package resolution

import (
	"strings"
	"testing"

	mcat "git.novox.be/novox/mesh-sdk/go/catalogue"
)

func busSeatDelivering(t *testing.T, delivers string) {
	t.Helper()
	was := mcat.Seats()
	t.Cleanup(func() { mcat.UseSeats(was) })
	mcat.UseSeats([]mcat.Seat{{Name: "mesh-broker", Scope: mcat.ScopeMesh, Delivers: delivers, Decision: "test"}})
}

func oldBroker() mcat.Manifest {
	return mcat.Manifest{Module: "old-broker", Provides: []mcat.Offer{{Name: "mesh-bus", Scope: mcat.ScopeMesh}},
		Claims: []mcat.Claim{{Name: "mesh-broker", Scope: mcat.ScopeMesh}}}
}

func newBroker() mcat.Manifest {
	return mcat.Manifest{Module: "new-broker", Provides: []mcat.Offer{{Name: "mesh-bus", Scope: mcat.ScopeMesh}},
		Claims: []mcat.Claim{{Name: "mesh-broker", Scope: mcat.ScopeMesh}}}
}

// Nothing on record: exactly the old rule. One claimant holds; two are refused.
func TestWithNoHolderOnRecordTheSoleClaimantHoldsAndTwoAreRefused(t *testing.T) {
	busSeatDelivering(t, "mesh-bus")
	node := mcat.Node{Name: "anchor"}

	held, problems := checkClaims([]mcat.Manifest{oldBroker()}, node, nil, nil)
	if len(problems) != 0 || len(held) != 1 || held[0].Module != "old-broker" {
		t.Fatalf("a sole claimant did not hold the seat: held=%v problems=%v", held, problems)
	}
	_, problems = checkClaims([]mcat.Manifest{oldBroker(), newBroker()}, node, nil, nil)
	if len(problems) != 1 || !strings.Contains(problems[0], "both claim") {
		t.Fatalf("two claimants with nothing on record were not refused: %v", problems)
	}
}

// With a holder on record, the other eligible assignment is silent: not refused, and not holding.
func TestTheHolderOnRecordHoldsAndTheOtherClaimantStandsBesideIt(t *testing.T) {
	busSeatDelivering(t, "mesh-bus")
	node := mcat.Node{Name: "anchor"}
	record := []mcat.Held{{Claim: "mesh-broker", Scope: mcat.ScopeMesh, Node: "anchor", Module: "new-broker"}}

	held, problems := checkClaims([]mcat.Manifest{oldBroker(), newBroker()}, node, nil, record)
	if len(problems) != 0 {
		t.Fatalf("the assignment beside the holder was refused: %v", problems)
	}
	if len(held) != 1 || held[0].Module != "new-broker" {
		t.Fatalf("the holder on record is not the one holding: %v", held)
	}
}

// The record names a node too: an eligible module on another machine holds nothing, and its
// machine's set still resolves.
func TestAHolderOnRecordElsewhereLeavesThisMachinesClaimantSilent(t *testing.T) {
	busSeatDelivering(t, "mesh-bus")
	record := []mcat.Held{{Claim: "mesh-broker", Scope: mcat.ScopeMesh, Node: "anchor", Module: "new-broker"}}

	held, problems := checkClaims([]mcat.Manifest{oldBroker()}, mcat.Node{Name: "laptop"}, nil, record)
	if len(problems) != 0 || len(held) != 0 {
		t.Fatalf("a claimant elsewhere than the recorded holder was not simply silent: held=%v problems=%v",
			held, problems)
	}
}

// A machine being moved is handed its membership for the new bus as a sealed file in its own
// declaration — the machine's, not any module's (design 28, task 5.2).
func TestAMembershipForTheNewBusIsComposedAsASealedFile(t *testing.T) {
	r := mcat.Resolution{Node: "anchor"}
	got, err := Compose(r, mcat.Rendering{BusMembership: "sealed-blob"})
	if err != nil {
		t.Fatal(err)
	}
	var found map[string]any
	for _, res := range got.Resources {
		if res["id"] == BusMembershipID() {
			found = res
		}
	}
	if found == nil {
		t.Fatalf("no membership resource in %v", got.Resources)
	}
	if found["path"] != mcat.BusMembershipPath || found["sealed"] != "sealed-blob" || found["mode"] != "0600" {
		t.Fatalf("the membership is not a sealed 0600 file where the host reads it: %v", found)
	}
	// And a machine not being moved is handed nothing.
	got, _ = Compose(r, mcat.Rendering{})
	for _, res := range got.Resources {
		if res["id"] == BusMembershipID() {
			t.Fatal("a machine with no membership on record was handed one")
		}
	}
}

func TestARefusalWithNothingOnRecordNamesTheHandover(t *testing.T) {
	busSeatDelivering(t, "mesh-bus")
	elsewhere := []mcat.Held{{Claim: "mesh-broker", Scope: mcat.ScopeMesh, Node: "anchor", Module: "old-broker"}}

	_, problems := checkClaims([]mcat.Manifest{newBroker()}, mcat.Node{Name: "laptop"}, elsewhere, nil)
	if len(problems) != 1 {
		t.Fatalf("two derived claimants across machines were not refused: %v", problems)
	}
	if !strings.Contains(problems[0], "`seat mesh-broker --to anchor/old-broker`") {
		t.Fatalf("the refusal does not name the handover that records the holder: %s", problems[0])
	}
}