//go:build integration

package proxmox

import (
	"context"
	"crypto/rand"
	"encoding/hex"
	"errors"
	"fmt"
	"net"
	"net/http"
	"net/url"
	"os"
	"strconv"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/go-logr/logr"
	"github.com/go-logr/logr/funcr"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
	"go.opentelemetry.io/otel/sdk/trace/tracetest"
	"k8s.io/apimachinery/pkg/types"
	logf "sigs.k8s.io/controller-runtime/pkg/log"

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

// The real-host test of spec entry 21. It runs only with -tags=integration
// and skips itself unless PROXMOX_TEST_* names a host; see docs/testing.md
// for the variables and what one run asserts.
const (
	integrationProvider = "proxmox-integration"
	integrationImage    = "test-template"
	integrationMachine  = "small"
	integrationPort     = 3128
	// integrationDiskGiB is above the 3 GiB of the recon template, so a run
	// on such a template exercises the resize task; a larger template skips
	// it.
	integrationDiskGiB = 4

	// integrationCloudInit is the user-data the VM boots with. Nothing
	// asserts on the guest running it; it exists so the sentinel check can
	// prove that no span attribute carries the cloud-init text.
	integrationCloudInit = "#cloud-config\nruncmd:\n  - echo proxmox-integration\n"

	defaultIntegrationTimeout = 20 * time.Minute
	defaultIntegrationLogLvl  = 1
	getPollInterval           = 5 * time.Second
	cleanupBudget             = 5 * time.Minute
)

type integrationEnv struct {
	url, tokenFile, node, isoStorage string
	caFile, storage, bridge          string
	templateVMID, vlanTag            int
	vmidMin, vmidMax                 int
	insecure, keep                   bool
	timeout                          time.Duration
	logLevel                         int
}

// loadIntegrationEnv reads the PROXMOX_TEST_* variables, skipping the test
// under -short or when a required one is missing.
func loadIntegrationEnv(t *testing.T) integrationEnv {
	t.Helper()
	if testing.Short() {
		t.Skip("real-host test skipped under -short")
	}
	env := integrationEnv{timeout: defaultIntegrationTimeout, logLevel: defaultIntegrationLogLvl}
	var templateVMID string
	required := []struct {
		name string
		dst  *string
	}{
		{"PROXMOX_TEST_URL", &env.url},
		{"PROXMOX_TEST_TOKEN_FILE", &env.tokenFile},
		{"PROXMOX_TEST_NODE", &env.node},
		{"PROXMOX_TEST_TEMPLATE_VMID", &templateVMID},
		{"PROXMOX_TEST_ISO_STORAGE", &env.isoStorage},
	}
	for _, r := range required {
		v := os.Getenv(r.name)
		if v == "" {
			t.Skipf("%s is not set; the proxmox integration test needs a real Proxmox VE host (see docs/testing.md)", r.name)
		}
		*r.dst = v
	}
	env.templateVMID = envInt(t, "PROXMOX_TEST_TEMPLATE_VMID", 0)
	env.caFile = os.Getenv("PROXMOX_TEST_CA_FILE")
	env.storage = os.Getenv("PROXMOX_TEST_STORAGE")
	env.bridge = os.Getenv("PROXMOX_TEST_BRIDGE")
	env.vlanTag = envInt(t, "PROXMOX_TEST_VLAN_TAG", 0)
	env.vmidMin = envInt(t, "PROXMOX_TEST_VMID_MIN", defaultVMIDMin)
	env.vmidMax = envInt(t, "PROXMOX_TEST_VMID_MAX", defaultVMIDMax)
	if env.vmidMin > env.vmidMax {
		t.Fatalf("PROXMOX_TEST_VMID_MIN=%d is above PROXMOX_TEST_VMID_MAX=%d", env.vmidMin, env.vmidMax)
	}
	env.keep = os.Getenv("PROXMOX_TEST_KEEP") != ""
	if v := os.Getenv("PROXMOX_TEST_INSECURE"); v != "" {
		b, err := strconv.ParseBool(v)
		if err != nil {
			t.Fatalf("PROXMOX_TEST_INSECURE=%q: %v", v, err)
		}
		env.insecure = b
	}
	if v := os.Getenv("PROXMOX_TEST_TIMEOUT"); v != "" {
		d, err := time.ParseDuration(v)
		if err != nil {
			t.Fatalf("PROXMOX_TEST_TIMEOUT=%q: %v", v, err)
		}
		env.timeout = d
	}
	env.logLevel = envInt(t, "PROXMOX_TEST_LOG_LEVEL", defaultIntegrationLogLvl)
	return env
}

