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.Buckets
}

// 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.Buckets{},
	}

	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)
	fmt.Printf("buckets: %s\n", a.Buckets.String())
	for _, solution := range a.Buckets.FindTarget((a.Target)) {
		fmt.Println(solution)
	}
	return nil
}