snarf_mail: add time-based delete strategy

Signed-off-by: Colin McCabe <cmccabe@alumni.cmu.edu>

diff --git a/snarf_mail.rb b/snarf_mail.rb
index a22e72f..fc51b57 100755 (executable)
--- a/snarf_mail.rb
+++ b/snarf_mail.rb
@@ -9,6 +9,7 @@
 # http://ruby-doc.org/stdlib/libdoc/net/imap/rdoc/index.html
 #
 
+require 'date'
 require 'net/imap'
 require 'optparse'
 require 'ostruct'
@@ -17,15 +18,15 @@ class MyOptions
   def self.parse(args)
     opts = OpenStruct.new
     opts.mailboxes = Array.new
-    opts.delete_after = false
+    opts.delete = "none"
 
     # Fill in $opts values
     parser = OptionParser.new do |myparser|
       myparser.banner = "Usage: #{ File.basename($0) } [opts]"
       myparser.separator("Specific options:")
-      myparser.on("--delete-after", "-d",
-              "Delete emails after fetching them.") do |d|
-        opts.delete_after = true
+      myparser.on("--delete POLICY", "-d",
+              "Set delete policy to 'none' or 'old'. Default is 'none'.") do |d|
+        opts.delete = d
       end
       myparser.on("--username USERNAME", "-u",
               "Email account to fetch. (example: \
@@ -108,42 +109,25 @@ end
 def snarf_mailbox(imap, mailbox)
   full_count = 0
   first_time = true
-  count = 0
-
-  imap.select(mailbox)
-  imap.search(["NOT", "DELETED"]).each do |message_id|
-    if (first_time == true) then
-      # Print a dot immediately after making first contact with the server.
-      # It is reassuring to the user.
-      printf(".")
-      STDOUT.flush()
-      first_time = false
-    end
-    data = imap.fetch(message_id, [ "UID", "RFC822.HEADER", "RFC822.TEXT" ])
-    write_email_to_disk(mailbox, data)
-
-    count = count + 1
-    full_count = full_count + 1
-    if (count > 20)
-      # Print out a dot to signify progress
-      printf(".")
-      STDOUT.flush()
-      count = 0
-    end
-  end
 
-  puts "fetched: #{full_count} messages from #{mailbox}"
-end
+  searchterms = [ "NOT", "DELETED" ]
+  if $opts.delete == "old"
+    t = Date.today() - 365
+    time_str = t.strftime("%e-%b-%Y")
+    searchterms << "BEFORE" << time_str
+    prequel = "fetched and deleted: "
+  elsif $opts.delete == "none"
+    prequel = "fetched: "
+  else
+    raise "expected one of 'old', 'none' for delete argument."
+  end
 
-def snarf_and_delete_mailbox(imap, mailbox)
-  full_count = 0
-  first_time = true
   while true
     count = 0
     msg_seqnos = Array.new
 
     imap.select(mailbox)
-    imap.search(["NOT", "DELETED"]).each do |message_id|
+    imap.search(searchterms).each do |message_id|
       if (first_time == true) then
         # Print a dot immediately after making first contact with the server.
         # It is reassuring to the user.
@@ -159,7 +143,7 @@ def snarf_and_delete_mailbox(imap, mailbox)
       #break if (count > 20)
     end
     if (count == 0) then
-      puts "fetched and deleted: #{full_count} messages from #{mailbox}"
+      puts "#{prequel} #{full_count} messages from #{mailbox}"
       return
     end
 
@@ -167,9 +151,11 @@ def snarf_and_delete_mailbox(imap, mailbox)
     printf(".")
     STDOUT.flush()
 
-    # Delete messages
-    imap.store(msg_seqnos, "+FLAGS", [:Deleted])
-    imap.expunge
+    if ($opts.delete != "none"):
+      # Delete messages
+      imap.store(msg_seqnos, "+FLAGS", [:Deleted])
+      imap.expunge
+    end
   end
 end
 
@@ -191,11 +177,7 @@ when :list
   end
 when :snarf
   $opts.mailboxes.each do |mailbox|
-    if ($opts.delete_after == true)
-      snarf_and_delete_mailbox(imap, mailbox)
-    else
-      snarf_mailbox(imap, mailbox)
-    end
+    snarf_mailbox(imap, mailbox)
   end
 else
   raise "unknown action #{$opts.action}"