// Copyright The OpenTelemetry Authors
// Licensed 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 internal

import (
	"net/http"
	"net/http/httptest"
	"net/url"
	"strconv"
	"testing"

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

	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/codes"
)

var hc = &HTTPConv{
	NetConv: nc,

	EnduserIDKey:                 attribute.Key("enduser.id"),
	HTTPClientIPKey:              attribute.Key("http.client_ip"),
	HTTPFlavorKey:                attribute.Key("http.flavor"),
	HTTPMethodKey:                attribute.Key("http.method"),
	HTTPRequestContentLengthKey:  attribute.Key("http.request_content_length"),
	HTTPResponseContentLengthKey: attribute.Key("http.response_content_length"),
	HTTPRouteKey:                 attribute.Key("http.route"),
	HTTPSchemeHTTP:               attribute.String("http.scheme", "http"),
	HTTPSchemeHTTPS:              attribute.String("http.scheme", "https"),
	HTTPStatusCodeKey:            attribute.Key("http.status_code"),
	HTTPTargetKey:                attribute.Key("http.target"),
	HTTPURLKey:                   attribute.Key("http.url"),
	HTTPUserAgentKey:             attribute.Key("http.user_agent"),
}

func TestHTTPClientResponse(t *testing.T) {
	const stat, n = 201, 397
	resp := &http.Response{
		StatusCode:    stat,
		ContentLength: n,
	}
	got := hc.ClientResponse(resp)
	assert.Equal(t, 2, cap(got), "slice capacity")
	assert.ElementsMatch(t, []attribute.KeyValue{
		attribute.Key("http.status_code").Int(stat),
		attribute.Key("http.response_content_length").Int(n),
	}, got)
}

func TestHTTPSClientRequest(t *testing.T) {
	req := &http.Request{
		Method: http.MethodGet,
		URL: &url.URL{
			Scheme: "https",
			Host:   "127.0.0.1:443",
			Path:   "/resource",
		},
		Proto:      "HTTP/1.0",
		ProtoMajor: 1,
		ProtoMinor: 0,
	}

	assert.Equal(
		t,
		[]attribute.KeyValue{
			attribute.String("http.method", "GET"),
			attribute.String("http.flavor", "1.0"),
			attribute.String("http.url", "https://127.0.0.1:443/resource"),
			attribute.String("net.peer.name", "127.0.0.1"),
		},
		hc.ClientRequest(req),
	)
}

func TestHTTPClientRequest(t *testing.T) {
	const (
		user  = "alice"
		n     = 128
		agent = "Go-http-client/1.1"
	)
	req := &http.Request{
		Method: http.MethodGet,
		URL: &url.URL{
			Scheme: "http",
			Host:   "127.0.0.1:8080",
			Path:   "/resource",
		},
		Proto:      "HTTP/1.0",
		ProtoMajor: 1,
		ProtoMinor: 0,
		Header: http.Header{
			"User-Agent": []string{agent},
		},
		ContentLength: n,
	}
	req.SetBasicAuth(user, "pswrd")

	assert.Equal(
		t,
		[]attribute.KeyValue{
			attribute.String("http.method", "GET"),
			attribute.String("http.flavor", "1.0"),
			attribute.String("http.url", "http://127.0.0.1:8080/resource"),
			attribute.String("net.peer.name", "127.0.0.1"),
			attribute.Int("net.peer.port", 8080),
			attribute.String("http.user_agent", agent),
			attribute.Int("http.request_content_length", n),
			attribute.String("enduser.id", user),
		},
		hc.ClientRequest(req),
	)
}

func TestHTTPClientRequestRequired(t *testing.T) {
	req := new(http.Request)
	var got []attribute.KeyValue
	assert.NotPanics(t, func() { got = hc.ClientRequest(req) })
	want := []attribute.KeyValue{
		attribute.String("http.method", "GET"),
		attribute.String("http.flavor", ""),
		attribute.String("http.url", ""),
		attribute.String("net.peer.name", ""),
	}
	assert.Equal(t, want, got)
}

func TestHTTPServerRequest(t *testing.T) {
	got := make(chan *http.Request, 1)
	handler := func(w http.ResponseWriter, r *http.Request) {
		got <- r
		w.WriteHeader(http.StatusOK)
	}

	srv := httptest.NewServer(http.HandlerFunc(handler))
	defer srv.Close()

	srvURL, err := url.Parse(srv.URL)
	require.NoError(t, err)
	srvPort, err := strconv.ParseInt(srvURL.Port(), 10, 32)
	require.NoError(t, err)

	resp, err := srv.Client().Get(srv.URL)
	require.NoError(t, err)
	require.NoError(t, resp.Body.Close())

	req := <-got
	peer, peerPort := splitHostPort(req.RemoteAddr)

	const user = "alice"
	req.SetBasicAuth(user, "pswrd")

