From e8dd5f6ae5dd3b8c2b1bfd5cfdf092c99d0075b2 Mon Sep 17 00:00:00 2001
From: Jonathan Kolyer <jonathan@jamkazam.com>
Date: Wed, 19 Mar 2014 04:24:42 +0000
Subject: [PATCH] VRFS-1483 state transitions and optimistic locking

---
 db/up/emails.sql                              |  8 +-
 ruby/lib/jam_ruby/app/mailers/batch_mailer.rb |  5 +-
 ruby/lib/jam_ruby/models/email_batch.rb       | 76 ++++++++++++++++++-
 3 files changed, 84 insertions(+), 5 deletions(-)

diff --git a/db/up/emails.sql b/db/up/emails.sql
index 47a33d105..9c68b643e 100644
--- a/db/up/emails.sql
+++ b/db/up/emails.sql
@@ -6,8 +6,12 @@ CREATE TABLE email_batches (
 
     aasm_state VARCHAR(32) NOT NULL default 'pending',
 
-    test_emails TEXT NOT NULL,
-    batch_size INTEGER NOT NULL default 1000,
+    test_emails TEXT NOT NULL default '',
+
+    qualified_count INTEGER NOT NULL default 0,
+    sent_count INTEGER NOT NULL default 0,
+
+    lock_version INTEGER,
 
     started_at TIMESTAMP,
     completed_at TIMESTAMP,
diff --git a/ruby/lib/jam_ruby/app/mailers/batch_mailer.rb b/ruby/lib/jam_ruby/app/mailers/batch_mailer.rb
index 8b16acd08..899e01b16 100644
--- a/ruby/lib/jam_ruby/app/mailers/batch_mailer.rb
+++ b/ruby/lib/jam_ruby/app/mailers/batch_mailer.rb
@@ -6,7 +6,8 @@ module JamRuby
     sendgrid_category :use_subject_lines
     sendgrid_unique_args :env => Environment.mode
 
-    def send_batch_email(batch_id, user_id)
+    def send_batch_email(batch_id, user_ids)
+      @users = User.find_all_by_id(user_ids)
       @user = User.where(:id => user_id).limit(1).first
       batch = EmailBatch.where(:id => batch_id).limit(1).first
       @body = batch.merged_body(user)
@@ -17,6 +18,7 @@ module JamRuby
         format.text
         format.html
       end
+      batch.did_send(user.email)
     end
 
     def send_batch_email_test(batch_id, email_addy)
@@ -29,6 +31,7 @@ module JamRuby
         format.text
         format.html
       end
+      batch.did_send(email_addy)
     end
 
   end
diff --git a/ruby/lib/jam_ruby/models/email_batch.rb b/ruby/lib/jam_ruby/models/email_batch.rb
index 9df7d3d30..d3b396c1e 100644
--- a/ruby/lib/jam_ruby/models/email_batch.rb
+++ b/ruby/lib/jam_ruby/models/email_batch.rb
@@ -2,21 +2,55 @@ module JamRuby
   class EmailBatch < ActiveRecord::Base
     self.table_name = "email_batches"
 
+    attr_accessible :lock_version
+
     VAR_FIRST_NAME = '@FIRSTNAME'
     VAR_LAST_NAME = '@LASTNAME'
 
     DEFAULT_SENDER = "support@jamkazam.com"
 
+    include AASM
+    aasm do
+      state :pending, :initial => true
+      state :testing
+      state :tested
+      state :batching
+      state :batched
+      state :disabled
+
+      event :enable do
+        transitions :from => :disabled, :to => :pending
+      end
+      event :do_test_run, :after => Proc.new { running_tests } do
+        transitions :from => [:pending, :tested, :batched], :to => :testing
+      end
+      event :did_test_run do
+        transitions :from => :testing, :to => :tested
+      end
+      event :do_batch_run, :after => Proc.new { running_batch } do
+        transitions :from => [:tested, :pending, :batched], :to => :batching
+      end
+      event :did_batch_run do
+        transitions :from => :batching, :to => :batched
+      end
+      event :disable do
+        transitions :from => [:pending, :tested, :batched], :to => :disabled
+      end
+    end
+
     # has_many :email_batch_results, :class_name => 'JamRuby::EmailBatchResult'
 
     def self.qualified_users
       User.select(:email)
         .where(:opt_out_email_batch => false)
-        .order('created_at DESC')
     end
 
     def deliver
-      self.class.qualified_users.each
+      self.do_batch_run!
+
+      self.class.qualified_users.find_each do |uu|
+        BatchMailer.send_batch_email_test(self.id, uu.id).deliver
+      end
     end
 
     def test_users
@@ -31,6 +65,8 @@ module JamRuby
     end
 
     def send_test_batch
+      self.do_test_run!
+
       self.test_users.each do |uu|
         BatchMailer.send_batch_email_test(self.id, uu.email).deliver
       end
@@ -40,5 +76,41 @@ module JamRuby
       body.gsub(VAR_FIRST_NAME, user.first_name).gsub(VAR_LAST_NAME, user.last_name)
     end
 
+    def did_send(email)
+      self.update_with_conflict_validation({ :sent_count => self.sent_count + 1 })
+      if self.sent_count >= self.qualified_count
+        if batching?
+          self.did_batch_run!
+        elsif testing?
+          self.did_test_run!
+        end
+      end
+    end
+
+    protected
+
+    def update_with_conflict_validation(*args)
+      num_try = 0
+      update_attributes(*args)
+    rescue ActiveRecord::StaleObjectError
+      num_try += 1
+      if 5 > num_try
+        self.reload
+        retry
+      end
+    end
+    
+    def running_batch
+      self.update_attributes({:qualified_count => self.class.qualified_users.count,
+                               :sent_count => 0 
+                             })
+    end
+
+    def running_test
+      self.update_attributes({:qualified_count => self.class.qualified_users.count,
+                               :sent_count => 0 
+                             })
+    end
+
   end
 end