package processor

import (
	"context"
	"os"
	"sync"
	"testing"
	"time"

	"github.com/alicebob/miniredis/v2"
	"github.com/google/uuid"
	"github.com/redis/go-redis/v9"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"

	"apskel-pos-be/internal/appcontext"
	"apskel-pos-be/internal/constants"
	"apskel-pos-be/internal/models"
	"apskel-pos-be/internal/repository"
)

// pointPaymentEnv is an order flow wired as in the app, against Postgres and a
// miniredis for payment codes.
type pointPaymentEnv struct {
	t        *testing.T
	db       *gorm.DB
	orders   *OrderProcessorImpl
	payments *PointPaymentProcessor
	codes    *PaymentCodeProcessor
	org      uuid.UUID
	cashier  uuid.UUID
	outlet   uuid.UUID
	point    uuid.UUID
	cash     uuid.UUID
	walkIn   uuid.UUID
	ctx      context.Context
}

func newPointPaymentEnv(t *testing.T) *pointPaymentEnv {
	t.Helper()
	dsn := os.Getenv("TEST_DATABASE_URL")
	if dsn == "" {
		t.Skip("TEST_DATABASE_URL not set")
	}
	db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{Logger: logger.Default.LogMode(logger.Silent)})
	require.NoError(t, err)
	e := &pointPaymentEnv{t: t, db: db, org: uuid.New(), cashier: uuid.New(), outlet: uuid.New(), cash: uuid.New()}
	e.exec(`INSERT INTO organizations (id, name, plan_type) VALUES (?, 'point pay test', 'basic')`, e.org)
	e.exec(`INSERT INTO users (id, organization_id, name, email, password_hash, role) VALUES (?, ?, 'Kasir', ?, 'x', 'cashier')`, e.cashier, e.org, e.cashier.String()+"@t")
	e.exec(`INSERT INTO outlets (id, organization_id, name) VALUES (?, ?, 'Kemang')`, e.outlet, e.org)
	e.exec(`INSERT INTO payment_methods (id, organization_id, name, type) VALUES (?, ?, 'Tunai', 'cash')`, e.cash, e.org)
	var ids []string
	require.NoError(t, db.Raw(`SELECT id::text FROM payment_methods WHERE organization_id = ? AND type = 'point'`, e.org).Scan(&ids).Error)
	require.Len(t, ids, 1)
	e.point = uuid.MustParse(ids[0])
	require.NoError(t, db.Raw(`SELECT id::text FROM customers WHERE organization_id = ? AND is_default`, e.org).Scan(&ids).Error)
	e.walkIn = uuid.MustParse(ids[0])
	t.Cleanup(func() {
		db.Exec(`DELETE FROM wallet_lot_allocations WHERE lot_id IN (SELECT id FROM wallet_lots WHERE organization_id = ?)`, e.org)
		db.Exec(`DELETE FROM wallet_lots WHERE organization_id = ?`, e.org)
		db.Exec(`DELETE FROM wallet_transactions WHERE organization_id = ?`, e.org)
		db.Exec(`DELETE FROM customer_wallets WHERE organization_id = ?`, e.org)
		db.Exec(`DELETE FROM payments WHERE order_id IN (SELECT id FROM orders WHERE organization_id = ?)`, e.org)
		db.Exec(`DELETE FROM orders WHERE organization_id = ?`, e.org)
		db.Exec(`DELETE FROM loyalty_setting_changes WHERE organization_id = ?`, e.org)
		db.Exec(`DELETE FROM outlet_settings WHERE outlet_id = ?`, e.outlet)
		db.Exec(`DELETE FROM payment_methods WHERE organization_id = ?`, e.org)
		db.Exec(`DELETE FROM customers WHERE organization_id = ?`, e.org)
		db.Exec(`DELETE FROM outlets WHERE id = ?`, e.outlet)
		db.Exec(`DELETE FROM users WHERE id = ?`, e.cashier)
		db.Exec(`DELETE FROM organizations WHERE id = ?`, e.org)
	})

