package kvm2

import (
	"errors"
	"slices"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/digitalocean/go-libvirt"

	"gitea.home.hrajfrisbee.cz/kacerr/egress-proxies-operator/internal/provider"
)

func TestDelete_malformedIDIsPermanent(t *testing.T) {
	t.Parallel()
	for _, id := range []string{"", "proxy-x", "hosts/beelink/proxy-x", "hosts//domains/proxy-x", "hosts/beelink/domains/"} {
		t.Run(id, func(t *testing.T) {
			t.Parallel()
			fx := newFixture(t, 1)
			err := fx.p.Delete(fx.ctx, id)
			assertProviderError(t, err, "delete", provider.ErrPermanent)
			var pe *provider.Error
			if errors.As(err, &pe) && pe.ID != id {
				t.Errorf("error.ID = %q, want %q", pe.ID, id)
			}
			if got := fx.dialer.dials.Load(); got != 0 {
				t.Errorf("dials = %d, want 0", got)
			}
		})
	}
}

func TestDelete_twiceSucceeds(t *testing.T) {
	t.Parallel()
	fx := newFixture(t, 1)
	id := fx.create(testName)
	for i := range 2 {
		if err := fx.p.Delete(fx.ctx, id); err != nil {
			t.Fatalf("Delete #%d error = %v", i+1, err)
		}
	}
	if fx.hasDomain(testName) {
		t.Error("domain still defined after Delete")
	}
	if got := fx.logs.matching("domain already gone"); len(got) != 1 {
		t.Errorf("'already gone' lines = %d, want 1 from the second Delete", len(got))
	}
	if got := fx.logs.matching("kvm2 domain deleted"); len(got) != 2 {
		t.Errorf("'deleted' lines = %d, want 2", len(got))
	}
}

func TestDelete_removesOverlayAndSeed(t *testing.T) {
	t.Parallel()
	fx := newFixture(t, 1)
	id := fx.create(testName)
	if err := fx.p.Delete(fx.ctx, id); err != nil {
		t.Fatalf("Delete() error = %v", err)
	}
	for _, name := range []string{overlayVolumeName(testName), seedVolumeName(testName)} {
		if fx.fake.vol(name) != nil {
			t.Errorf("volume %s still present after Delete", name)
		}
	}
	base := "base-" + testProvider + "-debian-13.qcow2"
	for _, name := range []string{base, base + ".sha256"} {
		if fx.fake.vol(name) == nil {
			t.Errorf("shared base volume %s removed by Delete", name)
		}
	}
}

func TestDelete_runningDomainDestroyedFirst(t *testing.T) {
	t.Parallel()
	fx := newFixture(t, 1)
	id := fx.create(testName)
	before := len(fx.fake.callLog())
	if err := fx.p.Delete(fx.ctx, id); err != nil {
		t.Fatalf("Delete() error = %v", err)
	}
	calls := fx.fake.callLog()[before:]
	destroy := slices.Index(calls, "DomainDestroy")
	undefine := slices.Index(calls, "DomainUndefineFlags")
	volDelete := slices.Index(calls, "StorageVolDelete")
	if destroy < 0 || undefine < 0 || volDelete < 0 || !(destroy < undefine && undefine < volDelete) {
		t.Errorf("call order = %v, want destroy before undefine before volume deletes", calls)
	}
	if n := strings.Count(strings.Join(calls, " "), "StorageVolDelete"); n != 2 {
		t.Errorf("StorageVolDelete calls = %d, want 2 (overlay and seed)", n)
	}
}

func TestDelete_stoppedDomainSkipsDestroy(t *testing.T) {
	t.Parallel()
	fx := newFixture(t, 1)
	id := fx.create(testName)
	fx.withDomain(testName, func(d *fakeDomain) { d.state = libvirt.DomainShutoff })
	if err := fx.p.Delete(fx.ctx, id); err != nil {
		t.Fatalf("Delete() error = %v", err)
	}
	if fx.hasDomain(testName) {
		t.Error("domain still defined after Delete")
	}
	if got := fx.logs.matching("domain not running, destroy skipped"); len(got) != 1 {
		t.Errorf("'destroy skipped' lines = %d, want 1:\n%s", len(got), strings.Join(fx.logs.all(), "\n"))
	}
	if got := fx.fake.callCount("DomainUndefineFlags"); got != 1 {
		t.Errorf("DomainUndefineFlags calls = %d, want 1", got)
	}
}

