database.py

#!/usr/bin/env python3

import codecs
import configparser
import json
import logging
import os
import praw
import sys
import time
from datetime import datetime, timedelta, timezone
from peewee import *

# Set up logging 
logging.basicConfig(filename = os.path.join(sys.path[0], "copykun.log"), format = "%(asctime)s %(message)s")
logger = logging.getLogger("copykun")
logger.setLevel(logging.DEBUG)

# Read the config file
if not os.path.isfile(os.path.join(sys.path[0], "copykun.cfg")):
    logger.critical("Configuration file not found: copykun.cfg")
    exit(1) 
config = configparser.ConfigParser()
with codecs.open(os.path.join(sys.path[0], "copykun.cfg"), "r", "utf8") as f:
    config.read_file(f)

database = SqliteDatabase(os.path.join(sys.path[0], config.get("Database", "db_name")), threadlocals = True)

class BaseModel(Model):
    class Meta:
        database = database
        
'''
A reddit submission which contains a link to content to copy
'''
class Post(BaseModel):
    id = CharField(primary_key = True)
    
'''
Reddit content copied by the bot
'''
class Content(BaseModel):
    permalink = CharField()
    created = IntegerField()
    edited = IntegerField(null = True)
    last_checked = IntegerField()
    update_interval = IntegerField()
    post = ForeignKeyField(Post, related_name = "content", null = True)
    
'''
A reply posted by the bot
'''
class Reply(BaseModel):
    permalink = CharField()
    latest_content = TextField()
    post = ForeignKeyField(Post, related_name = "replies")
    
'''
An edit made to a reply by the bot
'''
class Edit(BaseModel):
    content = TextField()
    edit_time = IntegerField()
    post = ForeignKeyField(Post, related_name = "edits")
    
class Database(object):
    
    def __init__(self): 
        database.connect()
        
    def __del__(self):
        database.close()
    
    def create_tables(self):
        database.create_tables([Post, Content, Reply, Edit])

    '''
    Check if a given post exists in the database
    '''
    def is_post_in_db(self, post_id):
        return Post.select().where(Post.id == post_id).exists()     
    
    '''
    Retrieve an interator of Posts which need to be checked for edits
    '''
    def get_posts_to_check_edits(self):
        now = datetime.utcnow().timestamp()
        cutoff = (datetime.utcnow() + timedelta(-7)).timestamp()
        posts = Post.select().join(Content).where(now > Content.last_checked + Content.update_interval and Content.created >= cutoff)
        return posts
            
    def get_reply_to_post(self, post_id):
        return Reply.select().join(Post).where(Post.id == post_id).first()
    
    def save_objects(self, objs):
        with database.transaction():
            for obj in objs:
                obj.save()