// envInt reads a non-negative integer variable, def when it is unset.
func envInt(t *testing.T, name string, def int) int {
	t.Helper()
	v := os.Getenv(name)
	if v == "" {
		return def
	}
	n, err := strconv.Atoi(v)
	if err != nil || n < 0 {
		t.Fatalf("%s=%q: want a non-negative integer", name, v)
	}
	return n
}

// providerConfig is what the operator would load for this host: one node,
// one template, one machine type.
func (e integrationEnv) providerConfig() provider.ProviderConfig {
	return provider.ProviderConfig{
		Name: integrationProvider,
		Type: "proxmox",
		Proxmox: &provider.ProxmoxConfig{
			URL:                   e.url,
			TokenFile:             e.tokenFile,
			CAFile:                e.caFile,
			InsecureSkipTLSVerify: e.insecure,
			Nodes:                 []string{e.node},
			ISOStorage:            e.isoStorage,
			Storage:               e.storage,
			Bridge:                e.bridge,
			VLANTag:               e.vlanTag,
			VMIDRange:             &provider.ProxmoxVMIDRange{Min: e.vmidMin, Max: e.vmidMax},
			Templates:             map[string]provider.ProxmoxTemplate{integrationImage: {VMID: e.templateVMID}},
			MachineTypes: map[string]provider.ProxmoxMachineType{
				integrationMachine: {Cores: 1, MemoryMiB: 1024, DiskGiB: integrationDiskGiB},
			},
		},
	}
}

// integrationLog routes the provider's logr output into t.Log through funcr
// at the chosen verbosity, keeps every line for assertions, and strips the
// key/value pairs that are constant for the run (stated once up front) so
// each line stays short. Lines arriving after the test ended are dropped:
// t.Log panics then.
type integrationLog struct {
	t *testing.T

	mu    sync.Mutex
	drop  []string
	lines []string
	done  bool
}

func newIntegrationLog(t *testing.T, level int, drop ...string) (*integrationLog, logr.Logger) {
	t.Helper()
	sink := &integrationLog{t: t, drop: drop}
	t.Cleanup(func() {
		sink.mu.Lock()
		defer sink.mu.Unlock()
		sink.done = true
	})
	log := funcr.New(func(prefix, args string) { sink.write(prefix, args) }, funcr.Options{Verbosity: level})
	return sink, log
}

// dropValue adds a rendered pair (`"key"="value"`) to strip from later lines.
func (l *integrationLog) dropValue(key, value string) {
	l.mu.Lock()
	defer l.mu.Unlock()
	l.drop = append(l.drop, fmt.Sprintf("%q=%q", key, value))
}

func (l *integrationLog) write(prefix, args string) {
	l.mu.Lock()
	defer l.mu.Unlock()
	l.lines = append(l.lines, args)
	if l.done {
		return
	}
	for _, d := range l.drop {
		args = strings.ReplaceAll(args, " "+d, "")
	}
	l.t.Logf("%s %s %s", time.Now().Format("15:04:05.000"), prefix, args)
}

func (l *integrationLog) matching(substr string) []string {
	l.mu.Lock()
	defer l.mu.Unlock()
	var out []string
	for _, line := range l.lines {
		if strings.Contains(line, substr) {
			out = append(out, line)
		}
	}
	return out
}

// newIntegrationProvider builds the provider the way New does, with the
// span recorder's tracer on the transport, so the HTTP spans land in the
// same recorder as provider.WithTracing's provider.* spans. The bare client
// is returned too, for the test's own read-only inspection of the host.
func newIntegrationProvider(t *testing.T, pc provider.ProviderConfig, tp *sdktrace.TracerProvider) (*Provider, *httpAPI) {
	t.Helper()
	cfg := withDefaults(*pc.Proxmox)
	client, err := newHTTPAPI(cfg, tracing.WithTracerProvider(tp))
	if err != nil {
		t.Fatalf("newHTTPAPI error = %v", err)
	}
	return newProvider(pc.Name, cfg, observe(client, pc.Name)), client
}

