um-cseg / chez-betty

chezbetty/datalayer.py

import functools

from .models.model import *
from .models import event
from .models import transaction
from .models import account
from .models.pool import Pool
from .models.user import User
from .models import request
from .models import receipt
from .models.item import Item
from .models.box import Box
from .models import box_item
from .models import item_vendor
from .models import box_vendor
from .models import ephemeron

from .utility import notify_pool_out_of_credit
from .utility import notify_new_top_wall_of_shame

import math


def top_debtor_wrapper(fn):
    '''Wrapper function for transactions that watches for a new top debtor.

    Should wrap any function that creates a purchase or deposit transaction.
    Can't put this inside the Transaction class b/c the add/flush operations are
    at a higher level.'''
    @functools.wraps(fn)
    def wrapper(*args, **kwargs):
        # Record top debtor before new transaction
        old_top_debtor = DBSession.query(User).order_by(User.balance).limit(1).one()

        # Execute transaction. Txn function should call add() and flush()
        ret = fn(*args, **kwargs)

        # Check whether the top debtor has changed
        new_top_debtor = DBSession.query(User).order_by(User.balance).limit(1).one()
        print(old_top_debtor, new_top_debtor)
        if new_top_debtor != old_top_debtor:
            notify_new_top_wall_of_shame(new_top_debtor)

        return ret

    return wrapper


def can_undo_event(e):
    if e.type != 'deposit' and e.type != 'purchase' and e.type != 'restock' \
       and e.type != 'inventory' and e.type != 'emptycashbox' \
       and e.type != 'emptysafe' \
       and e.type != 'donation' and e.type != 'withdrawal' \
       and e.type != 'reimbursement':
        return False
    if e.deleted:
        return False
    return True


# Call this to remove an event from chez betty. Only works with cash deposits
def undo_event(e, user):
    assert(can_undo_event(e))

    line_items = {}

    for t in e.transactions:

        if t.to_account_virt:
            t.to_account_virt.balance -= t.amount
        if t.fr_account_virt:
            t.fr_account_virt.balance += t.amount
        if t.to_account_cash:
            t.to_account_cash.balance -= t.amount
        if t.fr_account_cash:
            t.fr_account_cash.balance += t.amount

        if t.type == 'purchase':
            # Re-add the stock to the items that were purchased
            for s in t.subtransactions:
                line_items[s.item_id] = s.quantity
                Item.from_id(s.item_id).in_stock += s.quantity

        elif t.type == 'restock':
            # Include the global cost so we can repopulate the box on the
            # restock page.
            line_items['global_cost'] = '{}'.format(t.amount_restock_cost)

            # Record who we reimbursed this to
            if t.to_account_cash:
                line_items['reimbursee'] = t.to_account_cash.id

            # Add all of the boxes and items to the return list
            # Also remove the stock this restock added to each item
            for i,s in zip(range(len(t.subtransactions)), t.subtransactions):
                if s.type == 'restocklineitem':
                    item = Item.from_id(s.item_id)
                    line_items[i] = '{},{},{},{},{},{},{}'.format(
                        'item', s.item_id, s.quantity, s.wholesale,
                        s.coupon_amount, s.sales_tax, s.bottle_deposit)
                    item.in_stock -= s.quantity
                elif s.type == 'restocklinebox':
                    line_items[i] = '{},{},{},{},{},{},{}'.format(
                        'box', s.box_id, s.quantity, s.wholesale,
                        s.coupon_amount, s.sales_tax, s.bottle_deposit)
                    for ss in s.subsubtransactions:
                        item = Item.from_id(ss.item_id)
                        item.in_stock -= ss.quantity

        elif t.type == 'inventory':
            # Change the stock of all the items by reversing the inventory count
            for s in t.subtransactions:
                quantity_diff = s.quantity - s.quantity_counted
                s.item.in_stock += quantity_diff
                line_items[s.item_id] = s.quantity_counted

        elif t.type == 'donation':
            line_items['donation'] = '{}'.format(t.amount)

        # Don't need anything for emptycashbox. On those transactions no
        # other tables are changed.


    # Just need to delete the event. All transactions will understand they
    # were deleted as well.
    e.delete(user)

    return line_items

def can_delete_item(item):
    if len(item.boxes) == 0 and\
       len(item.vendors) == 0 and\
       len(item.subtransactions) == 0 and\
       len(item.subsubtransactions) == 0:
       return True
    return False

def delete_item(item):
    boxitems = DBSession.query(box_item.BoxItem).filter(box_item.BoxItem.item_id==item.id).all()
    for bi in boxitems:
        DBSession.delete(bi)
    itemvendors = DBSession.query(item_vendor.ItemVendor).filter(item_vendor.ItemVendor.item_id==item.id).all()
    for iv in itemvendors:
        DBSession.delete(iv)
    DBSession.delete(item)

def can_delete_box(box):
    if len(box.items) == 0 and\
       len(box.vendors) == 0 and\
       len(box.subtransactions) == 0:
       return True
    return False

def delete_box(box):
    boxitems = DBSession.query(box_item.BoxItem).filter(box_item.BoxItem.box_id==box.id).all()
    for bi in boxitems:
        DBSession.delete(bi)
    boxvendors = DBSession.query(box_vendor.BoxVendor).filter(box_vendor.BoxVendor.box_id==box.id).all()
    for bv in boxvendors:
        DBSession.delete(bv)
    DBSession.delete(box)


