package handlers_test

import (
	"net/http"
	"net/http/httptest"
	"testing"

	"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/delivery"
	"sneak.berlin/go/webhooker/internal/handlers"
	"sneak.berlin/go/webhooker/internal/session"
)

// paramDeliveryID is the chi URL parameter name the replay handler
// reads.
const paramDeliveryID = "deliveryID"

// replayTargetURL is a public destination, so a target configured with
// it is one the SSRF guard would accept. Nothing in these tests
// dispatches to it: the notifier is recorded, not run.
const replayTargetURL = "http://93.184.216.34/hook"

// seedFailedDelivery records an event, a terminally failed delivery of
// it to the given target, and the attempt that failed.
func seedFailedDelivery(
	t *testing.T,
	dbMgr *database.WebhookDBManager,
	webhookID, targetID string,
) (*database.Event, *database.Delivery) {
	t.Helper()

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

	event := &database.Event{
		WebhookID:    webhookID,
		EntrypointID: "entrypoint-" + webhookID,
		Method:       http.MethodPost,
		Headers:      `{"X-Test":["yes"]}`,
		Body:         `{"replay":"me"}`,
		ContentType:  contentTypeJSON,
	}

	require.NoError(t, webhookDB.Omit(
		clause.Associations,
	).Create(event).Error)

	dlv := &database.Delivery{
		EventID:  event.ID,
		TargetID: targetID,
		Status:   database.DeliveryStatusFailed,
	}

	require.NoError(t, webhookDB.Omit(
		clause.Associations,
	).Create(dlv).Error)

	result := &database.DeliveryResult{
		DeliveryID: dlv.ID,
		AttemptNum: 1,
		Success:    false,
		StatusCode: http.StatusBadGateway,
		Error:      "connection refused",
	}

	require.NoError(t, webhookDB.Omit(
		clause.Associations,
	).Create(result).Error)

	return event, dlv
}

// loadDelivery reads a delivery back out of a webhook's database.
func loadDelivery(
	t *testing.T, webhookDB *gorm.DB, deliveryID string,
) database.Delivery {
	t.Helper()

	var dlv database.Delivery

	require.NoError(
		t,
		webhookDB.First(&dlv, "id = ?", deliveryID).Error,
	)

	return dlv
}

// listDeliveries reads every delivery of an event.
func listDeliveries(
	t *testing.T, webhookDB *gorm.DB, eventID string,
) []database.Delivery {
	t.Helper()

	var deliveries []database.Delivery

	require.NoError(t, webhookDB.Where(
		"event_id = ?", eventID,
	).Find(&deliveries).Error)

	return deliveries
}

// theOtherDelivery returns the one delivery in the slice that is not
// excludeID. Identity is used rather than an ordering because the rows
// are minted milliseconds apart and their ids are random.
func theOtherDelivery(
	t *testing.T,
	deliveries []database.Delivery,
	excludeID string,
) database.Delivery {
	t.Helper()

	var found []database.Delivery

	for _, d := range deliveries {
		if d.ID != excludeID {
			found = append(found, d)
		}
	}

	require.Len(t, found, 1)

	return found[0]
}

// postReplay runs the real replay handler for one delivery.
func postReplay(
	t *testing.T,
	h *handlers.Handlers,
	sess *session.Session,
	webhookID, deliveryID string,
) *httptest.ResponseRecorder {
	t.Helper()

	req := postRequest(
		"/source/"+webhookID+"/deliveries/"+
			deliveryID+"/replay",
		authenticatedCookies(
			t, sess, deleteTestUserID, deleteTestUsername,
		),
		map[string]string{
			paramSourceID:   webhookID,
			paramDeliveryID: deliveryID,
		},
	)

	w := httptest.NewRecorder()
	h.HandleDeliveryReplay().ServeHTTP(w, req)

	return w
}

// TestHandleDeliveryReplay_AppendsDeliveryAndLeavesOriginal is the
// core requirement: replaying a failed delivery succeeds, appends a
// new delivery, and leaves the original row and its recorded attempt
// exactly as they were.
//
// It also pins the two things a replay would be wrong to get from the
// original: the task carries the target's CURRENT configuration, which
// this test changes between the failure and the replay, and it carries
// the stored EVENT body rather than anything the failed attempt
// received back.
func TestHandleDeliveryReplay_AppendsDeliveryAndLeavesOriginal(
	t *testing.T,
) {
	t.Parallel()

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

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

	t.Cleanup(app.RequireStop)

	wh := seedWebhook(t, db)
	tgt := seedConfiguredTarget(
		t, db, wh.ID, database.TargetTypeHTTP,
		`{"url":"`+replayTargetURL+`"}`,
	)

	event, original := seedFailedDelivery(
		t, dbMgr, wh.ID, tgt.ID,
	)

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

	before := loadDelivery(t, webhookDB, original.ID)