// randomUID is a UUID-shaped string, so the run's VM never collides with a
// previous run's leftovers or with a real Proxy's.
func randomUID(t *testing.T) string {
	t.Helper()
	var b [16]byte
	if _, err := rand.Read(b[:]); err != nil {
		t.Fatalf("reading random bytes: %v", err)
	}
	h := hex.EncodeToString(b[:])
	return h[0:8] + "-" + h[8:12] + "-" + h[12:16] + "-" + h[16:20] + "-" + h[20:32]
}

// stepDone logs one lifecycle step with its duration; the log is the record
// of how long a clone or a boot took on this host.
func stepDone(t *testing.T, step string, start time.Time) {
	t.Helper()
	t.Logf("step %s: %s", step, time.Since(start).Round(time.Millisecond))
}

// waitUntil polls cond every interval until it is true or ctx ends.
func waitUntil(ctx context.Context, t *testing.T, interval time.Duration, what string, cond func() bool) {
	t.Helper()
	ticker := time.NewTicker(interval)
	defer ticker.Stop()
	for !cond() {
		select {
		case <-ticker.C:
		case <-ctx.Done():
			t.Fatalf("gave up waiting for %s: %v", what, ctx.Err())
		}
	}
}

// qemuVMs lists the cluster's QEMU VMs by VMID.
func qemuVMs(ctx context.Context, t *testing.T, client *httpAPI) map[int]vmResource {
	t.Helper()
	rs, err := client.ClusterResources(ctx)
	if err != nil {
		t.Fatalf("listing cluster resources: %v", err)
	}
	out := make(map[int]vmResource, len(rs))
	for _, r := range rs {
		if r.Type == "qemu" {
			out[r.VMID] = r
		}
	}
	return out
}

// vmidByName finds the VM named name, as a crashed Create may have left it.
func vmidByName(ctx context.Context, t *testing.T, client *httpAPI, name string) (int, bool) {
	t.Helper()
	for vmid, r := range qemuVMs(ctx, t, client) {
		if r.Name == name {
			return vmid, true
		}
	}
	return 0, false
}

// seedOnStorage reports whether the ISO storage on node holds name's seed.
// It is one extra read-only GET of /nodes/{node}/storage/{storage}/content
// (captured as storage_content_iso.json): the seam has no method to list
// storage content, and gets none for a test.
func seedOnStorage(ctx context.Context, t *testing.T, client *httpAPI, node, storage, name string) bool {
	t.Helper()
	var content []struct {
		VolID string `json:"volid"`
	}
	path := apiPath("nodes", node, "storage", storage, "content")
	if err := client.do(ctx, http.MethodGet, path, url.Values{"content": {"iso"}}, nil, &content); err != nil {
		t.Fatalf("listing iso content of %s on %s: %v", storage, node, err)
	}
	want := seedVolID(storage, name)
	for _, c := range content {
		if c.VolID == want {
			return true
		}
	}
	return false
}

// checkNode runs the health check and requires the one node Ready, with the
// details an admin reads.
func checkNode(ctx context.Context, t *testing.T, built provider.Provider, env integrationEnv) {
	t.Helper()
	checker, ok := built.(provider.Checker)
	if !ok {
		t.Fatalf("New() returned %T, which is not a provider.Checker", built)
	}
	targets := checker.Check(ctx)
	if len(targets) != 1 {
		t.Fatalf("Check() returned %d targets, want 1: %+v", len(targets), targets)
	}
	ts := targets[0]
	if !ts.Ready || ts.Reason != provider.ReasonReachable {
		t.Fatalf("Check() = ready %v reason %q message %q, want Ready/%s (details %v)", ts.Ready, ts.Reason, ts.Message, provider.ReasonReachable, ts.Details)
	}
	for _, key := range []string{"pveVersion", "kernel", "tokenID", "isoStorageAvailGiB", "templates"} {
		if ts.Details[key] == "" {
			t.Errorf("Check() details lack %q: %v", key, ts.Details)
		}
	}
	if ts.Details["templates"] != "1/1" {
		t.Errorf("Check() templates = %q, want 1/1", ts.Details["templates"])
	}
	t.Logf("node %s (%s): pve %s, kernel %s, token %s, %s free on %s, templates %s, latency %s",
		ts.Name, ts.Address, ts.Details["pveVersion"], ts.Details["kernel"], ts.Details["tokenID"],
		ts.Details["isoStorageAvailGiB"]+" GiB", env.isoStorage, ts.Details["templates"], ts.Latency.Round(time.Millisecond))
}

