package user

import (
	"encoding/json"
	"net/http"
	"strings"
	"testing"
	"time"

	"git.golem15.com/golem15/sm-user-plugin/classes"
	"git.golem15.com/golem15/sm-user-plugin/controllers"
	"git.golem15.com/golem15/sm-user-plugin/models"
	"gorm.io/gorm"
)

// TestLastSeen covers users.last_seen (D-17, D-29): login and refresh stamp
// it at most once per five minutes, a failing write never fails them, and it
// never reaches a user API payload.
func TestLastSeen(t *testing.T) {
	app, gdb := sessionApp(t, "0s")
	user := insertUser(t, gdb, "last-seen@example.test", "correct-horse")
	const credentials = `{"email":"last-seen@example.test","password":"correct-horse"}`

	lastSeen := func() *time.Time {
		t.Helper()
		var row struct{ LastSeen *time.Time }
		if err := gdb.Raw(`SELECT last_seen FROM users WHERE id = ?`, user.ID).Scan(&row).Error; err != nil {
			t.Fatal(err)
		}
		return row.LastSeen
	}
	setLastSeen := func(age time.Duration) time.Time {
		t.Helper()
		at := time.Now().Add(-age).Truncate(time.Microsecond)
		if err := gdb.Exec(`UPDATE users SET last_seen = ? WHERE id = ?`, at, user.ID).Error; err != nil {
			t.Fatal(err)
		}
		return at
	}
	login := func() (string, map[string]any, string) {
		t.Helper()
		rec := postJSON(t, controllers.Login(app), "/_user/api/v1/login", credentials)
		if rec.Code != http.StatusOK {
			t.Fatalf("login %d %s", rec.Code, rec.Body.String())
		}
		var body struct {
			Token string         `json:"token"`
			User  map[string]any `json:"user"`
		}
		if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
			t.Fatal(err)
		}
		if body.Token == "" || len(body.User) == 0 {
			t.Fatalf("login body %s", rec.Body.String())
		}
		return body.Token, body.User, rec.Body.String()
	}
	refresh := func(token string) (string, string) {
		t.Helper()
		rec := bearer(t, controllers.Refresh(app), http.MethodPost, "/_user/api/v1/refresh", token)
		if rec.Code != http.StatusOK {
			t.Fatalf("refresh %d %s", rec.Code, rec.Body.String())
		}
		var body map[string]any
		if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
			t.Fatal(err)
		}
		next, _ := body["token"].(string)
		if next == "" || len(body) != 1 {
			t.Fatalf("refresh body %s", rec.Body.String())
		}
		return next, rec.Body.String()
	}
	updatedAt := func() time.Time {
		t.Helper()
		var at time.Time
		if err := gdb.Raw(`SELECT updated_at FROM users WHERE id = ?`, user.ID).Scan(&at).Error; err != nil {
			t.Fatal(err)
		}
		return at
	}

	if lastSeen() != nil {
		t.Fatal("a new user already has last_seen")
	}
	stampedBefore := updatedAt()

	// A login stamps it.
	started := time.Now().Add(-time.Second)
	token, payload, raw := login()
	first := lastSeen()
	if first == nil || first.Before(started) || first.After(time.Now().Add(time.Second)) {
		t.Fatalf("last_seen after the first login = %v", first)
	}
	if !updatedAt().Equal(stampedBefore) {
		t.Fatal("stamping last_seen touched updated_at")
	}
	// A second login and a refresh inside five minutes leave it alone.
	token2, _, _ := login()
	if got := lastSeen(); got == nil || !got.Equal(*first) {
		t.Fatalf("a second login inside five minutes moved last_seen: %v -> %v", first, got)
	}
	token, _ = refresh(token)
	if got := lastSeen(); got == nil || !got.Equal(*first) {
		t.Fatalf("a refresh inside five minutes moved last_seen: %v -> %v", first, got)
	}

	// Six minutes later a refresh stamps it again, and so does a login.
	old := setLastSeen(6 * time.Minute)
	_, refreshRaw := refresh(token)
	afterRefresh := lastSeen()
	if afterRefresh == nil || !afterRefresh.After(old.Add(5*time.Minute)) {
		t.Fatalf("a refresh after six minutes did not stamp last_seen: %v (was %v)", afterRefresh, old)
	}
	old = setLastSeen(6 * time.Minute)
	login()
	if got := lastSeen(); got == nil || !got.After(old.Add(5*time.Minute)) {
		t.Fatalf("a login after six minutes did not stamp last_seen: %v", got)
	}
	// Four minutes is inside the window.
	recent := setLastSeen(4 * time.Minute)
	refresh(token2)
	if got := lastSeen(); got == nil || !got.Equal(recent) {
		t.Fatalf("a refresh after four minutes moved last_seen: %v -> %v", recent, got)
	}