	// The operator fixes the destination, which is the whole reason
	// to replay. The replay must use this, not the config the
	// original delivery ran against.
	const fixedConfig = `{"url":"http://93.184.216.34/fixed"}`

	require.NoError(t, db.DB().Model(&database.Target{}).
		Where("id = ?", tgt.ID).
		Update("config", fixedConfig).Error)

	w := postReplay(t, h, sess, wh.ID, original.ID)

	require.Equal(t, http.StatusSeeOther, w.Code)
	assert.Equal(
		t,
		"/source/"+wh.ID+"/logs?replay=queued",
		w.Header().Get("Location"),
	)

	deliveries := listDeliveries(t, webhookDB, event.ID)
	require.Len(
		t, deliveries, 2,
		"replay must append a delivery, not reuse one",
	)

	replayed := theOtherDelivery(t, deliveries, original.ID)
	assert.Equal(t, tgt.ID, replayed.TargetID)
	assert.Equal(t, event.ID, replayed.EventID)
	assert.Equal(
		t, database.DeliveryStatusPending, replayed.Status,
	)

	assertDeliveryUntouched(t, webhookDB, before)

	tasks := notif.Tasks()
	require.Len(t, tasks, 1)
	assertReplayTask(
		t, tasks[0], wh.ID, event, tgt, replayed.ID, fixedConfig,
	)
	assertNoLeakedTarget(t, webhookDB)
}

// assertDeliveryUntouched proves a delivery row is exactly as it was
// read before: same terminal status, same timestamps, and the same
// recorded attempts.
func assertDeliveryUntouched(
	t *testing.T,
	webhookDB *gorm.DB,
	before database.Delivery,
) {
	t.Helper()

	after := loadDelivery(t, webhookDB, before.ID)
	assert.Equal(
		t, before.Status, after.Status,
		"replay must not resurrect the original delivery",
	)
	assert.Equal(t, before.UpdatedAt, after.UpdatedAt)
	assert.Equal(t, before.CreatedAt, after.CreatedAt)

	var attempts int64

	require.NoError(t, webhookDB.
		Model(&database.DeliveryResult{}).
		Where("delivery_id = ?", before.ID).
		Count(&attempts).Error)
	assert.Equal(
		t, int64(1), attempts,
		"the original delivery's attempt history must stand",
	)
}

// assertReplayTask proves the task handed to the delivery engine is
// the one the receiver would build for this event and this target, and
// that it carries wantConfig — the target's configuration as it stands
// now rather than as the original delivery ran against it.
func assertReplayTask(
	t *testing.T,
	task delivery.Task,
	webhookID string,
	event *database.Event,
	target *database.Target,
	wantDeliveryID, wantConfig string,
) {
	t.Helper()

	assert.Equal(t, wantDeliveryID, task.DeliveryID)
	assert.Equal(t, event.ID, task.EventID)
	assert.Equal(t, webhookID, task.WebhookID)
	assert.Equal(t, event.EntrypointID, task.EntrypointID)
	assert.Equal(t, target.ID, task.TargetID)
	assert.Equal(t, target.Type, task.TargetType)
	assert.JSONEq(
		t, wantConfig, task.TargetConfig,
		"replay must use the target's current configuration",
	)
	assert.Equal(t, event.Method, task.Method)
	assert.Equal(t, event.Headers, task.Headers)
	assert.Equal(t, event.ContentType, task.ContentType)
	assert.Equal(t, 1, task.AttemptNum)
	require.NotNil(t, task.Body)
	assert.Equal(
		t, event.Body, *task.Body,
		"replay re-sends the stored event body",
	)
}

// assertNoLeakedTarget proves the per-webhook database holds no target
// rows. AutoMigrate creates the table there because Delivery declares
// the relation, so it is a ROW that signals a leak: an association
// write would have upserted the whole target, plaintext config and
// all, into the event database. See
// https://git.eeqj.de/sneak/webhooker/issues/206.
func assertNoLeakedTarget(t *testing.T, webhookDB *gorm.DB) {
	t.Helper()

	var leaked int64

	require.NoError(t, webhookDB.Unscoped().
		Model(&database.Target{}).Count(&leaked).Error)
	assert.Zero(
		t, leaked,
		"replay must not write the target into the event database",
	)
}

// TestHandleDeliveryReplay_RefusesDeletedTarget proves the required
// refusal: a target deleted since the delivery ran is reported as
// deleted rather than erroring, and nothing is created or queued.
func TestHandleDeliveryReplay_RefusesDeletedTarget(t *testing.T) {
	t.Parallel()

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

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

	t.Cleanup(app.RequireStop)

	wh := seedWebhook(t, db)
	tgt := seedConfiguredTarget(
		t, db, wh.ID, database.TargetTypeHTTP,
		`{"url":"`+replayTargetURL+`"}`,
	)

	event, original := seedFailedDelivery(
		t, dbMgr, wh.ID, tgt.ID,
	)

