#!/usr/bin/env python3
import click
from tabulate import tabulate
from datetime import datetime

from pos.config import Config
from pos.logging import init_logging, get_logger
from pos.database import Database, User, Event, Product, Transaction

config = Config()
conf_db = config.core['DATABASE']

init_logging(config.logging)
log = get_logger('cli')

db = Database(**conf_db)


def get_total(transaction):
    return sum(o.product.price * o.quantity
               for o in transaction.orders)


def get_income(event):
    return sum(get_total(t) for t in event.transactions)


@click.group()
def cli():
    pass


@cli.group('user')
def user():
    pass


def tabulate_users(users):
    tab = [["UID", "Username", "Enabled", "Created at"]]
    for u in users:
        tab.append([u.uid, u.username, u.is_active, u.created_at])
    return tabulate(tab, headers='firstrow')


@user.command('add')
@click.argument('username')
@click.argument('password')
def user_add(username, password):
    user = User(username=username, password=password)
    with db.get_session() as session:
        session.add(user)
    print("User succesfully added.")


@user.command('list')
def user_list():
    with db.get_session() as session:
        users = session.query(User).all()

    if users:
        print(tabulate_users(users))
    else:
        print("No users found.")


@cli.group('event')
def event():
    pass


def tabulate_events(events):
    tab = [["UID", "Name", "Starts at", "Ends at", "Income", "Created at"]]

    for e in events:
        tab.append([e.uid, e.name, e.starts_at,
                    e.ends_at, get_income(e), e.created_at])

    return tabulate(tab, headers='firstrow')


@event.command('add')
@click.argument('name')
@click.option('--start')
@click.option('--end')
def event_add(name, start, end):
    start = datetime.strptime(start, "%Y-%m-%d %H:%M")
    end = datetime.strptime(end, "%Y-%m-%d %H:%M")
    event = Event(name=name, starts_at=start, ends_at=end)

    with db.get_session() as session:
        session.add(event)
    print("Event succesfully added.")


@event.command('list')
def event_list():
    with db.get_session() as session:
        events = session.query(Event).all()

    if events:
        print(tabulate_events(events))
    else:
        print("No events found.")


@cli.group('product')
def product():
    pass


def tabulate_products(products):
    tab = [["UID", "Name", "Price", "Enabled", "Created at"]]
    for p in products:
        tab.append([p.uid, p.name, p.price, p.is_active, p.created_at])
    return tabulate(tab, headers='firstrow')


@product.command('add')
@click.argument('name')
@click.argument('price')
def product_add(name, price):
    product = Product(name=name, price=price)
    with db.get_session() as session:
        session.add(product)
    print("Product succesfully added.")


@product.command('list')
def product_list():
    with db.get_session() as session:
        products = session.query(Product).all()

    if products:
        print(tabulate_products(products))
    else:
        print("No products found.")


@cli.group('transaction')
def transaction():
    pass


def tabulate_orders(orders):
    tab = [["Product", "Price", "Quantity", "Total"]]
    for o in orders:
        if o.quantity > 0:
            tab.append([o.product.name, o.product.price, o.quantity,
                        o.product.price * o.quantity])
    return tabulate(tab, headers='firstrow')


def print_transactions(transactions):
    for t in transactions:
        print("Listing transaction #{} ({}):".format(t.uid, t.created_at))
        print(tabulate_orders(t.orders))
        print("Total:", get_total(t))
        print()


@transaction.command('list')
def transaction_list():
    with db.get_session() as session:
        transactions = session.query(Transaction).all()

    if transactions:
        print_transactions(transactions)
    else:
        print("No transactions found.")


if __name__ == '__main__':
    cli()