From 1246ce50fd4e779c4b20a077fdd3a122084ba750 Mon Sep 17 00:00:00 2001
From: Ferdinand Thiessen <rpm@fthiessen.de>
Date: Fri, 29 Jan 2021 23:28:43 +0100
Subject: [PATCH] [Plugin] Balance: Route and method to query all balances.

---
 flaschengeist/plugins/balance/__init__.py     | 17 +++++++++++++++
 .../plugins/balance/balance_controller.py     | 21 +++++++++++++++++++
 flaschengeist/plugins/balance/models.py       | 14 +++++++++++--
 3 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/flaschengeist/plugins/balance/__init__.py b/flaschengeist/plugins/balance/__init__.py
index f67e924..c64ca0b 100644
--- a/flaschengeist/plugins/balance/__init__.py
+++ b/flaschengeist/plugins/balance/__init__.py
@@ -291,3 +291,20 @@ def reverse_transaction(transaction_id, current_session: Session):
         reversal = balance_controller.reverse_transaction(transaction, current_session._user)
         return HTTP.created(reversal)
     raise Forbidden
+
+
+@balance_bp.route("/balance", methods=["GET"])
+@login_required(permission=permissions.SHOW_OTHER)
+def get_balances(current_session: Session):
+    """Get all balances
+
+    Route: ``/balance`` | Method: ``GET``
+
+    Args:
+        current_session: Session sent with Authorization Header
+
+    Returns:
+        JSON Array containing credit, debit and userid for each user or HTTP error
+    """
+    balances = balance_controller.get_balances()
+    return jsonify([{"userid": u, "credit": v[0], "debit": v[1]} for u, v in balances.items()])
diff --git a/flaschengeist/plugins/balance/balance_controller.py b/flaschengeist/plugins/balance/balance_controller.py
index 35050ff..f363855 100644
--- a/flaschengeist/plugins/balance/balance_controller.py
+++ b/flaschengeist/plugins/balance/balance_controller.py
@@ -39,6 +39,27 @@ def get_balance(user, start: datetime = None, end: datetime = None):
     return credit, debit, credit - debit
 
 
+def get_balances(start: datetime = None, end: datetime = None):
+    debit = db.session.query(Transaction.sender_id, func.sum(Transaction.amount)).filter(Transaction.sender_ != None)
+    credit = db.session.query(Transaction.receiver_id, func.sum(Transaction.amount)).filter(Transaction.receiver_ != None)
+    if start:
+        debit = debit.filter(start <= Transaction.time)
+        credit = credit.filter(start <= Transaction.time)
+    if end:
+        debit = debit.filter(Transaction.time <= end)
+        credit = credit.filter(Transaction.time <= end)
+
+    debit = debit.group_by(Transaction._sender_id).all()
+    credit = credit.group_by(Transaction._receiver_id).all()
+    all = {}
+    for uid, cred in credit:
+        all[uid] = [cred, 0]
+    for uid, deb in debit:
+        all.setdefault(uid, [0, 0])
+        all[uid][1] = deb
+    return all
+
+
 def send(sender: User, receiver, amount: float, author: User):
     """Send credit from one user to an other
 
diff --git a/flaschengeist/plugins/balance/models.py b/flaschengeist/plugins/balance/models.py
index e981ad9..03ab890 100644
--- a/flaschengeist/plugins/balance/models.py
+++ b/flaschengeist/plugins/balance/models.py
@@ -1,6 +1,8 @@
 from datetime import datetime
 from typing import Optional
 
+from sqlalchemy.ext.hybrid import hybrid_property
+
 from flaschengeist.database import db
 from flaschengeist.models.user import User
 from flaschengeist.models import ModelSerializeMixin, UtcDateTime
@@ -31,14 +33,22 @@ class Transaction(db.Model, ModelSerializeMixin):
     author_: User = db.relationship("User", foreign_keys=[_author_id])
     original_ = db.relationship("Transaction", uselist=False, backref=db.backref("reversal_", remote_side=[id]))
 
-    @property
+    @hybrid_property
     def sender_id(self):
         return self.sender_.userid if self.sender_ else None
 
-    @property
+    @sender_id.expression
+    def sender_id(cls):
+        return db.select([User.userid]).where(cls._sender_id == User._id).as_scalar()
+
+    @hybrid_property
     def receiver_id(self):
         return self.receiver_.userid if self.receiver_ else None
 
+    @receiver_id.expression
+    def receiver_id(cls):
+        return db.select([User.userid]).where(cls._receiver_id == User._id).as_scalar()
+
     @property
     def author_id(self):
         return self.author_.userid