package eshop

import (
	"bytes"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"

	"fotbal-club/internal/config"
	"fotbal-club/internal/models"
	eshoppkg "fotbal-club/internal/services/eshop"

	"github.com/gin-gonic/gin"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
)

// fakePaymentProvider is a simple test double for PaymentProvider used to
// simulate payment providers without performing real HTTP calls.
type fakePaymentProvider struct {
	called bool
	result *eshoppkg.PaymentResult
	err    error
}

func (f *fakePaymentProvider) CreatePayment(order *models.EshopOrder) (*eshoppkg.PaymentResult, error) {
	f.called = true
	return f.result, f.err
}

// TestCheckoutController_ManualPaymentFallback_CreatesOrderAndPayment verifies
// that when no online payment providers are enabled, Checkout creates an order
// and a manual_email payment and returns the expected JSON response.
func TestCheckoutController_ManualPaymentFallback_CreatesOrderAndPayment(t *testing.T) {
	gin.SetMode(gin.TestMode)

	// In-memory SQLite DB for isolated test
	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	if err != nil {
		t.Fatalf("failed to open in-memory db: %v", err)
	}

	// Migrate the minimal set of tables needed for checkout
	if err := db.AutoMigrate(
		&models.EshopProduct{},
		&models.EshopCart{},
		&models.EshopCartItem{},
		&models.EshopOrder{},
		&models.EshopOrderItem{},
		&models.EshopPayment{},
	); err != nil {
		t.Fatalf("failed to migrate schemas: %v", err)
	}

	// Seed one active product
	product := models.EshopProduct{
		Slug:       "test-product",
		Name:       "Test Product",
		PriceCents: 10000,
		Currency:   "CZK",
		VATRate:    21,
		Active:     true,
	}
	if err := db.Create(&product).Error; err != nil {
		t.Fatalf("failed to seed product: %v", err)
	}

	// Seed cart with one item for a specific session token
	const sessionToken = "test-session-token"
	cart := models.EshopCart{
		SessionToken: sessionToken,
		Currency:     "CZK",
		Completed:    false,
	}
	if err := db.Create(&cart).Error; err != nil {
		t.Fatalf("failed to seed cart: %v", err)
	}

	cartItem := models.EshopCartItem{
		CartID:         cart.ID,
		ProductID:      product.ID,
		Quantity:       2,
		UnitPriceCents: product.PriceCents,
		Currency:       product.Currency,
	}
	if err := db.Create(&cartItem).Error; err != nil {
		t.Fatalf("failed to seed cart item: %v", err)
	}

	// Config with no online payment providers -> forces manual_email fallback
	cfg := &config.Config{
		ContactEmail:   "eshop-support@example.com",
		RevolutEnabled: false,
	}

	ctrl := &CheckoutController{
		DB:     db,
		Config: cfg,
	}

	// Build checkout request payload
	body := map[string]interface{}{
		"first_name": "Jan",
		"last_name":  "Novák",
		"email":      "jan.novak@example.com",
		"phone":      "+420123456789",
		"billing_address": map[string]string{
			"street":  "Testovací 123",
			"city":    "Praha",
			"zip":     "11000",
			"country": "CZ",
		},
		"shipping_address": map[string]string{
			"packet_point_id": "PACKETA123",
		},
		"shipping_method": "packeta",
	}

	payload, err := json.Marshal(body)
	if err != nil {
		t.Fatalf("failed to marshal request body: %v", err)
	}

	req, err := http.NewRequest(http.MethodPost, "/api/v1/eshop/checkout", bytes.NewReader(payload))
	if err != nil {
		t.Fatalf("failed to create request: %v", err)
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("X-Session-Token", sessionToken)

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Request = req

	// Execute handler
	ctrl.Checkout(c)

	if w.Code != http.StatusOK {
		t.Fatalf("expected status 200, got %d, body: %s", w.Code, w.Body.String())
	}

	// Parse JSON response
	var resp struct {
		OrderID       uint   `json:"order_id"`
		OrderNumber   string `json:"order_number"`
		ManualPayment bool   `json:"manual_payment"`
		ContactEmail  string `json:"contact_email"`
	}
	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
		t.Fatalf("failed to unmarshal response: %v (body: %s)", err, w.Body.String())
	}

	if resp.OrderID == 0 {
		t.Fatalf("expected non-zero order_id in response")
	}
	if !resp.ManualPayment {
		t.Errorf("expected manual_payment=true in response")
	}
	if resp.ContactEmail != cfg.ContactEmail {
		t.Errorf("expected contact_email %q, got %q", cfg.ContactEmail, resp.ContactEmail)
	}

	// Load order with related items and payments
	var order models.EshopOrder
	if err := db.Preload("Items").Preload("Payments").First(&order, resp.OrderID).Error; err != nil {
		t.Fatalf("failed to load created order: %v", err)
	}