	// Deletes are soft, so the delivery history outlives the target.
	require.NoError(t, db.DB().Where(
		"id = ?", tgt.ID,
	).Delete(&database.Target{}).Error)

	w := postReplay(t, h, sess, wh.ID, original.ID)

	require.Equal(t, http.StatusSeeOther, w.Code)
	assert.Equal(
		t,
		"/source/"+wh.ID+"/logs?replay=target-deleted",
		w.Header().Get("Location"),
	)

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

	assert.Len(
		t, listDeliveries(t, webhookDB, event.ID), 1,
		"a refused replay must create no delivery",
	)
	assert.Empty(
		t, notif.Tasks(),
		"a refused replay must queue nothing",
	)

	// The refusal is specific, which is why the target is looked up
	// including soft-deleted rows: an id that never named a target
	// is a different outcome, and a different message, from one the
	// operator deleted.
	_, orphan := seedFailedDelivery(
		t, dbMgr, wh.ID, "target-that-never-existed",
	)

	missing := postReplay(t, h, sess, wh.ID, orphan.ID)
	require.Equal(t, http.StatusSeeOther, missing.Code)
	assert.Equal(
		t,
		"/source/"+wh.ID+"/logs?replay=target-missing",
		missing.Header().Get("Location"),
	)
}

// TestHandleDeliveryReplay_RefusesWhileEarlierReplayInFlight proves
// the replay-storm guard: a second replay of the same event to the
// same target is refused while the first is still queued, so repeated
// submissions cannot stack copies of work the engine has not done.
func TestHandleDeliveryReplay_RefusesWhileEarlierReplayInFlight(
	t *testing.T,
) {
	t.Parallel()

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

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

	t.Cleanup(app.RequireStop)

	wh := seedWebhook(t, db)
	tgt := seedConfiguredTarget(
		t, db, wh.ID, database.TargetTypeHTTP,
		`{"url":"`+replayTargetURL+`"}`,
	)

	event, original := seedFailedDelivery(
		t, dbMgr, wh.ID, tgt.ID,
	)

	first := postReplay(t, h, sess, wh.ID, original.ID)
	require.Equal(t, http.StatusSeeOther, first.Code)
	require.Equal(
		t,
		"/source/"+wh.ID+"/logs?replay=queued",
		first.Header().Get("Location"),
	)

	second := postReplay(t, h, sess, wh.ID, original.ID)
	require.Equal(t, http.StatusSeeOther, second.Code)
	assert.Equal(
		t,
		"/source/"+wh.ID+"/logs?replay=in-flight",
		second.Header().Get("Location"),
	)

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

	assert.Len(
		t, listDeliveries(t, webhookDB, event.ID), 2,
		"the refused second replay must add nothing",
	)
	assert.Len(
		t, notif.Tasks(), 1,
		"only the first replay reaches the delivery engine",
	)

	// A delivery the engine has not finished is not replayable
	// either, which is the same rule seen from the other side.
	queued := theOtherDelivery(
		t, listDeliveries(t, webhookDB, event.ID), original.ID,
	)

	pending := postReplay(t, h, sess, wh.ID, queued.ID)
	require.Equal(t, http.StatusSeeOther, pending.Code)
	assert.Equal(
		t,
		"/source/"+wh.ID+"/logs?replay=not-terminal",
		pending.Header().Get("Location"),
	)
}

// TestHandleSourceLogs_RendersReplayControlAndBanner proves the action
// reaches the page it belongs on: a finished delivery renders a POST
// form carrying a CSRF token, and the outcome code a refusal redirects
// with becomes a readable message.
func TestHandleSourceLogs_RendersReplayControlAndBanner(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)

	wh := seedWebhook(t, db)
	tgt := seedConfiguredTarget(
		t, db, wh.ID, database.TargetTypeHTTP,
		`{"url":"`+replayTargetURL+`"}`,
	)

	_, original := seedFailedDelivery(t, dbMgr, wh.ID, tgt.ID)

	body := renderSourceLogsPage(t, h, sess, wh.ID)

	assert.Contains(
		t, body,
		`action="/source/`+wh.ID+`/deliveries/`+
			original.ID+`/replay"`,
	)
	assert.Contains(t, body, `method="POST"`)
	assert.Contains(t, body, `name="csrf_token"`)
	assert.Contains(t, body, ">Replay<")

	refused := renderSourceLogsPageWithQuery(
		t, h, sess, wh.ID, "?replay=target-deleted",
	)

	assert.Contains(t, refused, "alert-error")
	assert.Contains(t, refused, "has been deleted")

	// An outcome code nobody issued renders no banner at all.
	unknown := renderSourceLogsPageWithQuery(
		t, h, sess, wh.ID, "?replay=made-up",
	)

	assert.NotContains(t, unknown, "alert-error")
	assert.NotContains(t, unknown, "alert-success")
	assert.NotContains(t, unknown, "made-up")
}