small-distance-courier-service

Small Distance Courier Service

Approach

• The SOLID design principles
• Test Driven Development
• Clean Code

Language

• Kotlin

Acceptance Criteria

Part 1 : Estimate the total delivery cost of each package with an offer code (If applicable).

• Only one offer code can be applied for any given package.
• Package should meet the required mentioned offer criteria:
• OFR001 10% Discount, Distance < 200 Km, Weight 70-200 KG.
• OFR002 7% Discount, Distance 50-150 Km, Weight 100-250 KG.
• OFR003 5% Discount, Distance 50-250 Km, Weight 10-150 KG.
• If offer code is not valid/found, discounted amount will be equal to 0.
• Code should be extensible & scalable for more offer codes.
• Delivery Cost = Base Delivery Cost + (Package Total Weight * 10) + (Distance to Destination * 5).
• Discount = (Offer / 100) * Delivery Cost.
• Total Cost = Delivery Cost - Discount.
• All input numbers will be whole numbers (Base Delivery Cost, Number of Packages, Package Weight in Kg, Distance in Km).

Part 2: Calculate the estimated delivery time for every package by maximizing no. of packages in every shipment.

• Each Vehicle has a limit (L) on maximum weight (kg) that it can carry.
• All Vehicles travel at the same speed (S km/hr) and in the same route.
• Delivery should meet the required mentioned delivery criteria:
• Shipment should contain max packages vehicle can carry in a trip. (Optimum Combination nearing vehicle max weight limit but not exceeding it).
• We should prefer heavier packages when there are multiple shipments with the same no. of packages.
• If the weights are also the same, preference should be given to the shipment which can be delivered first. (Shortest Distance).
• Always travelling at max speed.
• Post package delivery, vehicle will return back to the source station with the same speed and will be available for another shipment.
• All input numbers will be whole numbers (Number of Vehicles, Max Speed, Max Weight).
• Round Of estimated delivery time up to 2 digits. (for example 3.456 becomes 3.45) (Truncate).

Additional Acceptance Criteria

• Expansion : If offer code is not valid/found, discounted amount will be equal to 0 (Application: Invalid / Can not be found). OR Discount will not be provided if no offer code is applied (User : Did not provide).
• Expansion : Round Of estimated delivery time up to 2 digits. (for example 3.456 becomes 3.45) (Truncate). Truncate all digital Output to be consistent with the requirement.

Use Case

Actor : User

• Input Base Delivery Cost, Number of Packages.
• Input Package ID, Package Weight in Kg, Distance in Km, Offer Code (If applicable).
• Input No. of Vehicles, Max speed, Max (L) Weight.

Actor : Application

• Output directives.
• Validate Input Base Delivery Cost, Number of Packages.
• Validate Input Package ID, Package Weight in Kg, Distance in Km, Offer Code (If applicable).
• Validate Input No. of Vehicles, Max speed, Max (L) Weight.
• Output Error (If applicable).
• Validate Offer Criteria.
• Estimate the total delivery cost of each package with an offer code (If applicable).
• Validate Deliver Criteria.
• Calculate the estimated delivery time for every package by maximizing no. of packages in every shipment.

Edge Cases

• User input leading or/and trailing whitespace/s.
• User input duplicate packages identified by package ID.
• User input N number of packages more than N number of vehicles to deliver, Calculate util all undelivered packages delivery time is update.
• User input 30 number of packages more than 2 number of vehicle to deliver, Stress test the application to take more.

Assumptions

• No use of threading given it's a Small Distance Courier Service for I/O.
• Since the loading is sequential by direct input one line at a time, it is not expected for a user to input hundreds of lines.
• No use of set, to keep the packages in order, Sets have no inherent order, while ArrayLists maintain the order of elements, Adding elements to a set may not preserve the insertion order. ArrayLists provide constant time access to elements using their index, while accessing elements in a set is typically done through iteration.
• No use of interface contracts instead opt for use case classes over interface contracts to minimize implementation overhead, particularly when a single class requires multiple interfaces. This approach also reduces over-engineering, preventing unnecessary complexity in the codebase.
• No use nor expression of DTO, DAO as the application lacks network and database functionalities.