import os

from cs50 import SQL
from flask import Flask, flash, redirect, render_template, request, session
from flask_session import Session
from tempfile import mkdtemp
from werkzeug.exceptions import default_exceptions, HTTPException, InternalServerError
from werkzeug.security import check_password_hash, generate_password_hash
from datetime import datetime

from helpers import apology, login_required, lookup, usd

# Configure application
app = Flask(__name__)

# Ensure templates are auto-reloaded
app.config["TEMPLATES_AUTO_RELOAD"] = True


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


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

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

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

# Make sure API key is set
if not os.environ.get("API_KEY"):
    raise RuntimeError("API_KEY not set")


@app.route("/")
@login_required
def index():
    """Show portfolio of stocks"""
    # getting user info from DB
    user_id = session["user_id"]
    portfolio = db.execute("SELECT * FROM portfolio WHERE id = ?", user_id)
    cash_list = db.execute("SELECT cash FROM users WHERE id = ?", user_id)
    cash = cash_list[0]["cash"]
    grand_total = cash

    # list throught user protfolio and all needed information to the portfolio list
    for row in portfolio:
        stock = lookup(row["symbol"])
        price = float(stock["price"])
        name = stock["name"]
        amount = int(row["amount"])
        total = price * amount

        row["name"] = name
        row["price"] = usd(price)
        row["total"] = usd(total)

        grand_total += total

    # money formatting and returning html
    cash = usd(cash)
    grand_total = usd(grand_total)
    return render_template("index.html", portfolio=portfolio, cash=cash, grand_total=grand_total)


@app.route("/buy", methods=["GET", "POST"])
@login_required
def buy():
    """Buy shares of stock"""
    # User reached route via POST (as by submitting a form via POST)
    # get user inputs and check if they are valid
    if request.method == "POST":
        user_id = session["user_id"]
        symbol = request.form.get("symbol")
        shares = request.form.get("shares")

        if symbol == "":
            return apology("Missing symbol")

        elif shares == "":
            return apology("Missing number of shares")

        elif not shares.isdigit() or int(shares) < 1:
            return apology("Number of shares must be bigger than 1.")

        # getting stock info from API
        stock = lookup(symbol)
        shares = int(shares)
        symbol = symbol.upper()

        if not stock:
            return apology("Not existing symbol")

        # compare total stock price vs funds
        price = stock["price"]
        total_price = price * shares
        row = db.execute("SELECT * FROM users WHERE id = ?", user_id)
        funds = float(row[0]["cash"])

        if funds < total_price:
            return apology("You don't have enough money")

        # update users cash, insert transcation to history table
        now = datetime.now()
        now = now.strftime("%Y-%m-%d %H:%M:%S")
        db.execute("UPDATE users SET cash = cash - ? WHERE id = ?", total_price, user_id)
        db.execute("INSERT INTO history (id, symbol, shares, price, transacted) VALUES (?, ?, ?, ?, ?)", user_id,
                   symbol, shares, total_price, now)

        # check if user already owns this stock, change portfolio
        owned = db.execute("SELECT * FROM portfolio WHERE id = ? AND symbol = ?", user_id, symbol)
        if len(owned) > 0:
            db.execute("UPDATE portfolio SET amount = amount + ? WHERE id = ? AND symbol = ?", shares, user_id, symbol)
        else:
            db.execute("INSERT INTO portfolio (id, symbol, amount) VALUES (?, ?, ?)", user_id, symbol, shares)

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

    else:
        return render_template("buy.html")


@app.route("/history")
@login_required
def history():
    """Show history of transactions"""
    # getting user history logs from DB
    user_id = session["user_id"]
    history = db.execute("SELECT * FROM history WHERE id = ?", user_id)

    return render_template("history.html", history=history)


@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", 403)

        # Ensure password was submitted
        elif not request.form.get("password"):
            return apology("must provide password", 403)

