package database_test

import (
	"context"
	"testing"
	"time"

	"github.com/google/uuid"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"gorm.io/gorm"
	"sneak.berlin/go/webhooker/internal/database"
)

// readTotals reads a webhook database's row of running totals,
// asserting that it has exactly one.
func readTotals(t *testing.T, db *gorm.DB) database.Totals {
	t.Helper()

	var rows []database.Totals

	require.NoError(t, db.Find(&rows).Error)
	require.Len(t, rows, 1)

	return rows[0]
}

// TestWebhookDBManager_TotalsRowSurvivesReopen verifies that a new
// event database starts with one row of zero totals, and that opening
// it again keeps that row and what was added to it.
func TestWebhookDBManager_TotalsRowSurvivesReopen(t *testing.T) {
	t.Parallel()

	mgr, lc := setupTestWebhookDBManager(t)
	ctx := context.Background()
	require.NoError(t, lc.Start(ctx))

	defer func() { require.NoError(t, lc.Stop(ctx)) }()

	webhookID := uuid.New().String()

	db, err := mgr.GetDB(webhookID)
	require.NoError(t, err)

	fresh := readTotals(t, db)
	assert.Equal(t, database.Totals{ID: fresh.ID}, fresh)

	require.NoError(t, database.AddTotals(db, database.Totals{
		Events: 2, Deliveries: 3, Failures: 1,
	}))

	// Drop the cached connection so the next open reopens the file,
	// as a restart would.
	require.NoError(t, mgr.CloseAll())

	db, err = mgr.GetDB(webhookID)
	require.NoError(t, err)

	assert.Equal(t, database.Totals{
		ID: fresh.ID, Events: 2, Deliveries: 3, Failures: 1,
	}, readTotals(t, db))
}

// TestRetentionReaper_AddsWhatItRemovesToTotals verifies that a sweep
// leaves the lifetime totals alone and adds the events, deliveries and
// failed deliveries it deletes to the removed totals, so the totals
// within retention match the rows still stored.
func TestRetentionReaper_AddsWhatItRemovesToTotals(t *testing.T) {
	t.Parallel()

	env := setupRetentionTest(t)

	webhookID := createWebhook(t, env.mainDB.DB(), 30)

	db, err := env.mgr.GetDB(webhookID)
	require.NoError(t, err)

	now := time.Now()
	expired := now.Add(-40 * 24 * time.Hour)

	seedEventChain(t, db, webhookID, expired)
	expiredFailure := seedEventChain(t, db, webhookID, expired)
	recentFailure := seedEventChain(
		t, db, webhookID, now.Add(-24*time.Hour),
	)

	for _, id := range []string{
		expiredFailure.deliveryID, recentFailure.deliveryID,
	} {
		require.NoError(t, db.Model(&database.Delivery{}).
			Where("id = ?", id).
			Update("status", database.DeliveryStatusFailed).Error)
	}

	// The totals storing those rows would have left.
	require.NoError(t, database.AddTotals(db, database.Totals{
		Events: 3, Deliveries: 3, Failures: 2,
	}))

	env.reaper.ExportSweep(context.Background())

	totals := readTotals(t, db)
	assert.Equal(t, database.Totals{
		ID:     totals.ID,
		Events: 3, Deliveries: 3, Failures: 2,
		EventsRemoved: 2, DeliveriesRemoved: 2, FailuresRemoved: 1,
	}, totals)

	var events, deliveries, failures int64

	require.NoError(t, db.Model(&database.Event{}).Count(&events).Error)
	require.NoError(t, db.Model(&database.Delivery{}).
		Count(&deliveries).Error)
	require.NoError(t, db.Model(&database.Delivery{}).
		Where("status = ?", database.DeliveryStatusFailed).
		Count(&failures).Error)

	assert.Equal(t, events, totals.EventsWithinRetention())
	assert.Equal(t, deliveries, totals.DeliveriesWithinRetention())
	assert.Equal(t, failures, totals.FailuresWithinRetention())

	// A sweep with nothing left to remove changes nothing.
	env.reaper.ExportSweep(context.Background())

	assert.Equal(t, totals, readTotals(t, db))
}