package orchestrator

import (
	"context"
	"encoding/json"
	"errors"
	"net/netip"
	"strconv"
	"strings"
	"testing"
	"time"

	"cloudipvalidator/internal/db"
)

func eventPayload(t *testing.T, d *db.DB, eventType string) string {
	t.Helper()
	var p string
	if err := d.QueryRowContext(context.Background(),
		`SELECT payload FROM events WHERE event_type=? ORDER BY id DESC LIMIT 1`, eventType).Scan(&p); err != nil {
		t.Fatalf("read %s event: %v", eventType, err)
	}
	return p
}

func TestScanStatusIdleBeforeAnyScan(t *testing.T) {
	// Zero-value Orchestrator literal (as several tests build it) must work.
	o := &Orchestrator{}
	st := o.ScanStatus()
	if st.State != ScanIdle || st.Running || st.StartedAt != nil {
		t.Fatalf("expected idle, got %+v", st)
	}
	if o.CancelScan() {
		t.Fatalf("nothing to cancel")
	}
}

func TestScanJobSingleFlightAndProgress(t *testing.T) {
	o, d, mock := newTestOrchestrator(t, 180)
	mock.SeedMany("fip", 600)
	mock.SeedWithPort("busy", "203.0.113.9", "svc", "port-x")
	mock.PageSize = 100
	mock.PageDelay = 40 * time.Millisecond

	st, started := o.StartScan(ScanOptions{})
	if !started || !st.Running || st.State != ScanListing || st.StartedAt == nil {
		t.Fatalf("expected a started listing job, got started=%v %+v", started, st)
	}
	st2, started2 := o.StartScan(ScanOptions{DryRun: true})
	if started2 || !st2.Running || st2.DryRun {
		t.Fatalf("second start must join the running job (not dry-run), got started=%v %+v", started2, st2)
	}

	// The synchronous wrapper joins the same job instead of scanning twice.
	type out struct {
		res     db.SubmitIPsResult
		scanned int
		err     error
	}
	ch := make(chan out, 1)
	go func() {
		r, n, err := o.ScanFloatingIPs(context.Background())
		ch <- out{r, n, err}
	}()

	// Progress is visible while the job runs.
	sawProgress := false
	for i := 0; i < 200 && o.ScanStatus().Running; i++ {
		if s := o.ScanStatus(); s.Pages > 0 && s.Pages < 7 {
			sawProgress = true
		}
		time.Sleep(5 * time.Millisecond)
	}
	got := <-ch
	if got.err != nil || got.scanned != 600 || len(got.res.Added) != 600 {
		t.Fatalf("wrapper result: %+v", got)
	}
	if !sawProgress {
		t.Fatalf("expected to observe intermediate progress")
	}

	fin := waitScan(t, o)
	if fin.State != ScanDone || fin.Running || fin.FinishedAt == nil || fin.Error != "" {
		t.Fatalf("expected done, got %+v", fin)
	}
	if fin.Pages != 7 || fin.Discovered != 601 || fin.Free != 600 || fin.Added != 600 {
		t.Fatalf("unexpected counters: %+v", fin)
	}
	if countEvents(t, d, "fip_scan") != 1 {
		t.Fatalf("expected exactly one fip_scan event, got %d", countEvents(t, d, "fip_scan"))
	}
	var p struct {
		ScannedFree int `json:"scanned_free"`
		Pages       int `json:"pages"`
		Added       int `json:"added"`
	}
	if err := json.Unmarshal([]byte(eventPayload(t, d, "fip_scan")), &p); err != nil || p.ScannedFree != 600 || p.Added != 600 || p.Pages != 7 {
		t.Fatalf("fip_scan payload: %+v err=%v", p, err)
	}

