package kvm2

import (
	"errors"
	"strings"
	"testing"
	"time"

	"github.com/digitalocean/go-libvirt"

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

func listIDs(list []provider.Instance) []string {
	ids := make([]string, len(list))
	for i, inst := range list {
		ids[i] = inst.ID
	}
	return ids
}

func TestListByTag_excludesUnmarkedDomains(t *testing.T) {
	t.Parallel()
	fx := newFixture(t, 1)
	id := fx.create(testName)
	fx.fake.addDomain("legacy-vm", libvirt.DomainRunning, "")
	fx.fake.addDomain("unmarked", libvirt.DomainRunning, `<instance><managed>false</managed><uid>x</uid></instance>`)
	fx.fake.addDomain("unrelated", libvirt.DomainShutoff, `<instance><note>hand made</note></instance>`)
	list, err := fx.p.ListByTag(fx.ctx)
	if err != nil {
		t.Fatalf("ListByTag() error = %v", err)
	}
	if got := listIDs(list); len(got) != 1 || got[0] != id {
		t.Errorf("ListByTag = %v, want only %s", got, id)
	}
	if list[0].UID != testUID || list[0].CreatedAt.IsZero() {
		t.Errorf("listed = %+v, want uid and createdAt", list[0])
	}
	if got := fx.logs.matching("kvm2 domains listed"); len(got) != 1 || !strings.Contains(got[0], `"hosts"=1`) || !strings.Contains(got[0], `"managed"=1`) {
		t.Errorf("listed line = %v", got)
	}
}

func TestListByTag_emptyUIDStillListed(t *testing.T) {
	t.Parallel()
	fx := newFixture(t, 1)
	fx.fake.addDomain("proxy-nouid", libvirt.DomainRunning, managedMetadata("", time.Now()))
	list, err := fx.p.ListByTag(fx.ctx)
	if err != nil {
		t.Fatalf("ListByTag() error = %v", err)
	}
	if len(list) != 1 || list[0].UID != "" || list[0].ID != formatProviderID(testHost, "proxy-nouid") {
		t.Errorf("ListByTag = %+v, want the domain listed with an empty UID", list)
	}
}

func TestListByTag_acrossHostsInConfigOrder(t *testing.T) {
	t.Parallel()
	cfg := twoHosts()
	cfg.Hosts[1].Pool = ""
	first, second := newFakeBackend(), newFakeBackend()
	first.addDomain("proxy-z", libvirt.DomainRunning, managedMetadata("uid-z", time.Now()))
	first.addDomain("proxy-a", libvirt.DomainShutoff, managedMetadata("uid-a", time.Now()))
	second.addDomain("proxy-b", libvirt.DomainRunning, managedMetadata("uid-b", time.Now()))
	p := newProvider(testProvider, cfg, &hostDialer{backends: map[string]backend{"beelink": first, "lab2": second}})
	ctx, _ := captureContext()
	list, err := p.ListByTag(ctx)
	if err != nil {
		t.Fatalf("ListByTag() error = %v", err)
	}
	want := []string{formatProviderID("beelink", "proxy-a"), formatProviderID("beelink", "proxy-z"), formatProviderID("lab2", "proxy-b")}
	if got := listIDs(list); strings.Join(got, ",") != strings.Join(want, ",") {
		t.Errorf("ListByTag = %v, want %v (config order, then name order)", got, want)
	}
	if list[0].UID != "uid-a" || list[1].UID != "uid-z" || list[2].UID != "uid-b" {
		t.Errorf("uids = %s, %s, %s, want uid-a, uid-z, uid-b", list[0].UID, list[1].UID, list[2].UID)
	}
}

func TestListByTag_doesNotReadStateOrAddresses(t *testing.T) {
	t.Parallel()
	fx := newFixture(t, 2)
	id := fx.create(testName)
	fx.setAddrs(testName, libvirt.DomainInterfaceAddressesSrcAgent, "10.0.0.5")
	fx.fake.addDomain("proxy-off", libvirt.DomainShutoff, managedMetadata("uid-off", time.Now()))
	before := len(fx.fake.callLog())

