Switch DB from SQLite to Postgres.

.env.example

@@ -0,0 +1,6 @@
+BOT_TOKEN='your-bot-token'
+DB_HOST= ""
+DB_NAME= ""
+DB_USER=""
+DB_PASS=""
+DB_PORT=""

README.md

@@ -56,10 +56,26 @@ So I created **OppTickBot** — a personal tool that turned into something I now
 
 - Python 3.10+
 - [python-telegram-bot](https://github.com/python-telegram-bot/python-telegram-bot) v22+ (with job-queue extra)
-- SQLite for storing opportunities
+- PostgreSQL for storing opportunities
 - dateutil + regex for date parsing
 - Pillow + pytesseract (optional) for OCR on images
 
+### Database Structure
+
+The project uses PostgreSQL. The main table is `opportunities` which maps to the following schema:
+- `opp_id` (TEXT PRIMARY KEY): Unique identifier.
+- `user_id` (BIGINT): Telegram user ID.
+- `title` (TEXT): Opportunity title.
+- `opp_type` (TEXT): Category (Internship, Scholarship, Event, etc.).
+- `deadline` (TEXT): Datetime for the deadline.
+- `priority` (TEXT): Priority level.
+- `description` (TEXT): Extracted or user-provided description.
+- `message_text` (TEXT): Original raw text.
+- `link` (TEXT): Related URL.
+- `archived` (INTEGER DEFAULT 0): Whether it is archived.
+- `done` (INTEGER DEFAULT 0): Whether it is completed.
+- `missed_notified` (INTEGER DEFAULT 0): Has user been notified of missing deadline.
+
 ### Setup (Local Development)
 
 ```bash
@@ -74,8 +90,21 @@ source .venv/bin/activate   # Windows: .venv\Scripts\activate
 # 3. Install dependencies
 pip install -r requirements.txt
 
-# 4. Create .env file with your token
-echo "BOT_TOKEN=your_bot_token_here" > .env
+# 4. Create .env file with your credentials
+cp .env.example .env
+
+# Open the .env file and populate it with your actual values:
+# BOT_TOKEN="your-bot-token"
+# DB_HOST="localhost"
+# DB_NAME="opptick_db"
+# DB_USER="postgres"
+# DB_PASS="password"
+# DB_PORT="5432"
+
 
 # 5. Run the bot
-python bot.py
+python bot.py
+```
+
+**TODO listed in `db.py`**:
+- In `Database.init_db()` there is a TODO to "find a better way to not re-init db on every call". Currently, creating a new `Database` instance triggers `init_db()` which checks and executes `CREATE TABLE IF NOT EXISTS` and `ALTER TABLE ... ADD COLUMN IF NOT EXISTS` statements. Ideally, this should happen once at application startup or via a standalone migration script to avoid unnecessary query overhead.

bot.py

@@ -1,6 +1,5 @@
 import os
 import logging
-import sqlite3
 import uuid
 import re
 import io
@@ -9,6 +8,8 @@
 from dotenv import load_dotenv
 from dateutil.parser import parse as date_parse
 
+from db import Database
+
 from telegram import (
     Update, InlineKeyboardButton, InlineKeyboardMarkup, ReplyKeyboardMarkup
 )
@@ -26,8 +27,8 @@
     OCR_AVAILABLE = False
 
 # Load environment
-if os.path.exists(".env"):
-    load_dotenv()
+
+load_dotenv()
 BOT_TOKEN = os.getenv("BOT_TOKEN")
 if not BOT_TOKEN:
     raise ValueError("BOT_TOKEN missing! Set in .env or Railway Variables.")
