package host

import (
	"context"
	"os"
	"strings"
	"testing"

	"github.com/carlosframework/platform/internal/hostclaim"
	"github.com/carlosframework/platform/internal/hostguard"
	"github.com/carlosframework/platform/internal/release"
)

type retiredReceiptLockStore struct {
	*rollbackDisk
	held bool
}

func (s *retiredReceiptLockStore) Lock(context.Context, string) (func(), error) {
	if s.held {
		return nil, os.ErrPermission
	}
	s.held = true
	return func() { s.held = false }, nil
}

func TestPlan14GenerationRetirementReceiptLockOrder(t *testing.T) {
	f, disk, _ := generationLaunchFixture(t)
	in, err := f.root.Guard.Root.Installation(t.Context(), f.target.Host, hostguard.Captured{Incarnation: f.target.Incarnation, Stamp: f.target.Stamp})
	if err != nil {
		t.Fatal(err)
	}
	state := &retiredReceiptLockStore{rollbackDisk: &rollbackDisk{dir: t.TempDir()}}
	f.root.Guard.Root = hostguard.NewRootAuthority(state)
	if err := f.root.Guard.EstablishRoot(t.Context(), in, func(*hostclaim.Claim) error { return nil }); err != nil {
		t.Fatal(err)
	}
	if _, err := f.root.Serve(t.Context(), f.peer, f.req); err != nil {
		t.Fatal(err)
	}
	r := readGenerationLaunch(t, disk)
	if err := f.root.stop(t.Context(), f.peer, *f.req.Reservation); err != nil {
		t.Fatal(err)
	}
	if err := f.journal.CloseWriters(t.Context(), f.target); err != nil {
		t.Fatal(err)
	}
	calls := 0
	v := generationRetirement{guard: f.root.Guard, journal: f.journal, kernel: func(context.Context, release.GenerationReservation) (string, error) { return "", os.ErrPermission }, retiredKernel: func(_ context.Context, _ release.GenerationReservation, view hostguard.FenceView) (string, error) {
		if !state.held || view.Host != f.target.Host {
			t.Fatal("retirement verification escaped exclusion")
		}
		calls++
		return strings.Repeat("a", 64), nil
	}}
	if err := v.retire(t.Context(), &release.RootGenerations{Store: disk}, r); err != nil {
		t.Fatal(err)
	}
	if calls != 1 || state.held {
		t.Fatalf("verification calls=%d lock=%v", calls, state.held)
	}
}