package main

import (
	"bytes"
	"io"
	"os"
	"strings"
	"testing"

	"github.com/novox/mesh-controller/internal/inventory"
)

// "4 machine(s), all doing what they were told, all heard from, running what the mesh would send
// them, and every module current with its source" was true for eleven hours of a mesh in which no
// module could reach another (novox/hq 04-ISSUES/145). Every question it answers is about the mesh
// and a machine agreeing; none of them dials anything.

// printed captures what a function writes to stdout.
func printed(t *testing.T, f func() error) string {
	t.Helper()
	old := os.Stdout
	r, w, err := os.Pipe()
	if err != nil {
		t.Fatal(err)
	}
	os.Stdout = w
	runErr := f()
	_ = w.Close()
	os.Stdout = old
	var buf bytes.Buffer
	if _, err := io.Copy(&buf, r); err != nil {
		t.Fatal(err)
	}
	if runErr != nil {
		t.Fatal(runErr)
	}
	return buf.String()
}

func TestTheAllWellSentenceSaysWhatItDoesNotCover(t *testing.T) {
	// A mesh with nothing to say. The sentence below was true of a mesh in which no module could
	// reach another, for eleven hours.
	got := printed(t, func() error {
		return printStatus(answers{nodes: []inventory.Node{{Name: "anchor"}, {Name: "laptop"}}})
	})
	if !strings.Contains(got, "all doing what they were told") {
		t.Fatalf("a mesh with nothing to say did not print the all-well sentence:\n%s", got)
	}
	// And now says what it is not a claim about.
	for _, want := range []string{"Nothing here dials a provision", "04-ISSUES/145"} {
		if !strings.Contains(got, want) {
			t.Fatalf("the all-well sentence does not say %q:\n%s", want, got)
		}
	}
}

func TestAMeshWithSomethingToSayDoesNotPrintTheScopeLine(t *testing.T) {
	// The scope belongs to the all-well sentence. A mesh with something wrong has specific things to
	// read, and appending a caveat to those is noise.
	got := printed(t, func() error {
		return printStatus(answers{
			nodes:   []inventory.Node{{Name: "anchor"}},
			untaken: map[string]map[string]int{"anchor": {"route-proxy": 3}},
		})
	})
	if strings.Contains(got, "Nothing here dials a provision") {
		t.Fatalf("a mesh with a held module printed the all-well scope line:\n%s", got)
	}
	if strings.Contains(got, "all doing what they were told") {
		t.Fatalf("a mesh with a held module printed the all-well sentence:\n%s", got)
	}
	if !strings.Contains(got, "route-proxy") {
		t.Fatalf("the held module is not named:\n%s", got)
	}
}