	// itemsTotal = 2 * 10000, shippingPrice = 7900 for Packeta -> 27900
	var expectedItemsTotal int64 = int64(2 * 10000)
	var expectedShipping int64 = 7900
	var expectedTotal int64 = expectedItemsTotal + expectedShipping

	if order.TotalAmountCents != expectedTotal {
		t.Errorf("unexpected order total: got %d, want %d", order.TotalAmountCents, expectedTotal)
	}
	if order.ShippingPriceCents != expectedShipping {
		t.Errorf("unexpected shipping price: got %d, want %d", order.ShippingPriceCents, expectedShipping)
	}
	if order.Status != "awaiting_payment" {
		t.Errorf("unexpected order status: got %q, want %q", order.Status, "awaiting_payment")
	}

	if len(order.Items) != 1 {
		t.Fatalf("expected 1 order item, got %d", len(order.Items))
	}

	if len(order.Payments) != 1 {
		t.Fatalf("expected 1 payment, got %d", len(order.Payments))
	}
	payment := order.Payments[0]
	if payment.Provider != "manual_email" {
		t.Errorf("expected payment provider manual_email, got %q", payment.Provider)
	}
	if payment.AmountCents != order.TotalAmountCents {
		t.Errorf("unexpected payment amount: got %d, want %d", payment.AmountCents, order.TotalAmountCents)
	}
	if payment.Status != "pending" {
		t.Errorf("unexpected payment status: got %q, want %q", payment.Status, "pending")
	}
}

// TestCheckoutController_RevolutWebhook_UpdatesPaymentAndOrderStatuses
// verifies that a Revolut webhook with COMPLETED status correctly updates
// payment status to "paid", order status to "paid", and marks the cart as completed.
func TestCheckoutController_RevolutWebhook_Paid_UpdatesOrderAndCart(t *testing.T) {
	gin.SetMode(gin.TestMode)

	// In-memory SQLite DB for isolated test
	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	if err != nil {
		t.Fatalf("failed to open in-memory db: %v", err)
	}

	// Migrate minimal tables needed for webhook logic
	if err := db.AutoMigrate(
		&models.EshopCart{},
		&models.EshopCartItem{},
		&models.EshopOrder{},
		&models.EshopPayment{},
	); err != nil {
		t.Fatalf("failed to migrate schemas: %v", err)
	}

	const (
		paymentID    = "123456"
		sessionToken = "webhook-session"
	)

	// Seed cart for the given session token
	cart := models.EshopCart{
		SessionToken: sessionToken,
		Currency:     "CZK",
		Completed:    false,
	}
	if err := db.Create(&cart).Error; err != nil {
		t.Fatalf("failed to seed cart: %v", err)
	}

	// Seed order linked to the same session token
	order := models.EshopOrder{
		SessionToken:       sessionToken,
		Status:             "awaiting_payment",
		Currency:           "CZK",
		TotalAmountCents:   15000,
		ShippingMethod:     "packeta",
		ShippingPriceCents: 7900,
	}
	if err := db.Create(&order).Error; err != nil {
		t.Fatalf("failed to seed order: %v", err)
	}

	// Seed pending Revolut payment for the order
	payment := models.EshopPayment{
		OrderID:           order.ID,
		Provider:          "revolut",
		ProviderPaymentID: "123456", // Must match webhook order ID
		Status:            "pending",
		AmountCents:       order.TotalAmountCents,
		Currency:          order.Currency,
	}
	if err := db.Create(&payment).Error; err != nil {
		t.Fatalf("failed to seed payment: %v", err)
	}

	ctrl := &CheckoutController{
		DB:     db,
		Config: &config.Config{},
	}

	// Build Revolut webhook payload with COMPLETED status
	body := map[string]interface{}{
		"type":     "ORDER_COMPLETED",
		"order_id": "123456",
		"order": map[string]interface{}{
			"id":                "123456",
			"amount":            10000,
			"currency":          "CZK",
			"status":            "COMPLETED",
			"merchant_order_id": "TEST-001",
			"created_at":        "2024-01-01T12:00:00Z",
		},
		"timestamp": "2024-01-01T12:00:00Z",
	}
	payload, err := json.Marshal(body)
	if err != nil {
		t.Fatalf("failed to marshal webhook body: %v", err)
	}

	req, err := http.NewRequest(http.MethodPost, "/api/v1/eshop/payments/revolut/webhook", bytes.NewReader(payload))
	if err != nil {
		t.Fatalf("failed to create webhook request: %v", err)
	}
	req.Header.Set("Content-Type", "application/json")

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Request = req

	// Execute webhook handler
	ctrl.RevolutWebhook(c)

	if w.Code != http.StatusOK {
		t.Fatalf("expected status 200, got %d, body: %s", w.Code, w.Body.String())
	}

