add events

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()