package sse

import (
	"net/http/httptest"
	"strings"
	"testing"
	"time"
)

func TestEventRingPushReplay(t *testing.T) {
	ring := newEventRing(5)

	// 推 3 条
	for i := 1; i <= 3; i++ {
		ring.push(StoredEvent{
			ID:        string(rune('0' + i)),
			EventType: "test",
			Data:      []byte(`{"n":` + string(rune('0'+i)) + `}`),
			Timestamp: time.Now(),
		})
	}

	// 空 afterID → 首次连接，不回放（缓冲区未满）
	rec := httptest.NewRecorder()
	ring.replay("", rec, rec)
	if rec.Body.Len() > 0 {
		t.Error("首次连接不应回放事件，实际:", rec.Body.String())
	}

	// 有 afterID → 从下一条开始回放
	rec2 := httptest.NewRecorder()
	ring.replay("1", rec2, rec2)
	body := rec2.Body.String()
	if !strings.Contains(body, "id: 2") {
		t.Error("afterID=1 应该回放 id:2，实际:", body)
	}
	if !strings.Contains(body, "id: 3") {
		t.Error("afterID=1 应该回放 id:3，实际:", body)
	}
	if strings.Contains(body, "id: 1") {
		t.Error("afterID=1 不应回放 id:1，实际:", body)
	}

	// 不存在的 afterID → 从头回放全部
	rec3 := httptest.NewRecorder()
	ring.replay("999", rec3, rec3)
	body3 := rec3.Body.String()
	if !strings.Contains(body3, "id: 1") {
		t.Error("不存在的 afterID 应从头回放，实际:", body3)
	}
}

func TestEventRingOverflow(t *testing.T) {
	ring := newEventRing(3)

	// 推 5 条（超过容量 3，最旧的 2 条被覆盖）
	for i := 1; i <= 5; i++ {
		ring.push(StoredEvent{
			ID:        string(rune('0' + i)),
			EventType: "test",
			Data:      []byte(`{}`),
			Timestamp: time.Now(),
		})
	}

	if !ring.full {
		t.Fatal("推了 5 条进容量 3 的缓冲区，应该已满")
	}

	// afterID=2 已被覆盖 → 找不到位置，从头回放全部
	rec := httptest.NewRecorder()
	ring.replay("2", rec, rec)
	body := rec.Body.String()
	if !strings.Contains(body, "id: 3") || !strings.Contains(body, "id: 5") {
		t.Error("缓冲区溢出后应能回放可用范围，实际:", body)
	}
}

func TestEventRingConcurrent(t *testing.T) {
	ring := newEventRing(100)

	done := make(chan bool, 10)
	for i := 0; i < 10; i++ {
		go func() {
			for j := 0; j < 200; j++ {
				ring.push(StoredEvent{
					ID:        "evt",
					EventType: "test",
					Data:      []byte(`{}`),
					Timestamp: time.Now(),
				})
			}
			done <- true
		}()
	}
	for i := 0; i < 10; i++ {
		<-done
	}
	// 只验证不 panic，不验证内容（并发下顺序无意义）
}