# Call this to make a new item request
def new_request(user, request_text, vendor, vendor_url=None):
    r = request.Request(user, request_text, vendor, vendor_url)
    DBSession.add(r)
    DBSession.flush()
    return r


# Call this to let a user purchase items
@top_debtor_wrapper
def purchase(user, account, items):
    assert(hasattr(user, "id"))
    assert(len(items) > 0)

    # TODO: Parameterize
    discount = Decimal(0)
    if user.balance > 20.0:
        discount = Decimal('0.05')

    # Need to calculate a total
    amount = Decimal(0)
    for item, quantity in items.items():
        amount += Decimal(item.price * quantity)

    intermediate = amount - (amount * discount).quantize(Decimal('.01'), rounding=ROUND_HALF_UP)

    # Calculate a potential wall of shame fee
    fee = None
    fee_amount = Decimal(0)
    result = user.balance - intermediate
    fee_percent = Decimal(0)
    if result <= Decimal('-5'):
        remainder = (user.balance - intermediate) * Decimal('-1')
        offset = user.balance * Decimal('-1')
        if user.balance > Decimal('-5'):
            offset = Decimal('5')
        fee_percent = math.floor(offset / Decimal('5')) * Decimal('5')

        while True:
            extra = remainder - offset

            if remainder < fee_percent + Decimal('5'):
                fee_amount += ((fee_percent * Decimal('0.01')) * extra)
                break

            else:
                fee_amount += ((fee_percent * Decimal('0.01')) * (fee_percent + Decimal('5') - offset))
                fee_percent += Decimal('5')
                offset = fee_percent

        fee_percent = (fee_amount / intermediate) * Decimal('100')
        if fee_percent < Decimal('0.1'):
            fee_percent = Decimal('0.1')

        fee_amount = (intermediate * (fee_percent * Decimal('0.01'))).quantize(Decimal('.01'), rounding=ROUND_HALF_UP)


    if fee_amount != 0:
        if discount != 0:
            # Only do this complicated math if we have to merge a good
            # standing discount with a wall of shame fee
            final = intermediate + fee_amount
            discount = (-1 * ((final / amount) - Decimal('1')))
        else:
            # Just use wall of shame fee
            discount = fee_percent * Decimal('-0.01')

    if discount == 0:
        # Make sure we handle the no discount normal case correctly
        discount = None

    e = event.Purchase(user)
    DBSession.add(e)
    DBSession.flush()
    t = transaction.Purchase(e, account, discount)
    DBSession.add(t)
    DBSession.flush()
    amount = Decimal(0)
    for item, quantity in items.items():
        item.in_stock -= quantity
        line_amount = Decimal(item.price * quantity)
        pli = transaction.PurchaseLineItem(t, line_amount, item, quantity,
                                           item.price, item.wholesale)
        DBSession.add(pli)
        amount += line_amount
    if discount:
        amount = round(amount - (amount * discount), 2)
    t.update_amount(amount)

    if isinstance(account, Pool):
        if account.balance < (account.credit_limit * -1):
            owner = User.from_id(account.owner)
            notify_pool_out_of_credit(owner, account)

    return t


# Call this when a user puts money in the dropbox and needs to deposit it
# to their account
# If `merge==True`, then try to squash multiple deposits in a row together
@top_debtor_wrapper
def deposit(user, account, amount, merge=True):
    assert(amount > 0.0)
    assert(hasattr(user, "id"))

    # Keep track of how much this deposit will be once merged (if needed)
    deposit_total = amount

    # Get recent deposits that we might merge with this one
    events_to_delete = []
    if merge:
        recent_deposits = event.Deposit.get_user_recent(user)
        for d in recent_deposits:
            # Only look at transaction events with 1 CashDeposit transaction
            if len(d.transactions) == 1 and d.transactions[0].type == 'cashdeposit':
                t = d.transactions[0]
                # Must be a deposit to the same account
                if t.to_account_virt_id == account.id:
                    deposit_total += t.amount
                    events_to_delete.append(d)


    # TODO (added on 2016/05/14): Make adding the new deposit and deleting
    # the old ones a single atomic unit

    # Add the new deposit (which may be a cumulative total)
    prev = user.balance
    e = event.Deposit(user)
    DBSession.add(e)
    DBSession.flush()
    t = transaction.CashDeposit(e, account, deposit_total)
    DBSession.add(t)

