package main

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
)

// Where a builder publishes.
//
// Preferably from the mesh: a builder that is a module requires an artifact store, and the mesh
// writes it a binding saying which machine answers and on what port. Reading it means the address
// is not a setting somebody keeps in step by hand.

func binding(t *testing.T, body string) string {
	t.Helper()
	path := filepath.Join(t.TempDir(), "artifact-store.json")
	if err := os.WriteFile(path, []byte(body), 0o644); err != nil {
		t.Fatal(err)
	}
	return path
}

func TestTheMeshSaysWhereToPublish(t *testing.T) {
	t.Setenv("MESH_BINDING", binding(t, `{"binding":1,"provision":"artifact-store",
		"from":"anchor","at":"anchor.internal","serves":{"port":5000,"scheme":"http"}}`))
	where, err := whereToPublish()
	if err != nil {
		t.Fatal(err)
	}
	if where != "anchor.internal:5000" {
		t.Fatalf("got %q", where)
	}
}

func TestABindingWithNoAddressIsRefused(t *testing.T) {
	// The provider is not on the private network, so there is no name to reach it by. Falling
	// back to anything would publish to a store on the wrong machine and be found out much later.
	t.Setenv("MESH_BINDING", binding(t, `{"binding":1,"from":"anchor","serves":{"port":5000}}`))
	_, err := whereToPublish()
	if err == nil {
		t.Fatal("a binding with nowhere to reach was accepted")
	}
	if !strings.Contains(err.Error(), "anchor") {
		t.Fatalf("the failure does not name the machine: %v", err)
	}
}

func TestABindingWithNoPortIsRefused(t *testing.T) {
	t.Setenv("MESH_BINDING", binding(t, `{"binding":1,"from":"a","at":"a.internal","serves":{}}`))
	if _, err := whereToPublish(); err == nil {
		t.Fatal("a binding saying nothing about a port was accepted")
	}
}

func TestTheVariableStillWorksForABuilderRunByAPerson(t *testing.T) {
	// Which is how this started and how it is still run while being developed.
	t.Setenv("MESH_BINDING", "")
	t.Setenv("MESH_REGISTRY", "127.0.0.1:5000")
	where, err := whereToPublish()
	if err != nil {
		t.Fatal(err)
	}
	if where != "127.0.0.1:5000" {
		t.Fatalf("got %q", where)
	}
}

func TestNeitherIsRefusedRatherThanGuessed(t *testing.T) {
	t.Setenv("MESH_BINDING", "")
	t.Setenv("MESH_REGISTRY", "")
	if _, err := whereToPublish(); err == nil {
		t.Fatal("a builder with nowhere to publish reported somewhere")
	}
}