@@ -39,36 +40,14 @@
 )
 logger = logging.getLogger(__name__)
 
+
+host=os.environ["DB_HOST"]
+database=os.environ["DB_NAME"]
+user=os.environ["DB_USER"]
+password=os.environ["DB_PASS"]
+port=os.environ["DB_PORT"]
 # DB setup
-DB_FILE = 'opportunities.db'
-def init_db():
-    conn = sqlite3.connect(DB_FILE)
-    c = conn.cursor()
-    c.execute('''
-        CREATE TABLE IF NOT EXISTS opportunities (
-            opp_id TEXT PRIMARY KEY,
-            user_id INTEGER,
-            title TEXT,
-            opp_type TEXT,
-            deadline TEXT,
-            priority TEXT,
-            description TEXT,
-            message_text TEXT,
-            link TEXT,
-            archived INTEGER DEFAULT 0,
-            done INTEGER DEFAULT 0,
-            missed_notified INTEGER DEFAULT 0
-        )
-    ''')
-    # Safe migration for existing databases
-    for col, defn in [("link", "TEXT"), ("missed_notified", "INTEGER DEFAULT 0")]:
-        try:
-            c.execute(f"ALTER TABLE opportunities ADD COLUMN {col} {defn}")
-        except sqlite3.OperationalError:
-            pass
-    conn.commit()
-    conn.close()
-init_db()
+db = Database(host,database,user,password,port)
 
 # Conversation states
 DEADLINE, TYPE, PRIORITY, TITLE, DESCRIPTION, LINK, CONFIRM = range(7)
@@ -355,15 +334,7 @@ async def confirm_callback(update: Update, context: ContextTypes.DEFAULT_TYPE) -
     link         = context.user_data.get('link', '')
 
     try:
-        conn = sqlite3.connect(DB_FILE)
-        conn.execute(
-            'INSERT INTO opportunities '
-            '(opp_id, user_id, title, opp_type, deadline, priority, description, message_text, link) '
-            'VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)',
-            (opp_id, user_id, title, opp_type, deadline.isoformat(), priority, desc, message_text, link)
-        )
-        conn.commit()
-        conn.close()
+        db.add_opportunity(opp_id, user_id, title, opp_type, deadline.isoformat(), priority, desc, message_text, link)
     except Exception as e:
         logger.error('DB error: %s', e)
         await query.edit_message_text('⚠️ Error saving. Please try again.')
@@ -433,15 +404,10 @@ def schedule_reminders(job_queue, user_id, opp_id, deadline, priority, title, de
 async def check_missed(context: ContextTypes.DEFAULT_TYPE) -> None:
     """Fires once daily; notifies each overdue opportunity ONCE only."""
     now = datetime.now()
-    conn = sqlite3.connect(DB_FILE)
-    c = conn.cursor()
-    c.execute(
-        'SELECT user_id, opp_id, title, description, opp_type, link, deadline '
-        'FROM opportunities '
-        'WHERE deadline < ? AND archived = 0 AND done = 0 AND missed_notified = 0',
-        (now.isoformat(),)
-    )
-    for uid, opp_id, title, desc, opp_type, link, dl_str in c.fetchall():
+    missed = db.get_missed_opportunities(now.isoformat())
+
+    for row in missed:
+        uid, opp_id, title, desc, opp_type, link, dl_str = row
         try:
             dl    = datetime.fromisoformat(str(dl_str))
             desc_s = str(desc) if desc else ''
@@ -461,24 +427,17 @@ async def check_missed(context: ContextTypes.DEFAULT_TYPE) -> None:
                 InlineKeyboardButton('✅ Mark as Done', callback_data=f'done_{opp_id}')
             ]])
             await context.bot.send_message(chat_id=uid, text=msg, reply_markup=keyboard, parse_mode='Markdown')
-            conn.execute('UPDATE opportunities SET missed_notified = 1 WHERE opp_id = ?', (opp_id,))
-            conn.commit()
+            db.mark_missed_notified(opp_id)
         except Exception as exc:
             logger.error('Missed-notify failed for %s: %s', opp_id, exc)
-    conn.close()
 
 async def mark_done_callback(update: Update, context: ContextTypes.DEFAULT_TYPE) -> int:
     query = update.callback_query
     await query.answer()
     if query.data.startswith('done_'):
         opp_id = query.data.split('_')[1]
         user_id = query.from_user.id
-        conn = sqlite3.connect(DB_FILE)
-        c = conn.cursor()
-        c.execute('UPDATE opportunities SET done=1, archived=1 WHERE opp_id = ? AND user_id = ?', (opp_id, user_id))
-        updated = c.rowcount
-        conn.commit()
-        conn.close()
+        updated = db.mark_done(opp_id, user_id)
         if updated > 0:
             for job in context.job_queue.jobs():
                 if job.name and opp_id in job.name:
@@ -490,11 +449,7 @@ async def mark_done_callback(update: Update, context: ContextTypes.DEFAULT_TYPE)
 
 async def list_opps(update: Update, context: ContextTypes.DEFAULT_TYPE):
     user_id = update.message.from_user.id
-    conn = sqlite3.connect(DB_FILE)
-    c = conn.cursor()
-    c.execute('SELECT opp_id, title, opp_type, deadline, priority, description FROM opportunities WHERE user_id = ? AND archived = 0 AND done = 0 ORDER BY deadline', (user_id,))
-    opps = c.fetchall()
-    conn.close()
+    opps = db.get_active_opportunities(user_id)
     if not opps:
         await update.message.reply_text("No active opportunities.")
