package main

import (

"binary-tree/handlers"

"flag"

"fmt"

"log"

"net/http"

)

var port int

func initConfig() {

// Define the port flag

flag.IntVar(&port, "port", 8080, "HTTP server port")

// Parse the flags

flag.Parse()

}

func main() {

initConfig()

mux := http.NewServeMux()

// add calculation endpoint

mux.HandleFunc("/calculate", handlers.CalculationHandler)

address := fmt.Sprintf(":%d", port)

log.Printf("Server started, listening on port %d\n", port)

panic(http.ListenAndServe(address, RecoveryMiddleware(mux)))

}

// RecoveryMiddleware is an HTTP middleware that recovers gracefully

// from panics in the HTTP handlers down the chain. Instead of crashing the server,

// it logs the error and responds with a generic "Internal server error" message.

func RecoveryMiddleware(next http.Handler) http.Handler {

return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

defer func() {

if err := recover(); err != nil {

log.Printf("Recovered from panic: %v", err)

// Send a generic server error message to the client

http.Error(w, "Internal server error", http.StatusInternalServerError)

}

}()

next.ServeHTTP(w, r)

})

}