package httpapi

import (
	"bytes"
	"sync"
	"sync/atomic"
	"testing"
	"time"
)

func TestRawContentCacheCoalescesConcurrentLoads(t *testing.T) {
	t.Parallel()

	cache := newRawContentCache(8, 8*1024*1024)
	var loads int32
	want := []byte("coalesced")

	var wg sync.WaitGroup
	for i := 0; i < 12; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			got, err, _ := cache.GetOrLoad("shared-id", func() ([]byte, error) {
				atomic.AddInt32(&loads, 1)
				time.Sleep(15 * time.Millisecond)
				return want, nil
			})
			if err != nil {
				t.Errorf("GetOrLoad() error = %v", err)
				return
			}
			if !bytes.Equal(got, want) {
				t.Errorf("GetOrLoad() content mismatch = %q, want %q", got, want)
			}
		}()
	}
	wg.Wait()

	if got := atomic.LoadInt32(&loads); got != 1 {
		t.Fatalf("loader call count = %d, want 1", got)
	}
}

func TestRawContentCacheEvictionCausesReload(t *testing.T) {
	t.Parallel()

	cache := newRawContentCache(1, 3)
	var loadsA int32
	var loadsB int32

	if _, err, _ := cache.GetOrLoad("a", func() ([]byte, error) {
		atomic.AddInt32(&loadsA, 1)
		return []byte("aaa"), nil
	}); err != nil {
		t.Fatalf("GetOrLoad(a) error = %v", err)
	}
	if _, err, _ := cache.GetOrLoad("b", func() ([]byte, error) {
		atomic.AddInt32(&loadsB, 1)
		return []byte("bbb"), nil
	}); err != nil {
		t.Fatalf("GetOrLoad(b) error = %v", err)
	}
	if _, err, _ := cache.GetOrLoad("a", func() ([]byte, error) {
		atomic.AddInt32(&loadsA, 1)
		return []byte("aaa"), nil
	}); err != nil {
		t.Fatalf("GetOrLoad(a second) error = %v", err)
	}

	if got := atomic.LoadInt32(&loadsB); got != 1 {
		t.Fatalf("loadsB = %d, want 1", got)
	}
	if got := atomic.LoadInt32(&loadsA); got != 2 {
		t.Fatalf("loadsA = %d, want 2", got)
	}
}