package handlers_test

import (
	"net/http"
	"net/http/httptest"
	"regexp"
	"strings"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"gorm.io/gorm"
	"gorm.io/gorm/clause"
	"sneak.berlin/go/webhooker/internal/database"
	"sneak.berlin/go/webhooker/internal/handlers"
	"sneak.berlin/go/webhooker/internal/logger"
	"sneak.berlin/go/webhooker/internal/session"
)

// failedHighlight is how the list marks a number of failed deliveries
// that is not zero.
const failedHighlight = `class="font-medium text-red-600"`

// listWebhook adds a webhook with the given name, owned by the test
// user.
func listWebhook(
	t *testing.T, db *database.Database, name string,
) *database.Webhook {
	t.Helper()

	wh := &database.Webhook{UserID: deleteTestUserID, Name: name}
	require.NoError(t, db.DB().Omit(clause.Associations).Create(wh).Error)

	return wh
}

// renderWebhookList runs the real webhook list handler as the test user
// and returns the rendered page.
func renderWebhookList(
	t *testing.T, h *handlers.Handlers, sess *session.Session,
) string {
	t.Helper()

	cookies := authenticatedCookies(
		t, sess, deleteTestUserID, deleteTestUsername,
	)

	w := httptest.NewRecorder()
	h.HandleSourceList().ServeHTTP(
		w, getRequest(t, "/hooks", cookies, nil),
	)
	require.Equal(t, http.StatusOK, w.Code)

	return w.Body.String()
}

// listCard returns one webhook's entry in a rendered webhook list, its
// markup as rendered and its text with the markup taken out and each
// run of space made one space.
func listCard(t *testing.T, page, webhookID string) (string, string) {
	t.Helper()

	_, card, found := strings.Cut(page, `href="/hook/`+webhookID+`"`)
	require.True(t, found, "the list has no entry for %s", webhookID)

	card, _, _ = strings.Cut(card, "</a>")
	text := regexp.MustCompile(`<[^>]*>`).ReplaceAllString(card, " ")

	return card, strings.Join(strings.Fields(text), " ")
}

// receiveEvents posts the given number of events to an entrypoint
// through the real receiver, and returns the webhook's event database
// and its events, oldest first.
func receiveEvents(
	t *testing.T,
	h *handlers.Handlers,
	dbMgr *database.WebhookDBManager,
	webhookID, path string,
	count int,
) (*gorm.DB, []database.Event) {
	t.Helper()

	router := receiverRouter(h)

	for range count {
		require.Equal(t, http.StatusOK, postReceiver(t, router, path))
	}

	webhookDB, err := dbMgr.GetDB(webhookID)
	require.NoError(t, err)

	events := listEvents(t, webhookDB)
	require.Len(t, events, count)

	return webhookDB, events
}

// seedFailingWebhook adds a webhook with two entrypoints, one inactive,
// and four targets, one inactive. Three events each reach the three
// active targets. Two deliveries failed in the last 24 hours, one 30
// hours ago, and one was delivered. It returns the webhook and its
// newest event.
func seedFailingWebhook(
	t *testing.T,
	h *handlers.Handlers,
	db *database.Database,
	dbMgr *database.WebhookDBManager,
) (*database.Webhook, database.Event) {
	t.Helper()

	wh := listWebhook(t, db, "failing")
	path := statsEntrypoint(t, db, wh.ID, true)

	statsEntrypoint(t, db, wh.ID, false)

	first := seedTarget(t, db, wh.ID, database.TargetTypeLog)
	second := seedTarget(t, db, wh.ID, database.TargetTypeLog)

	seedTarget(t, db, wh.ID, database.TargetTypeLog)

	inactive := seedTarget(t, db, wh.ID, database.TargetTypeLog)
	require.NoError(t, db.DB().Model(inactive).
		Update("active", false).Error)

	webhookDB, events := receiveEvents(t, h, dbMgr, wh.ID, path, 3)
	now := time.Now()

	statsFinish(t, webhookDB,
		statsDelivery(t, webhookDB, events[0].ID, first.ID),
		database.DeliveryStatusFailed, now.Add(-30*time.Hour))
	statsFinish(t, webhookDB,
		statsDelivery(t, webhookDB, events[1].ID, first.ID),
		database.DeliveryStatusFailed, now.Add(-time.Hour))
	statsFinish(t, webhookDB,
		statsDelivery(t, webhookDB, events[2].ID, first.ID),
		database.DeliveryStatusFailed, now.Add(-time.Minute))
	statsFinish(t, webhookDB,
		statsDelivery(t, webhookDB, events[2].ID, second.ID),
		database.DeliveryStatusDelivered, now.Add(-time.Minute))

	return wh, events[2]
}

// seedHealthyWebhook adds a webhook with one entrypoint and one target,
// both active, and two events, both delivered. It returns the webhook
// and its newest event.
func seedHealthyWebhook(
	t *testing.T,
	h *handlers.Handlers,
	db *database.Database,
	dbMgr *database.WebhookDBManager,
) (*database.Webhook, database.Event) {
	t.Helper()

	wh := listWebhook(t, db, "healthy")
	path := statsEntrypoint(t, db, wh.ID, true)
	target := seedTarget(t, db, wh.ID, database.TargetTypeLog)

	webhookDB, events := receiveEvents(t, h, dbMgr, wh.ID, path, 2)

	for _, ev := range events {
		statsFinish(t, webhookDB,
			statsDelivery(t, webhookDB, ev.ID, target.ID),
			database.DeliveryStatusDelivered, time.Now())
	}

	return wh, events[1]
}

// lastEventText is how the list shows the arrival of an event.
func lastEventText(ev database.Event) string {
	return ev.CreatedAt.UTC().Format("2006-01-02 15:04:05 UTC")
}

