package service

import (
	"context"
	"net/http"
	"net/http/httptest"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	notifPb "github.com/topfans/backend/pkg/proto/notification"
	"github.com/topfans/backend/pkg/push"
	"google.golang.org/protobuf/types/known/structpb"
)

// fakePusher 记录最近一次 Push 调用;用于验证 CreateNotification 是否触发推送。
type fakePusher struct {
	mu      sync.Mutex
	calls   []push.Payload
	err     error
	delay   time.Duration
}

func (f *fakePusher) Send(_ context.Context, p push.Payload) error {
	if f.delay > 0 {
		time.Sleep(f.delay)
	}
	f.mu.Lock()
	defer f.mu.Unlock()
	f.calls = append(f.calls, p)
	return f.err
}

func (f *fakePusher) last() push.Payload {
	f.mu.Lock()
	defer f.mu.Unlock()
	if len(f.calls) == 0 {
		return push.Payload{}
	}
	return f.calls[len(f.calls)-1]
}

func (f *fakePusher) count() int {
	f.mu.Lock()
	defer f.mu.Unlock()
	return len(f.calls)
}

// TestTriggerPush_NoPusherNoDevice 验证:未注入 pusher/device 时不触发推送,
// CreateNotification 仍正常返回(不影响主流程)。
// 注:CreateNotification 需要真 DB,缺 DB 时跳过。
func TestTriggerPush_NoPusherNoDevice(t *testing.T) {
	db, ok := setupTestDB(t)
	if !ok {
		t.Skip("skipping: test DB not available")
	}
	svc := NewNotificationService(db, nil, nil)

	data, _ := structpb.NewStruct(map[string]interface{}{"target_id": int64(1)})
	resp, err := svc.CreateNotification(context.Background(), &notifPb.CreateNotificationRequest{
		UserId: 880500,
		StarId: 1,
		Type:   "system",
		Title:  "triggerPush-disabled",
		Data:   data,
	})
	require.NoError(t, err)
	require.NotNil(t, resp)
	assert.Greater(t, resp.Id, int64(0))

	// cleanup
	t.Cleanup(func() {
		ctx := context.Background()
		_ = db.WithContext(ctx).Exec(`DELETE FROM public.notifications WHERE user_id=$1`, 880500).Error
		_ = db.WithContext(ctx).Exec(`DELETE FROM public.notification_stats WHERE user_id=$1`, 880500).Error
	})
}

// TestTriggerPush_HTTPEndToEnd 验证:CreateNotification 后通过 httptest mock 验证 HTTP 出站载荷。
// 1) 用 httptest 模拟 uniCloud 云函数;2) 把 mock URL 注入 UniPushClient;
// 3) 触发 CreateNotification;4) 等 goroutine 完成;5) 检查 mock 收到的请求。
//
// 由于 triggerPush 用 goroutine 异步发,我们用 polling 等一下(最多 2s)。
func TestTriggerPush_HTTPEndToEnd(t *testing.T) {
	db, ok := setupTestDB(t)
	if !ok {
		t.Skip("skipping: test DB not available")
	}

	var (
		mu      sync.Mutex
		hitCnt  int
	)

	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var p push.Payload
		_ = decodeJSON(r, &p)
		mu.Lock()
		hitCnt++
		mu.Unlock()
		w.WriteHeader(200)
		_, _ = w.Write([]byte(`{"errcode":0}`))
	}))
	defer srv.Close()

	// 注入 UniPushClient + 一个不会 panic 的 deviceService(用 nil db 也能跑,因为我们提前塞好 cids 走不通)
	// 这里 deviceService 用 nil,所以 triggerPush 会因为 s.device == nil 直接返回 —— 这条路径已被上面测过。
	// 真正能验证 HTTP 出站的是把 deviceService.ListActiveCIDs 替换掉。
	//
	// 替代方案:在测试里直接把 pusher 用 fakePusher,然后断言 payload 字段正确。
	fp := &fakePusher{}
	notifSvc := NewNotificationService(db, nil, fp)

	data, _ := structpb.NewStruct(map[string]interface{}{
		"target_id": int64(1234),
		"actor_id":  int64(99),
	})
	resp, err := notifSvc.CreateNotification(context.Background(), &notifPb.CreateNotificationRequest{
		UserId: 880501,
		StarId: 1,
		Type:   "like",
		Title:  "张三 赞了你的《藏品A》",
		Content: "查看详情",
		Data:   data,
	})
	require.NoError(t, err)
	require.NotNil(t, resp)
	assert.Greater(t, resp.Id, int64(0))

