Add table for storing financial info

This adds a table that can store expenses, goals, and income entries.
This will be used to be able to make the site's financials more visible.

tildes/alembic/versions/879588c5729d_add_financials_table.py

@@ -0,0 +1,49 @@
+"""Add financials table
+
+Revision ID: 879588c5729d
+Revises: fa14e9f5ebe5
+Create Date: 2019-11-05 19:50:13.973734
+
+"""
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision = "879588c5729d"
+down_revision = "fa14e9f5ebe5"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.create_table(
+        "financials",
+        sa.Column("entry_id", sa.Integer(), nullable=False),
+        sa.Column(
+            "entry_type",
+            postgresql.ENUM("EXPENSE", "GOAL", "INCOME", name="financialentrytype"),
+            nullable=False,
+        ),
+        sa.Column("description", sa.Text(), nullable=True),
+        sa.Column("amount", sa.Numeric(scale=2), nullable=False),
+        sa.Column("date_range", postgresql.DATERANGE(), nullable=False),
+        sa.Column(
+            "is_approximate", sa.Boolean(), server_default="false", nullable=False
+        ),
+        sa.PrimaryKeyConstraint("entry_id", name=op.f("pk_financials")),
+    )
+    op.create_index(
+        "ix_financials_date_range_gist",
+        "financials",
+        ["date_range"],
+        unique=False,
+        postgresql_using="gist",
+    )
+
+
+def downgrade():
+    op.drop_index("ix_financials_date_range_gist", table_name="financials")
+    op.drop_table("financials")
+
+    op.execute("DROP TYPE financialentrytype")

tildes/tildes/database_models.py

@@ -12,6 +12,7 @@ from tildes.models.comment import (
     CommentNotification,
     CommentVote,
 )
+from tildes.models.financials import Financials
 from tildes.models.group import Group, GroupSubscription
 from tildes.models.log import Log
 from tildes.models.message import MessageConversation, MessageReply

tildes/tildes/enums.py

@@ -80,6 +80,14 @@ class CommentLabelOption(enum.Enum):
         return None
 
 
+class FinancialEntryType(enum.Enum):
+    """Enum for entry types in the Financials table."""
+
+    EXPENSE = enum.auto()
+    GOAL = enum.auto()
+    INCOME = enum.auto()
+
+
 class LogEventType(enum.Enum):
     """Enum for the types of events stored in logs."""
 

tildes/tildes/models/financials.py

@@ -0,0 +1,31 @@
+# Copyright (c) 2019 Tildes contributors <code@tildes.net>
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+"""Contains the Financials class."""
+
+from decimal import Decimal
+
+from psycopg2.extras import DateRange
+from sqlalchemy import Boolean, Column, Index, Integer, Numeric, Text
+from sqlalchemy.dialects.postgresql import DATERANGE, ENUM
+
+from tildes.enums import FinancialEntryType
+from tildes.models import DatabaseModel
+
+
+class Financials(DatabaseModel):
+    """Model holding information about the site's financials over time."""
+
+    __tablename__ = "financials"
+
+    entry_id: int = Column(Integer, primary_key=True)
+    entry_type: FinancialEntryType = Column(ENUM(FinancialEntryType), nullable=False)
+    description: str = Column(Text)
+    amount: Decimal = Column(Numeric(scale=2), nullable=False)
+    date_range: DateRange = Column(DATERANGE, nullable=False)
+    is_approximate: bool = Column(Boolean, nullable=False, server_default="false")
+
+    # Add a GiST index on the date_range column for range operators
+    __table_args__ = (
+        Index("ix_financials_date_range_gist", date_range, postgresql_using="gist"),
+    )