	// Reload payment, order and cart
	var updatedPayment models.EshopPayment
	if err := db.First(&updatedPayment, payment.ID).Error; err != nil {
		t.Fatalf("failed to load updated payment: %v", err)
	}

	if updatedPayment.Status != "paid" {
		t.Errorf("unexpected payment status: got %q, want %q", updatedPayment.Status, "paid")
	}

	var updatedOrder models.EshopOrder
	if err := db.First(&updatedOrder, order.ID).Error; err != nil {
		t.Fatalf("failed to load updated order: %v", err)
	}
	if updatedOrder.Status != "paid" {
		t.Errorf("unexpected order status: got %q, want %q", updatedOrder.Status, "paid")
	}

	var updatedCart models.EshopCart
	if err := db.First(&updatedCart, cart.ID).Error; err != nil {
		t.Fatalf("failed to load updated cart: %v", err)
	}
	if !updatedCart.Completed {
		t.Errorf("expected cart to be marked completed, but it was not")
	}
}

// TestCheckoutController_FullPaidFlow_Revolut_E2E covers the full flow
// checkout → Revolut payment creation (via fake provider) → Revolut webhook
// updating payment/order status and marking the cart as completed.
func TestCheckoutController_FullPaidFlow_Revolut_E2E(t *testing.T) {
	gin.SetMode(gin.TestMode)

	// In-memory SQLite DB for isolated test
	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	if err != nil {
		t.Fatalf("failed to open in-memory db: %v", err)
	}

	// Migrate tables needed for checkout + payments
	if err := db.AutoMigrate(
		&models.EshopProduct{},
		&models.EshopCart{},
		&models.EshopCartItem{},
		&models.EshopOrder{},
		&models.EshopOrderItem{},
		&models.EshopPayment{},
	); err != nil {
		t.Fatalf("failed to migrate schemas: %v", err)
	}

	// Seed one active product
	product := models.EshopProduct{
		Slug:       "e2e-product",
		Name:       "E2E Product",
		PriceCents: 15000,
		Currency:   "CZK",
		VATRate:    21,
		Active:     true,
	}
	if err := db.Create(&product).Error; err != nil {
		t.Fatalf("failed to seed product: %v", err)
	}

	// Seed cart with one item for a specific session token
	const sessionToken = "e2e-session-token"
	cart := models.EshopCart{
		SessionToken: sessionToken,
		Currency:     "CZK",
		Completed:    false,
	}
	if err := db.Create(&cart).Error; err != nil {
		t.Fatalf("failed to seed cart: %v", err)
	}

	cartItem := models.EshopCartItem{
		CartID:         cart.ID,
		ProductID:      product.ID,
		Quantity:       1,
		UnitPriceCents: product.PriceCents,
		Currency:       product.Currency,
	}
	if err := db.Create(&cartItem).Error; err != nil {
		t.Fatalf("failed to seed cart item: %v", err)
	}

	// Config with Revolut enabled so that Checkout chooses Revolut provider
	cfg := &config.Config{
		ContactEmail:   "eshop-support@example.com",
		RevolutEnabled: true,
	}

	const (
		providerPaymentID = "555666"
		redirectURL       = "https://gw.gopay.test/pay/555666"
	)

	fakeProv := &fakePaymentProvider{
		result: &eshoppkg.PaymentResult{
			RedirectURL:       redirectURL,
			ProviderPaymentID: providerPaymentID,
			RawPayloadJSON:    `{"id":555666,"gw_url":"` + redirectURL + `"}`,
		},
	}

	ctrl := &CheckoutController{
		DB:     db,
		Config: cfg,
	}

	body := map[string]interface{}{
		"first_name": "Petr",
		"last_name":  "Svoboda",
		"email":      "petr.svoboda@example.com",
		"phone":      "+420777000111",
		"billing_address": map[string]string{
			"street":  "E2E 1",
			"city":    "Praha",
			"zip":     "11000",
			"country": "CZ",
		},
		"shipping_address": map[string]string{
			"packet_point_id": "PACKETA-E2E",
		},
		"shipping_method": "packeta",
	}

	checkoutPayload, err := json.Marshal(body)
	if err != nil {
		t.Fatalf("failed to marshal checkout body: %v", err)
	}

	req, err := http.NewRequest(http.MethodPost, "/api/v1/eshop/checkout", bytes.NewReader(checkoutPayload))
	if err != nil {
		t.Fatalf("failed to create checkout request: %v", err)
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("X-Session-Token", sessionToken)