	txm := repository.NewTxManager(db)
	settings := NewLoyaltySettingsProcessor(repository.NewLoyaltySettingsRepository(db), txm)
	wallet := NewWalletProcessor(repository.NewWalletRepository(db))
	e.payments = NewPointPaymentProcessor(repository.NewPointPaymentRepository(db), settings, repository.NewWalletQueryRepository(db), wallet, txm)
	mr := miniredis.RunT(t)
	client := redis.NewClient(&redis.Options{Addr: mr.Addr()})
	t.Cleanup(func() { client.Close() })
	e.codes = NewPaymentCodeProcessor(repository.NewPaymentCodeRepository(client), pinVerifierFake{good: "482913"})

	e.orders = &OrderProcessorImpl{
		orderRepo:          repository.NewOrderRepositoryImpl(db),
		orderItemRepo:      repository.NewOrderItemRepositoryImpl(db),
		paymentRepo:        repository.NewPaymentRepositoryImpl(db),
		paymentMethodRepo:  repository.NewPaymentMethodRepositoryImpl(db),
		splitBillProcessor: nil,
		txManager:          txm,
	}
	e.orders.SetLoyalty(NewEarningProcessor(repository.NewEarningRepository(db), settings, wallet, txm))
	e.orders.SetPointPayments(e.payments, e.codes, pinVerifierFake{good: "482913"})

	// The outlet earns 1 EnakPoint per Rp 100 and accepts EnakPoint.
	s, err := settings.Outlet(context.Background(), e.outlet)
	require.NoError(t, err)
	s.Point.Enabled = true
	s.PointPayment.AcceptPayment = true
	_, err = settings.UpdateOutlet(context.Background(), e.org, e.outlet, e.cashier, *s)
	require.NoError(t, err)

	e.ctx = context.WithValue(context.Background(), appcontext.UserIDKey, e.cashier.String())
	return e
}

func (e *pointPaymentEnv) exec(q string, args ...any) {
	e.t.Helper()
	require.NoError(e.t, e.db.Exec(q, args...).Error)
}

// customerWith creates a customer holding the given EnakPoint.
func (e *pointPaymentEnv) customerWith(points int64) uuid.UUID {
	e.t.Helper()
	id := uuid.New()
	e.exec(`INSERT INTO customers (id, organization_id, name) VALUES (?, ?, 'c')`, id, e.org)
	if points > 0 {
		require.NoError(e.t, repository.NewTxManager(e.db).WithTransaction(context.Background(), func(ctx context.Context) error {
			_, err := NewWalletProcessor(repository.NewWalletRepository(e.db)).Credit(ctx, WalletCreditInput{WalletEntry: WalletEntry{
				CustomerID: id, Currency: constants.WalletCurrencyPoint, Type: constants.WalletTxTypeMigration, Amount: points,
				ReferenceType: constants.WalletRefTypeLegacyPoints, ReferenceID: uuid.New(), Description: "Saldo awal"}})
			return err
		}))
	}
	return id
}

func (e *pointPaymentEnv) order(customer uuid.UUID, subtotal float64) uuid.UUID {
	e.t.Helper()
	id := uuid.New()
	e.exec(`INSERT INTO orders (id, organization_id, outlet_id, user_id, customer_id, order_number, order_type,
		subtotal, tax_amount, total_amount, remaining_amount, payment_status)
		VALUES (?, ?, ?, ?, ?, ?, 'dine_in', ?, 0, ?, ?, 'pending')`,
		id, e.org, e.outlet, e.cashier, customer, "PP-"+id.String()[:8], subtotal, subtotal, subtotal)
	return id
}

func (e *pointPaymentEnv) code(customer uuid.UUID) string {
	e.t.Helper()
	c, err := e.codes.Issue(context.Background(), customer, "482913", models.CustomerPinRequestInfo{})
	require.NoError(e.t, err)
	return c.Code
}

func (e *pointPaymentEnv) payPoints(order uuid.UUID, points int64, code string) (*models.PaymentResponse, error) {
	return e.orders.CreatePayment(e.ctx, &models.CreatePaymentRequest{OrderID: order, PaymentMethodID: e.point, Points: &points, PaymentCode: &code})
}

func (e *pointPaymentEnv) balance(customer uuid.UUID) int64 {
	e.t.Helper()
	var b int64
	require.NoError(e.t, e.db.Raw(`SELECT COALESCE(SUM(point_balance), 0) FROM customer_wallets WHERE customer_id = ?`, customer).Scan(&b).Error)
	return b
}