	// A new scan after completion starts a fresh job; everything is requeued
	// or reordered (idempotent), nothing added.
	mock.PageDelay = 0
	st3, started3 := o.StartScan(ScanOptions{})
	if !started3 {
		t.Fatalf("a finished job must not block a new one: %+v", st3)
	}
	fin = waitScan(t, o)
	if fin.State != ScanDone || fin.Added != 0 || fin.Reordered != 600 {
		t.Fatalf("rescan: %+v", fin)
	}
}

func TestScanJobDryRunLeavesQueueUntouched(t *testing.T) {
	ctx := context.Background()
	o, d, mock := newTestOrchestrator(t, 180)
	mock.SeedMany("fip", 450)
	mock.PageSize = 200
	if err := d.SeedQueue(ctx, []string{"9.9.9.9"}); err != nil {
		t.Fatal(err)
	}

	o.StartScan(ScanOptions{DryRun: true, ClearFirst: true}) // ClearFirst is ignored for dry runs
	st := waitScan(t, o)
	if st.State != ScanDone || !st.DryRun || st.Free != 450 || st.Pages != 3 || st.Added != 0 {
		t.Fatalf("dry run status: %+v", st)
	}
	if got := queuedAddresses(t, d); len(got) != 1 || got["9.9.9.9"] != db.IPQueued {
		t.Fatalf("dry run must not touch the queue, got %d rows", len(got))
	}
	if countEvents(t, d, "fip_scan") != 0 || countEvents(t, d, "queue_cleared") != 0 {
		t.Fatalf("dry run must not emit scan/clear events")
	}
}

func TestScanJobReadErrorLeavesQueueUntouched(t *testing.T) {
	ctx := context.Background()
	o, d, mock := newTestOrchestrator(t, 180)
	mock.SeedMany("fip", 450)
	mock.PageSize = 200
	if err := d.SeedQueue(ctx, []string{"9.9.9.9"}); err != nil {
		t.Fatal(err)
	}
	// Page 1 succeeds, page 2 fails: the 200 already read must NOT be queued.
	mock.ListFailures = []error{nil, errors.New("neutron exploded")}

	o.StartScan(ScanOptions{})
	st := waitScan(t, o)
	if st.State != ScanError || !strings.Contains(st.Error, "neutron exploded") || st.FinishedAt == nil {
		t.Fatalf("expected error state, got %+v", st)
	}
	if st.Pages != 1 || st.Added != 0 {
		t.Fatalf("expected 1 page read and nothing added, got %+v", st)
	}
	if got := queuedAddresses(t, d); len(got) != 1 || got["9.9.9.9"] != db.IPQueued {
		t.Fatalf("queue must be untouched after a read error, got %d rows", len(got))
	}
	if countEvents(t, d, "fip_scan") != 0 {
		t.Fatalf("no fip_scan event on failure")
	}

	// The wrapper reports the same error.
	mock.ListFailure = errors.New("still down")
	if _, _, err := o.ScanFloatingIPs(ctx); err == nil || !strings.Contains(err.Error(), "still down") {
		t.Fatalf("expected wrapped list error, got %v", err)
	}
}

func TestScanJobClearFirst(t *testing.T) {
	ctx := context.Background()
	o, d, mock := newTestOrchestrator(t, 180)
	mock.Seed("fip-1", "1.1.1.1", "svc")
	if err := d.SeedQueue(ctx, []string{"9.9.9.9", "8.8.8.8"}); err != nil {
		t.Fatal(err)
	}

	st, _ := o.StartScan(ScanOptions{ClearFirst: true})
	if st.State != ScanClearing {
		t.Fatalf("expected clearing as first state, got %s", st.State)
	}
	fin := waitScan(t, o)
	if fin.State != ScanDone || fin.Added != 1 {
		t.Fatalf("clear-first scan: %+v", fin)
	}
	if got := queuedAddresses(t, d); len(got) != 1 || got["1.1.1.1"] != db.IPQueued {
		t.Fatalf("expected only the scanned address, got %v", got)
	}
	var payload struct {
		Count     int      `json:"count"`
		Addresses []string `json:"addresses"`
	}
	if err := json.Unmarshal([]byte(eventPayload(t, d, "queue_cleared")), &payload); err != nil || payload.Count != 2 || len(payload.Addresses) != 2 {
		t.Fatalf("queue_cleared payload: %+v err=%v", payload, err)
	}
}

