About

Web API for measuring distance between two airports using CTeleport API. API has the only endpoint where IATA codes should be passed.

Launch

You can launch it by docker:

• go to command prompt;
• cd to root directory of the solution (where is docker-compose file located);
• write docker compose up;
• go to localhost:5051/swagger.

Internal design

Solution represents clean architecture.

Solution contains 4 projects:

• API - has queries/commands implementation, controllers, DI container;
• Application - business-logic. Contains query-handlers, validators, pipelines. Also contains contracts for anti-corruption layer;
• CTeleportClient - encapsulates interaction with external system. Implements contracts for anti-corruption layer. As we use only GET-request - it's enough to retry requests. We don't have need to handle idempotency. So i implemented retry policy by Polly.
• CacheClient - encapsulates interaction with cache. Use distributed redis-caching.

Request-flow

• request arrives in controller and it sends it to mediator where the request is validated by validator;
  • if request has some errors - validator throws exception which is intercepted in middleware and converts it to specific HTTP status-code (this logic is implemented in AirportControl.API.ServiceCollectionExtensions);
  • if everything is ok we get into GetDistanceQueryHandler;
• then we call CTeleportProvider which take data from cache or goes to third-party API:
  • if cache contains such key we read data from cache and immediately give it to Application layer;
  • if cache doesn't contain such key we go further and call third-party API.
• then we calculate distance between airports by there location. We do it in use-case. As an improvement we can allocate calculating code to another service. It will fit if we will have multiple use-cases that need to calculate distance between two points;
• than we save calculated value to cache and return to consumer.