	const clientIP = "127.0.0.5"
	req.Header.Add("X-Forwarded-For", clientIP)

	assert.ElementsMatch(t,
		[]attribute.KeyValue{
			attribute.String("http.method", "GET"),
			attribute.String("http.scheme", "http"),
			attribute.String("http.flavor", "1.1"),
			attribute.String("net.host.name", srvURL.Hostname()),
			attribute.Int("net.host.port", int(srvPort)),
			attribute.String("net.sock.peer.addr", peer),
			attribute.Int("net.sock.peer.port", peerPort),
			attribute.String("http.user_agent", "Go-http-client/1.1"),
			attribute.String("enduser.id", user),
			attribute.String("http.client_ip", clientIP),
		},
		hc.ServerRequest("", req))
}

func TestHTTPServerName(t *testing.T) {
	req := new(http.Request)
	var got []attribute.KeyValue
	const (
		host = "test.semconv.server"
		port = 8080
	)
	portStr := strconv.Itoa(port)
	server := host + ":" + portStr
	assert.NotPanics(t, func() { got = hc.ServerRequest(server, req) })
	assert.Contains(t, got, attribute.String("net.host.name", host))
	assert.Contains(t, got, attribute.Int("net.host.port", port))

	req = &http.Request{Host: "alt.host.name:" + portStr}
	// The server parameter does not include a port, ServerRequest should use
	// the port in the request Host field.
	assert.NotPanics(t, func() { got = hc.ServerRequest(host, req) })
	assert.Contains(t, got, attribute.String("net.host.name", host))
	assert.Contains(t, got, attribute.Int("net.host.port", port))
}

func TestHTTPServerRequestFailsGracefully(t *testing.T) {
	req := new(http.Request)
	var got []attribute.KeyValue
	assert.NotPanics(t, func() { got = hc.ServerRequest("", req) })
	want := []attribute.KeyValue{
		attribute.String("http.method", "GET"),
		attribute.String("http.scheme", "http"),
		attribute.String("http.flavor", ""),
		attribute.String("net.host.name", ""),
	}
	assert.ElementsMatch(t, want, got)
}

func TestMethod(t *testing.T) {
	assert.Equal(t, attribute.String("http.method", "POST"), hc.method("POST"))
	assert.Equal(t, attribute.String("http.method", "GET"), hc.method(""))
	assert.Equal(t, attribute.String("http.method", "garbage"), hc.method("garbage"))
}

func TestScheme(t *testing.T) {
	assert.Equal(t, attribute.String("http.scheme", "http"), hc.scheme(false))
	assert.Equal(t, attribute.String("http.scheme", "https"), hc.scheme(true))
}

func TestProto(t *testing.T) {
	tests := map[string]string{
		"HTTP/1.0": "1.0",
		"HTTP/1.1": "1.1",
		"HTTP/2":   "2.0",
		"HTTP/3":   "3.0",
		"SPDY":     "SPDY",
		"QUIC":     "QUIC",
		"other":    "other",
	}

	for proto, want := range tests {
		expect := attribute.String("http.flavor", want)
		assert.Equal(t, expect, hc.proto(proto), proto)
	}
}

func TestServerClientIP(t *testing.T) {
	tests := []struct {
		xForwardedFor string
		want          string
	}{
		{"", ""},
		{"127.0.0.1", "127.0.0.1"},
		{"127.0.0.1,127.0.0.5", "127.0.0.1"},
	}
	for _, test := range tests {
		got := serverClientIP(test.xForwardedFor)
		assert.Equal(t, test.want, got, test.xForwardedFor)
	}
}

func TestRequiredHTTPPort(t *testing.T) {
	tests := []struct {
		https bool
		port  int
		want  int
	}{
		{true, 443, -1},
		{true, 80, 80},
		{true, 8081, 8081},
		{false, 443, 443},
		{false, 80, -1},
		{false, 8080, 8080},
	}
	for _, test := range tests {
		got := requiredHTTPPort(test.https, test.port)
		assert.Equal(t, test.want, got, test.https, test.port)
	}
}

func TestFirstHostPort(t *testing.T) {
	host, port := "127.0.0.1", 8080
	hostport := "127.0.0.1:8080"
	sources := [][]string{
		{hostport},
		{"", hostport},
		{"", "", hostport},
		{"", "", hostport, ""},
		{"", "", hostport, "127.0.0.3:80"},
	}

	for _, src := range sources {
		h, p := firstHostPort(src...)
		assert.Equal(t, host, h, src)
		assert.Equal(t, port, p, src)
	}
}

func TestRequestHeader(t *testing.T) {
	ips := []string{"127.0.0.5", "127.0.0.9"}
	user := []string{"alice"}
	h := http.Header{"ips": ips, "user": user}

