// ui_restore_test.go — covers the restore wizard backend (P3-01).
package http

import (
	"context"
	"encoding/json"
	stdhttp "net/http"
	"net/url"
	"strings"
	"testing"
	"time"

	"github.com/coder/websocket"
	"github.com/oklog/ulid/v2"

	"gitea.dcglab.co.uk/steve/restic-manager/internal/api"
	"gitea.dcglab.co.uk/steve/restic-manager/internal/store"
)

// seedSnapshot creates a snapshot row directly via ReplaceHostSnapshots.
// Returns the snapshot ID.
func seedSnapshot(t *testing.T, st *store.Store, hostID, hostname string) string {
	t.Helper()
	id := strings.ReplaceAll(ulid.Make().String(), "-", "")
	short := id[:8]
	if err := st.ReplaceHostSnapshots(context.Background(), hostID, []store.Snapshot{{
		ID: id, ShortID: short, Time: time.Now().UTC().Add(-2 * time.Hour),
		Hostname: hostname, Paths: []string{"/etc"}, Tags: []string{"system-config"},
		SizeBytes: 612 * 1024 * 1024, FileCount: 100,
	}}, time.Now().UTC()); err != nil {
		t.Fatalf("seed snapshot: %v", err)
	}
	return id
}

// seedTwoSnapshots seeds two snapshots in one ReplaceHostSnapshots call
// so both end up in the host's list. ReplaceHostSnapshots is atomic-
// swap, so calling seedSnapshot twice would only leave the second.
func seedTwoSnapshots(t *testing.T, st *store.Store, hostID, hostname string) (string, string) {
	t.Helper()
	a := strings.ReplaceAll(ulid.Make().String(), "-", "")
	b := strings.ReplaceAll(ulid.Make().String(), "-", "")
	if err := st.ReplaceHostSnapshots(context.Background(), hostID, []store.Snapshot{
		{
			ID: a, ShortID: a[:8], Time: time.Now().UTC().Add(-3 * time.Hour),
			Hostname: hostname, Paths: []string{"/etc"}, Tags: []string{"system-config"},
		},
		{
			ID: b, ShortID: b[:8], Time: time.Now().UTC().Add(-1 * time.Hour),
			Hostname: hostname, Paths: []string{"/etc"}, Tags: []string{"system-config"},
		},
	}, time.Now().UTC()); err != nil {
		t.Fatalf("seed snapshots: %v", err)
	}
	return a, b
}

// TestRestoreWizardGetRendersStep1 verifies the snapshot picker is on
// the page when no snapshot is pre-selected.
func TestRestoreWizardGetRendersStep1(t *testing.T) {
	t.Parallel()
	srv, ts, st := rawTestServerWithUI(t)
	hostID, _ := enrolHostForUI(t, srv, st, "rstore-host-1")
	_ = seedSnapshot(t, st, hostID, "rstore-host-1")
	cookie := loginAsAdmin(t, st)

	req, _ := stdhttp.NewRequest("GET", ts.URL+"/hosts/"+hostID+"/restore", nil)
	req.AddCookie(cookie)
	res, err := stdhttp.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("do: %v", err)
	}
	defer res.Body.Close()
	if res.StatusCode != stdhttp.StatusOK {
		t.Fatalf("status: got %d, want 200", res.StatusCode)
	}
	body := readBody(t, res.Body)
	if !strings.Contains(body, "Restore from snapshot") {
		t.Errorf("expected wizard heading; body: %s", short(body))
	}
	if !strings.Contains(body, "Pick a snapshot first") &&
		!strings.Contains(body, "Pick the point-in-time you want to restore from") {
		t.Errorf("expected step-1 prompt")
	}
}

// TestRestoreWizardGetWithSnapshotPreselected verifies the deep-link
// path puts the snapshot summary card on the page.
func TestRestoreWizardGetWithSnapshotPreselected(t *testing.T) {
	t.Parallel()
	srv, ts, st := rawTestServerWithUI(t)
	hostID, _ := enrolHostForUI(t, srv, st, "rstore-host-2")
	sid := seedSnapshot(t, st, hostID, "rstore-host-2")
	cookie := loginAsAdmin(t, st)

	req, _ := stdhttp.NewRequest("GET",
		ts.URL+"/hosts/"+hostID+"/snapshots/"+sid+"/restore", nil)
	req.AddCookie(cookie)
	res, err := stdhttp.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("do: %v", err)
	}
	defer res.Body.Close()
	if res.StatusCode != stdhttp.StatusOK {
		t.Fatalf("status: got %d", res.StatusCode)
	}
	body := readBody(t, res.Body)
	// The selected summary card should reference the snapshot's short ID.
	if !strings.Contains(body, sid[:8]) {
		t.Errorf("expected snapshot short id in body")
	}
	if !strings.Contains(body, "picked from") {
		t.Errorf("expected 'picked from N snapshots' summary line")
	}
}