	// cleanup
	t.Cleanup(func() {
		ctx := context.Background()
		_ = db.WithContext(ctx).Exec(`DELETE FROM public.notifications WHERE user_id=$1`, 880501).Error
		_ = db.WithContext(ctx).Exec(`DELETE FROM public.notification_stats WHERE user_id=$1`, 880501).Error
	})

	// 由于 deviceSvc=nil,triggerPush 直接 return 不发推送,这里断言不会发生调用
	// (我们要测的是 HTTP 出站,见下一个 TestTriggerPush_FullFlow).
	assert.Equal(t, 0, fp.count(), "deviceSvc=nil 时 triggerPush 直接跳过")
}

// TestTriggerPush_FullFlow 完整链路验证:
//   - 用 httptest 作为云函数 mock
//   - 手动构造 UserDeviceService(共享 db)+ UniPushClient(指向 httptest URL)
//   - 先 RegisterDevice 注册 cid,再 CreateNotification,断言 mock 收到的 payload 包含 cids/title/data。
func TestTriggerPush_FullFlow(t *testing.T) {
	db, ok := setupTestDB(t)
	if !ok {
		t.Skip("skipping: test DB not available")
	}

	var (
		mu     sync.Mutex
		got    push.Payload
		hitCnt int
	)
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var p push.Payload
		_ = decodeJSON(r, &p)
		mu.Lock()
		got = p
		hitCnt++
		mu.Unlock()
		w.WriteHeader(200)
		_, _ = w.Write([]byte(`{"errcode":0}`))
	}))
	defer srv.Close()

	deviceSvc := NewUserDeviceService(db)
	pushCli := push.NewUniPushClient(srv.URL, 2*time.Second, nil)
	notifSvc := NewNotificationService(db, deviceSvc, pushCli)

	userID := int64(880502)
	cid := "test-cid-trigger-" + time.Now().Format("150405.000")

	// cleanup
	t.Cleanup(func() {
		ctx := context.Background()
		_ = db.WithContext(ctx).Exec(`DELETE FROM public.user_devices WHERE user_id=$1`, userID).Error
		_ = db.WithContext(ctx).Exec(`DELETE FROM public.notifications WHERE user_id=$1`, userID).Error
		_ = db.WithContext(ctx).Exec(`DELETE FROM public.notification_stats WHERE user_id=$1`, userID).Error
	})

	// 1) 注册 cid
	regResp, err := deviceSvc.RegisterDevice(context.Background(), userID, &notifPb.RegisterDeviceRequest{
		Cid: cid, Platform: "ios", AppVersion: "1.0.0", DeviceModel: "iPhone",
	})
	require.NoError(t, err)
	require.NotNil(t, regResp)
	assert.Greater(t, regResp.Id, int64(0))

	// 2) CreateNotification 触发推送
	data, _ := structpb.NewStruct(map[string]interface{}{
		"target_id": int64(7777),
		"actor_id":  int64(99),
	})
	_, err = notifSvc.CreateNotification(context.Background(), &notifPb.CreateNotificationRequest{
		UserId: userID, StarId: 1, Type: "like",
		Title: "触发推送测试", Content: "你有一条新消息",
		Data:  data,
	})
	require.NoError(t, err)

	// 3) 等异步推送(最多 3s)
	deadline := time.Now().Add(3 * time.Second)
	for time.Now().Before(deadline) {
		mu.Lock()
		c := hitCnt
		mu.Unlock()
		if c >= 1 {
			break
		}
		time.Sleep(50 * time.Millisecond)
	}

	mu.Lock()
	finalCnt := hitCnt
	finalPayload := got
	mu.Unlock()
	assert.Equal(t, 1, finalCnt, "应触发 1 次推送")
	if finalCnt >= 1 {
		assert.Equal(t, "触发推送测试", finalPayload.Title)
		assert.Equal(t, "你有一条新消息", finalPayload.Content)
		assert.Contains(t, finalPayload.CIDs, cid, "payload.cids 应包含已注册的 cid")
		assert.NotEmpty(t, finalPayload.RequestID)
		assert.EqualValues(t, 7777, finalPayload.Data["target_id"])
		assert.EqualValues(t, int64(99), finalPayload.Data["actor_id"])
	}
	_ = strings.TrimSpace // 防止 lint 抱怨
}

// decodeJSON 辅助:读取 body 并 unmarshal。
func decodeJSON(r *http.Request, dst interface{}) error {
	defer r.Body.Close()
	dec := newJSONDecoder(r.Body)
	return dec.Decode(dst)
}