func (e *pointPaymentEnv) orderState(order uuid.UUID) (status string, remaining float64) {
	e.t.Helper()
	var row struct {
		PaymentStatus   string
		RemainingAmount float64
	}
	require.NoError(e.t, e.db.Raw(`SELECT payment_status, remaining_amount FROM orders WHERE id = ?`, order).Scan(&row).Error)
	return row.PaymentStatus, row.RemainingAmount
}

func TestPointPayment_FullPayment(t *testing.T) {
	e := newPointPaymentEnv(t)
	customer := e.customerWith(100000)
	order := e.order(customer, 50000)

	payment, err := e.payPoints(order, 50000, e.code(customer))
	require.NoError(t, err)
	assert.Equal(t, 50000.0, payment.Amount)
	require.NotNil(t, payment.PointsUsed)
	assert.Equal(t, int64(50000), *payment.PointsUsed)
	assert.Equal(t, 1.0, *payment.PointValue, "the value is frozen on the payment")
	status, remaining := e.orderState(order)
	assert.Equal(t, "completed", status)
	assert.Zero(t, remaining)
	assert.Equal(t, int64(50000), e.balance(customer))

	var ledger struct {
		Amount        int64
		ReferenceType string
		ReferenceID   string
		OutletID      string
		CreatedByUser string
	}
	require.NoError(t, e.db.Raw(`SELECT amount, reference_type, reference_id::text AS reference_id, outlet_id::text AS outlet_id,
		created_by_user::text AS created_by_user FROM wallet_transactions WHERE customer_id = ? AND type = 'PAYMENT'`, customer).Scan(&ledger).Error)
	assert.Equal(t, int64(-50000), ledger.Amount)
	assert.Equal(t, "PAYMENT", ledger.ReferenceType)
	assert.Equal(t, payment.ID.String(), ledger.ReferenceID)
	assert.Equal(t, e.outlet.String(), ledger.OutletID)
	assert.Equal(t, e.cashier.String(), ledger.CreatedByUser, "the cashier who took it")

	// Paid entirely with EnakPoint, so nothing earns (Q10).
	var earned int64
	require.NoError(t, e.db.Raw(`SELECT COUNT(*) FROM wallet_transactions WHERE reference_id = ? AND type = 'EARN'`, order).Scan(&earned).Error)
	assert.Zero(t, earned)
}

func TestPointPayment_PartialThenCash(t *testing.T) {
	e := newPointPaymentEnv(t)
	customer := e.customerWith(100000)
	order := e.order(customer, 87500)

	_, err := e.payPoints(order, 20000, e.code(customer))
	require.NoError(t, err)
	status, remaining := e.orderState(order)
	assert.Equal(t, "partial", status)
	assert.Equal(t, 67500.0, remaining)

	// The rest in cash settles it; earning counts only the part not paid with
	// EnakPoint: floor(67.500 / 100) = 675.
	_, err = e.orders.CreatePayment(e.ctx, &models.CreatePaymentRequest{OrderID: order, PaymentMethodID: e.cash, Amount: 67500})
	require.NoError(t, err)
	status, _ = e.orderState(order)
	assert.Equal(t, "completed", status)
	var earned int64
	require.NoError(t, e.db.Raw(`SELECT COALESCE(SUM(amount), 0) FROM wallet_transactions WHERE reference_id = ? AND type = 'EARN'`, order).Scan(&earned).Error)
	assert.Equal(t, int64(675), earned)
	assert.Equal(t, int64(100000-20000+675), e.balance(customer))
}

func TestPointPayment_PercentCap(t *testing.T) {
	e := newPointPaymentEnv(t)
	settings := NewLoyaltySettingsProcessor(repository.NewLoyaltySettingsRepository(e.db), repository.NewTxManager(e.db))
	s, err := settings.Outlet(context.Background(), e.outlet)
	require.NoError(t, err)
	s.PointPayment.MaxPaymentPercent = 50
	_, err = settings.UpdateOutlet(context.Background(), e.org, e.outlet, e.cashier, *s)
	require.NoError(t, err)

	customer := e.customerWith(100000)
	order := e.order(customer, 100000)

	preview, err := e.payments.Preview(context.Background(), e.org, order)
	require.NoError(t, err)
	assert.True(t, preview.Eligible)
	assert.Equal(t, int64(50000), preview.MaxPoints)
	assert.Equal(t, int64(100000), preview.PointBalance)

