package api

import (
	"bufio"
	"bytes"
	"net"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"
)

func TestWebSocketReaderRejectsClientDataAndReservedOpcodes(t *testing.T) {
	for _, opcode := range []byte{0x0, 0x1, 0x2, 0x3, 0xB, 0xF} {
		frame := append([]byte{0x80 | opcode, 0x80, 0, 0, 0, 0}, nil...)
		if _, _, err := readWebSocketFrame(bufio.NewReader(bytes.NewReader(frame))); err == nil {
			t.Fatalf("opcode 0x%x was accepted", opcode)
		}
	}
}

func TestWebSocketReaderRejectsOversizedControlFrame(t *testing.T) {
	frame := append([]byte{0x89, 0xFE, 0, 126, 0, 0, 0, 0}, bytes.Repeat([]byte{0}, 126)...)
	if _, _, err := readWebSocketFrame(bufio.NewReader(bytes.NewReader(frame))); err == nil {
		t.Fatal("oversized ping control frame was accepted")
	}
}

func TestWebSocketWriterDoesNotBlockForeverOnSlowClient(t *testing.T) {
	sender, receiver := net.Pipe()
	defer sender.Close()
	defer receiver.Close()
	done := make(chan error, 1)
	go func() {
		done <- writeWebSocketFrameWithDeadline(sender, 0x1, bytes.Repeat([]byte{'x'}, maxWebSocketFrame), 20*time.Millisecond)
	}()
	select {
	case err := <-done:
		if err == nil {
			t.Fatal("write to a non-reading client unexpectedly succeeded")
		}
	case <-time.After(time.Second):
		t.Fatal("write to a non-reading client blocked past its deadline")
	}
}

func TestWebSocketHandshakeRequiresRFC6455Version(t *testing.T) {
	service := &Service{}
	request := httptest.NewRequest(http.MethodGet, "/v1/events", nil)
	request.Header.Set("Upgrade", "websocket")
	request.Header.Set("Connection", "Upgrade")
	request.Header.Set("Sec-WebSocket-Version", "12")
	request.Header.Set("Sec-WebSocket-Key", "dGhlIHNhbXBsZSBub25jZQ==")
	recorder := httptest.NewRecorder()
	service.controlPlaneEvent(recorder, request)
	if recorder.Code != http.StatusBadRequest {
		t.Fatalf("version 12 status = %d, want 400", recorder.Code)
	}
}

func TestWebSocketMessageBudgetIsBoundedAndResets(t *testing.T) {
	start := time.Unix(1000, 0)
	window := start
	count := 0
	for i := 0; i < webSocketMessageLimit; i++ {
		if !allowWebSocketMessage(start, &window, &count) {
			t.Fatalf("message %d was rejected within the budget", i)
		}
	}
	if allowWebSocketMessage(start, &window, &count) {
		t.Fatal("message over the WebSocket budget was accepted")
	}
	if !allowWebSocketMessage(start.Add(webSocketMessageWindow), &window, &count) {
		t.Fatal("WebSocket message budget did not reset")
	}
}