	got := hc.RequestHeader(h)
	assert.Equal(t, 2, cap(got), "slice capacity")
	assert.ElementsMatch(t, []attribute.KeyValue{
		attribute.StringSlice("http.request.header.ips", ips),
		attribute.StringSlice("http.request.header.user", user),
	}, got)
}

func TestReponseHeader(t *testing.T) {
	ips := []string{"127.0.0.5", "127.0.0.9"}
	user := []string{"alice"}
	h := http.Header{"ips": ips, "user": user}

	got := hc.ResponseHeader(h)
	assert.Equal(t, 2, cap(got), "slice capacity")
	assert.ElementsMatch(t, []attribute.KeyValue{
		attribute.StringSlice("http.response.header.ips", ips),
		attribute.StringSlice("http.response.header.user", user),
	}, got)
}

func TestClientStatus(t *testing.T) {
	tests := []struct {
		code int
		stat codes.Code
		msg  bool
	}{
		{0, codes.Error, true},
		{http.StatusContinue, codes.Unset, false},
		{http.StatusSwitchingProtocols, codes.Unset, false},
		{http.StatusProcessing, codes.Unset, false},
		{http.StatusEarlyHints, codes.Unset, false},
		{http.StatusOK, codes.Unset, false},
		{http.StatusCreated, codes.Unset, false},
		{http.StatusAccepted, codes.Unset, false},
		{http.StatusNonAuthoritativeInfo, codes.Unset, false},
		{http.StatusNoContent, codes.Unset, false},
		{http.StatusResetContent, codes.Unset, false},
		{http.StatusPartialContent, codes.Unset, false},
		{http.StatusMultiStatus, codes.Unset, false},
		{http.StatusAlreadyReported, codes.Unset, false},
		{http.StatusIMUsed, codes.Unset, false},
		{http.StatusMultipleChoices, codes.Unset, false},
		{http.StatusMovedPermanently, codes.Unset, false},
		{http.StatusFound, codes.Unset, false},
		{http.StatusSeeOther, codes.Unset, false},
		{http.StatusNotModified, codes.Unset, false},
		{http.StatusUseProxy, codes.Unset, false},
		{306, codes.Error, true},
		{http.StatusTemporaryRedirect, codes.Unset, false},
		{http.StatusPermanentRedirect, codes.Unset, false},
		{http.StatusBadRequest, codes.Error, false},
		{http.StatusUnauthorized, codes.Error, false},
		{http.StatusPaymentRequired, codes.Error, false},
		{http.StatusForbidden, codes.Error, false},
		{http.StatusNotFound, codes.Error, false},
		{http.StatusMethodNotAllowed, codes.Error, false},
		{http.StatusNotAcceptable, codes.Error, false},
		{http.StatusProxyAuthRequired, codes.Error, false},
		{http.StatusRequestTimeout, codes.Error, false},
		{http.StatusConflict, codes.Error, false},
		{http.StatusGone, codes.Error, false},
		{http.StatusLengthRequired, codes.Error, false},
		{http.StatusPreconditionFailed, codes.Error, false},
		{http.StatusRequestEntityTooLarge, codes.Error, false},
		{http.StatusRequestURITooLong, codes.Error, false},
		{http.StatusUnsupportedMediaType, codes.Error, false},
		{http.StatusRequestedRangeNotSatisfiable, codes.Error, false},
		{http.StatusExpectationFailed, codes.Error, false},
		{http.StatusTeapot, codes.Error, false},
		{http.StatusMisdirectedRequest, codes.Error, false},
		{http.StatusUnprocessableEntity, codes.Error, false},
		{http.StatusLocked, codes.Error, false},
		{http.StatusFailedDependency, codes.Error, false},
		{http.StatusTooEarly, codes.Error, false},
		{http.StatusUpgradeRequired, codes.Error, false},
		{http.StatusPreconditionRequired, codes.Error, false},
		{http.StatusTooManyRequests, codes.Error, false},
		{http.StatusRequestHeaderFieldsTooLarge, codes.Error, false},
		{http.StatusUnavailableForLegalReasons, codes.Error, false},
		{http.StatusInternalServerError, codes.Error, false},
		{http.StatusNotImplemented, codes.Error, false},
		{http.StatusBadGateway, codes.Error, false},
		{http.StatusServiceUnavailable, codes.Error, false},
		{http.StatusGatewayTimeout, codes.Error, false},
		{http.StatusHTTPVersionNotSupported, codes.Error, false},
		{http.StatusVariantAlsoNegotiates, codes.Error, false},
		{http.StatusInsufficientStorage, codes.Error, false},
		{http.StatusLoopDetected, codes.Error, false},
		{http.StatusNotExtended, codes.Error, false},
		{http.StatusNetworkAuthenticationRequired, codes.Error, false},
		{600, codes.Error, true},
	}

