plugins/seen: Utilize UNIQUE restrictions to cheat

Takes advantage of the UNIQUE constraint to simplify code.  Includes a
conversion mechanism for those with tables that don't have the
constraint.

Signed-off-by: gry <Gry@Gshellz.org>

plugins/seen.py

@@ -42,23 +42,29 @@ class Seen(object):
         self.cursor  = self.connection.cursor()
         if (not self.db_exists):
             # create the db
-            self.cursor.execute('''CREATE TABLE seen (nick text, timestamp text, network text, channel text, message text)''')
-            self.connection.commit()
+            self.cursor.execute('CREATE TABLE seen (nick text, timestamp text, network text, channel text, message text, UNIQUE ( nick, network ))')
             print("[DEBUG] Database created for the first time")
+        else:
+            # This is hacky, but I'm lazy
+            self.cursor.execute('PRAGMA index_list(seen)')
+            if not self.cursor.fetchone():
+                # Gotta give the table the unique constraint; shifting data to a temp table so we can DROP the original, and then rename the temp table
+                self.cursor.execute('CREATE TABLE seen_temp (nick text, timestamp text, network text, channel text, message text, UNIQUE ( nick, network ))')
+                self.cursor.execute('INSERT INTO seen_temp SELECT * FROM seen')
+                self.cursor.execute('DROP TABLE seen')
+                self.cursor.execute('ALTER TABLE seen_temp RENAME TO seen')
+                print("[DEBUG] Database schema updated")
+        self.connection.commit()
     def handle_message(self, channel, nick, message):
         # print("Message '{0}' from '{1}' in '{2}'".format(message, nick, channel))
         # add to db
         # nick, timestamp, network, channel message
-        self.cursor.execute('SELECT * FROM seen WHERE nick=? and network = ?', (nick, self.network))
-        if (self.cursor.fetchone()):
-            self.cursor.execute('UPDATE seen SET nick = ?, timestamp = ?, network = ?, channel = ?, message = ? WHERE nick=? and network = ?',(nick, time.time(), self.network, channel, message, nick, self.network) )
-        else:
-            self.cursor.execute('INSERT INTO seen VALUES (?, ?, ?, ?, ?)', (nick, time.time(), self.network, channel, message))
+        self.cursor.execute('INSERT OR REPLACE INTO seen VALUES (?, ?, ?, ?, ?)', (nick, time.time(), self.network, channel, message))
         self.connection.commit()
     def handle_command(self, channel, user, cmd, args):
         if cmd == "seen":
             nick = args[0]
-            self.cursor.execute('SELECT * FROM seen WHERE nick=? and network = ?', (nick, self.network))
+            self.cursor.execute('SELECT * FROM seen WHERE nick = ? and network = ?', (nick, self.network))
             info = self.cursor.fetchone()
             if (info):
                 # ('gry', '2013-01-31 14:50:02.419198', 'gnu', '#guppy', '-seen gry')