	list, err := fx.p.ListByTag(fx.ctx)
	if err != nil {
		t.Fatalf("ListByTag() error = %v", err)
	}
	if len(list) != 2 || list[0].ID != id || list[1].ID != formatProviderID(testHost, "proxy-off") {
		t.Fatalf("ListByTag = %v, want the two managed domains", listIDs(list))
	}
	for _, inst := range list {
		if inst.State != "" || inst.IP != "" {
			t.Errorf("listed %s = state %q ip %q, want both empty: GC does not use them", inst.ID, inst.State, inst.IP)
		}
		if inst.UID == "" || inst.CreatedAt.IsZero() {
			t.Errorf("listed %s lacks uid or createdAt: %+v", inst.ID, inst)
		}
	}
	for _, rpc := range fx.fake.callLog()[before:] {
		switch rpc {
		case "ConnectListAllDomains", "DomainGetMetadata":
		default:
			t.Errorf("ListByTag made %s; want only the listing and one metadata read per domain", rpc)
		}
	}
	if got := fx.logs.matching("kvm2 listed instance"); len(got) != 2 || strings.Contains(got[0], `"state"=`) {
		t.Errorf("listed instance lines = %v, want two without a state", got)
	}
}

func TestListByTag_unreachableHostFailsWhole(t *testing.T) {
	t.Parallel()
	first := newFakeBackend()
	first.addDomain("proxy-a", libvirt.DomainRunning, managedMetadata("uid-a", time.Now()))
	d := &hostDialer{
		backends: map[string]backend{"beelink": first},
		errs:     map[string]error{"lab2": errors.New("dial tcp 192.0.2.2:22: i/o timeout")},
	}
	p := newProvider(testProvider, twoHosts(), d)
	ctx, _ := captureContext()
	list, err := p.ListByTag(ctx)
	if list != nil {
		t.Errorf("ListByTag = %v, want nil with the error", list)
	}
	assertProviderError(t, err, "list", provider.ErrTransient)
}

func TestListByTag_unreadableDomainSkipped(t *testing.T) {
	t.Parallel()
	tests := []struct {
		name  string
		setup func(fx *fixture)
		line  string
	}{
		{
			name: "corrupt metadata on one domain",
			setup: func(fx *fixture) {
				fx.fake.addDomain("proxy-bad", libvirt.DomainRunning, "<bogus>not an instance</bogus>")
			},
			line: "skipping domain with unreadable metadata",
		},
		{
			name: "metadata rpc fails for the first domain only",
			setup: func(fx *fixture) {
				fx.fake.addDomain("proxy-bad", libvirt.DomainRunning, managedMetadata("uid-bad", time.Now()))
				var calls int
				fx.fake.mu.Lock()
				fx.fake.hooks["DomainGetMetadata"] = func() error {
					calls++
					if calls == 1 {
						return fakeErr(libvirt.ErrInternalError, "internal error: metadata read failed")
					}
					return nil
				}
				fx.fake.mu.Unlock()
			},
			line: "skipping domain with unreadable metadata",
		},
		{
			name: "domain gone between listing and metadata read",
			setup: func(fx *fixture) {
				fx.fake.addDomain("proxy-bad", libvirt.DomainRunning, managedMetadata("uid-bad", time.Now()))
				var calls int
				fx.fake.mu.Lock()
				fx.fake.hooks["DomainGetMetadata"] = func() error {
					calls++
					if calls == 1 {
						return fakeErr(libvirt.ErrNoDomain, "Domain not found")
					}
					return nil
				}
				fx.fake.mu.Unlock()
			},
			line: "skipping domain with unreadable metadata",
		},
	}
	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			fx := newFixture(t, 1)
			fx.fake.addDomain("proxy-good", libvirt.DomainRunning, managedMetadata("uid-good", time.Now()))
			tc.setup(fx)
			list, err := fx.p.ListByTag(fx.ctx)
			if err != nil {
				t.Fatalf("ListByTag() error = %v", err)
			}
			if got := listIDs(list); len(got) != 1 || got[0] != formatProviderID(testHost, "proxy-good") {
				t.Errorf("ListByTag = %v, want only proxy-good", got)
			}
			if got := fx.logs.matching(tc.line); len(got) != 1 || !strings.Contains(got[0], `"name"="proxy-bad"`) {
				t.Errorf("skip line = %v, want one naming proxy-bad", got)
			}
		})
	}
}

func TestListByTag_includesInactiveDomains(t *testing.T) {
	t.Parallel()
	fx := newFixture(t, 1)
	id := fx.create(testName)
	fx.withDomain(testName, func(d *fakeDomain) { d.state = libvirt.DomainShutoff })
	list, err := fx.p.ListByTag(fx.ctx)
	if err != nil {
		t.Fatalf("ListByTag() error = %v", err)
	}
	if len(list) != 1 || list[0].ID != id || list[0].UID != testUID {
		t.Errorf("ListByTag = %+v, want the shut-off domain listed with its uid", list)
	}
}