	for _, test := range tests {
		c, msg := hc.ClientStatus(test.code)
		assert.Equal(t, test.stat, c)
		if test.msg && msg == "" {
			t.Errorf("expected non-empty message for %d", test.code)
		} else if !test.msg && msg != "" {
			t.Errorf("expected empty message for %d, got: %s", test.code, msg)
		}
	}
}

func TestServerStatus(t *testing.T) {
	tests := []struct {
		code int
		stat codes.Code
		msg  bool
	}{
		{0, codes.Error, true},
		{http.StatusContinue, codes.Unset, false},
		{http.StatusSwitchingProtocols, codes.Unset, false},
		{http.StatusProcessing, codes.Unset, false},
		{http.StatusEarlyHints, codes.Unset, false},
		{http.StatusOK, codes.Unset, false},
		{http.StatusCreated, codes.Unset, false},
		{http.StatusAccepted, codes.Unset, false},
		{http.StatusNonAuthoritativeInfo, codes.Unset, false},
		{http.StatusNoContent, codes.Unset, false},
		{http.StatusResetContent, codes.Unset, false},
		{http.StatusPartialContent, codes.Unset, false},
		{http.StatusMultiStatus, codes.Unset, false},
		{http.StatusAlreadyReported, codes.Unset, false},
		{http.StatusIMUsed, codes.Unset, false},
		{http.StatusMultipleChoices, codes.Unset, false},
		{http.StatusMovedPermanently, codes.Unset, false},
		{http.StatusFound, codes.Unset, false},
		{http.StatusSeeOther, codes.Unset, false},
		{http.StatusNotModified, codes.Unset, false},
		{http.StatusUseProxy, codes.Unset, false},
		{306, codes.Error, true},
		{http.StatusTemporaryRedirect, codes.Unset, false},
		{http.StatusPermanentRedirect, codes.Unset, false},
		{http.StatusBadRequest, codes.Unset, false},
		{http.StatusUnauthorized, codes.Unset, false},
		{http.StatusPaymentRequired, codes.Unset, false},
		{http.StatusForbidden, codes.Unset, false},
		{http.StatusNotFound, codes.Unset, false},
		{http.StatusMethodNotAllowed, codes.Unset, false},
		{http.StatusNotAcceptable, codes.Unset, false},
		{http.StatusProxyAuthRequired, codes.Unset, false},
		{http.StatusRequestTimeout, codes.Unset, false},
		{http.StatusConflict, codes.Unset, false},
		{http.StatusGone, codes.Unset, false},
		{http.StatusLengthRequired, codes.Unset, false},
		{http.StatusPreconditionFailed, codes.Unset, false},
		{http.StatusRequestEntityTooLarge, codes.Unset, false},
		{http.StatusRequestURITooLong, codes.Unset, false},
		{http.StatusUnsupportedMediaType, codes.Unset, false},
		{http.StatusRequestedRangeNotSatisfiable, codes.Unset, false},
		{http.StatusExpectationFailed, codes.Unset, false},
		{http.StatusTeapot, codes.Unset, false},
		{http.StatusMisdirectedRequest, codes.Unset, false},
		{http.StatusUnprocessableEntity, codes.Unset, false},
		{http.StatusLocked, codes.Unset, false},
		{http.StatusFailedDependency, codes.Unset, false},
		{http.StatusTooEarly, codes.Unset, false},
		{http.StatusUpgradeRequired, codes.Unset, false},
		{http.StatusPreconditionRequired, codes.Unset, false},
		{http.StatusTooManyRequests, codes.Unset, false},
		{http.StatusRequestHeaderFieldsTooLarge, codes.Unset, false},
		{http.StatusUnavailableForLegalReasons, codes.Unset, false},
		{http.StatusInternalServerError, codes.Error, false},
		{http.StatusNotImplemented, codes.Error, false},
		{http.StatusBadGateway, codes.Error, false},
		{http.StatusServiceUnavailable, codes.Error, false},
		{http.StatusGatewayTimeout, codes.Error, false},
		{http.StatusHTTPVersionNotSupported, codes.Error, false},
		{http.StatusVariantAlsoNegotiates, codes.Error, false},
		{http.StatusInsufficientStorage, codes.Error, false},
		{http.StatusLoopDetected, codes.Error, false},
		{http.StatusNotExtended, codes.Error, false},
		{http.StatusNetworkAuthenticationRequired, codes.Error, false},
		{600, codes.Error, true},
	}

	for _, test := range tests {
		c, msg := hc.ServerStatus(test.code)
		assert.Equal(t, test.stat, c)
		if test.msg && msg == "" {
			t.Errorf("expected non-empty message for %d", test.code)
		} else if !test.msg && msg != "" {
			t.Errorf("expected empty message for %d, got: %s", test.code, msg)
		}
	}
}