Initial commit

pointsbot/database.py

@@ -0,0 +1,121 @@
+'''
+    A bot for Reddit to award points to helpful subreddit members.
+    Copyright (C) 2020  Collin U. Rapp
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+'''
+import functools
+import os.path
+import sqlite3 as sqlite
+
+### Globals ###
+
+# TODO put name/path in a config file?
+DB_NAME = 'pointsbot.db'
+DB_PATH = DB_NAME
+
+DB_SCHEMA = '''
+    CREATE TABLE IF NOT EXISTS redditor_points (
+        id TEXT UNIQUE NOT NULL,
+        name TEXT UNIQUE NOT NULL,
+        points INTEGER DEFAULT 0
+    )
+'''
+
+### Decorators ###
+
+
+def transaction(func):
+    @functools.wraps(func)
+    def newfunc(*args, **kwargs):
+        conn = sqlite.connect(DB_PATH)
+        conn.row_factory = sqlite.Row
+        cursor = conn.cursor()
+
+        ret = func(cursor, *args, **kwargs)
+
+        cursor.close()
+        if conn.in_transaction:
+            conn.commit()
+        conn.close()
+
+        return ret
+    return newfunc
+
+
+### Private Functions ###
+
+# These functions are intended for internal use, since they need to be explicity
+# passed a database cursor. The public methods below are wrapped with the
+# transaction decorator to remove the need for keeping a connection or cursor
+# opened for the entire life of the program.
+
+
+def _init(cursor):
+    if not exists():
+        cursor.execute(DB_SCHEMA)
+
+
+def _add_redditor(cursor, redditor):
+    insert_stmt = '''
+        INSERT OR IGNORE INTO redditor_points (id, name)
+        VALUES (:id, :name)
+        '''
+    cursor.execute(insert_stmt, {'id': redditor.id, 'name': redditor.name})
+    return cursor.rowcount
+
+
+def _add_point(cursor, redditor):
+    points = _get_redditor_points(cursor, redditor, add_if_none=True)
+    params = {'id': redditor.id, 'name': redditor.name, 'points': points + 1}
+    update_stmt = '''
+        UPDATE redditor_points
+        SET points = :points
+        WHERE id = :id AND name = :name
+        '''
+    cursor.execute(update_stmt, params)
+    return cursor.rowcount
+
+
+def _get_redditor_points(cursor, redditor, add_if_none=False):
+    params = {'id': redditor.id, 'name': redditor.name}
+    select_stmt = '''
+        SELECT points
+        FROM redditor_points
+        WHERE id = :id AND name = :name
+        '''
+    cursor.execute(select_stmt, params)
+    row = cursor.fetchone()   # TODO check if more than one row
+    if row:
+        points = row['points']
+    elif add_if_none:
+        points = 0
+        _add_redditor(cursor, redditor)
+
+    return points
+
+
+### Public Functions ###
+
+
+def exists():
+    return os.path.exists(DB_PATH)
+
+
+# Public wrappers for the database access functions
+init                = transaction(_init)
+add_redditor        = transaction(_add_redditor)
+add_point           = transaction(_add_point)
+get_redditor_points = transaction(_get_redditor_points)
+