package main

import (
	"bytes"
	"strings"
	"testing"
	"time"

	"github.com/novox/mesh-controller/internal/catalogue"
	"github.com/novox/mesh-controller/internal/link"
)

// The live case of 2026-10-07, 20:27 UTC: a person's `push` of one machine moved mail to a new build whose
// automx container had a new image, and recreated it; the push's answer said nothing of it. The push now
// says, per machine, every module it moves and what that recreates — before it is sent. A module whose
// build did not change, and one new to the machine, are not moves.
func TestAPushSaysWhatItRecreates(t *testing.T) {
	open := aMesh(t)
	ctx := t.Context()
	inv := open.inventory
	start := time.Now().Add(-time.Hour)
	image := func(c string) string { return "registry.invalid:5000/mailu/x@sha256:" + strings.Repeat(c, 64) }
	for _, b := range []link.BuildResult{
		aContainerBuild(t, "mailu", "c74f407a", catalogue.PolicyRecord, start,
			map[string][2]string{"smtp": {image("a"), ""}, "automx": {image("c"), ""}}),
		aContainerBuild(t, "postgres", "c1111111", "", start.Add(time.Second),
			map[string][2]string{"server": {image("e"), ""}}),
	} {
		if _, _, err := takeIn(ctx, inv, b); err != nil {
			t.Fatal(err)
		}
	}
	for _, m := range []string{"mailu", "postgres"} {
		if _, err := inv.Assign(ctx, "anchor", m); err != nil {
			t.Fatal(err)
		}
	}
	if err := inv.RecordSent(ctx, nodeID(t, open, "anchor"), "d-anchor",
		map[string]string{"mailu": "c74f407a", "postgres": "c1111111"}); err != nil {
		t.Fatal(err)
	}
	// Mail's new build: automx's image changes, smtp's does not.
	if _, _, err := takeIn(ctx, inv, aContainerBuild(t, "mailu", "1ab84e69", catalogue.PolicyRecord,
		start.Add(time.Minute), map[string][2]string{"smtp": {image("a"), ""}, "automx": {image("d"), ""}})); err != nil {
		t.Fatal(err)
	}

	// Composed as a person's push composes it.
	plan, settings, err := planFor(ctx, open, "anchor")
	if err != nil {
		t.Fatal(err)
	}
	gens, err := generators(ctx, open)
	if err != nil {
		t.Fatal(err)
	}
	declared, err := declarationWith(ctx, open, "anchor", plan, settings, gens, Allocating)
	if err != nil {
		t.Fatal(err)
	}
	if declared.Builds["mailu"] != "1ab84e69" {
		t.Fatalf("a person's push carries mail at %q", declared.Builds["mailu"])
	}

	var said bytes.Buffer
	sayWhatAPushRecreates(ctx, open, []readyNode{{node: "anchor", declared: declared}}, &said)
	out := said.String()
	for _, want := range []string{"anchor moves 1 module(s)", "mailu", "c74f407a → 1ab84e69",
		"recreates 1 of mailu's 2 container(s) (with a new image: automx)"} {
		if !strings.Contains(out, want) {
			t.Fatalf("the push says %q; it does not say %q", out, want)
		}
	}
	if strings.Contains(out, "postgres") {
		t.Fatalf("a module whose build did not change is said to move: %q", out)
	}

	// A machine never sent anything before has no moves to say.
	said.Reset()
	sayWhatAPushRecreates(ctx, open, []readyNode{{node: "laptop", declared: declared}}, &said)
	if said.Len() != 0 {
		t.Fatalf("a machine with no last send is said to move: %q", said.String())
	}
}