    # And then delete the old events that we merged together
    for e in events_to_delete:
        undo_event(e, user)

    return dict(prev=prev,
                new=user.balance,
                amount=deposit_total,
                transaction=t,
                event=e)


# Call this when a credit card transaction deposits money into an account
@top_debtor_wrapper
def cc_deposit(user, account, amount, txn_id, last4):
    assert(amount > 0.0)
    assert(hasattr(user, "id"))

    prev = user.balance
    e = event.Deposit(user)
    DBSession.add(e)
    DBSession.flush()
    t = transaction.CCDeposit(e, account, amount, txn_id, last4)
    DBSession.add(t)
    return dict(prev=prev,
                new=user.balance,
                amount=amount,
                transaction=t,
                event=e)


# Call this to deposit bitcoins to the user account
@top_debtor_wrapper
def bitcoin_deposit(user, amount, btc_transaction, address, amount_btc):
    assert(amount > 0.0)
    assert(hasattr(user, "id"))

    prev = user.balance
    e = event.Deposit(user)
    DBSession.add(e)
    DBSession.flush()
    t = transaction.BTCDeposit(e, user, amount, btc_transaction, address, amount_btc)
    DBSession.add(t)
    return dict(prev=prev,
                new=user.balance,
                amount=amount,
                transaction=t)


# Call this to say money was given to chez betty but we don't know whose
# account to put it into
def temporary_deposit(amount):
    assert(amount > 0.0)

    return ephemeron.Ephemeron.add_decimal('deposit', amount)


# Call this to adjust a user's balance
@top_debtor_wrapper
def adjust_user_balance(user, adjustment, notes, admin):
    e = event.Adjustment(admin, notes)
    DBSession.add(e)
    DBSession.flush()
    t = transaction.Adjustment(e, user, adjustment)
    DBSession.add(t)
    return e


@top_debtor_wrapper
def transfer_user_money(sender, recipient, amount, notes, admin):
    e = event.Adjustment(admin, notes)
    DBSession.add(e)
    DBSession.flush()
    t1 = transaction.Adjustment(e, sender, -1*amount)
    DBSession.add(t1)
    t2 = transaction.Adjustment(e, recipient, amount)
    DBSession.add(t2)
    return e


# Call this when an admin restocks chezbetty
def restock(items, global_cost, donation, reimbursee, admin, timestamp=None):
    e = event.Restock(admin, timestamp)
    DBSession.add(e)
    DBSession.flush()
    t = transaction.Restock(e, Decimal(global_cost), reimbursee)
    DBSession.add(t)
    DBSession.flush()
    if donation != Decimal(0):
        d = transaction.Donation(e, donation, reimbursee)
        DBSession.add(d)
        DBSession.flush()
    # Start with the global cost when calculating the total amount
    amount = Decimal(global_cost)

    # Add all of the items as subtransactions
    for thing, quantity, total, wholesale, coupon, salestax, btldeposit in items:
        if type(thing) is Item:
            item = thing
            # Add the stock to the item
            item.in_stock += quantity
            # Make sure the item is enabled (now that we have some in stock)
            item.enabled = True
            # Create a subtransaction to track that this item was added
            rli = transaction.RestockLineItem(t, total, item, quantity, wholesale, coupon, salestax, btldeposit)
            DBSession.add(rli)
            #amount += Decimal(total)

        elif type(thing) is Box:
            box = thing

            # Create a subtransaction to record that the box was restocked
            rlb = transaction.RestockLineBox(t, total, box, quantity, wholesale, coupon, salestax, btldeposit)
            DBSession.add(rlb)
            DBSession.flush()

            # Iterate all the subitems and update the stock
            for itembox in box.items:
                subitem = itembox.item
                subquantity = itembox.quantity * quantity
                subitem.enabled = True
                subitem.in_stock += subquantity

                rlbi = transaction.RestockLineBoxItem(rlb, subitem, subquantity)
                DBSession.add(rlbi)

        amount += Decimal(total)

    t.update_amount(amount)
    return e


# Call this when a user runs inventory
def reconcile_items(items, admin):
    e = event.Inventory(admin)
    DBSession.add(e)
    DBSession.flush()
    t = transaction.Inventory(e)
    DBSession.add(t)
    DBSession.flush()
    total_amount_missing = Decimal(0)
    for item, quantity in items.items():
        # Record the restock line item even if the number hasn't changed.
        # This lets us track when we have counted items.
        quantity_missing = item.in_stock - quantity
        line_amount = quantity_missing * item.wholesale
        ili = transaction.InventoryLineItem(t, line_amount, item, item.in_stock,
                                quantity, item.wholesale)
        DBSession.add(ili)
        total_amount_missing += ili.amount
        item.in_stock = quantity
    t.update_amount(total_amount_missing)
    DBSession.add(t)
    DBSession.flush()
    return t


