package service

import (
	"context"
	"crypto/hmac"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"io"
	"net/http"
	"net/http/httptest"
	"sync"
	"testing"

	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/repository"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"gorm.io/gorm"
)

// setupPushDeliveryService 创建 PushTokenRepo + PushDeliveryService 测试实例。
func setupPushDeliveryService(t *testing.T) (*gorm.DB, *repository.PushTokenRepo, *PushDeliveryService) {
	t.Helper()
	db := setupServiceTestDB(t)
	repo := repository.NewPushTokenRepo(db)
	svc := NewPushDeliveryService(repo, "test-vapid-public", "test-vapid-private", "mailto:test@example.com")
	return db, repo, svc
}

// setupWebhookDeliveryService 创建 WebhookSubscriptionRepo + WebhookDeliveryService 测试实例。
func setupWebhookDeliveryService(t *testing.T) (*gorm.DB, *repository.WebhookSubscriptionRepo, *WebhookDeliveryService) {
	t.Helper()
	db := setupServiceTestDB(t)
	repo := repository.NewWebhookSubscriptionRepo(db)
	svc := NewWebhookDeliveryService(repo)
	return db, repo, svc
}

// ========== PushDeliveryService.SendPushNotification ==========

func TestPushDeliveryService_SendPushNotification_成功(t *testing.T) {
	db, _, svc := setupPushDeliveryService(t)
	account := createTestAccount(t, db)
	user := createTestUser(t, db, account.ID)

	// 创建推送令牌
	createTestPushToken(t, db, user.ID, "push-token-ios-001", "ios")
	createTestPushToken(t, db, user.ID, "push-token-android-002", "android")

	payload := PushPayload{
		Title: "测试推送",
		Body:  "这是一条测试推送消息",
		Data:  map[string]interface{}{"conversation_id": 123},
	}

	err := svc.SendPushNotification(context.Background(), user.ID, payload)
	require.NoError(t, err)
	// 当前实现仅记录日志，不返回错误
}

func TestPushDeliveryService_SendPushNotification_无令牌(t *testing.T) {
	db, _, svc := setupPushDeliveryService(t)
	account := createTestAccount(t, db)
	user := createTestUser(t, db, account.ID)

	payload := PushPayload{
		Title: "测试推送",
		Body:  "无令牌推送",
	}

	err := svc.SendPushNotification(context.Background(), user.ID, payload)
	require.NoError(t, err)
	// 无令牌时跳过推送，不返回错误
}

// ========== WebhookDeliveryService.DeliverEvent ==========

func TestWebhookDeliveryService_DeliverEvent_成功(t *testing.T) {
	db, _, svc := setupWebhookDeliveryService(t)
	account := createTestAccount(t, db)

	// 使用 httptest 创建模拟 webhook 端点
	var receivedRequest struct {
		body       []byte
		signature  string
		event      string
		deliveryID string
		mu         sync.Mutex
	}

	testServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		receivedRequest.mu.Lock()
		defer receivedRequest.mu.Unlock()

		bodyBytes, _ := io.ReadAll(r.Body)
		receivedRequest.body = bodyBytes
		receivedRequest.signature = r.Header.Get("X-Webhook-Signature")
		receivedRequest.event = r.Header.Get("X-Webhook-Event")
		receivedRequest.deliveryID = r.Header.Get("X-Webhook-Delivery-ID")
		w.WriteHeader(http.StatusOK)
	}))
	t.Cleanup(func() { testServer.Close() })

	// 创建 webhook 订阅指向测试服务器
	eventsJSON, _ := json.Marshal([]string{"message_created"})
	sub := &model.WebhookSubscription{
		AccountID: account.ID,
		URL:       testServer.URL,
		Events:    eventsJSON,
		Secret:    "test-webhook-secret-key",
		Active:    true,
	}
	require.NoError(t, db.Create(sub).Error)

	payload := map[string]interface{}{
		"conversation_id": 42,
		"message_id":      100,
		"content":         "Hello webhook",
	}

	err := svc.DeliverEvent(context.Background(), account.ID, "message_created", payload)
	require.NoError(t, err)

	// 验证测试服务器收到了正确的请求
	receivedRequest.mu.Lock()
	defer receivedRequest.mu.Unlock()

	assert.NotEmpty(t, receivedRequest.body, "webhook 端点应收到请求体")

	// 验证 X-Webhook-Signature 头
	expectedSig := SignPayload(receivedRequest.body, "test-webhook-secret-key")
	assert.Equal(t, expectedSig, receivedRequest.signature, "X-Webhook-Signature 应匹配 HMAC-SHA256 签名")

	// 验证 X-Webhook-Event 头
	assert.Equal(t, "message_created", receivedRequest.event, "X-Webhook-Event 应为 message_created")

	// 验证 X-Webhook-Delivery-ID 头
	assert.NotEmpty(t, receivedRequest.deliveryID, "X-Webhook-Delivery-ID 不应为空")
}

func TestWebhookDeliveryService_DeliverEvent_无订阅(t *testing.T) {
	db, _, svc := setupWebhookDeliveryService(t)
	account := createTestAccount(t, db)

	payload := map[string]interface{}{"id": 1}
	err := svc.DeliverEvent(context.Background(), account.ID, "message_created", payload)
	require.NoError(t, err)
	// 无匹配订阅时不发送，不返回错误
}

// ========== SignPayload ==========

func TestSignPayload_正确计算HMACSHA256(t *testing.T) {
	payload := []byte(`{"event":"message_created","data":{"id":1}}`)
	secret := "my-secret-key"

	// 手动计算 HMAC-SHA256 用于比对
	mac := hmac.New(sha256.New, []byte(secret))
	mac.Write(payload)
	expectedHex := hex.EncodeToString(mac.Sum(nil))

	result := SignPayload(payload, secret)
	assert.Equal(t, expectedHex, result)
}

func TestSignPayload_不同密钥产生不同签名(t *testing.T) {
	payload := []byte(`{"event":"test"}`)

	sig1 := SignPayload(payload, "secret-one")
	sig2 := SignPayload(payload, "secret-two")
	assert.NotEqual(t, sig1, sig2, "不同密钥应产生不同签名")
}

func TestSignPayload_相同密钥和载荷产生相同签名(t *testing.T) {
	payload := []byte(`{"event":"consistent"}`)
	secret := "same-secret"

	sig1 := SignPayload(payload, secret)
	sig2 := SignPayload(payload, secret)
	assert.Equal(t, sig1, sig2, "相同密钥和载荷应产生相同签名")
}