Update and rename app_Version2.py to app.py

Author: Yug2920

app.py

@@ -0,0 +1,148 @@
+# app.py
+from flask import Flask, render_template, request, redirect, url_for, session, jsonify
+import sqlite3
+import pandas as pd
+from datetime import datetime
+# Import libraries for Clerk, Charting, and PDF (install these!)
+# from clerk_sdk import Clerk # Placeholder: You would install and configure the official Clerk SDK
+# import matplotlib.pyplot as plt # For Chart generation
+# from reportlab.pdfgen import canvas # For PDF Report generation
+
+app = Flask(__name__)
+# IMPORTANT: Replace with a secure, long, random key
+app.secret_key = 'YOUR_SUPER_SECRET_KEY_HERE'
+DATABASE = 'expense_tracker.db'
+
+# --- 1. Database Initialization ---
+def init_db():
+    conn = sqlite3.connect(DATABASE)
+    cursor = conn.cursor()
+    # 'user_id' is crucial for multi-user support and is where Clerk/Auth data comes in
+    cursor.execute('''
+        CREATE TABLE IF NOT EXISTS transactions (
+            id INTEGER PRIMARY KEY,
+            user_id TEXT NOT NULL,
+            type TEXT NOT NULL, -- 'INCOME' or 'EXPENSE'
+            description TEXT NOT NULL,
+            amount REAL NOT NULL,
+            currency TEXT NOT NULL,
+            date TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+        )
+    ''')
+    conn.commit()
+    conn.close()
+
+# Call this once when the app starts
+init_db()
+
+# --- 2. Authentication Mock/Placeholder ---
+# In a real app, you would use a middleware/decorator provided by Clerk
+# to verify the user's session and get the actual 'current_user_id'.
+
+def get_current_user_id():
+    # Placeholder: In a real app, this would come from Clerk/Auth session data.
+    # We are using a simple session mock for this example.
+    return session.get('user_id', 'mock_user_123') # Default to a mock ID if not logged in
+
+# Mock login (replace with actual Clerk redirect/callback flow)
+@app.route('/login')
+def login():
+    # After successful Clerk sign-in, you would set the session user ID
+    session['user_id'] = 'clerk_user_abc_456'
+    return redirect(url_for('dashboard'))
+
+# Mock logout (replace with actual Clerk sign-out flow)
+@app.route('/logout')
+def logout():
+    session.pop('user_id', None)
+    return redirect(url_for('index'))
+
+
+# --- 3. Core Endpoints ---
+
+@app.route('/')
+def index():
+    if 'user_id' not in session:
+        # Redirect to the authentication page placeholder
+        return render_template('login.html', clerk_publishable_key='YOUR_CLERK_PUBLISHABLE_KEY')
+    return redirect(url_for('dashboard'))
+
+@app.route('/dashboard')
+def dashboard():
+    user_id = get_current_user_id()
+    conn = sqlite3.connect(DATABASE)
+    conn.row_factory = sqlite3.Row
+    cursor = conn.cursor()
+    
+    # Fetch all transactions for the logged-in user
+    transactions = cursor.execute('SELECT * FROM transactions WHERE user_id = ? ORDER BY date DESC', (user_id,)).fetchall()
+    
+    # Calculate wallet/balance (remaining money)
+    income_query = cursor.execute('SELECT SUM(amount) FROM transactions WHERE user_id = ? AND type = "INCOME"', (user_id,)).fetchone()[0] or 0
+    expense_query = cursor.execute('SELECT SUM(amount) FROM transactions WHERE user_id = ? AND type = "EXPENSE"', (user_id,)).fetchone()[0] or 0
+    wallet_balance = income_query - expense_query
+    
+    conn.close()
+    
+    # We'll assume a base currency for display (e.g., USD)
+    base_currency = 'USD' 
+    
+    return render_template('index.html', 
+                           transactions=transactions, 
+                           balance=wallet_balance,
+                           base_currency=base_currency)
+
+@app.route('/add', methods=['POST'])
+def add_transaction():
+    user_id = get_current_user_id()
+    if not user_id:
+        return jsonify({'error': 'Unauthorized'}), 401
+    
+    data = request.form
+    type = data.get('type') # 'INCOME' or 'EXPENSE'
+    description = data.get('description')
+    amount = float(data.get('amount'))
+    currency = data.get('currency', 'USD') # Default currency
+    
+    conn = sqlite3.connect(DATABASE)
+    cursor = conn.cursor()
+    cursor.execute('''
+        INSERT INTO transactions (user_id, type, description, amount, currency)
+        VALUES (?, ?, ?, ?, ?)
+    ''', (user_id, type, description, amount, currency))
+    conn.commit()
+    conn.close()
+    
+    return redirect(url_for('dashboard'))
+
+
+# --- 4. Report Generation (PDF/Chart) Placeholder ---
+
+@app.route('/report/pdf')
+def generate_pdf_report():
+    user_id = get_current_user_id()
+    # 1. Fetch data for the user (same as dashboard, but perhaps date-filtered)
+    # 2. Use 'reportlab' to create a PDF document
+    # 3. Return the PDF file as a response
+    return "PDF Report Generation (requires reportlab library)", 200
+
+@app.route('/report/chart')
+def generate_chart():
+    user_id = get_current_user_id()
+    # 1. Fetch data
+    # 2. Use 'matplotlib' to create a chart (e.g., pie chart of expense categories)
+    # 3. Save the chart as an image (PNG)
+    # 4. Return the chart image or a page that displays it
+    return "Chart Generation (requires matplotlib library)", 200
+
+# --- 5. Currency Conversion (Placeholder) ---
+# For full currency support, you would integrate a currency exchange API (e.g., ExchangeRate-API)
+@app.route('/convert', methods=['POST'])
+def convert_currency():
+    # Logic to convert an amount from one currency to the base currency
+    # For simplicity, this is not implemented but shows where it would go.
+    return "Currency Conversion Endpoint Placeholder", 200
+
+if __name__ == '__main__':
+    # Flask runs on http://127.0.0.1:5000/
+    app.run(debug=True)