// TestSourceList_ShowsActivityOfEachWebhook checks the figures the list
// shows for a webhook with recent failures, a healthy one, a new one
// that has received no event, and one without an event database.
func TestSourceList_ShowsActivityOfEachWebhook(t *testing.T) {
	t.Parallel()

	var (
		h     *handlers.Handlers
		sess  *session.Session
		db    *database.Database
		dbMgr *database.WebhookDBManager
	)

	app := newTestApp(t, &h, &sess, &db, &dbMgr)
	app.RequireStart()

	t.Cleanup(app.RequireStop)

	failing, failingNewest := seedFailingWebhook(t, h, db, dbMgr)
	healthy, healthyNewest := seedHealthyWebhook(t, h, db, dbMgr)

	// Creating a webhook creates its event database.
	fresh := listWebhook(t, db, "fresh")
	require.NoError(t, dbMgr.CreateDB(fresh.ID))

	quiet := listWebhook(t, db, "quiet")

	page := renderWebhookList(t, h, sess)

	card, text := listCard(t, page, failing.ID)
	assert.Contains(t, text, "2 entrypoints, 1 inactive "+
		"4 targets, 1 inactive "+
		"3 events within retention "+
		"Last event "+lastEventText(failingNewest)+" "+
		"2 failed deliveries in the last 24 hours")
	assert.Contains(t, card,
		failedHighlight+">2 failed deliveries in the last 24 hours<")

	card, text = listCard(t, page, healthy.ID)
	assert.Contains(t, text, "1 entrypoint "+
		"1 target "+
		"2 events within retention "+
		"Last event "+lastEventText(healthyNewest)+" "+
		"0 failed deliveries in the last 24 hours")
	assert.NotContains(t, text, "inactive")
	assert.NotContains(t, card, failedHighlight)

	card, text = listCard(t, page, fresh.ID)
	assert.Contains(t, text, "0 entrypoints "+
		"0 targets "+
		"0 events within retention "+
		"No events yet "+
		"0 failed deliveries in the last 24 hours")
	assert.NotContains(t, card, failedHighlight)

	card, text = listCard(t, page, quiet.ID)
	assert.Contains(t, text, "0 entrypoints "+
		"0 targets "+
		"0 events within retention "+
		"No events yet "+
		"0 failed deliveries in the last 24 hours")
	assert.NotContains(t, card, failedHighlight)
	assert.False(t, dbMgr.DBExists(quiet.ID),
		"showing the list must not create an event database")
}

// TestSourceList_CountsOnlyEventsWithinRetention checks that once
// retention has removed one of a webhook's three events, the list
// counts the two still stored.
func TestSourceList_CountsOnlyEventsWithinRetention(t *testing.T) {
	t.Parallel()

	var (
		h     *handlers.Handlers
		sess  *session.Session
		db    *database.Database
		dbMgr *database.WebhookDBManager
		log   *logger.Logger
	)

	app := newTestApp(t, &h, &sess, &db, &dbMgr, &log)
	app.RequireStart()

	t.Cleanup(app.RequireStop)

	wh := &database.Webhook{
		UserID: deleteTestUserID, Name: "pruned", RetentionDays: 14,
	}
	require.NoError(t, db.DB().Omit(clause.Associations).Create(wh).Error)

	path := statsEntrypoint(t, db, wh.ID, true)
	webhookDB, events := receiveEvents(t, h, dbMgr, wh.ID, path, 3)

	statsAge(t, webhookDB, events[0].ID, time.Now().Add(-15*24*time.Hour))
	statsPrune(t, db, dbMgr, log, webhookDB)
	require.Len(t, listEvents(t, webhookDB), 2)

	_, text := listCard(t, renderWebhookList(t, h, sess), wh.ID)
	assert.Contains(t, text,
		"1 entrypoint 0 targets 2 events within retention")
}

// TestSourceList_UnreadableEventDatabase checks that a webhook whose
// event database cannot be read says so in its entry instead of
// showing zeros, and that the rest of the list is still shown.
func TestSourceList_UnreadableEventDatabase(t *testing.T) {
	t.Parallel()

	var (
		h     *handlers.Handlers
		sess  *session.Session
		db    *database.Database
		dbMgr *database.WebhookDBManager
	)

	app := newTestApp(t, &h, &sess, &db, &dbMgr)
	app.RequireStart()

	t.Cleanup(app.RequireStop)

	broken := listWebhook(t, db, "broken")
	statsEntrypoint(t, db, broken.ID, true)

	brokenDB, err := dbMgr.GetDB(broken.ID)
	require.NoError(t, err)
	require.NoError(t,
		brokenDB.Migrator().DropTable(&database.EventTotals{}))

	quiet := listWebhook(t, db, "quiet")

	page := renderWebhookList(t, h, sess)

	_, text := listCard(t, page, broken.ID)
	assert.Contains(t, text,
		"1 entrypoint 0 targets The event figures could not be read.")
	assert.NotContains(t, text, "events")
	assert.NotContains(t, text, "failed")

	_, text = listCard(t, page, quiet.ID)
	assert.Contains(t, text, "No events yet")
}