// Licensed to Apache Software Foundation (ASF) under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Apache Software Foundation (ASF) licenses this file to you under
// the Apache License, Version 2.0 (the "License"); you may
// not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

package http

import (
	"bufio"
	"net"
	"net/http"
	"testing"
	"time"

	"github.com/apache/skywalking-go/plugins/core"
	"github.com/apache/skywalking-go/plugins/core/operator"

	"github.com/stretchr/testify/assert"
)

func TestServerInvoke(t *testing.T) {
	defer core.ResetTracingContext()
	interceptor := &ServerInterceptor{}
	request, err := http.NewRequest("GET", "http://localhost/", http.NoBody)
	assert.Nil(t, err, "new request error should be nil")
	responseWriter := &testResponseWriter{}
	invocation := operator.NewInvocation(nil, responseWriter, request)
	err = interceptor.BeforeInvoke(invocation)
	assert.Nil(t, err, "before invoke error should be nil")
	assert.NotNil(t, invocation.GetContext(), "context should not be nil")

	time.Sleep(100 * time.Millisecond)

	err = interceptor.AfterInvoke(invocation)
	assert.Nil(t, err, "after invoke error should be nil")

	time.Sleep(100 * time.Millisecond)
	spans := core.GetReportedSpans()
	assert.NotNil(t, spans, "spans should not be nil")
	assert.Equal(t, 1, len(spans), "spans length should be 1")
	assert.Equal(t, "GET:/", spans[0].OperationName(), "operation name should be GET:/")
	assert.Nil(t, spans[0].Refs(), "refs should be nil")
	assert.Greater(t, spans[0].EndTime(), spans[0].StartTime(), "end time should be greater than start time")
}

func TestServerInvokeError(t *testing.T) {
	defer core.ResetTracingContext()
	interceptor := &ServerInterceptor{}
	request, _ := http.NewRequest("GET", "http://localhost/", http.NoBody)
	responseWriter := &testResponseWriter{}
	invocation := operator.NewInvocation(nil, responseWriter, request)
	_ = interceptor.BeforeInvoke(invocation)

	wrapped, _ := invocation.Args()[0].(*writerWrapper)

	wrapped.WriteHeader(http.StatusInternalServerError)

	time.Sleep(100 * time.Millisecond)
	_ = interceptor.AfterInvoke(invocation)
	time.Sleep(100 * time.Millisecond)

	spans := core.GetReportedSpans()
	assert.True(t, spans[0].IsError(), "span should be error")
}

type testResponseWriter struct {
	http.ResponseWriter
}

func (t *testResponseWriter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
	listen, err := net.Listen("tcp", ":0")
	if err != nil {
		return nil, nil, err
	}
	defer listen.Close()
	dial, err := net.Dial(listen.Addr().Network(), listen.Addr().String())
	if err != nil {
		return nil, nil, err
	}
	return dial, nil, nil
}

func (t *testResponseWriter) WriteHeader(code int) {
}

func (t *testResponseWriter) Write(b []byte) (int, error) {
	return len(b), nil
}
