abstract factory and builder implementation in fastapi

main.py

@@ -2,9 +2,11 @@ import uvicorn
 from fastapi import FastAPI
 from scripts.logging.logging import logger
 from scripts.services.area import shape
+from scripts.services.meals import meals
 
 app = FastAPI()
 app.include_router(shape)
+app.include_router(meals)
 if __name__ == "__main__":
     try:
         uvicorn.run(app, port=8765)

scripts/constants/endpoints.py

 class EndPoints:
     circle_area = "/circle_area"
     rectangle_area = "/rectangle_area"
+    meals_maker = "/meal"

scripts/core/handlers/meals_builder.py

+from abc import ABC, abstractmethod
+
+
+# Product class that we want to build with the builder pattern
+class Meal:
+    def __init__(self):
+        self.drink = None
+        self.payasam = None
+        self.side = None
+        self.dessert = None
+
+    def __repr__(self):
+        return f"Meal(drink={self.drink}, payasam={self.payasam}, side={self.side}, dessert={self.dessert})"
+
+
+# Abstract builder interface
+class MealBuilder(ABC):
+    @abstractmethod
+    def add_drink(self):
+        pass
+
+    @abstractmethod
+    def add_payasam(self):
+        pass
+
+    @abstractmethod
+    def add_side(self):
+        pass
+
+    @abstractmethod
+    def add_dessert(self):
+        pass
+
+    @abstractmethod
+    def get_meal(self):
+        pass
+
+
+# Concrete builder that builds a combo meal
+class ComboMealBuilder(MealBuilder):
+    def __init__(self):
+        self.meal = Meal()
+
+    def add_drink(self):
+        self.meal.drink = "Thumbs UP"
+
+    def add_payasam(self):
+        self.meal.payasam = "Pradaman"
+
+    def add_side(self):
+        self.meal.side = "Fries"
+
+    def add_dessert(self):
+        self.meal.dessert = "Apple pie"
+
+    def get_meal(self):
+        return self.meal
+
+
+# Director class that uses the builder to build the meal
+class MealAssembler:
+    def __init__(self, builder: MealBuilder):
+        self.builder = builder
+
+    def assemble_meal(self):
+        self.builder.add_drink()
+        self.builder.add_payasam()
+        self.builder.add_side()
+        self.builder.add_dessert()
+        return self.builder.get_meal()

scripts/services/area.py

@@ -5,6 +5,7 @@ from scripts.core.handlers.shape_handler import CircleFactory, AreaCalculator, R
 shape = APIRouter()
 
 
+# CREATIONAL PATTERN -ABSTRACT FACTORY METHOD
 # Register endpoints that use the abstract factory
 @shape.get(EndPoints.circle_area, tags=["Area of a Circle"])
 async def circle_area(radius: float):

scripts/services/meals.py

+from fastapi import APIRouter
+from scripts.constants.endpoints import EndPoints
+from scripts.core.handlers.meals_builder import ComboMealBuilder, MealAssembler
+
+meals = APIRouter()
+
+
+# CREATIONAL PATTERN BUILDER METHOD
+# Register endpoint that uses the builder to build a meal
+@meals.get(EndPoints.meals_maker, tags=["meals"])
+async def get_meal():
+    builder = ComboMealBuilder()
+    meal_assembler = MealAssembler(builder)
+    meal = meal_assembler.assemble_meal()
+    return {"meal": str(meal)}