	_, err = e.payPoints(order, 50001, e.code(customer))
	assert.ErrorIs(t, err, ErrPointPaymentRejected)
	_, err = e.payPoints(order, 30000, e.code(customer))
	require.NoError(t, err)
	_, err = e.payPoints(order, 20001, e.code(customer))
	assert.ErrorIs(t, err, ErrPointPaymentRejected, "earlier EnakPoint counts toward the cap")
	_, err = e.payPoints(order, 20000, e.code(customer))
	require.NoError(t, err)
	assert.Equal(t, int64(50000), e.balance(customer))
}

func TestPointPayment_Refusals(t *testing.T) {
	e := newPointPaymentEnv(t)
	customer := e.customerWith(100000)
	other := e.customerWith(100000)

	// A walk-in order cannot be paid with EnakPoint.
	walkInOrder := e.order(e.walkIn, 10000)
	preview, err := e.payments.Preview(context.Background(), e.org, walkInOrder)
	require.NoError(t, err)
	assert.False(t, preview.Eligible)
	assert.Contains(t, preview.Reason, "walk-in")
	_, err = e.payPoints(walkInOrder, 1000, "123456")
	assert.ErrorIs(t, err, ErrPointPaymentRejected)

	order := e.order(customer, 10000)
	_, err = e.payPoints(order, 1000, "000000")
	assert.ErrorIs(t, err, ErrPointPaymentRejected, "a wrong code")
	_, err = e.payPoints(order, 1000, e.code(other))
	assert.ErrorIs(t, err, ErrPointPaymentRejected, "another customer's code")
	missing := int64(1000)
	_, err = e.orders.CreatePayment(e.ctx, &models.CreatePaymentRequest{OrderID: order, PaymentMethodID: e.point, Points: &missing})
	assert.ErrorIs(t, err, ErrPointPaymentRejected, "no code at all")

	code := e.code(customer)
	_, err = e.payPoints(order, 1000, code)
	require.NoError(t, err)
	_, err = e.payPoints(order, 1000, code)
	assert.ErrorIs(t, err, ErrPointPaymentRejected, "a code is used once, so a double tap takes once")
	_, err = e.payPoints(order, 9001, e.code(customer))
	assert.ErrorIs(t, err, ErrPointPaymentRejected, "no change is given: not more than what is left")

	// Splitting with the EnakPoint method would skip the balance, so it is refused.
	e.orders.splitBillProcessor = splitFake{}
	_, err = e.orders.SplitBill(e.ctx, &models.SplitBillRequest{OrderID: order, PaymentMethodID: e.point, Type: "AMOUNT", Amount: 1000})
	assert.ErrorIs(t, err, ErrPointPaymentRejected)

	assert.Equal(t, int64(99000), e.balance(customer), "only the one payment took anything")
	assert.Equal(t, int64(100000), e.balance(other))
}

// Two payments for the same customer at once, on two orders: the balance is taken
// once, never twice. Authorization is taken as given so only the balance decides.
func TestPointPayment_ConcurrentForOneCustomer(t *testing.T) {
	e := newPointPaymentEnv(t)
	customer := e.customerWith(30000)
	orders := []uuid.UUID{e.order(customer, 20000), e.order(customer, 20000)}

	var wg sync.WaitGroup
	results := make([]error, len(orders))
	for i, order := range orders {
		wg.Add(1)
		go func(i int, order uuid.UUID) {
			defer wg.Done()
			_, results[i] = e.payments.Pay(e.ctx, PointPaymentInput{
				OrderID: order, PaymentMethodID: e.point, Points: 20000,
				Authorize: func(context.Context, uuid.UUID) error { return nil },
			})
		}(i, order)
	}
	wg.Wait()

	succeeded := 0
	for _, err := range results {
		if err == nil {
			succeeded++
		} else {
			assert.ErrorIs(t, err, ErrPointPaymentRejected)
		}
	}
	assert.Equal(t, 1, succeeded, "30.000 EnakPoint pays one 20.000 order, not two")
	assert.Equal(t, int64(10000), e.balance(customer))

