ## Configuration
 
 ```yaml
@@ -27,7 +29,12 @@ my_calendar_name:
       - field: summary # summary and description supported
         operator: matches # match against regex pattern
         val: # array of values also supported
-          - "/Team A/i"
+          - '/Team A/i'
+   alarms: # (optional) create/clear alarms for filtered events
+     clear_existing: true # (optional) if true, existing alarms will be removed, default: false 
+     triggers: # (optional) triggers for new alarms. Description will be the alarm summary, action is 'DISPLAY'
+       - '-P1DT0H0M0S' # iso8061 supported
+       - 2 days # supports full day[s], hour[s], minute[s], no combination in one trigger
 ```
 
 ## Additional Rules

config.yml.example

@@ -5,3 +5,8 @@ rota:
     - field: start_time
       operator: equals
       val: '09:00'
+  alarms:
+    clear_existing: true
+    triggers:
+      - '-P1DT0H0M0S'
+      - '-P1DT1H1M2S'

lib/ical_filter_proxy/calendar.rb

@@ -1,24 +1,47 @@
 module IcalFilterProxy
   class Calendar
-    attr_accessor :ical_url, :api_key, :timezone, :filter_rules
+    attr_accessor :ical_url, :api_key, :timezone, :filter_rules, :clear_existing_alarms, :alarm_triggers
 
     def initialize(ical_url, api_key, timezone = 'UTC')
       self.ical_url = ical_url
       self.api_key = api_key
       self.timezone = timezone
 
       self.filter_rules = []
+      self.clear_existing_alarms = false
+      self.alarm_triggers = []
     end
 
     def add_rule(field, operator, value)
       self.filter_rules << FilterRule.new(field, operator, value)
     end
 
+    def add_alarm_trigger(alarm_trigger)
+      self.alarm_triggers << alarm_trigger
+    end
+
+    def set_clear_existing_alarms
+      self.clear_existing_alarms = true
+    end
+
     def filtered_calendar
       filtered_calendar = Icalendar::Calendar.new
+
       filtered_events.each do |original_event|
         filtered_calendar.add_event(original_event)
       end
+
+      filtered_calendar.events.select do |e|
+        e.alarms.clear if clear_existing_alarms
+        alarm_triggers.each do |t|
+          e.alarm do |a|
+            a.action = "DISPLAY"
+            a.description = e.summary
+            a.trigger = t
+          end
+        end
+      end
+
       filtered_calendar.to_ical
     end
 
@@ -39,7 +62,7 @@ def original_ics
     end
 
     def raw_original_ical
-      open(ical_url).read
+      URI.open(ical_url).read
     end
   end
 end

lib/ical_filter_proxy/calendar_builder.rb

@@ -10,6 +10,7 @@ def initialize(calendar_config)
     def build
       create_calendar
       add_rules
+      add_alarms
 
       calendar
     end
@@ -33,5 +34,36 @@ def add_rules
       end
     end
 
+    def add_alarms
+      alarms = calendar_config["alarms"]
+      return unless alarms
+
+      if alarms["clear_existing"] == true
+        calendar.set_clear_existing_alarms
+      end
+
+      triggers = alarms["triggers"]
+      return unless triggers
+
+      triggers.each do |trigger|
+        calendar.add_alarm_trigger(generate_iso_format(trigger))
+        end
+    end
+
+    def generate_iso_format(input)
+      case input
+      when /(\d+)\s+days?/i
+        return "-P#{$1}D"
+      when /(\d+)\s+hours?/i
+        return "-PT#{$1}H"
+      when /(\d+)\s+minutes?/i
+        return "-PT#{$1}M"
+      when /^-P.*/
+        return input
+      else
+        raise "Unknown trigger pattern: " + input
+      end
+    end
+
   end
 end

spec/ical_filter_proxy_spec.rb

@@ -49,7 +49,11 @@ def example_config
         'api_key' => 'abc12',
         'rules' => [
           { 'field' => 'start_time', 'operator' => 'equals', 'val' => '09:00' }
-        ]
+        ],
+        'alarms' => {
+          'clear_existing' => true,
+          'triggers'=> [ '-P1DT0H0M0S', '-P1DT1H1M2S' ]
+        }
       }
     }
   end