func TestDelete_toleratesMissingVolumesAndPool(t *testing.T) {
	t.Parallel()
	t.Run("domain without volumes", func(t *testing.T) {
		t.Parallel()
		fx := newFixture(t, 1)
		fx.fake.addDomain(testName, libvirt.DomainRunning, managedMetadata(testUID, time.Now()))
		if err := fx.p.Delete(fx.ctx, formatProviderID(testHost, testName)); err != nil {
			t.Fatalf("Delete() error = %v", err)
		}
		if fx.hasDomain(testName) {
			t.Error("domain still defined after Delete")
		}
		if got := fx.fake.callCount("StorageVolDelete"); got != 0 {
			t.Errorf("StorageVolDelete calls = %d, want 0 for absent volumes", got)
		}
	})
	t.Run("pool gone", func(t *testing.T) {
		t.Parallel()
		fx := newFixture(t, 1)
		fx.p.cfg.Hosts[0].Pool = "retired"
		fx.fake.addDomain(testName, libvirt.DomainShutoff, managedMetadata(testUID, time.Now()))
		if err := fx.p.Delete(fx.ctx, formatProviderID(testHost, testName)); err != nil {
			t.Fatalf("Delete() error = %v", err)
		}
		if fx.hasDomain(testName) {
			t.Error("domain still defined after Delete")
		}
		if got := fx.logs.matching("pool not found, no volumes to delete"); len(got) != 1 || !strings.Contains(got[0], `"pool"="retired"`) {
			t.Errorf("'pool not found' V(1) line = %v", got)
		}
	})
	t.Run("nothing at all", func(t *testing.T) {
		t.Parallel()
		fx := newFixture(t, 1)
		if err := fx.p.Delete(fx.ctx, formatProviderID(testHost, testName)); err != nil {
			t.Fatalf("Delete() error = %v", err)
		}
	})
}

func TestDelete_unconfiguredHostIsNoOp(t *testing.T) {
	t.Parallel()
	fx := newFixture(t, 1)
	id := formatProviderID("nas9", testName)
	if err := fx.p.Delete(fx.ctx, id); err != nil {
		t.Fatalf("Delete() error = %v, want nil", err)
	}
	if got := fx.dialer.dials.Load(); got != 0 {
		t.Errorf("dials = %d, want 0", got)
	}
	if got := fx.fake.callLog(); len(got) != 0 {
		t.Errorf("backend calls = %v, want none", got)
	}
	if got := fx.logs.matching("host is not configured; delete has nothing to clean up"); len(got) != 1 || !strings.Contains(got[0], `"host"="nas9"`) {
		t.Errorf("V(1) line = %v, want one naming the host", got)
	}
}

func TestDelete_noOpLinesAreSilentAtV0(t *testing.T) {
	t.Parallel()
	fx := newFixture(t, 0)
	fx.p.cfg.Hosts[0].Pool = "retired"
	for _, id := range []string{formatProviderID("nas9", testName), formatProviderID(testHost, testName)} {
		if err := fx.p.Delete(fx.ctx, id); err != nil {
			t.Fatalf("Delete(%s) error = %v, want nil", id, err)
		}
	}
	if lines := fx.logs.all(); len(lines) != 0 {
		t.Errorf("Delete logged %d lines at V(0), want none:\n%s", len(lines), strings.Join(lines, "\n"))
	}
}

func TestDelete_concurrentSameNameSafe(t *testing.T) {
	t.Parallel()
	fx := newFixture(t, 1)
	id := fx.create(testName)
	const n = 10
	errs := make([]error, n)
	var wg sync.WaitGroup
	for i := range n {
		wg.Add(1)
		go func() {
			defer wg.Done()
			errs[i] = fx.p.Delete(fx.ctx, id)
		}()
	}
	wg.Wait()
	for i, err := range errs {
		if err != nil {
			t.Errorf("Delete #%d error = %v, want nil", i, err)
		}
	}
	if fx.hasDomain(testName) {
		t.Error("domain still defined after concurrent Deletes")
	}
	for _, name := range []string{overlayVolumeName(testName), seedVolumeName(testName)} {
		if fx.fake.vol(name) != nil {
			t.Errorf("volume %s still present", name)
		}
	}
	if got := fx.fake.callCount("DomainUndefineFlags"); got != 1 {
		t.Errorf("DomainUndefineFlags calls = %d, want 1 (the lock serialises the rest)", got)
	}
}

func TestDelete_undefineUsesNvramFlag(t *testing.T) {
	t.Parallel()
	fx := newFixture(t, 1)
	id := fx.create(testName)
	if err := fx.p.Delete(fx.ctx, id); err != nil {
		t.Fatalf("Delete() error = %v", err)
	}
	fx.fake.mu.Lock()
	flags, ok := fx.fake.undefineFlags[testName]
	fx.fake.mu.Unlock()
	if !ok {
		t.Fatal("DomainUndefineFlags was not called")
	}
	for _, want := range []libvirt.DomainUndefineFlagsValues{libvirt.DomainUndefineNvram, libvirt.DomainUndefineManagedSave, libvirt.DomainUndefineSnapshotsMetadata} {
		if flags&want == 0 {
			t.Errorf("undefine flags = %d, lack %d", flags, want)
		}
	}
}