Markov: allow for auto-context insertion

this should result in no chains having a null context --- if no pre-existing
context is created, one is created for the channel/nick and used. this makes,
for example, arbitrary queries "private" to that nick (again unless that has
been overridden). shouldn't affect much of anything, but adding this made
the context-less learning code obsolete, which is fine since it was never used
anyway

modules/Markov.py

@@ -54,11 +54,9 @@ class Markov(Module):
         self.stop = '__stop'
 
         # set up regexes, for replying to specific stuff
-        trainpattern = '^!markov\s+train\s+(.*)$'
         learnpattern = '^!markov\s+learn\s+(.*)$'
         replypattern = '^!markov\s+reply(\s+min=(\d+))?(\s+max=(\d+))?(\s+(.*)$|$)'
 
-        self.trainre = re.compile(trainpattern)
         self.learnre = re.compile(learnpattern)
         self.replyre = re.compile(replypattern)
 
@@ -163,11 +161,14 @@ class Markov(Module):
         target = event.target()
         nick = irclib.nm_to_n(event.source())
 
+        if not irclib.is_channel(target):
+            target = nick
+
         self.lines_seen.append((nick, datetime.now()))
         self.connection = connection
 
         # don't learn from commands
-        if self.trainre.search(what) or self.learnre.search(what) or self.replyre.search(what):
+        if self.learnre.search(what) or self.replyre.search(what):
             return
 
         self._learn_line(what, target)
@@ -177,10 +178,7 @@ class Markov(Module):
 
         target = event.target()
 
-        if self.trainre.search(what):
+        if self.learnre.search(what):
-            return self.reply(connection, event, self.markov_train(connection, event, nick,
-              userhost, what, admin_unlocked))
-        elif self.learnre.search(what):
             return self.reply(connection, event, self.markov_learn(connection, event, nick,
               userhost, what, admin_unlocked))
         elif self.replyre.search(what) and not self.shut_up:
@@ -202,21 +200,6 @@ class Markov(Module):
                     self.lines_seen.append(('.self.said.', datetime.now()))
                     return self.reply(connection, event, '{0:s}'.format(self._generate_line(target, line=what)))
 
-    def markov_train(self, connection, event, nick, userhost, what, admin_unlocked):
-        """Learn lines from a file. Good for initializing a brain."""
-
-        match = self.trainre.search(what)
-        if match and admin_unlocked:
-            filename = match.group(1)
-
-            try:
-                for line in open(filename, 'r'):
-                    self._learn_line(line)
-
-                return 'Learned from \'{0:s}\'.'.format(filename)
-            except IOError:
-                return 'No such file \'{0:s}\'.'.format(filename)
-
     def markov_learn(self, connection, event, nick, userhost, what, admin_unlocked):
         """Learn one line, as provided to the command."""
 
@@ -431,10 +414,10 @@ class Markov(Module):
                 max_id = self._get_max_chain_id()
                 rand_id = random.randint(1,max_id)
                 query = ('SELECT v FROM markov_chain WHERE k1 = ? AND k2 = ? AND '
-                  '(context_id = ? OR context_id IS NULL) AND id >= {0:d} LIMIT 1'.format(rand_id))
+                  '(context_id = ?) AND id >= {0:d} LIMIT 1'.format(rand_id))
             else:
                 query = ('SELECT v FROM markov_chain WHERE k1 = ? AND k2 = ? AND '
-                  '(context_id = ? OR context_id IS NULL)')
+                  '(context_id = ?)')
             cursor = db.execute(query, (k1,k2,context_id))
             results = cursor.fetchall()
 
@@ -454,7 +437,7 @@ class Markov(Module):
         values = []
         try:
             db = self.get_db()
-            query = 'SELECT k2 FROM markov_chain WHERE v = ? AND (context_id = ? OR context_id IS NULL)'
+            query = 'SELECT k2 FROM markov_chain WHERE v = ? AND (context_id = ?)'
             cursor = db.execute(query, (v,context_id))
             results = cursor.fetchall()
 
@@ -529,7 +512,52 @@ class Markov(Module):
             if result:
                 return result['id']
             else:
-                return None
+                # auto-generate a context to keep things private
+                self._add_context_for_target(target)
+                return self._get_context_id_for_target(target)
+        except sqlite3.Error as e:
+            db.close()
+            print('sqlite error in Markov._get_context_id_for_target: ' + str(e))
+            raise
+
+    def _add_context_for_target(self, target):
+
+        """Create a new context for the desired/input target."""
+
+        try:
+            db = self.get_db()
+            cur = db.cursor()
+            statement = 'INSERT INTO markov_context (context) VALUES (?)'
+            cur.execute(statement, (target,))
+            statement = '''
+                INSERT INTO markov_target_to_context_map (target, context_id)
+                    VALUES (?, (SELECT id FROM markov_context WHERE context = ?))
+                '''
+            cur.execute(statement, (target,target))
+            db.commit()
+            db.close()
+        except sqlite3.Error as e:
+            db.rollback()
+            db.close()
+            print("sqlite error in Markov._add_context_for_target: " + str(e))
+            raise
+        try:
+            db = self.get_db()
+            query = '''
+                SELECT mc.id FROM markov_context mc
+                  INNER JOIN markov_target_to_context_map mt
+                    ON mt.context_id = mc.id
+                    WHERE mt.target = ?
+                '''
+            cursor = db.execute(query, (target,))
+            result = cursor.fetchone()
+            db.close()
+            if result:
+                return result['id']
+            else:
+                # auto-generate a context to keep things private
+                self._add_context_for_target(target)
+                return self._get_context_id_for_target(target)
         except sqlite3.Error as e:
             db.close()
             print('sqlite error in Markov._get_context_id_for_target: ' + str(e))