// 6440 free addresses (the real stand's size) plus a few out-of-order ones:
// everything is queued in ascending numeric IP order within a sane time.
func TestScanJobEnqueuesAllInAscendingOrderAtScale(t *testing.T) {
	if testing.Short() {
		t.Skip("scale test skipped in -short mode")
	}
	ctx := context.Background()
	o, d, mock := newTestOrchestrator(t, 180)
	o.ScanPageSize = 200
	mock.SeedMany("fip", 6440)
	// IDs sort before "fip-*", addresses sort numerically before 198.18.*;
	// 10.0.0.9 < 10.0.0.200 numerically but not as strings.
	mock.Seed("aaa-2", "10.0.0.200", "svc")
	mock.Seed("aaa-1", "10.0.0.9", "svc")
	mock.SeedWithPort("occupied", "203.0.113.1", "svc", "port-x")

	start := time.Now()
	o.StartScan(ScanOptions{})
	st := waitScanFor(t, o, 5*time.Minute) // -race is an order of magnitude slower
	elapsed := time.Since(start)

	if st.State != ScanDone || st.Free != 6442 || st.Added != 6442 || st.Discovered != 6443 || st.Pages != 33 {
		t.Fatalf("scan status: %+v", st)
	}
	if elapsed > 3*time.Minute {
		t.Fatalf("scanning 6442 addresses took %v", elapsed)
	}
	t.Logf("scan+enqueue of %d addresses took %v", st.Added, elapsed)

	items, err := d.ListIPs(ctx)
	if err != nil || len(items) != 6442 {
		t.Fatalf("queue: n=%d err=%v", len(items), err)
	}
	var prev netip.Addr
	for i, it := range items {
		ip := netip.MustParseAddr(it.IPAddress)
		if i > 0 && ip.Compare(prev) <= 0 {
			t.Fatalf("queue not ascending at %d: %s after %s", i, it.IPAddress, prev)
		}
		if it.Sequence != i {
			t.Fatalf("expected contiguous sequences, row %d has %d", i, it.Sequence)
		}
		prev = ip
	}
	if items[0].IPAddress != "10.0.0.9" || items[1].IPAddress != "10.0.0.200" {
		t.Fatalf("numeric ordering broken: %s, %s", items[0].IPAddress, items[1].IPAddress)
	}
	if _, stale := queuedAddresses(t, d)["203.0.113.1"]; stale {
		t.Fatalf("occupied address must not be queued")
	}
}

func TestScanJobCancelAndLifetimeContext(t *testing.T) {
	ctx := context.Background()
	o, d, mock := newTestOrchestrator(t, 180)
	mock.SeedMany("fip", 100)
	mock.PageSize = 10
	mock.PageDelay = 5 * time.Second
	if err := d.SeedQueue(ctx, []string{"9.9.9.9"}); err != nil {
		t.Fatal(err)
	}

	o.StartScan(ScanOptions{})
	time.Sleep(20 * time.Millisecond)
	start := time.Now()
	if !o.CancelScan() {
		t.Fatalf("expected a running scan to be cancelled")
	}
	if time.Since(start) > 3*time.Second {
		t.Fatalf("cancel took too long")
	}
	st := o.ScanStatus()
	if st.State != ScanCancelled || st.Running || st.FinishedAt == nil {
		t.Fatalf("expected cancelled, got %+v", st)
	}
	if got := queuedAddresses(t, d); len(got) != 1 {
		t.Fatalf("cancelled scan must not enqueue, got %d rows", len(got))
	}

	// Cancelling the process-lifetime context also stops a running scan.
	life, cancelLife := context.WithCancel(context.Background())
	o.SetContext(life)
	o.StartScan(ScanOptions{})
	time.Sleep(20 * time.Millisecond)
	cancelLife()
	if st := waitScan(t, o); st.State != ScanCancelled {
		t.Fatalf("expected cancelled by lifetime ctx, got %+v", st)
	}
}

func TestScanJobDeadline(t *testing.T) {
	o, _, mock := newTestOrchestrator(t, 180)
	o.Cfg.FIPScanTimeoutSeconds = 1
	mock.SeedMany("fip", 20)
	mock.PageSize = 10
	mock.PageDelay = 10 * time.Second

	o.StartScan(ScanOptions{})
	st := waitScan(t, o)
	if st.State != ScanError || !strings.Contains(st.Error, "timed out") {
		t.Fatalf("expected timeout error, got %+v", st)
	}
}

func TestScanFloatingIPsWrapperHonoursCallerContext(t *testing.T) {
	o, _, mock := newTestOrchestrator(t, 180)
	mock.SeedMany("fip", 20)
	mock.PageSize = 10
	mock.PageDelay = 5 * time.Second

	ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond)
	defer cancel()
	if _, _, err := o.ScanFloatingIPs(ctx); !errors.Is(err, context.DeadlineExceeded) {
		t.Fatalf("expected the caller's ctx error, got %v", err)
	}
	// The job itself keeps going until cancelled (cleanup cancels it).
	if !o.ScanStatus().Running {
		t.Fatalf("background job should still be running")
	}
}

func TestSortAddressesAscending(t *testing.T) {
	in := []string{"10.0.0.10", "zzz", "10.0.0.9", "2001:db8::1", "9.255.255.255", "aaa", "10.0.0.2"}
	sortAddressesAscending(in)
	want := []string{"9.255.255.255", "10.0.0.2", "10.0.0.9", "10.0.0.10", "2001:db8::1", "aaa", "zzz"}
	for i := range want {
		if in[i] != want[i] {
			t.Fatalf("got %v want %v", in, want)
		}
	}
}

func TestClearQueueEventPayloadIsTruncated(t *testing.T) {
	ctx := context.Background()
	o, d, _ := newTestOrchestrator(t, 180)
	var addrs []string
	for i := 0; i < 120; i++ {
		addrs = append(addrs, "10.1.0."+strconv.Itoa(i))
	}
	if err := d.SeedQueue(ctx, addrs); err != nil {
		t.Fatal(err)
	}
	res, err := o.ClearQueue(ctx)
	if err != nil || len(res.Deleted) != 120 {
		t.Fatalf("clear: %+v err=%v", res, err)
	}
	var p struct {
		Count     int      `json:"count"`
		Addresses []string `json:"addresses"`
		Truncated bool     `json:"truncated"`
	}
	if err := json.Unmarshal([]byte(eventPayload(t, d, "queue_cleared")), &p); err != nil {
		t.Fatal(err)
	}
	if p.Count != 120 || len(p.Addresses) != 50 || !p.Truncated || p.Addresses[0] != "10.1.0.0" {
		t.Fatalf("payload: count=%d addrs=%d truncated=%v", p.Count, len(p.Addresses), p.Truncated)
	}
}

func TestDeleteIPsDisassociatesOnlyAttachedFIPs(t *testing.T) {
	ctx := context.Background()
	o, d, mock := newTestOrchestrator(t, 180)
	mock.Seed("fip-a", "1.1.1.1", "svc")
	mock.Seed("fip-b", "2.2.2.2", "svc")
	if _, err := d.SubmitIPs(ctx, []string{"1.1.1.1", "2.2.2.2", "3.3.3.3"}); err != nil {
		t.Fatal(err)
	}
	if err := d.RegisterValidator(ctx, "validator-1", "host-1", "port-1", "v0.1"); err != nil {
		t.Fatal(err)
	}
	claimed, err := d.ClaimNextQueued(ctx, "validator-1", time.Minute)
	if err != nil || claimed == nil || claimed.IPAddress != "1.1.1.1" {
		t.Fatalf("claim: %+v err=%v", claimed, err)
	}
	if err := mock.AssociateFloatingIP(ctx, "fip-a", "port-1"); err != nil {
		t.Fatal(err)
	}
	if err := d.SetFIPAssociated(ctx, claimed.ID, "fip-a", time.Minute); err != nil {
		t.Fatal(err)
	}
	// An unrelated, externally associated FIP must stay as it is.
	if err := mock.AssociateFloatingIP(ctx, "fip-b", "other-port"); err != nil {
		t.Fatal(err)
	}

	res, err := o.DeleteIPs(ctx, []string{"1.1.1.1", "2.2.2.2", "nope"})
	if err != nil || len(res.Deleted) != 2 || len(res.NotFound) != 1 {
		t.Fatalf("delete: %+v err=%v", res, err)
	}
	a, _ := mock.GetFloatingIPByAddress(ctx, "1.1.1.1")
	b, _ := mock.GetFloatingIPByAddress(ctx, "2.2.2.2")
	if a.PortID != "" {
		t.Fatalf("attached fip must be disassociated, still on %q", a.PortID)
	}
	if b.PortID != "other-port" {
		t.Fatalf("row without recorded fip_id must not trigger a disassociate, got %q", b.PortID)
	}
	v, _ := d.GetValidator(ctx, "validator-1")
	if v.State != db.ValidatorIdle {
		t.Fatalf("validator must be freed, got %s", v.State)
	}
}