package wsconn

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

	"github.com/gorilla/websocket"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// 基本煙測：確認 wsconn 能在真實 WebSocket 之上做雙向傳輸。
//
// 不深度測試（邏輯與 POC 完全一致，POC 已驗證）；此測試主要保證：
//   - package 可編譯
//   - New / Read / Write / Close / SetReadDeadline 可實際運作
//   - 符合 net.Conn 介面
func TestConn_ReadWrite(t *testing.T) {
	// 啟動一個 echo server：把收到的 bytes 原封寫回。
	var upgrader = websocket.Upgrader{
		CheckOrigin: func(r *http.Request) bool { return true },
	}

	done := make(chan struct{})
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		ws, err := upgrader.Upgrade(w, r, nil)
		if err != nil {
			t.Errorf("upgrade failed: %v", err)
			return
		}
		defer ws.Close()
		defer close(done)

		conn := New(ws)
		// 讀一整塊 → 寫回
		buf := make([]byte, 64)
		n, err := conn.Read(buf)
		if err != nil {
			t.Errorf("server read failed: %v", err)
			return
		}
		if _, err := conn.Write(buf[:n]); err != nil {
			t.Errorf("server write failed: %v", err)
		}
	}))
	defer server.Close()

	wsURL := "ws" + strings.TrimPrefix(server.URL, "http") + "/"

	dialer := websocket.DefaultDialer
	rawClient, _, err := dialer.Dial(wsURL, nil)
	require.NoError(t, err)
	defer rawClient.Close()

	client := New(rawClient)

	// 寫 → 讀回
	payload := []byte("hello wsconn")
	_, err = client.Write(payload)
	require.NoError(t, err)

	buf := make([]byte, len(payload))
	_, err = io.ReadFull(client, buf)
	require.NoError(t, err)
	assert.Equal(t, payload, buf)

	// 等 server goroutine 結束
	select {
	case <-done:
	case <-time.After(2 * time.Second):
		t.Fatal("server goroutine 未在 2s 內完成")
	}
}

func TestConn_SetDeadline_ExpiredReadReturnsError(t *testing.T) {
	// 建一個永遠不送資料的 server，讓 client read deadline 觸發 timeout。
	var upgrader = websocket.Upgrader{CheckOrigin: func(r *http.Request) bool { return true }}
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		ws, err := upgrader.Upgrade(w, r, nil)
		if err != nil {
			return
		}
		defer ws.Close()
		// 故意 block — 等 client 斷開
		_, _, _ = ws.NextReader()
	}))
	defer server.Close()

	wsURL := "ws" + strings.TrimPrefix(server.URL, "http") + "/"
	raw, _, err := websocket.DefaultDialer.Dial(wsURL, nil)
	require.NoError(t, err)
	defer raw.Close()

	c := New(raw)
	require.NoError(t, c.SetReadDeadline(time.Now().Add(50*time.Millisecond)))

	buf := make([]byte, 16)
	_, err = c.Read(buf)
	assert.Error(t, err, "過期 deadline 下 Read 應回 error")
}