cs50/psets/9/finance/app.py

import logging
from datetime import datetime

from cs50 import SQL
from flask import Flask, flash, redirect, render_template, request, session
from flask_session import Session
from werkzeug.security import check_password_hash, generate_password_hash

from helpers import apology, login_required, lookup, usd

# Configure application
app = Flask(__name__)

# Custom filter
app.jinja_env.filters["usd"] = usd

# Configure session to use filesystem (instead of signed cookies)
app.config["SESSION_PERMANENT"] = False
app.config["SESSION_TYPE"] = "filesystem"
Session(app)

# Configure CS50 Library to use SQLite database
db = SQL("sqlite:///finance.db")
# db = SQL("postgresql://postgres:password@db/finance")

@app.after_request
def after_request(response):
    """Ensure responses aren't cached"""
    response.headers["Cache-Control"] = "no-cache, no-store, must-revalidate"
    response.headers["Expires"] = 0
    response.headers["Pragma"] = "no-cache"
    return response


@app.route("/")
@login_required
def index():
    # Get actual cash of the logged-in user
    user = db.execute("SELECT * FROM users WHERE id = ?", session["user_id"])
    transactions = db.execute("SELECT symbol, SUM(shares), SUM(costs) FROM transactions WHERE user_id = ? GROUP BY symbol", session["user_id"])

    # Calculations
    stocks_total = 0.0
    portfolio = []
    for holding in transactions:
        if holding['SUM(shares)'] <= 0:
            continue
        symbol = holding['symbol']
        stock = lookup(symbol)
        symbol_price = float(stock['price'])
        holding['actual_price'] = symbol_price * holding['SUM(shares)']
        stocks_total += int(holding['actual_price'])
        holding['difference'] = holding['actual_price'] + holding['SUM(costs)']
        holding['percentage'] = holding['difference'] / holding['actual_price'] * 100
        portfolio.append(holding)

    print(portfolio)
    total = float(user[0]["cash"]) + stocks_total
    return render_template("index.html", user=user[0], portfolio=portfolio, stocks_total=stocks_total, total=total)


@app.route("/buy", methods=["GET", "POST"])
@login_required
def buy():
    if request.method == "POST":
        # Ensure symbol was given
        if not request.form.get("symbol"):
            return apology("must provide symbol", 400)
        symbol = request.form.get("symbol")

        # Ensure shares was given
        if not request.form.get("shares"):
            return apology("must provide shares", 400)
        shares = request.form.get("shares")

        # Check for digit shares
        if not shares.isdigit():
            return apology("must provide a digit number of shares", 400)
        shares = float(shares)

        # Check for digit shares
        if not shares.is_integer():
            return apology("must provide a integer number of shares", 400)
        shares = int(shares)

        # Check if shares are greater than 0
        if shares <= 0:
            return apology("must provide a positive number of shares", 400)

        # Lookup the actual price
        stock_prices = lookup(symbol)

        # Check if symbol is valid
        if not stock_prices:
            return apology("symbol not found", 400)

        # Get the cash of the user
        rows = db.execute("SELECT * FROM users WHERE id = ?", session["user_id"])
        cash = float(rows[0]["cash"])
        logging.debug("cash = " + str(cash))

        # Calculate the costs
        costs = float(stock_prices["price"]) * shares
        logging.debug("costs = " + str(stock_prices["price"]) +
                      " * " + str(shares) + " = " + str(costs))

        # Check if user has enough money
        if costs > cash:
            return apology("not enough money left", 400)

        # Buy and save transaction
        cash -= costs
        db.execute("UPDATE users SET cash = ? WHERE id = ? ", cash, session["user_id"])
        db.execute("INSERT INTO transactions (user_id, buy_sell, datetime, symbol, shares, costs) VALUES(?, ?, ?, ?, ?, ?)",session["user_id"], 1, datetime.now(), symbol, shares, -costs)

        # Show notification about bought
        flash(f"Bought {shares} shares of {symbol} for {usd(costs)}!")

        # Redirect user to home page
        return redirect("/")

    # User reached route via GET (as by clicking a link or via redirect)
    else:
        return render_template("buy.html")


@app.route("/history")
@login_required
def history():
    # Show history of transactions
    transactions = db.execute("SELECT * FROM transactions WHERE user_id = ?", session["user_id"])
    if not transactions: transactions = []
    return render_template("history.html", transactions=transactions)


@app.route("/login", methods=["GET", "POST"])
def login():
    """Log user in"""

    # Forget any user_id
    session.clear()

    # User reached route via POST (as by submitting a form via POST)
    if request.method == "POST":
        # Ensure username was submitted
        if not request.form.get("username"):
            return apology("must provide username", 400)
        username = request.form.get("username")