func TestProxmox_lifecycle(t *testing.T) {
	env := loadIntegrationEnv(t)
	pc := env.providerConfig()
	sink, log := newIntegrationLog(t, env.logLevel,
		fmt.Sprintf("%q=%q", "provider", integrationProvider),
		fmt.Sprintf("%q=%q", "node", env.node))
	ctx, cancel := context.WithTimeout(logf.IntoContext(context.Background(), log), env.timeout)
	defer cancel()

	t.Logf("provider=%s url=%s node=%s template=%d isoStorage=%s storage=%q bridge=%q vlanTag=%d vmids %d..%d budget=%s log level %d; provider, node and name are left off every provider log line",
		integrationProvider, env.url, env.node, env.templateVMID, env.isoStorage, env.storage, env.bridge, env.vlanTag,
		env.vmidMin, env.vmidMax, env.timeout, env.logLevel)
	if env.insecure {
		t.Log("PROXMOX_TEST_INSECURE is set: the API's certificate is NOT verified for this run")
	}

	// 1. New returns without a request.
	start := time.Now()
	built, err := New(ctx, pc)
	elapsed := time.Since(start)
	if err != nil {
		t.Fatalf("New() error = %v", err)
	}
	if elapsed > 100*time.Millisecond {
		t.Errorf("New() took %s, want under 100ms: it must not make a request", elapsed)
	}
	if lines := sink.matching(`"msg"="proxmox api call"`); len(lines) > 0 {
		t.Errorf("New() called the API before any operation: %q", lines)
	}
	stepDone(t, "1 New", start)

	// 2. Check reports the node Ready with details.
	start = time.Now()
	checkNode(ctx, t, built, env)
	stepDone(t, "2 Check", start)

	// 3. Every later call goes through the tracing decorator, with the
	// transport's HTTP spans recorded alongside.
	sr := tracetest.NewSpanRecorder()
	tp := sdktrace.NewTracerProvider(sdktrace.WithSpanProcessor(sr))
	t.Cleanup(func() { _ = tp.Shutdown(context.Background()) })
	p, client := newIntegrationProvider(t, pc, tp)
	traced := provider.WithTracing(pc.Name, p, tracing.WithTracerProvider(tp))

	// 4. Create.
	uid := randomUID(t)
	name := provider.NameFromUID(types.UID(uid))
	sink.dropValue("name", name)
	req := provider.CreateRequest{
		Name:      name,
		UID:       uid,
		Namespace: "integration",
		ProxyName: "proxmox-lifecycle",
		Placement: provider.Placement{Zone: env.node, MachineType: integrationMachine, Image: integrationImage},
		CloudInit: integrationCloudInit,
		Port:      integrationPort,
	}
	t.Logf("VM name %s, uid %s", name, uid)

	deleted := false
	t.Cleanup(func() {
		if deleted {
			return
		}
		cctx, ccancel := context.WithTimeout(logf.IntoContext(context.Background(), log), cleanupBudget)
		defer ccancel()
		vmid, found := vmidByName(cctx, t, client, name)
		if env.keep {
			msg := "PROXMOX_TEST_KEEP is set: the VM and its seed stay. Clean up as root on " + env.node + " with:\n"
			if found {
				msg += fmt.Sprintf("  qm stop %d\n  qm destroy %d --purge\n", vmid, vmid)
			}
			t.Log(msg + "  pvesm free " + seedVolID(env.isoStorage, name))
			return
		}
		if !found {
			// No VM, but a seed may be left: Delete of an absent VM still
			// deletes it.
			vmid = vmidFor(uid, env.vmidMin, env.vmidMax, 0)
		}
		if err := p.Delete(cctx, formatProviderID(vmid, name)); err != nil {
			t.Errorf("cleanup Delete of VM %d error = %v; remove it and %s by hand", vmid, err, seedVolID(env.isoStorage, name))
		}
	})

