accountant/accountant/api/models/operations.py

"""
    This file is part of Accountant.

    Accountant is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Accountant is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
"""
import arrow

from sqlalchemy import func, case, desc, true, false, text
from sqlalchemy.orm import column_property

from accountant import db


class Operation(db.Model):
    id = db.Column(db.Integer, primary_key=True)

    operation_date = db.Column(
        db.Date,
        nullable=False,
        default=arrow.now().date(),
        server_default=func.current_date(),
        index=True
    )
    label = db.Column(db.String(500), nullable=False)
    value = db.Column(db.Numeric(15, 2), nullable=False)

    scheduled_operation_id = db.Column(
        db.Integer,
        db.ForeignKey('scheduled_operation.id'),
        index=True
    )

    scheduled_operation = db.relationship(
        "ScheduledOperation", backref=db.backref('entry', lazy="dynamic")
    )

    account_id = db.Column(db.Integer, db.ForeignKey('account.id'), index=True)

    account = db.relationship(
        'Account', backref=db.backref('operation', lazy="dynamic")
    )

    category = db.Column(db.String(100), nullable=True, index=True)

    pointed = db.Column(
        db.Boolean,
        nullable=False,
        default=False,
        server_default=false()
    )

    confirmed = db.Column(
        db.Boolean,
        nullable=False,
        default=True,
        server_default=true()
    )

    canceled = db.Column(
        db.Boolean,
        nullable=False,
        default=False,
        server_default=false()
    )

    sold = column_property(
        func.sum(
            case(
                whens={canceled: text("0")},
                else_=value
            )
        ).over(
            partition_by=[account_id],
            order_by=["operation_date", desc("value"), desc("label"), id]
        ).label("sold")
    )

    def __init__(self, label, value, account_id, operation_date=None,
                 category=None, pointed=False, confirmed=True, canceled=False,
                 scheduled_operation_id=None):
        self.operation_date = operation_date
        self.label = label
        self.value = value
        self.category = category
        self.account_id = account_id
        self.scheduled_operation_id = scheduled_operation_id
        self.pointed = pointed
        self.confirmed = confirmed
        self.canceled = canceled

    @classmethod
    def query(cls, session, begin=None, end=None):
        end = arrow.now().ceil('month').date() if not end else end

        # We have to use a join because the sold is not computed from the
        # begining.
        base_query = session.query(
            cls.id,
            cls.sold
        ).subquery()

        query = session.query(
            cls.id,
            cls.operation_date,
            cls.label,
            cls.value,
            base_query.c.sold,
            cls.category,
            cls.scheduled_operation_id,
            cls.account_id,
            cls.pointed,
            cls.confirmed,
            cls.canceled
        ).join(
            base_query, base_query.c.id == cls.id
        ).filter(
            cls.operation_date >= str(begin),
            cls.operation_date <= str(end)
        ).order_by(
            desc(cls.operation_date),
            cls.value,
            cls.label,
        )

        return query

    @classmethod
    def get_categories_for_range(cls, session, account, begin, end):
        if isinstance(account, int) or isinstance(account, str):
            account_id = account
        else:
            account_id = account.id

        query = session.query(
            cls.category,
            func.sum(
                case([(func.sign(cls.value) == -1, cls.value)], else_=0)
            ).label("expenses"),
            func.sum(
                case([(func.sign(cls.value) == 1, cls.value)], else_=0)
            ).label("revenues"),
            func.sum(cls.value).label("balance")
        ).filter(
            cls.account_id == account_id
        ).filter(
            cls.operation_date >= str(begin),
            cls.operation_date <= str(end)
        ).order_by(
            cls.category
        ).group_by(
            cls.category
        )

        return query

    @classmethod
    def get_ohlc_per_day_for_range(cls, session, account, begin=None, end=None):
        if isinstance(account, int) or isinstance(account, str):
            account_id = account
        else:
            account_id = account.id

        end = end if end else arrow.now().ceil('month').date()

        sold = func.sum(cls.value).over(
            order_by=[cls.operation_date, desc(cls.value), cls.label]
        )

        previous = sold - cls.value

        subquery = session.query(
            cls.operation_date,
            sold.label("sold"),
            previous.label("previous")
        ).filter(
            cls.account_id == account_id,
            cls.canceled == false()
        ).subquery()

        query = session.query(
            subquery.c.operation_date,
            func.first_value(subquery.c.previous).over(
                partition_by=subquery.c.operation_date
            ).label("open"),
            func.max(
                func.greatest(
                    subquery.c.previous, subquery.c.sold
                )
            ).over(
                partition_by=subquery.c.operation_date
            ).label('high'),
            func.min(
                func.least(
                    subquery.c.previous, subquery.c.sold
                )
            ).over(
                partition_by=subquery.c.operation_date
            ).label('low'),
            func.last_value(subquery.c.sold).over(
                partition_by=subquery.c.operation_date
            ).label('close')
        ).distinct()

        if begin:
            query = query.filter(subquery.c.operation_date >= str(begin))

        if end:
            query = query.filter(subquery.c.operation_date <= str(end))

        query = query.order_by(
            subquery.c.operation_date
        )

        return query