add events

alembic/versions/abfbb3d96037_create_user_event_table.py

@@ -11,7 +11,6 @@ from typing import Sequence, Union
 from alembic import op
 import sqlalchemy as sa
 import sqlalchemy.dialects.postgresql as psql
-import uuid
 
 # revision identifiers, used by Alembic.
 revision: str = "abfbb3d96037"
@@ -22,16 +21,29 @@ depends_on: Union[str, Sequence[str], None] = None
 
 def upgrade() -> None:
     """Upgrade schema."""
+
+    op.execute("CREATE EXTENSION IF NOT EXISTS pgcrypto;")
+
     op.create_table(
-        "user_event_table",
+        "user_events",
-        sa.Column("id", sa.UUID(as_uuid=True), nullable=False, default=uuid.uuid4),
+        sa.Column(
-        sa.Column("sequence", sa.Integer(), nullable=False),
+            "id",
+            sa.UUID(as_uuid=True),
+            nullable=False,
+            server_default=sa.text("gen_random_uuid()"),
+        ),
+        sa.Column("sequence", sa.Integer(), nullable=False, autoincrement=True),
         sa.Column("event_payload", psql.JSONB, nullable=False),
-        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            nullable=False,
+            server_default=sa.text("NOW()"),
+        ),
         sa.PrimaryKeyConstraint("id", "sequence"),
     )
 
 
 def downgrade() -> None:
     """Downgrade schema."""
-    op.drop_table("user_event_table")
+    op.drop_table("user_event")

create_events.py

@@ -0,0 +1,141 @@
+import os
+from dotenv import load_dotenv
+import psycopg2
+import uuid
+import json
+
+load_dotenv()
+
+conn_params = {
+    "host": os.getenv("POSTGRES_HOST"),
+    "port": os.getenv("POSTGRES_PORT"),
+    "dbname": os.getenv("POSTGRES_DB"),
+    "user": os.getenv("POSTGRES_USER"),
+    "password": os.getenv("POSTGRES_PASSWORD"),
+}
+
+
+class User:
+
+    def __init__(self, cursor, name, age, hair_color):
+        self.cursor = cursor
+        self.id = uuid.uuid4()
+        self.name = name
+        self.age = age
+        self.hair_color = hair_color
+
+        self._fire_created_user_event()
+
+    def update_user_details(self, name=None, age=None, hair_color=None):
+        if name:
+            self.name = name
+        if age:
+            self.age = age
+        if hair_color:
+            self.hair_color = hair_color
+
+        self._fire_updated_user_event()
+
+    def delete_user(self):
+        self._fire_deleted_user_event()
+
+    def _fire_created_user_event(self):
+        event = CreateUserEvent(self)
+        self._fire_event(event)
+
+    def _fire_updated_user_event(self):
+        event = UpdateUserEvent(self)
+        self._fire_event(event)
+
+    def _fire_deleted_user_event(self):
+        event = DeleteUserEvent(self)
+        self._fire_event(event)
+
+    def _fire_event(self, event):
+        query = f"INSERT INTO user_events (event_payload) VALUES ('{event.to_json()}')"
+        self.cursor.execute(query)
+
+
+class CreateUserEvent:
+
+    def __init__(self, user):
+        self._user = user
+
+    def to_json(self):
+        return json.dumps(
+            {
+                "event_type": "user_created",
+                "payload": {
+                    "id": self._user.id,
+                    "name": self._user.name,
+                    "age": self._user.age,
+                    "hair_color": self._user.hair_color,
+                },
+            },
+            default=str,
+        )
+
+
+class UpdateUserEvent:
+    def __init__(self, user):
+        self._user = user
+
+    def to_json(self):
+        return json.dumps(
+            {
+                "event_type": "user_updated",
+                "payload": {
+                    "id": self._user.id,
+                    "name": self._user.name,
+                    "age": self._user.age,
+                    "hair_color": self._user.hair_color,
+                },
+            },
+            default=str,
+        )
+
+
+class DeleteUserEvent:
+    def __init__(self, user):
+        self._user = user
+
+    def to_json(self):
+        return json.dumps(
+            {
+                "event_type": "user_deleted",
+                "payload": {"id": self._user.id},
+            },
+            default=str,
+        )
+
+
+def main():
+
+    try:
+        # Connect to PostgreSQL
+        conn = psycopg2.connect(**conn_params)
+        cur = conn.cursor()
+
+        my_user = User(cursor=cur, name="John", age=95, hair_color="Gray")
+
+        my_user.update_user_details(age=96)
+
+        my_user.delete_user()
+
+        # Commit the transaction
+        conn.commit()
+
+        print("Done")
+
+    except Exception as e:
+        print("Error:", e)
+
+    finally:
+        if cur:
+            cur.close()
+        if conn:
+            conn.close()
+
+
+if __name__ == "__main__":
+    main()

run_show.sh

@@ -0,0 +1,5 @@
+docker compose down
+docker compose up -d
+sleep 2s
+alembic upgrade head
+python3 create_events.py