# Call this when the cash box gets emptied
def reconcile_safe(amount, admin):

This code seems to be duplicated in your project.

    assert(amount>=0)

    e = event.EmptySafe(admin)
    DBSession.add(e)
    DBSession.flush()

    safe_c = account.get_cash_account("safe")
    expected_amount = safe_c.balance
    amount_missing = expected_amount - amount

    if amount_missing != 0.0:
        # If the amount in the safe doesn't match what we expected there to
        # be, we need to adjust the amount in the cash box be transferring
        # to or from a null account

        if amount_missing > 0:
            # We got less in the box than we expected
            # Move money from the safe account to null with transaction type
            # "lost"
            t1 = transaction.Lost(e, account.get_cash_account("safe"), amount_missing)
            DBSession.add(t1)

        else:
            # We got more in the box than expected! Use a found transaction
            # to reconcile the difference
            t1 = transaction.Found(e, account.get_cash_account("safe"), abs(amount_missing))
            DBSession.add(t1)


    # Now move all the money from the safe to chezbetty
    t2 = transaction.EmptySafe(e, amount)
    DBSession.add(t2)
    return e


# Call this to move all of the money from the cash box to the safe.
# We don't actually count the amount, so we do no reconciling here, but it
# means that money isn't sitting in the store.
def cashbox_to_safe(admin):
    e = event.EmptyCashBox(admin)
    DBSession.add(e)
    DBSession.flush()

    t = transaction.EmptyCashBox(e)
    DBSession.add(t)
    return e


# Call this to move money from the safe to the bank.
def safe_to_bank(amount, admin):
    assert(amount>=0)

    e = event.EmptySafe(admin)
    DBSession.add(e)
    DBSession.flush()

    t = transaction.EmptySafe(e, amount)
    DBSession.add(t)
    return e


# Call this when bitcoins are converted to USD
def reconcile_bitcoins(amount, admin, expected_amount=None):

This code seems to be duplicated in your project.

    assert(amount>0)

    e = event.EmptyBitcoin(admin)
    DBSession.add(e)
    DBSession.flush()

    btcbox_c = account.get_cash_account("btcbox")
    if expected_amount == None:
        expected_amount = btcbox_c.balance
    amount_missing = expected_amount - amount

    if amount_missing != 0.0:
        # Value of bitcoins fluctated and we didn't make as much as we expected

        if amount_missing > 0:
            # We got less in bitcoins than we expected
            # Move money from the btcbox account to null with transaction type
            # "lost"
            t1 = transaction.Lost(e, account.get_cash_account("btcbox"), amount_missing)
            DBSession.add(t1)

        else:
            # We got more in bitcoins than expected! Use a found transaction
            # to reconcile the difference
            t1 = transaction.Found(e, account.get_cash_account("btcbox"), abs(amount_missing))
            DBSession.add(t1)


    # Now move all the money from the bitcoin box to chezbetty
    t2 = transaction.EmptyBitcoin(e, amount)
    DBSession.add(t2)
    return expected_amount


# Call this to make a miscellaneous adjustment to the chezbetty account
def reconcile_misc(amount, notes, admin):
    assert(amount != 0.0)

    e = event.Reconcile(admin, notes)
    DBSession.add(e)
    DBSession.flush()

    if amount < 0.0:
        t = transaction.Lost(e, account.get_cash_account("chezbetty"), abs(amount))
    else:
        t = transaction.Found(e, account.get_cash_account("chezbetty"), amount)
    DBSession.add(t)
    return t


# Call this to make a cash donation to Chez Betty
def add_donation(amount, notes, admin, timestamp=None):
    e = event.Donation(admin, notes, timestamp)
    DBSession.add(e)
    DBSession.flush()
    t = transaction.Donation(e, amount)
    DBSession.add(t)
    return e


# Call this to withdraw cash funds from Chez Betty into another account
def add_withdrawal(amount, notes, reimbursee, admin, timestamp=None):
    e = event.Withdrawal(admin, notes, timestamp)
    DBSession.add(e)
    DBSession.flush()
    t = transaction.Withdrawal(e, amount, reimbursee)
    DBSession.add(t)
    return e


# Call this to reimburse a reimbursee
def add_reimbursement(amount, notes, reimbursee, admin, timestamp=None):
    e = event.Reimbursement(admin, notes, timestamp)
    DBSession.add(e)
    DBSession.flush()
    t = transaction.Reimbursement(e, amount, reimbursee)
    DBSession.add(t)
    return e


def upload_receipt(event, admin, rfile):
    r = receipt.Receipt(event, admin, rfile)
    DBSession.add(r)
    DBSession.flush()
    return r