         return
@@ -513,12 +468,7 @@ async def delete(update: Update, context: ContextTypes.DEFAULT_TYPE):
         return
     opp_id = context.args[0]
     user_id = update.message.from_user.id
-    conn = sqlite3.connect(DB_FILE)
-    c = conn.cursor()
-    c.execute('DELETE FROM opportunities WHERE opp_id = ? AND user_id = ?', (opp_id, user_id))
-    deleted = c.rowcount
-    conn.commit()
-    conn.close()
+    deleted = db.delete_opportunity(opp_id, user_id)
     if deleted > 0:
         for job in context.job_queue.jobs():
             if job.name and opp_id in job.name:
@@ -533,12 +483,7 @@ async def archive(update: Update, context: ContextTypes.DEFAULT_TYPE):
         return
     opp_id = context.args[0]
     user_id = update.message.from_user.id
-    conn = sqlite3.connect(DB_FILE)
-    c = conn.cursor()
-    c.execute('UPDATE opportunities SET archived=1 WHERE opp_id = ? AND user_id = ?', (opp_id, user_id))
-    updated = c.rowcount
-    conn.commit()
-    conn.close()
+    updated = db.archive_opportunity(opp_id, user_id)
     if updated > 0:
         for job in context.job_queue.jobs():
             if job.name and opp_id in job.name:
@@ -553,12 +498,7 @@ async def done(update: Update, context: ContextTypes.DEFAULT_TYPE):
         return
     opp_id = context.args[0]
     user_id = update.message.from_user.id
-    conn = sqlite3.connect(DB_FILE)
-    c = conn.cursor()
-    c.execute('UPDATE opportunities SET done=1, archived=1 WHERE opp_id = ? AND user_id = ?', (opp_id, user_id))
-    updated = c.rowcount
-    conn.commit()
-    conn.close()
+    updated = db.mark_done(opp_id, user_id)
     if updated > 0:
         for job in context.job_queue.jobs():
             if job.name and opp_id in job.name:
@@ -571,15 +511,7 @@ async def summary(update: Update, context: ContextTypes.DEFAULT_TYPE):
     user_id = update.message.from_user.id
     now = datetime.now()
     week_end = now + timedelta(days=7)
-    conn = sqlite3.connect(DB_FILE)
-    c = conn.cursor()
-    c.execute(
-        'SELECT COUNT(*), opp_type FROM opportunities '
-        'WHERE user_id = ? AND deadline >= ? AND deadline <= ? AND archived=0 AND done=0 GROUP BY opp_type',
-        (user_id, now.isoformat(), week_end.isoformat())
-    )
-    sums = c.fetchall()
-    conn.close()
+    sums = db.get_weekly_summary(user_id, now.isoformat(), week_end.isoformat())
     if not sums:
         await update.message.reply_text("No upcoming this week.")
         return
@@ -594,14 +526,7 @@ async def error_handler(update: object, context: ContextTypes.DEFAULT_TYPE):
 # --- Reschedule reminders on startup ---
 def reschedule_all_reminders(job_queue: JobQueue):
     """Re-registers all pending reminders after a bot restart."""
