package agentd

// 问题② 真实流量采集后端测试(CI 可跑,无需 docker / 真 sing-box)。
//
// V2RayUsageSource 是「线上按租户记账」链路的源头:agent 读 sing-box v2ray_api
// StatsService 的 per-user 计数器 → 聚合 → ReportUsage。此前零测试覆盖。
// 这里:① parseUserStat 纯函数表驱动;② 起一个假 StatsService(loopback gRPC,
// 注册与 client.go 一致的规范全名),让真 Collect() 跑真解析/聚合/清零语义。

import (
	"context"
	"net"
	"testing"

	"github.com/wangjia/pangolin/server/internal/agentd/v2rayapi"
	"google.golang.org/grpc"
)

func TestParseUserStat(t *testing.T) {
	cases := []struct {
		name     string
		wantUUID string
		wantDir  string
		wantOK   bool
	}{
		{"user>>>abc>>>traffic>>>uplink", "abc", "uplink", true},
		{"user>>>abc>>>traffic>>>downlink", "abc", "downlink", true},
		{"inbound>>>mixed>>>traffic>>>uplink", "", "", false},    // 非 user 计数器
		{"user>>>abc>>>other>>>uplink", "", "", false},           // 第三段非 traffic
		{"user>>>abc>>>traffic", "", "", false},                  // 段数不足
		{"user>>>abc>>>traffic>>>uplink>>>extra", "", "", false}, // 段数过多
		{"", "", "", false},
	}
	for _, c := range cases {
		uuid, dir, ok := parseUserStat(c.name)
		if ok != c.wantOK || uuid != c.wantUUID || dir != c.wantDir {
			t.Errorf("parseUserStat(%q) = (%q,%q,%v), want (%q,%q,%v)",
				c.name, uuid, dir, ok, c.wantUUID, c.wantDir, c.wantOK)
		}
	}
}

// fakeStats 实现 v2ray StatsService.QueryStats:返回预设计数器,记录收到的请求。
type fakeStats struct {
	resp    *v2rayapi.QueryStatsResponse
	lastReq *v2rayapi.QueryStatsRequest
}

func (f *fakeStats) queryStats(_ any, _ context.Context, dec func(any) error, _ grpc.UnaryServerInterceptor) (any, error) {
	in := new(v2rayapi.QueryStatsRequest)
	if err := dec(in); err != nil {
		return nil, err
	}
	f.lastReq = in
	return f.resp, nil
}

// startFakeStats 在 loopback 起假 StatsService,返回地址 + 取最近请求的闭包。
// ServiceName 与 client.go 硬编码的规范全名一致,否则 raw Invoke 命中不到。
func startFakeStats(t *testing.T, resp *v2rayapi.QueryStatsResponse) (string, func() *v2rayapi.QueryStatsRequest) {
	t.Helper()
	lis, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatalf("listen: %v", err)
	}
	f := &fakeStats{resp: resp}
	srv := grpc.NewServer()
	srv.RegisterService(&grpc.ServiceDesc{
		ServiceName: "v2ray.core.app.stats.command.StatsService",
		HandlerType: (*any)(nil),
		Methods:     []grpc.MethodDesc{{MethodName: "QueryStats", Handler: f.queryStats}},
	}, f)
	go func() { _ = srv.Serve(lis) }()
	t.Cleanup(srv.Stop)
	return lis.Addr().String(), func() *v2rayapi.QueryStatsRequest { return f.lastReq }
}

func TestV2RayCollect(t *testing.T) {
	resp := &v2rayapi.QueryStatsResponse{Stat: []*v2rayapi.Stat{
		{Name: "user>>>uuid-a>>>traffic>>>uplink", Value: 1000},
		{Name: "user>>>uuid-a>>>traffic>>>downlink", Value: 2000},
		{Name: "user>>>uuid-b>>>traffic>>>uplink", Value: 500}, // b 只有上行
		{Name: "user>>>uuid-b>>>traffic>>>downlink", Value: 0},
		{Name: "user>>>uuid-c>>>traffic>>>uplink", Value: 0}, // c 全 0 → 应丢弃
		{Name: "user>>>uuid-c>>>traffic>>>downlink", Value: 0},
		{Name: "inbound>>>mixed>>>traffic>>>uplink", Value: 9999}, // 非 user → 应丢弃
	}}
	addr, lastReq := startFakeStats(t, resp)

	s := &V2RayUsageSource{addr: addr}
	entries := s.Collect()

	// 窗口语义:必须以 reset=true + pattern "user>>>" 拉取(取值并清零)。
	if r := lastReq(); r == nil || !r.Reset_ || r.Pattern != "user>>>" {
		t.Fatalf("QueryStats 请求 = %+v, 期望 Reset_=true Pattern=\"user>>>\"", r)
	}

	byUUID := make(map[string]struct{ up, down, mins int64 })
	for _, e := range entries {
		byUUID[e.DpUUID] = struct{ up, down, mins int64 }{e.BytesUp, e.BytesDown, e.SessionMinutes}
	}

	// uuid-c(全 0)与非 user 计数器都不应入账。
	if len(entries) != 2 {
		t.Fatalf("entries=%d (%+v), 期望 2(a/b;c 全0 与 inbound 丢弃)", len(entries), byUUID)
	}
	if a := byUUID["uuid-a"]; a.up != 1000 || a.down != 2000 || a.mins != 1 {
		t.Errorf("uuid-a = %+v, 期望 up=1000 down=2000 mins=1", a)
	}
	if b := byUUID["uuid-b"]; b.up != 500 || b.down != 0 || b.mins != 1 {
		t.Errorf("uuid-b = %+v, 期望 up=500 down=0 mins=1", b)
	}
	if _, ok := byUUID["uuid-c"]; ok {
		t.Errorf("uuid-c 全 0 不应入账")
	}
}