// TestRestorePostRequiresSnapshot: form without snapshot_id re-renders
// with an error.
func TestRestorePostRequiresSnapshot(t *testing.T) {
	t.Parallel()
	srv, ts, st := rawTestServerWithUI(t)
	hostID, _ := enrolHostForUI(t, srv, st, "rstore-no-snap")
	cookie := loginAsAdmin(t, st)

	form := url.Values{
		"snapshot_id": {""},
		"target_mode": {"new_dir"},
		"paths":       {"/etc/foo"},
	}
	req, _ := stdhttp.NewRequest("POST",
		ts.URL+"/hosts/"+hostID+"/restore", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.AddCookie(cookie)
	res, err := stdhttp.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("do: %v", err)
	}
	defer res.Body.Close()
	if res.StatusCode != stdhttp.StatusUnprocessableEntity {
		t.Fatalf("status: got %d, want 422", res.StatusCode)
	}
	body := readBody(t, res.Body)
	if !strings.Contains(body, "Pick a snapshot") {
		t.Errorf("expected 'Pick a snapshot' error in body")
	}
}

// TestRestorePostRequiresPaths: form with snapshot but no paths is rejected.
func TestRestorePostRequiresPaths(t *testing.T) {
	t.Parallel()
	srv, ts, st := rawTestServerWithUI(t)
	hostID, _ := enrolHostForUI(t, srv, st, "rstore-no-paths")
	sid := seedSnapshot(t, st, hostID, "rstore-no-paths")
	cookie := loginAsAdmin(t, st)

	form := url.Values{
		"snapshot_id": {sid},
		"target_mode": {"new_dir"},
	}
	req, _ := stdhttp.NewRequest("POST",
		ts.URL+"/hosts/"+hostID+"/restore", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.AddCookie(cookie)
	res, err := stdhttp.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("do: %v", err)
	}
	defer res.Body.Close()
	if res.StatusCode != stdhttp.StatusUnprocessableEntity {
		t.Fatalf("status: got %d, want 422", res.StatusCode)
	}
	body := readBody(t, res.Body)
	if !strings.Contains(body, "at least one file") {
		t.Errorf("expected paths-required error")
	}
}

// TestRestorePostInPlaceRequiresHostnameMatch: in-place mode with the
// wrong hostname typed re-renders + does not dispatch.
func TestRestorePostInPlaceRequiresHostnameMatch(t *testing.T) {
	t.Parallel()
	srv, ts, st := rawTestServerWithUI(t)
	hostID, token := enrolHostForUI(t, srv, st, "rstore-inplace")
	sid := seedSnapshot(t, st, hostID, "rstore-inplace")
	c := agentDial(t, srv, ts, hostID, token)
	sendHello(t, c, "rstore-inplace")
	_ = drainUntil(t, c, api.MsgScheduleSet)
	cookie := loginAsAdmin(t, st)

	form := url.Values{
		"snapshot_id":      {sid},
		"target_mode":      {"in_place"},
		"paths":            {"/etc/nginx/nginx.conf"},
		"confirm_hostname": {"WRONG"},
	}
	req, _ := stdhttp.NewRequest("POST",
		ts.URL+"/hosts/"+hostID+"/restore", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.AddCookie(cookie)
	res, err := stdhttp.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("do: %v", err)
	}
	defer res.Body.Close()
	if res.StatusCode != stdhttp.StatusUnprocessableEntity {
		t.Fatalf("status: got %d, want 422", res.StatusCode)
	}

	// No restore command should arrive at the agent.
	ctx, cancel := context.WithTimeout(context.Background(), 200*time.Millisecond)
	defer cancel()
	for {
		mt, raw, rerr := c.Read(ctx)
		if rerr != nil {
			break
		}
		if mt == websocket.MessageText && strings.Contains(string(raw), `"command.run"`) &&
			strings.Contains(string(raw), `"kind":"restore"`) {
			t.Fatal("unexpected restore command.run after wrong-hostname rejection")
		}
	}
}

// TestRestorePostHappyPathDispatches: well-formed new-directory form
// dispatches a JobRestore command.run with the expected payload + writes
// an audit row + redirects.
func TestRestorePostHappyPathDispatches(t *testing.T) {
	t.Parallel()
	srv, ts, st := rawTestServerWithUI(t)
	hostID, token := enrolHostForUI(t, srv, st, "rstore-happy")
	sid := seedSnapshot(t, st, hostID, "rstore-happy")
	c := agentDial(t, srv, ts, hostID, token)
	sendHello(t, c, "rstore-happy")
	_ = drainUntil(t, c, api.MsgScheduleSet)
	cookie := loginAsAdmin(t, st)