        # Ensure password was submitted
        if not request.form.get("password"):
            return apology("must provide password", 400)
        password = request.form.get("password")

        # Query database for username
        rows = db.execute("SELECT * FROM users WHERE username = ?", username)

        # Ensure username exists and password is correct
        if len(rows) != 1 or not check_password_hash(rows[0]["hash"], password):
            return apology("invalid username and/or password", 400)

        # Remember which user has logged in
        session["user_id"] = rows[0]["id"]

        # Redirect user to home page
        return redirect("/")

    # User reached route via GET (as by clicking a link or via redirect)
    else:
        return render_template("login.html")


@app.route("/logout")
def logout():
    """Log user out"""

    # Forget any user_id
    session.clear()

    # Redirect user to login form
    return redirect("/")


@app.route("/quote", methods=["GET", "POST"])
@login_required
def quote():
    """Get stock quote."""
    if request.method == "POST":
        symbol = request.form.get("symbol")
        logging.debug("symbol = " + symbol)
        if not symbol:
            return apology("must provide symbol", 400)
        stock_prices = lookup(symbol)
        logging.debug("stock_prices = " + str(stock_prices))
        if not stock_prices:
            return apology("symbol not found", 400)

        return render_template("quoted.html", stock_prices=stock_prices)
    else:
        return render_template("quote.html")


@app.route("/register", methods=["GET", "POST"])
def register():
    """Register user"""
    # User reached route via POST (as by submitting a form via POST)
    if request.method == "POST":
        username = request.form.get("username")
        # Ensure username was submitted
        if not username:
            return apology("must provide username", 400)
        # Check if user already existing
        if db.execute("SELECT * FROM users WHERE username = ?", username):
            return apology("user already exists", 400)

        password = request.form.get("password")
        # Ensure password was submitted
        if not password:
            return apology("must provide password", 400)

        confirmation = request.form.get("confirmation")
        # Ensure password was submitted
        if not confirmation:
            # Query database for username
            return apology("must provide confirmation", 400)

        # Ensure password is identical with confirmation
        if password != confirmation:
            return apology("password and confirmation does not match", 400)

        # Add user to db
        password_hash = generate_password_hash(password)
        db.execute("INSERT INTO users (username, hash) VALUES(?, ?)", username, password_hash)

        # Redirect user to home page
        return redirect("/")

    # User reached route via GET (as by clicking a link or via redirect)
    else:
        return render_template("register.html")


@app.route("/sell", methods=["GET", "POST"])
@login_required
def sell():
    # Get portfolio
    transactions = db.execute(
        "SELECT symbol, SUM(shares), SUM(costs) FROM transactions WHERE user_id = ? GROUP BY symbol", session["user_id"])

    if request.method == "POST":
        # Ensure symbol was given
        if not request.form.get("symbol"):
            return apology("must provide symbol", 400)
        symbol = request.form.get("symbol")

        # Ensure shares was given
        if not request.form.get("shares"):
            return apology("must provide shares", 400)
        shares = request.form.get("shares")

        # Check for digit shares
        if not shares.isdigit():
            return apology("must provide a digit number of shares", 400)
        shares = float(shares)

        # Check for digit shares
        if not shares.is_integer():
            return apology("must provide a integer number of shares", 400)
        shares = int(shares)

        # Check if shares are greater than 0
        if shares <= 0:
            return apology("must provide a positive number of shares", 400)

        # Calculate the costs
        stock_prices = lookup(symbol)
        # Check if symbol is valid
        if not stock_prices:
            return apology("symbol not found", 400)

        # Check if enough shares available
        old_shares = 0
        for transaction in transactions:
            if transaction['symbol'] == symbol:
                old_shares = transaction['SUM(shares)']

        if shares > old_shares:
            return apology("You have only " + str(old_shares) + " shares of " + symbol + " available!", 400)

        # Get the cash of the user
        user = db.execute("SELECT * FROM users WHERE id = ?", session["user_id"])
        cash = float(user[0]["cash"])

        profit = float(stock_prices["price"]) * shares

        # Buy and save transaction
        cash += profit
        db.execute("UPDATE users SET cash = ? WHERE id = ? ", cash, session["user_id"])
        db.execute("INSERT INTO transactions (user_id, buy_sell, datetime, symbol, shares, costs) VALUES(?, ?, ?, ?, ?, ?)",
                   session["user_id"], 0, datetime.now(), symbol, -shares, profit)

        # Show notification about bought
        flash(f"Sold {shares} shares of {symbol} for {usd(profit)}!")

        # Redirect user to home page
        return redirect("/")

    # User reached route via GET (as by clicking a link or via redirect)
    else:
        portfolio = []
        for transaction in transactions:
            if transaction['SUM(shares)'] <= 0:
                continue
            portfolio.append(transaction)

        return render_template("sell.html", portfolio=portfolio)