	// And the wallet still reconciles.
	found, err := repository.NewWalletReconciliationRepository(e.db).FindDiscrepancies(context.Background(), 1000)
	require.NoError(t, err)
	for _, d := range found {
		assert.NotEqual(t, customer, d.CustomerID, d.Check)
	}
}

func TestPointPayment_InApp(t *testing.T) {
	e := newPointPaymentEnv(t)
	owner := e.customerWith(100000)
	stranger := e.customerWith(100000)
	order := e.order(owner, 60000)
	info := models.CustomerPinRequestInfo{}

	// Another customer cannot pay it, and is not told it exists.
	_, err := e.orders.PayWithPointsInApp(e.ctx, stranger, order, 1000, "482913", info)
	assert.ErrorIs(t, err, repository.ErrPointPaymentOrderNotFound)
	_, err = e.orders.PayWithPointsInApp(e.ctx, owner, uuid.New(), 1000, "482913", info)
	assert.ErrorIs(t, err, repository.ErrPointPaymentOrderNotFound)

	// The session alone is not enough: a wrong PIN takes nothing.
	_, err = e.orders.PayWithPointsInApp(e.ctx, owner, order, 1000, "000000", info)
	var pe *PinError
	require.ErrorAs(t, err, &pe)
	assert.Equal(t, PinErrInvalid, pe.Code)
	assert.Equal(t, int64(100000), e.balance(owner))

	// The owner pays part, then the rest, with the same rules as at the cashier.
	payment, err := e.orders.PayWithPointsInApp(e.ctx, owner, order, 10000, "482913", info)
	require.NoError(t, err)
	assert.Equal(t, int64(10000), *payment.PointsUsed)
	status, remaining := e.orderState(order)
	assert.Equal(t, "partial", status)
	assert.Equal(t, 50000.0, remaining)

	_, err = e.orders.PayWithPointsInApp(e.ctx, owner, order, 50001, "482913", info)
	assert.ErrorIs(t, err, ErrPointPaymentRejected, "not more than what is left")
	_, err = e.orders.PayWithPointsInApp(e.ctx, owner, order, 50000, "482913", info)
	require.NoError(t, err)
	status, _ = e.orderState(order)
	assert.Equal(t, "completed", status)
	assert.Equal(t, int64(40000), e.balance(owner))
	assert.Equal(t, int64(100000), e.balance(stranger))

	var createdBy *string
	require.NoError(t, e.db.Raw(`SELECT created_by_user::text FROM wallet_transactions WHERE customer_id = ? AND type = 'PAYMENT' LIMIT 1`, owner).Scan(&createdBy).Error)
	assert.Nil(t, createdBy, "no cashier took an in-app payment")
}

// The payment method report counts only money actually received as money in; the
// EnakPoint part is listed apart (F9).
func TestPointPayment_ReportKeepsEnakPointOutOfCashIn(t *testing.T) {
	e := newPointPaymentEnv(t)
	customer := e.customerWith(100000)
	order := e.order(customer, 87500)
	_, err := e.payPoints(order, 20000, e.code(customer))
	require.NoError(t, err)
	_, err = e.orders.CreatePayment(e.ctx, &models.CreatePaymentRequest{OrderID: order, PaymentMethodID: e.cash, Amount: 67500})
	require.NoError(t, err)

	report, err := NewAnalyticsProcessorImpl(repository.NewAnalyticsRepositoryImpl(e.db), nil).GetPaymentMethodAnalytics(context.Background(),
		&models.PaymentMethodAnalyticsRequest{OrganizationID: e.org, DateFrom: time.Now().Add(-time.Hour), DateTo: time.Now().Add(time.Hour)})
	require.NoError(t, err)
	assert.Equal(t, 67500.0, report.Summary.TotalAmount, "money in is the cash, not the order total")
	assert.Equal(t, 20000.0, report.Summary.PointAmount)
	assert.Equal(t, int64(20000), report.Summary.PointsUsed)
	assert.Equal(t, 87500.0, report.Summary.TotalWithPoints)
	require.Len(t, report.Data, 2)
	for _, d := range report.Data {
		assert.Equal(t, d.PaymentMethodType != "point", d.CountsAsCashIn, d.PaymentMethodName)
	}
}