	start = time.Now()
	id, err := traced.Create(ctx, req)
	if err != nil {
		t.Fatalf("Create() error = %v", err)
	}
	vmid, gotName, err := parseProviderID(id)
	if err != nil || gotName != name {
		t.Fatalf("Create() = %q, want vms/<vmid>/%s (parse error %v)", id, name, err)
	}
	if vmid < env.vmidMin || vmid > env.vmidMax {
		t.Errorf("Create() VMID %d is outside %d..%d", vmid, env.vmidMin, env.vmidMax)
	}
	sink.dropValue("vmid", strconv.Itoa(vmid))
	createReturned := time.Now()
	t.Logf("VM %d, id %s", vmid, id)
	stepDone(t, "4 Create", start)

	// 5. Create again: same ID, nothing new in the cluster.
	start = time.Now()
	before := len(qemuVMs(ctx, t, client))
	again, err := traced.Create(ctx, req)
	if err != nil {
		t.Fatalf("second Create() error = %v", err)
	}
	if again != id {
		t.Errorf("second Create() = %q, want %q", again, id)
	}
	if after := len(qemuVMs(ctx, t, client)); after != before {
		t.Errorf("second Create() changed the cluster's VM count from %d to %d", before, after)
	}
	stepDone(t, "5 Create again", start)

	// 6. Get reaches Running with an IPv4, and reads back what Create wrote.
	start = time.Now()
	var inst *provider.Instance
	waitUntil(ctx, t, getPollInterval, "the VM to be Running with an IPv4", func() bool {
		var err error
		inst, err = traced.Get(ctx, id)
		if errors.Is(err, provider.ErrTransient) {
			t.Logf("Get(%s) is Transient while the guest boots: %v", id, err)
			return false
		}
		if err != nil {
			t.Fatalf("Get(%s) error = %v", id, err)
		}
		return inst.State == provider.StateRunning && net.ParseIP(inst.IP).To4() != nil
	})
	assertMarkReadBack(ctx, t, client, env.node, vmid, inst, uid)
	t.Logf("VM running at %s, %s after Create returned (createdAt %s)", inst.IP, time.Since(createReturned).Round(time.Millisecond), inst.CreatedAt.Format(time.RFC3339))
	stepDone(t, "6 Get until Running", start)

	// 7. ListByTag contains it.
	start = time.Now()
	list, err := traced.ListByTag(ctx)
	if err != nil {
		t.Fatalf("ListByTag() error = %v", err)
	}
	assertListed(t, list, inst)
	stepDone(t, "7 ListByTag", start)

	// 8. Reachability, logged only: this machine may not route to the VM's
	// network.
	start = time.Now()
	addr := net.JoinHostPort(inst.IP, "22")
	if conn, err := net.DialTimeout("tcp", addr, 3*time.Second); err != nil {
		t.Logf("TCP connect to %s failed (informational; the test host may not route to the VM's network): %v", addr, err)
	} else {
		_ = conn.Close()
		t.Logf("TCP connect to %s succeeded", addr)
	}
	stepDone(t, "8 TCP connect", start)

	if env.keep {
		t.Log("PROXMOX_TEST_KEEP is set: skipping Delete and the leftovers check")
	} else {
		// 9. Delete, Get is NotFound, Delete again.
		start = time.Now()
		if err := traced.Delete(ctx, id); err != nil {
			t.Fatalf("Delete() error = %v", err)
		}
		deleted = true
		if _, err := traced.Get(ctx, id); !errors.Is(err, provider.ErrNotFound) {
			t.Errorf("Get() after Delete error = %v, want ErrNotFound", err)
		}
		if err := traced.Delete(ctx, id); err != nil {
			t.Errorf("second Delete() error = %v, want nil", err)
		}
		stepDone(t, "9 Delete, Get, Delete", start)

		// 10. No VM with the name and no seed remain.
		start = time.Now()
		if left, ok := vmidByName(ctx, t, client, name); ok {
			t.Errorf("VM %d named %s is still in the cluster after Delete", left, name)
		}
		if seedOnStorage(ctx, t, client, env.node, env.isoStorage, name) {
			t.Errorf("%s is still on %s after Delete", seedVolID(env.isoStorage, name), env.node)
		}
		stepDone(t, "10 leftovers", start)
	}