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

        # Ensure username exists and password is correct
        if len(rows) != 1 or not check_password_hash(rows[0]["hash"], request.form.get("password")):
            return apology("invalid username and/or password", 403)

        # 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."""
    # User reached route via POST (as by submitting a form via POST)
    if request.method == "POST":
        # getting user input and checking if it's valid
        symbol = request.form.get("symbol")

        if symbol == "":
            return apology("Missing symbol")

        # getting stock info from API
        stock = lookup(symbol)

        if not stock:
            return apology("Not existing symbol")

        # creating html with info from API
        return render_template("quoted.html", symbol=stock["symbol"], name=stock["name"], price=usd(stock["price"]))

    else:
        return render_template("quote.html")


@app.route("/register", methods=["GET", "POST"])
def register():
    """Register user"""
    if request.method == "POST":

        # Getting user inputs and checking if he filled all
        name = request.form.get("username")
        password = request.form.get("password")
        confirmation = request.form.get("confirmation")

        if name == "":
            return apology("Missing username")

        elif password == "":
            return apology("Missing password")

        elif confirmation == "":
            return apology("Missing password confirmation")

        elif password != confirmation:
            return apology("Passwords not matching")

        # personal touch - password strength check
        upper = 0
        digits = 0
        symbols = 0
        for char in password:
            if char.isupper():
                upper += 1
            elif char.isdigit():
                digits += 1
            elif not char.islower():
                symbols += 1

        if upper < 1 or digits < 1 or symbols < 1:
            return apology("Password must contain 1 uppercase, 1 number and 1 symbol")

        # Checking inputs against DB
        rows = db.execute("SELECT * FROM users WHERE username == (?)", name)
        if len(rows) > 0:
            return apology("Username is already used")

        # convert password to hash and insert username + hash to db
        hash_pw = generate_password_hash(password)
        db.execute("INSERT INTO users (username, hash) VALUES (?, ?)", name, hash_pw)

        # remember which user is logged in and redirect to homepage
        rows = db.execute("SELECT * FROM users WHERE username = (?)", name)
        session["user_id"] = rows[0]["id"]

        return redirect("/")

    else:
        return render_template("register.html")


@app.route("/sell", methods=["GET", "POST"])
@login_required
def sell():
    """Sell shares of stock"""
    # getting user portfolio from DB
    user_id = session["user_id"]
    portfolio = db.execute("SELECT * FROM portfolio WHERE id = ?", user_id)

    if request.method == "POST":
        # get inputs from user and check if it's valid
        symbol = request.form.get("symbol")
        shares = int(request.form.get("shares"))
        owned_shares = db.execute("SELECT * FROM portfolio WHERE id = ? AND symbol = ?", user_id, symbol)
        stock = lookup(symbol)

        if shares < 1 or shares == "":
            return apology("Invalid number of shares")

        # checking difference between owned and want to sell shares
        difference = owned_shares[0]["amount"] - shares

        if difference < 0:
            return apology("You don't own that many shares")

        # update user's cash
        total_price = stock["price"] * shares
        db.execute("UPDATE users SET cash = cash + ? WHERE id = ?", total_price, user_id)

        # create entry in history
        now = datetime.now()
        now = now.strftime("%Y-%m-%d %H:%M:%S")
        db.execute("INSERT INTO history (id, symbol, shares, price, transacted) VALUES (?, ?, ?, ?, ?)", user_id,
                   symbol, shares * (-1), total_price, now)

        # if sold amount = owned amount, delete entry from portfolio
        if difference == 0:
            db.execute("DELETE FROM portfolio WHERE id = ? and symbol = ?", user_id, symbol)
        else:
            db.execute("UPDATE portfolio SET amount = ? WHERE id = ? and symbol = ?", difference, user_id, symbol)

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

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


def errorhandler(e):
    """Handle error"""
    if not isinstance(e, HTTPException):
        e = InternalServerError()
    return apology(e.name, e.code)


# Listen for errors
for code in default_exceptions:
    app.errorhandler(code)(errorhandler)