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Request = req

	ctrl.Checkout(c)

	if w.Code != http.StatusOK {
		t.Fatalf("checkout expected status 200, got %d, body: %s", w.Code, w.Body.String())
	}

	if !fakeProv.called {
		t.Fatalf("expected fake payment provider to be called during checkout")
	}

	var checkoutResp struct {
		OrderID            uint   `json:"order_id"`
		OrderNumber        string `json:"order_number"`
		PaymentProvider    string `json:"payment_provider"`
		PaymentRedirectURL string `json:"payment_redirect_url"`
		ManualPayment      bool   `json:"manual_payment"`
	}
	if err := json.Unmarshal(w.Body.Bytes(), &checkoutResp); err != nil {
		t.Fatalf("failed to unmarshal checkout response: %v (body: %s)", err, w.Body.String())
	}

	if checkoutResp.OrderID == 0 {
		t.Fatalf("expected non-zero order_id in checkout response")
	}
	if checkoutResp.PaymentProvider != "revolut" {
		t.Errorf("expected payment_provider=revolut, got %q", checkoutResp.PaymentProvider)
	}
	if checkoutResp.PaymentRedirectURL != redirectURL {
		t.Errorf("unexpected payment_redirect_url: got %q, want %q", checkoutResp.PaymentRedirectURL, redirectURL)
	}
	if checkoutResp.ManualPayment {
		t.Errorf("did not expect manual_payment=true for Revolut flow")
	}

	// Verify DB state after checkout but before webhook
	var order models.EshopOrder
	if err := db.Preload("Payments").First(&order, checkoutResp.OrderID).Error; err != nil {
		t.Fatalf("failed to load order after checkout: %v", err)
	}
	if order.Status != "awaiting_payment" {
		t.Errorf("unexpected order status after checkout: got %q, want %q", order.Status, "awaiting_payment")
	}
	if len(order.Payments) != 1 {
		t.Fatalf("expected 1 payment after checkout, got %d", len(order.Payments))
	}
	p := order.Payments[0]
	if p.Provider != "revolut" {
		t.Errorf("expected payment provider revolut, got %q", p.Provider)
	}
	if p.ProviderPaymentID != providerPaymentID {
		t.Errorf("unexpected provider payment id: got %q, want %q", p.ProviderPaymentID, providerPaymentID)
	}
	if p.Status != "pending" {
		t.Errorf("unexpected payment status after checkout: got %q, want %q", p.Status, "pending")
	}

	var cartBefore models.EshopCart
	if err := db.First(&cartBefore, cart.ID).Error; err != nil {
		t.Fatalf("failed to load cart after checkout: %v", err)
	}
	if cartBefore.Completed {
		t.Errorf("expected cart to be not completed before webhook")
	}

	// ---- Phase 2: Revolut webhook marks payment/order as paid and cart as completed ----
	webhookBody := map[string]interface{}{
		"type":     "ORDER_COMPLETED",
		"order_id": "555666",
		"order": map[string]interface{}{
			"id":                "555666",
			"amount":            10000,
			"currency":          "CZK",
			"status":            "COMPLETED",
			"merchant_order_id": "TEST-002",
			"created_at":        "2024-01-01T12:00:00Z",
		},
		"timestamp": "2024-01-01T12:00:00Z",
	}
	webhookPayload, err := json.Marshal(webhookBody)
	if err != nil {
		t.Fatalf("failed to marshal webhook body: %v", err)
	}

	webhookReq, err := http.NewRequest(http.MethodPost, "/api/v1/eshop/payments/revolut/webhook", bytes.NewReader(webhookPayload))
	if err != nil {
		t.Fatalf("failed to create webhook request: %v", err)
	}
	webhookReq.Header.Set("Content-Type", "application/json")

	webhookW := httptest.NewRecorder()
	webhookCtx, _ := gin.CreateTestContext(webhookW)
	webhookCtx.Request = webhookReq

	ctrl.RevolutWebhook(webhookCtx)

	if webhookW.Code != http.StatusOK {
		t.Fatalf("webhook expected status 200, got %d, body: %s", webhookW.Code, webhookW.Body.String())
	}

	// Reload payment, order and cart after webhook
	var updatedPayment models.EshopPayment
	if err := db.First(&updatedPayment, p.ID).Error; err != nil {
		t.Fatalf("failed to load updated payment after webhook: %v", err)
	}
	if updatedPayment.Status != "paid" {
		t.Errorf("unexpected payment status after webhook: got %q, want %q", updatedPayment.Status, "paid")
	}

	var updatedOrder models.EshopOrder
	if err := db.First(&updatedOrder, order.ID).Error; err != nil {
		t.Fatalf("failed to load updated order after webhook: %v", err)
	}
	if updatedOrder.Status != "paid" {
		t.Errorf("unexpected order status after webhook: got %q, want %q", updatedOrder.Status, "paid")
	}

	var updatedCart models.EshopCart
	if err := db.First(&updatedCart, cart.ID).Error; err != nil {
		t.Fatalf("failed to load updated cart after webhook: %v", err)
	}
	if !updatedCart.Completed {
		t.Errorf("expected cart to be completed after webhook, but it was not")
	}
}