	// 11. Spans: HTTP spans are children of the decorator's.
	assertLifecycleSpans(t, sr.Ended())
}

// assertMarkReadBack checks that Get's UID and CreatedAt are the mark
// Create wrote into the VM's description, read back from its config, and
// that CreatedAt is recent.
func assertMarkReadBack(ctx context.Context, t *testing.T, client *httpAPI, node string, vmid int, inst *provider.Instance, uid string) {
	t.Helper()
	cfg, err := client.VMConfig(ctx, node, vmid)
	if err != nil {
		t.Fatalf("reading the config of VM %d: %v", vmid, err)
	}
	written := parseDescription(cfg["description"])
	if inst.UID != uid || written.UID != uid {
		t.Errorf("Get() UID = %q, the VM's mark says %q, want %q", inst.UID, written.UID, uid)
	}
	if !inst.CreatedAt.Equal(written.CreatedAt) || inst.CreatedAt.IsZero() {
		t.Errorf("Get() CreatedAt = %s, the VM's mark says %s; want them equal and set", inst.CreatedAt, written.CreatedAt)
	} else if skew := time.Since(inst.CreatedAt).Abs(); skew > 5*time.Minute {
		t.Errorf("Get() CreatedAt = %s, %s from now; want within a few minutes", inst.CreatedAt, skew)
	}
}

// assertListed checks that list holds inst's ID with its UID and
// CreatedAt.
func assertListed(t *testing.T, list []provider.Instance, inst *provider.Instance) {
	t.Helper()
	for _, li := range list {
		if li.ID != inst.ID {
			continue
		}
		if li.UID != inst.UID || !li.CreatedAt.Equal(inst.CreatedAt) {
			t.Errorf("ListByTag() entry = %+v, want UID %q and CreatedAt %s", li, inst.UID, inst.CreatedAt)
		}
		return
	}
	t.Errorf("ListByTag() = %d instances, none with ID %s", len(list), inst.ID)
}

// assertLifecycleSpans checks that at least one provider.create span has an
// HTTP child, and that no attribute of any span carries the cloud-init text.
func assertLifecycleSpans(t *testing.T, spans []sdktrace.ReadOnlySpan) {
	t.Helper()
	satisfied := false
	for _, create := range spans {
		if create.Name() != "provider.create" {
			continue
		}
		parent := create.SpanContext().SpanID()
		children := 0
		for _, s := range spans {
			if s.Parent().SpanID() == parent && strings.HasPrefix(s.Name(), "HTTP ") {
				children++
			}
		}
		t.Logf("provider.create span %s: %d HTTP children", parent, children)
		if children > 0 {
			satisfied = true
		}
	}
	if !satisfied {
		names := make([]string, len(spans))
		for i, s := range spans {
			names[i] = s.Name()
		}
		t.Errorf("no provider.create span has an HTTP child; spans: %v", names)
	}
	for _, s := range spans {
		for _, a := range s.Attributes() {
			v := a.Value.Emit()
			if strings.Contains(v, integrationCloudInit) || strings.Contains(v, "#cloud-config") {
				t.Errorf("span %s attribute %s carries the cloud-init text", s.Name(), a.Key)
			}
		}
	}
}

// TestProxmoxCheck_realHost runs the health check against the host and
// creates nothing.
func TestProxmoxCheck_realHost(t *testing.T) {
	env := loadIntegrationEnv(t)
	pc := env.providerConfig()
	_, log := newIntegrationLog(t, env.logLevel,
		fmt.Sprintf("%q=%q", "provider", integrationProvider),
		fmt.Sprintf("%q=%q", "node", env.node))
	ctx, cancel := context.WithTimeout(logf.IntoContext(context.Background(), log), env.timeout)
	defer cancel()
	if env.insecure {
		t.Log("PROXMOX_TEST_INSECURE is set: the API's certificate is NOT verified for this run")
	}
	built, err := New(ctx, pc)
	if err != nil {
		t.Fatalf("New() error = %v", err)
	}
	checkNode(ctx, t, built, env)
}