	// A failing write never fails authentication: with a trigger that
	// refuses every last_seen update, login and refresh still answer 200
	// with the same body shape.
	// last_seen is ten minutes old, so both handlers attempt the write.
	blocked := setLastSeen(10 * time.Minute)
	drop := func() {
		gdb.Exec(`DROP TRIGGER IF EXISTS test_refuse_last_seen ON users`)
		gdb.Exec(`DROP FUNCTION IF EXISTS test_refuse_last_seen()`)
	}
	t.Cleanup(drop)
	for _, stmt := range []string{
		`CREATE OR REPLACE FUNCTION test_refuse_last_seen() RETURNS trigger AS $$ BEGIN RAISE EXCEPTION 'last_seen cannot be written in this test'; END $$ LANGUAGE plpgsql`,
		`CREATE TRIGGER test_refuse_last_seen BEFORE UPDATE OF last_seen ON users FOR EACH ROW EXECUTE FUNCTION test_refuse_last_seen()`,
	} {
		if err := gdb.Exec(stmt).Error; err != nil {
			t.Fatal(err)
		}
	}
	if err := classes.TouchLastSeen(t.Context(), gdb, user.ID); err == nil {
		t.Fatal("the test trigger does not refuse the write, or TouchLastSeen swallowed the failure")
	}
	failedToken, failedPayload, _ := login()
	_, failedRefreshRaw := refresh(failedToken)
	if got := lastSeen(); got == nil || !got.Equal(blocked) {
		t.Fatalf("last_seen changed although the write is refused: %v -> %v", blocked, got)
	}
	if len(failedPayload) != len(payload) {
		t.Fatalf("the login payload changed shape when the write failed: %v vs %v", failedPayload, payload)
	}
	for key := range payload {
		if _, ok := failedPayload[key]; !ok {
			t.Fatalf("the login payload lost %s when the write failed", key)
		}
	}
	if !strings.HasPrefix(failedRefreshRaw, `{"token":"`) || !strings.HasPrefix(refreshRaw, `{"token":"`) {
		t.Fatalf("refresh bodies: %s / %s", refreshRaw, failedRefreshRaw)
	}
	drop()

	// No user payload carries the admin columns; permissions stays null and
	// groups an empty list.
	current, _, _ := login()
	fetch := bearer(t, controllers.Fetch(app), http.MethodGet, "/_user/api/v1/fetch", current)
	if fetch.Code != http.StatusOK {
		t.Fatalf("fetch %d %s", fetch.Code, fetch.Body.String())
	}
	var fetched struct {
		User map[string]any `json:"user"`
	}
	if err := json.Unmarshal(fetch.Body.Bytes(), &fetched); err != nil {
		t.Fatal(err)
	}
	for name, body := range map[string]string{"login": raw, "fetch": fetch.Body.String(), "refresh": refreshRaw} {
		for _, key := range []string{"last_seen", "created_at", "updated_at", "LastSeen", "CreatedAt", "UpdatedAt", "Permissions"} {
			if strings.Contains(body, `"`+key+`"`) {
				t.Fatalf("the %s body carries %s: %s", name, key, body)
			}
		}
	}
	for name, got := range map[string]map[string]any{"login": payload, "fetch": fetched.User} {
		if value, ok := got["permissions"]; !ok || value != nil {
			t.Fatalf("%s payload permissions = %v (%v)", name, value, ok)
		}
		if groups, ok := got["groups"].([]any); !ok || len(groups) != 0 {
			t.Fatalf("%s payload groups = %v", name, got["groups"])
		}
	}

	// The model itself never serializes them either.
	now := time.Now()
	marshalled, err := json.Marshal(models.User{
		ID: 1, Email: "marshal@example.test", LastSeen: &now, CreatedAt: now, UpdatedAt: now,
		Permissions: models.PermissionSet{"blog.post": 1}, Groups: []models.UserGroup{{Name: "Admins"}},
	})
	if err != nil {
		t.Fatal(err)
	}
	lower := strings.ToLower(string(marshalled))
	for _, key := range []string{"last_seen", "lastseen", "permissions", "created_at", "createdat", "updated_at", "updatedat", "groups", "blog.post", "admins"} {
		if strings.Contains(lower, key) {
			t.Fatalf("a marshalled user carries %s: %s", key, marshalled)
		}
	}
	if strings.Contains(string(marshalled), `"Password"`) {
		t.Fatalf("a marshalled user carries the password: %s", marshalled)
	}

	// The helper itself: a deactivated user is stamped, an unknown id and a
	// zero id are no error, a missing handle is.
	if err := gdb.Exec(`UPDATE users SET last_seen = NULL, deleted_at = NOW() WHERE id = ?`, user.ID).Error; err != nil {
		t.Fatal(err)
	}
	if err := classes.TouchLastSeen(t.Context(), gdb, user.ID); err != nil || lastSeen() == nil {
		t.Fatalf("a deactivated user was not stamped: %v", err)
	}
	if err := classes.TouchLastSeen(t.Context(), gdb, 987654321); err != nil {
		t.Fatal(err)
	}
	if err := classes.TouchLastSeen(t.Context(), gdb, 0); err != nil {
		t.Fatal(err)
	}
	if err := classes.TouchLastSeen(t.Context(), (*gorm.DB)(nil), user.ID); err == nil {
		t.Fatal("TouchLastSeen without a handle")
	}
}