package service

import (
	"sync"
	"testing"
	"time"
)

// analyzeOnce 应合并并发同键分析请求，只执行一次 fn
func TestAnalyzeOnceDedup(t *testing.T) {
	var mu sync.Mutex
	calls := 0
	fn := func() (bool, string) {
		mu.Lock()
		calls++
		mu.Unlock()
		// 短暂阻塞确保所有并发调用在 singleflight 窗口内到达 Do，仅首次执行 fn
		time.Sleep(50 * time.Millisecond)
		return true, "dedup"
	}
	var wg sync.WaitGroup
	for i := 0; i < 10; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			if retry, _ := analyzeOnce("k", fn); !retry {
				t.Errorf("期望 retryable=true")
			}
		}()
	}
	wg.Wait()
	if calls != 1 {
		t.Fatalf("singleflight应只执行一次fn, got %d", calls)
	}
}