initial structure - reads cli arguments

cmd/buckets-of-fun/main.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+
+	"git.buddy.wtf/challenges/buckets-of-fun/lib/application"
+)
+
+func main() {
+	if err := run(); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
+
+func run() error {
+	flag.Parse()
+	app, err := application.New(flag.Args()...)
+	if err != nil {
+		return err
+	}
+	return app.Run()
+}

go.mod

@@ -0,0 +1,3 @@
+module git.buddy.wtf/challenges/buckets-of-fun
+
+go 1.13

lib/application/app.go

@@ -0,0 +1,51 @@
+package application
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+
+	"git.buddy.wtf/challenges/buckets-of-fun/lib/bucket"
+)
+
+// App holds context for the application
+type App struct {
+	Target  uint64
+	Buckets []bucket.Bucket
+}
+
+// New returns an instance of the app
+func New(args ...string) (*App, error) {
+	if len(args) < 2 {
+		msg := fmt.Sprintf("usage error: requires at least 2 arguments, received %d", len(args))
+		return nil, errors.New(msg)
+	}
+	target, err := strconv.ParseUint(args[0], 10, 64)
+	if err != nil {
+		return nil, errors.New("target must be a positive integer: " + err.Error())
+	}
+
+	app := App{
+		Target:  target,
+		Buckets: []bucket.Bucket{},
+	}
+
+	for _, arg := range args[1:] {
+		capacity, err := strconv.ParseUint(arg, 10, 64)
+		if err != nil {
+			return nil, errors.New("bucket capacity must be a positive integer: " + err.Error())
+		}
+		app.Buckets = append(app.Buckets, bucket.Bucket{Capacity: capacity})
+	}
+
+	return &app, nil
+}
+
+// Run runs the application
+func (a *App) Run() error {
+	fmt.Printf("target: %d\n", a.Target)
+	for i, bucket := range a.Buckets {
+		fmt.Printf("bucket %d: %d\n", i+1, bucket.Capacity)
+	}
+	return nil
+}

lib/bucket/bucket.go

@@ -0,0 +1,9 @@
+package bucket
+
+// Bucket to store volume
+type Bucket struct {
+	// Capacity amount the bucket can store
+	Capacity uint64
+	// Volume is the current volume of the bucket
+	Volume uint64
+}