Small Go HTTP API demonstrating a minimal service structure using chi router, middleware, and a mock database.

• Module: github.com/jetqin/goapi
• Entry: cmd/api/main.go
• Router: github.com/go-chi/chi
• Logger: github.com/sirupsen/logrus
• ASCII banner printed with github.com/common-nighthawk/go-figure
• Mock database in internal/tools/mockdb.go

• cmd/api/main.go — application entrypoint; sets up router and prints banner.
• api/api.go — small HTTP response helpers and error types.
• internal/handlers/ — HTTP handlers (e.g. GetCoinBalance).
• internal/middleware/ — middleware (authorization, logger).
• internal/tools/ — mock database and supporting types.

• Handlers register routes via handlers.RegisterHandlers(r).
• Middleware chain includes request logging and an authorization check that validates username (query) and Authorization header.
• tools.NewDatabaseInterface() returns a mock DatabaseInterface backed by mockDB implemented in internal/tools/mockdb.go.

1. Ensure dependencies are present (Go >= 1.25 recommended):

cd /path/to/goapi
go get ./...

2. Run the server:

go run cmd/api/main.go

3. Example request (valid credentials present in mock data):

curl -i 'http://localhost:8080/account/coins?username=alex' -H 'Authorization:123ABC'

Expected JSON response:

{"Code":200,"Balance":100}

• GET /account/coins?username={username}
  • Headers: Authorization: <token>
  • Success: 200 with CoinBalanceResponse JSON
  • Errors: 400/500 with Error JSON

• Address already in use: another process is listening on port 8080. Find and kill it, or change the port.
  • macOS example: lsof -i :8080 -sTCP:LISTEN then kill <PID>
• Wrong path: the current handler uses /account/coins (plural). If you hit /account/coin you'll get 404.
• Missing header/query: Authorization header and username query must be present. The middleware returns 400 for missing/invalid credentials.
• Dependencies: run go get to ensure third-party modules are installed.

• The project uses an in-memory mock DB for demo; swap mockDB for a real DB client by implementing DatabaseInterface.
• Consider adding an alias route for /account/coin if backward compatibility is required.
• Add unit tests for handlers and middleware.

For further changes, update the handlers in internal/handlers or the mock data in internal/tools/mockdb.go.