package stripe_test

import (
	"context"
	"crypto/hmac"
	"crypto/sha256"
	"encoding/hex"
	"fmt"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	gostripe "github.com/stripe/stripe-go/v79"
	"github.com/stripe/stripe-go/v79/client"

	"github.com/wangjia/pay/internal/provider"
	st "github.com/wangjia/pay/internal/provider/stripe"
)

const whSecret = "whsec_test_secret"

func fakeStripeAPI(t *testing.T) *httptest.Server {
	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		switch {
		case r.Method == http.MethodPost && strings.HasPrefix(r.URL.Path, "/v1/checkout/sessions"):
			// 创建 session
			fmt.Fprint(w, `{"id":"cs_test_123","object":"checkout.session","url":"https://checkout.stripe.com/c/pay/cs_test_123","amount_total":2999,"currency":"usd","payment_status":"unpaid"}`)
		case r.Method == http.MethodGet && strings.Contains(r.URL.Path, "/v1/checkout/sessions/cs_test_123"):
			// 查询 session — 已付
			fmt.Fprint(w, `{"id":"cs_test_123","object":"checkout.session","amount_total":2999,"currency":"usd","payment_status":"paid"}`)
		default:
			http.Error(w, `{"error":{"message":"not found"}}`, http.StatusNotFound)
		}
	}))
}

func newStripe(t *testing.T, ts *httptest.Server) *st.Provider {
	backends := &gostripe.Backends{
		API: gostripe.GetBackendWithConfig(gostripe.APIBackend, &gostripe.BackendConfig{
			URL: gostripe.String(ts.URL),
		}),
	}
	sc := client.New("sk_test_x", backends)
	return st.New(sc, whSecret)
}

func TestCreateCheckoutRedirect(t *testing.T) {
	ts := fakeStripeAPI(t)
	defer ts.Close()
	p := newStripe(t, ts)

	sess, err := p.Create(context.Background(), provider.CreateRequest{
		OutTradeNo: "PAY-1", Subject: "Pro Year", AmountMinor: 2999, Currency: "USD",
		ReturnURL: "https://x/return",
	})
	if err != nil {
		t.Fatalf("create: %v", err)
	}
	if sess.RenderType != provider.RenderRedirect || sess.ProviderRef != "cs_test_123" {
		t.Fatalf("session = %+v", sess)
	}
	if !strings.Contains(sess.Payload["url"].(string), "cs_test_123") {
		t.Fatalf("url = %v", sess.Payload["url"])
	}
}

func TestQueryPaid(t *testing.T) {
	ts := fakeStripeAPI(t)
	defer ts.Close()
	p := newStripe(t, ts)

	ev, err := p.Query(context.Background(), provider.QueryRequest{ProviderRef: "cs_test_123", Currency: "USD"})
	if err != nil {
		t.Fatalf("query: %v", err)
	}
	if ev.Status != provider.PaidSucceeded || ev.PaidAmountMinor != 2999 || ev.PaidCurrency != "USD" {
		t.Fatalf("event = %+v", ev)
	}
}

func TestVerifyWebhook(t *testing.T) {
	ts := fakeStripeAPI(t)
	defer ts.Close()
	p := newStripe(t, ts)

	payload := `{"id":"evt_1","object":"event","type":"checkout.session.completed","data":{"object":{"id":"cs_test_123","object":"checkout.session","amount_total":2999,"currency":"usd","payment_status":"paid"}}}`
	sig := signStripe(payload, whSecret, time.Now().Unix())

	ev, err := p.VerifyCallback(context.Background(), provider.CallbackInput{
		Raw:     []byte(payload),
		Headers: map[string]string{"Stripe-Signature": sig},
	})
	if err != nil {
		t.Fatalf("verify: %v", err)
	}
	if ev.ProviderRef != "cs_test_123" || ev.Status != provider.PaidSucceeded || ev.PaidAmountMinor != 2999 {
		t.Fatalf("event = %+v", ev)
	}
}

// 用错误的签名密钥(冒充攻击者伪造 webhook)→ ConstructEventWithOptions 内部 HMAC 校验
// 必失败,VerifyCallback 必须返回 error,绝不能返回 PaidEvent(哪怕 payload 里状态是 paid)。
func TestVerifyWebhookWrongSecretFails(t *testing.T) {
	ts := fakeStripeAPI(t)
	defer ts.Close()
	p := newStripe(t, ts)

	payload := `{"id":"evt_evil","object":"event","type":"checkout.session.completed","data":{"object":{"id":"cs_test_123","object":"checkout.session","amount_total":2999,"currency":"usd","payment_status":"paid"}}}`
	sig := signStripe(payload, "whsec_completely_different_secret", time.Now().Unix())

	ev, err := p.VerifyCallback(context.Background(), provider.CallbackInput{
		Raw:     []byte(payload),
		Headers: map[string]string{"Stripe-Signature": sig},
	})
	if err == nil {
		t.Fatalf("want 验签失败(签名密钥不匹配), got event = %+v", ev)
	}
	if ev != nil {
		t.Fatalf("验签失败时不应返回 PaidEvent, got %+v", ev)
	}
}

// signStripe 复刻 Stripe webhook 签名头: t=<ts>,v1=hex(HMAC-SHA256(secret, "<ts>.<payload>"))
func signStripe(payload, secret string, ts int64) string {
	mac := hmac.New(sha256.New, []byte(secret))
	fmt.Fprintf(mac, "%d.%s", ts, payload)
	return fmt.Sprintf("t=%d,v1=%s", ts, hex.EncodeToString(mac.Sum(nil)))
}