package localapi

import (
	"context"
	"net/http"
	"sync"
	"testing"
	"time"

	"gitea.dooplex.hu/admin/felhom-agent/internal/backup"
)

// The OS leg (agent v0.140.0) runs after a SUCCESSFUL primary backup, and only then; and it runs BEFORE the
// host-wide heavy-op gate is released, so a restore-test cannot start in the middle of it (`11` C10).
// Red-proof: drop the `b.Success &&` guard and the failed-backup sub-case fails; move the call after release()
// and the gate sub-case fails.
func TestAfterPrimaryBackup(t *testing.T) {
	run := func(t *testing.T, failErr string) (calls []int, gateHeld bool) {
		gate := &backup.InFlight{}
		b := &fakeBackups{failErr: failErr}
		srv := newTestServerS(t, &fakeGuests{}, b, &fakeStore{}, nil)
		srv.inFlight = gate
		var mu sync.Mutex
		done := make(chan struct{}, 1)
		srv.SetAfterPrimaryBackup(func(_ context.Context, vmid int) {
			rel, _, ok := gate.TryAcquire("probe")
			mu.Lock()
			calls = append(calls, vmid)
			gateHeld = !ok
			mu.Unlock()
			if ok {
				rel()
			}
			done <- struct{}{}
		})
		h := srv.Handler()
		if do(t, h, "POST", "/backup", "A", "").Code != http.StatusAccepted {
			t.Fatal("POST /backup not accepted")
		}
		select {
		case <-done:
		case <-time.After(500 * time.Millisecond):
		}
		time.Sleep(20 * time.Millisecond)
		mu.Lock()
		defer mu.Unlock()
		return calls, gateHeld
	}
	t.Run("success runs the leg under the gate", func(t *testing.T) {
		calls, held := run(t, "")
		if len(calls) != 1 {
			t.Fatalf("the leg ran %d time(s), want 1", len(calls))
		}
		if !held {
			t.Fatal("the heavy-op gate was free while the leg ran — a restore-test could overlap it")
		}
	})
	t.Run("a failed backup runs nothing", func(t *testing.T) {
		if calls, _ := run(t, "vzdump exploded"); len(calls) != 0 {
			t.Fatalf("the leg ran after a FAILED backup: %v", calls)
		}
	})
}