-    conn = sqlite3.connect(DB_FILE)
-    c = conn.cursor()
-    c.execute(
-        'SELECT user_id, opp_id, title, deadline, priority, description, opp_type, link '
-        'FROM opportunities WHERE archived = 0 AND done = 0'
-    )
-    rows = c.fetchall()
-    conn.close()
+    rows = db.get_all_active_reminders()
     now = datetime.now()
     for user_id, opp_id, title, dl_str, priority, desc, opp_type, link in rows:
         try:

db.py

@@ -0,0 +1,105 @@
+import os
+import psycopg2
+
+
+class Database:
+    _initialized = False 
+
+    def __init__(self, host, database, user, password, port):
+        self.conn = psycopg2.connect(
+            host=host,
+            database=database,
+            user=user,
+            password=password,
+            port=port
+        )
+        self.conn.autocommit = True
+
+        self.init_db() # TODO: find better way to not re init db on every call
+
+
+    def init_db(self):
+        """Create table and ensure missing columns exist"""
+        with self.conn.cursor() as c:
+            c.execute('''
+                CREATE TABLE IF NOT EXISTS opportunities (
+                    opp_id TEXT PRIMARY KEY,
+                    user_id BIGINT,
+                    title TEXT,
+                    opp_type TEXT,
+                    deadline TEXT,
+                    priority TEXT,
+                    description TEXT,
+                    message_text TEXT,
+                    archived INTEGER DEFAULT 0,
+                    done INTEGER DEFAULT 0
+                )
+            ''')
+
+            c.execute("ALTER TABLE opportunities ADD COLUMN IF NOT EXISTS link TEXT")
+            c.execute("ALTER TABLE opportunities ADD COLUMN IF NOT EXISTS missed_notified INTEGER DEFAULT 0")
+
+    # ---------------- CRUD Methods ---------------- #
+
+    def add_opportunity(self, opp_id, user_id, title, opp_type, deadline, priority, desc, message_text, link=None):
+        with self.conn.cursor() as c:
+            c.execute('''
+                INSERT INTO opportunities 
+                (opp_id, user_id, title, opp_type, deadline, priority, description, message_text, link) 
+                VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s)
+            ''', (opp_id, user_id, title, opp_type, deadline, priority, desc, message_text, link))
+
+    def get_missed_opportunities(self, now_iso):
+        with self.conn.cursor() as c:
+            c.execute('''
+                SELECT user_id, opp_id, title, description, opp_type, link, deadline 
+                FROM opportunities 
+                WHERE deadline < %s AND archived = 0 AND done = 0 AND missed_notified = 0
+            ''', (now_iso,))
+            return c.fetchall()
+
+    def mark_missed_notified(self, opp_id):
+        with self.conn.cursor() as c:
+            c.execute('UPDATE opportunities SET missed_notified = 1 WHERE opp_id = %s', (opp_id,))
+
+    def mark_done(self, opp_id, user_id):
+        with self.conn.cursor() as c:
+            c.execute('UPDATE opportunities SET done=1, archived=1 WHERE opp_id = %s AND user_id = %s', (opp_id, user_id))
+            return c.rowcount
+
+    def get_active_opportunities(self, user_id):
+        with self.conn.cursor() as c:
+            c.execute('''
+                SELECT opp_id, title, opp_type, deadline, priority, description 
+                FROM opportunities 
+                WHERE user_id = %s AND archived = 0 AND done = 0 ORDER BY deadline
+            ''', (user_id,))
+            return c.fetchall()
+
+    def delete_opportunity(self, opp_id, user_id):
+        with self.conn.cursor() as c:
+            c.execute('DELETE FROM opportunities WHERE opp_id = %s AND user_id = %s', (opp_id, user_id))
+            return c.rowcount
+
+    def archive_opportunity(self, opp_id, user_id):
+        with self.conn.cursor() as c:
+            c.execute('UPDATE opportunities SET archived=1 WHERE opp_id = %s AND user_id = %s', (opp_id, user_id))
+            return c.rowcount
+
+    def get_weekly_summary(self, user_id, now_iso, week_end_iso):
+        with self.conn.cursor() as c:
+            c.execute('''
+                SELECT COUNT(*) as count, opp_type FROM opportunities 
+                WHERE user_id = %s AND deadline >= %s AND deadline <= %s AND archived=0 AND done=0 
+                GROUP BY opp_type
+            ''', (user_id, now_iso, week_end_iso))
+            return c.fetchall()
+
+    def get_all_active_reminders(self):
+        with self.conn.cursor() as c:
+            c.execute('''
+                SELECT user_id, opp_id, title, deadline, priority, description, opp_type, link 
+                FROM opportunities 
+                WHERE archived = 0 AND done = 0
+            ''')
+            return c.fetchall()