package web

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

// deadlineRecorder 冒充 http.response：只有实现了 SetWriteDeadline，
// 才看得出 http.NewResponseController 有没有被中间件挡住。
type deadlineRecorder struct {
	*httptest.ResponseRecorder
	deadline time.Time
	got      bool
}

func (d *deadlineRecorder) SetWriteDeadline(t time.Time) error {
	d.deadline, d.got = t, true
	return nil
}

// P4 回归：gzipWriter 必须实现 Unwrap()。少了它，被 gzip 中间件包住的请求调
// http.NewResponseController(...).SetWriteDeadline/Flush 只会拿到 ErrNotSupported。
func TestGzipWriterUnwrapsToUnderlyingWriter(t *testing.T) {
	rec := &deadlineRecorder{ResponseRecorder: httptest.NewRecorder()}
	gw := &gzipWriter{ResponseWriter: rec}

	if err := http.NewResponseController(gw).SetWriteDeadline(time.Now().Add(time.Minute)); err != nil {
		t.Fatalf("ResponseController 没能穿过 gzipWriter: %v", err)
	}
	if !rec.got {
		t.Error("SetWriteDeadline 没有落到真正的 ResponseWriter 上")
	}
}

// P4 回归：导出是「一次性大响应」，得带上 Content-Length（下载进度条、
// 也顺带锁住「不再依赖隐式 200」），并把写死线放宽到全站 120s 之外。
func TestExportSetsContentLengthAndExtendsWriteDeadline(t *testing.T) {
	f := newMovementFixture(t)

	rec := &deadlineRecorder{ResponseRecorder: httptest.NewRecorder()}
	req := httptest.NewRequest("GET", "/admin/export/rondbackup", nil).WithContext(f.ctx)
	f.srv.exportRondbackup(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("导出返回 %d：%s", rec.Code, firstLine(rec.Body.String()))
	}
	if cl := rec.Header().Get("Content-Length"); cl != strconv.Itoa(rec.Body.Len()) {
		t.Errorf("Content-Length=%q，实际写出 %d 字节", cl, rec.Body.Len())
	}
	if ct := rec.Header().Get("Content-Type"); ct != "application/octet-stream" {
		t.Errorf("Content-Type 不对: %q", ct)
	}
	if !rec.got {
		t.Error("导出没有延长写死线（慢链路下会被全站 120s 截断）")
	}
}