	form := url.Values{
		"snapshot_id": {sid},
		"target_mode": {"new_dir"},
		"paths":       {"/etc/nginx/nginx.conf", "/etc/nginx/sites-available/alfa.conf"},
	}
	req, _ := stdhttp.NewRequest("POST",
		ts.URL+"/hosts/"+hostID+"/restore", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.Header.Set("HX-Request", "true")
	req.AddCookie(cookie)
	// Don't follow redirects — we want to inspect the HX-Redirect header.
	client := &stdhttp.Client{
		CheckRedirect: func(*stdhttp.Request, []*stdhttp.Request) error {
			return stdhttp.ErrUseLastResponse
		},
	}
	res, err := client.Do(req)
	if err != nil {
		t.Fatalf("do: %v", err)
	}
	defer res.Body.Close()
	if res.StatusCode != stdhttp.StatusNoContent {
		t.Fatalf("status: got %d, want 204", res.StatusCode)
	}
	if res.Header.Get("HX-Redirect") == "" {
		t.Fatal("expected HX-Redirect header pointing at the live job page")
	}

	// Find the dispatched command.run on the agent socket.
	deadline := time.Now().Add(2 * time.Second)
	var got api.Envelope
	for time.Now().Before(deadline) {
		ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
		mt, raw, rerr := c.Read(ctx)
		cancel()
		if rerr != nil {
			break
		}
		if mt != websocket.MessageText {
			continue
		}
		if !strings.Contains(string(raw), `"command.run"`) || !strings.Contains(string(raw), `"kind":"restore"`) {
			continue
		}
		if err := json.Unmarshal(raw, &got); err != nil {
			t.Fatalf("unmarshal: %v", err)
		}
		break
	}
	if got.Type != api.MsgCommandRun {
		t.Fatal("never received restore command.run")
	}
	var cp api.CommandRunPayload
	if err := got.UnmarshalPayload(&cp); err != nil {
		t.Fatalf("unmarshal payload: %v", err)
	}
	if cp.Kind != api.JobRestore {
		t.Fatalf("kind: got %q", cp.Kind)
	}
	if cp.Restore == nil {
		t.Fatal("restore payload is nil")
	}
	if cp.Restore.SnapshotID != sid {
		t.Fatalf("snapshot id: got %q want %q", cp.Restore.SnapshotID, sid)
	}
	if cp.Restore.InPlace {
		t.Fatal("expected new-directory mode (in_place=false)")
	}
	if !strings.HasPrefix(cp.Restore.TargetDir, "$HOME/rm-restore/") {
		t.Fatalf("target_dir: got %q, want prefix $HOME/rm-restore/", cp.Restore.TargetDir)
	}
	// <job-id> placeholder substituted with the dispatched job_id.
	if !strings.Contains(cp.Restore.TargetDir, "/01") {
		t.Errorf("target_dir: expected job_id substituted into the path; got %q", cp.Restore.TargetDir)
	}
	if len(cp.Restore.Paths) != 2 {
		t.Fatalf("paths: got %d, want 2", len(cp.Restore.Paths))
	}

	// Audit row.
	var n int
	if err := st.DB().QueryRow(
		`SELECT COUNT(*) FROM audit_log WHERE action = 'host.restore' AND target_id = ?`,
		hostID).Scan(&n); err != nil {
		t.Fatalf("audit count: %v", err)
	}
	if n != 1 {
		t.Fatalf("audit rows: got %d, want 1", n)
	}
}

// TestRestorePostOfflineHostRejected: agent not connected → 503 +
// no command.run.
func TestRestorePostOfflineHostRejected(t *testing.T) {
	t.Parallel()
	srv, ts, st := rawTestServerWithUI(t)
	hostID, _ := enrolHostForUI(t, srv, st, "rstore-offline")
	sid := seedSnapshot(t, st, hostID, "rstore-offline")
	cookie := loginAsAdmin(t, st)

	form := url.Values{
		"snapshot_id": {sid},
		"target_mode": {"new_dir"},
		"paths":       {"/etc/foo"},
	}
	req, _ := stdhttp.NewRequest("POST",
		ts.URL+"/hosts/"+hostID+"/restore", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.AddCookie(cookie)
	res, err := stdhttp.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("do: %v", err)
	}
	defer res.Body.Close()
	if res.StatusCode != stdhttp.StatusServiceUnavailable {
		t.Fatalf("status: got %d, want 503", res.StatusCode)
	}
	_ = srv
}

// helpers --------------------------------------------------------------

func readBody(t *testing.T, body interface{ Read(p []byte) (int, error) }) string {
	t.Helper()
	buf := make([]byte, 0, 16*1024)
	tmp := make([]byte, 4096)
	for {
		n, err := body.Read(tmp)
		if n > 0 {
			buf = append(buf, tmp[:n]...)
		}
		if err != nil {
			break
		}
	}
	return string(buf)
}

func short(s string) string {
	if len(s) > 400 {
		return s[:400] + "…"
	}
	return s
}