Delivery shell app

Computes discount
Computes discount along with est delivery time
Validate offers schema

Structuring

Services

Uses go way of designing services (DI) using Hexagonal architecture.

Offer service : Offer service is responsible for applying offer discount amount when meets the expected criteria.
Delivery Service: Delivery service responsible for computing delivery cost and applies offer discount if applicable by using offer service
Total delivery cost can be computed using method available on PackageDetails, so that all computation logic will be at one place (The better way could be have its own service).

📦 services
 ┣ 📂 delivery_svc
 ┃ ┣ 📜 default_svc.go
 ┃ ┗ 📜 delivery_svc.go
 ┣ 📂 offers_svc
 ┃ ┣ 📜 default_svc.go
 ┃ ┗ 📜 offers_svc.go
 ┗ 📂 shell_io_svc
 ┃ ┣ 📜 default_svc.go
 ┃ ┗ 📜 shell_io_svc.go

Models

The domain models

📦 models
 ┣ 📜 offers.go
 ┣ 📜 package_details.go
 ┣ 📜 package_stats.go
 ┗ 📜 vehicles.go

Clients

Write your own client

📦 clients
 ┣ 📜 base_client.go
 ┣ 📜 shell_client.go

Managing Offers

We have created a schema to validate whether give offer is valid or applicable.

type Offer struct {
  Code       OfferCode
  Conditions []Condition
  Discount   float64
}

Maintains a list of offers in offers.json file, which adheres to schema defined above. We can add any no of offers or remove existing ones from offers.json. The modifications to offers.json file wont require any other code changes. We can keep this offers.json in a database for maintainability and ease of deployments.

Schema definition

The current implementation calculates discount when all conditions specified for the offer code are met.

Facts

Fact	Data type
distance	decimal or integer
weight	decimal or integer

Operators

Operator	effect
lessThan	<
greaterThanOrEqual	<
lessThanOrEqual	<

scripts directory

Validates offers.json schema

 📦scripts
 ┣ 📂 src
 ┣ 📜 package.json
 ┗ 📜 tsconfig.json

Validating offers schema

Make sure to setup
Navigate to scripts directory
Install dependencies
```
  yarn setup
```
Validate offers.json data (format)
```
  yarn validate
```

Development & Testing

Developing

make dev

Build

This works for osx (Mac), for other operating system, refer to this doc.

# Build
make build
# Run app
make start

Sample (1) Input & Output

    100 3
    pkg1 5 5 OFR001
    pkg2 15 5 OFR002
    pkg3 10 100 OFR003
    2 70 200

    pkg1 0.00 175.00
    pkg2 0.00 275.00
    pkg3 35.00 665.00

Sample (2) Input & Output

    100 5
    PKG1 50 30 OFR001
    PKG2 75 125 OFR002
    PKG3 175 100 OFR008
    PKG4 110 60 OFR002
    PKG5 155 95 NA
    2 70 200

Sample (3) Input & Output

    100 7
    PKG1 3 30 OFR001
    PKG2 2 125 OFR002
    PKG3 3 100 OFR008
    PKG4 4 60 OFR002
    PKG5 1 95 NA
    PKG6 5 95 NA
    PKG7 6 95 NA
    2 70 6

Testing

make test
make coverage

Lint

Install golangci-lint. Refer Local Installation for installing.

make lint

TODO

CI/CD
There scope for improvement interns (bigO - knapsack)

lakshmaji/delivery-shell