//go:build integration

package link_test

import (
	"context"
	"testing"

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

func anOrderedMachine(t *testing.T) (*inventory.Inventory, link.Enrolment, string) {
	t.Helper()
	inv := inventory.ForTest(t)
	node, err := inv.AddNode(context.Background(), "home-server")
	if err != nil {
		t.Fatal(err)
	}
	return inv, link.Enrolment{Inventory: inv}, node.ID
}

func TestAnAccountOfAnOlderDeclarationIsRefusedByItsSequence(t *testing.T) {
	inv, heard, id := anOrderedMachine(t)
	ctx := context.Background()
	before := countFor(link.WriterNodeEngine("home-server"))
	if _, err := heard.Heard(ctx, ordered("d12", 57, 12, 41, "a", "b")); err != nil {
		t.Fatal(err)
	}
	if _, err := heard.Heard(ctx, ordered("d11", 57, 11, 40, "a")); err != nil {
		t.Fatal(err)
	}
	doing, _, err := inv.DoingOf(ctx, "home-server")
	if err != nil || doing.Declared != "d12" || doing.Applied != 2 {
		t.Fatalf("the older account replaced the newer: %+v (%v)", doing, err)
	}
	if got := countFor(link.WriterNodeEngine("home-server")) - before; got != 1 {
		t.Fatalf("the refusal was counted %d times, want once", got)
	}
	kept, err := inv.KeptOrder(ctx, id)
	if err != nil || kept != (inventory.ReportOrder{Epoch: 57, Sequence: 12, ReportSequence: 41}) {
		t.Fatalf("the order kept is %+v (%v)", kept, err)
	}
}

func TestAnOlderReportOfTheSameDeclarationIsRefused(t *testing.T) {
	inv, heard, _ := anOrderedMachine(t)
	ctx := context.Background()
	if _, err := heard.Heard(ctx, ordered("d12", 57, 12, 41, "a", "b")); err != nil {
		t.Fatal(err)
	}
	failed := ordered("d12", 57, 12, 40)
	failed.Failed = map[string]string{"b": "it failed a moment before it applied"}
	if _, err := heard.Heard(ctx, failed); err != nil {
		t.Fatal(err)
	}
	doing, _, _ := inv.DoingOf(ctx, "home-server")
	if doing.Outcome != inventory.OutcomeApplied {
		t.Fatalf("an older report of the same declaration replaced the newer: %+v", doing)
	}
	// A newer report of it — the next reconcile — is kept.
	again := ordered("d12", 57, 12, 42)
	again.Failed = map[string]string{"b": "it failed since"}
	if _, err := heard.Heard(ctx, again); err != nil {
		t.Fatal(err)
	}
	if doing, _, _ := inv.DoingOf(ctx, "home-server"); doing.Outcome != inventory.OutcomeFailed {
		t.Fatalf("a newer report of the same declaration was not kept: %+v", doing)
	}
}

func TestAnOrderedAccountIsNotJudgedByTheDigestSent(t *testing.T) {
	inv, heard, id := anOrderedMachine(t)
	ctx := context.Background()
	if err := inv.RecordSent(ctx, id, "d13", nil); err != nil {
		t.Fatal(err)
	}
	if _, err := heard.Heard(ctx, ordered("d12", 57, 12, 41, "a")); err != nil {
		t.Fatal(err)
	}
	if doing, said, _ := inv.DoingOf(ctx, "home-server"); !said || doing.Declared != "d12" {
		t.Fatalf("the newest account the machine gave was set aside by the digest: %+v", doing)
	}
	// And the machine reads an epoch: it orders its reports.
	if reads, err := inv.ReadsEpoch(ctx, id); err != nil || !reads {
		t.Fatalf("a machine whose reports carry a report sequence is not recorded as reading an epoch: %v", err)
	}
}

func TestAnUnorderedAccountClearsTheOrderAndTheEpoch(t *testing.T) {
	inv, heard, id := anOrderedMachine(t)
	ctx := context.Background()
	if _, err := heard.Heard(ctx, ordered("d12", 57, 12, 41, "a")); err != nil {
		t.Fatal(err)
	}
	if err := inv.RecordSent(ctx, id, "d13", nil); err != nil {
		t.Fatal(err)
	}
	if _, err := heard.Heard(ctx, link.Report{Node: "home-server", Declared: "d13", Applied: []string{"a", "b"}}); err != nil {
		t.Fatal(err)
	}
	if doing, _, _ := inv.DoingOf(ctx, "home-server"); doing.Declared != "d13" {
		t.Fatalf("an older node-engine's account of what was sent was not kept: %+v", doing)
	}
	if kept, _ := inv.KeptOrder(ctx, id); kept != (inventory.ReportOrder{}) {
		t.Fatalf("an unordered account left the order kept: %+v", kept)
	}
	if reads, _ := inv.ReadsEpoch(ctx, id); reads {
		t.Fatal("a node-engine that orders nothing is still sent an epoch")
	}
	// The next ordered account, whatever its numbers, has nothing to be older than.
	if _, err := heard.Heard(ctx, ordered("d14", 58, 14, 1, "a")); err != nil {
		t.Fatal(err)
	}
	if doing, _, _ := inv.DoingOf(ctx, "home-server"); doing.Declared != "d14" {
		t.Fatalf("the first ordered account after an unordered one was refused: %+v", doing)
	}
}