package backpack_test

import (
	"fmt"

	"git.golem15.com/golem15/summercms/modules/backpack"
	"git.golem15.com/golem15/summercms/modules/compass"
)

// Greeter is a service the acme.greeter plugin offers to other plugins.
type Greeter interface {
	Greet(name string) string
}

type englishGreeter struct{}

func (englishGreeter) Greet(name string) string { return "Hello, " + name }

func ExampleApp_Publish() {
	app := backpack.New(&compass.Config{})
	app.SetPlugins([]string{"acme.greeter", "acme.blog"})

	// acme.greeter, in its Register step: publish under the interface type.
	var greeter Greeter = englishGreeter{}
	if err := app.Publish(greeter); err != nil {
		fmt.Println(err)
		return
	}

	// acme.blog, in its Boot step: look the service up by the same type.
	if app.HasPlugin("acme.greeter") {
		if found, ok := app.Lookup[Greeter](); ok {
			fmt.Println(found.Greet("blog"))
		}
	}

	// A second Publish under the same type is refused.
	fmt.Println(app.Publish(greeter) != nil)
	// Output:
	// Hello, blog
	// true
}