morning-coffee/app.go

package main

import (
	"fmt"
	"log/slog"
	"net/http"
	"time"
)

type Route struct {
	Path    string
	Handler http.HandlerFunc
}

type BackgroundTask struct {
	Handler  func()
	Interval time.Duration
}

type App struct {
	Routes          []Route
	BackgroundTasks []BackgroundTask
	StaticRoot      string
}

func LoggingMiddleware(f http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		start := time.Now()
		f(w, r)
		slog.Info(fmt.Sprintf("%s - %s (%dms)", r.Method, r.URL, time.Now().Sub(start).Milliseconds()))
	}
}

func (a App) Start(addr string) {
	for _, route := range a.Routes {
		http.HandleFunc(route.Path, LoggingMiddleware(route.Handler))
	}

	if a.StaticRoot != "" {
		http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir(a.StaticRoot))))
	}

	for _, task := range a.BackgroundTasks {
		go func() {
			for {
				task.Handler()
				time.Sleep(task.Interval)
			}
		}()
	}

	http.ListenAndServe(addr, nil)
}

func (a *App) AddRoute(path string, handler http.HandlerFunc) {
	a.Routes = append(a.Routes, Route{Path: path, Handler: handler})
}

func NewApp(routes map[string]http.HandlerFunc, backgroundTasks []BackgroundTask, staticRoot string) *App {
	app := App{StaticRoot: staticRoot, BackgroundTasks: backgroundTasks}

	for route, handler := range routes {
		app.AddRoute(route, handler)
	}

	return &app
}