// Copyright Istio 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 main

import (
	"context"
	"fmt"
	"net/http"
	"testing"

	authv2 "github.com/envoyproxy/go-control-plane/envoy/service/auth/v2"
	authv3 "github.com/envoyproxy/go-control-plane/envoy/service/auth/v3"
	"google.golang.org/grpc"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/credentials/insecure"
)

func TestExtAuthz(t *testing.T) {
	server := NewExtAuthzServer()
	// Start the test server on random port.
	go server.run("localhost:0", "localhost:0")

	// Prepare the HTTP request.
	httpClient := &http.Client{}
	httpReq, err := http.NewRequest(http.MethodGet, fmt.Sprintf("http://localhost:%d/check", <-server.httpPort), nil)
	if err != nil {
		t.Fatal(err.Error())
	}

	// Prepare the gRPC request.
	conn, err := grpc.Dial(fmt.Sprintf("localhost:%d", <-server.grpcPort), grpc.WithTransportCredentials(insecure.NewCredentials()))
	if err != nil {
		t.Fatal(err.Error())
	}
	defer func() { _ = conn.Close() }()
	grpcV3Client := authv3.NewAuthorizationClient(conn)
	grpcV2Client := authv2.NewAuthorizationClient(conn)

	cases := []struct {
		name     string
		isGRPCV3 bool
		isGRPCV2 bool
		header   string
		want     int
	}{
		{
			name:   "HTTP-allow",
			header: "allow",
			want:   http.StatusOK,
		},
		{
			name:   "HTTP-deny",
			header: "deny",
			want:   http.StatusForbidden,
		},
		{
			name:     "GRPCv3-allow",
			isGRPCV3: true,
			header:   "allow",
			want:     int(codes.OK),
		},
		{
			name:     "GRPCv3-deny",
			isGRPCV3: true,
			header:   "deny",
			want:     int(codes.PermissionDenied),
		},
		{
			name:     "GRPCv2-allow",
			isGRPCV2: true,
			header:   "allow",
			want:     int(codes.OK),
		},
		{
			name:     "GRPCv2-deny",
			isGRPCV2: true,
			header:   "deny",
			want:     int(codes.PermissionDenied),
		},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			var got int
			if tc.isGRPCV3 {
				resp, err := grpcV3Client.Check(context.Background(), &authv3.CheckRequest{
					Attributes: &authv3.AttributeContext{
						Request: &authv3.AttributeContext_Request{
							Http: &authv3.AttributeContext_HttpRequest{
								Host:    "localhost",
								Path:    "/check",
								Headers: map[string]string{checkHeader: tc.header},
							},
						},
					},
				})
				if err != nil {
					t.Error(err)
				} else {
					got = int(resp.Status.Code)
				}
			} else if tc.isGRPCV2 {
				resp, err := grpcV2Client.Check(context.Background(), &authv2.CheckRequest{
					Attributes: &authv2.AttributeContext{
						Request: &authv2.AttributeContext_Request{
							Http: &authv2.AttributeContext_HttpRequest{
								Host:    "localhost",
								Path:    "/check",
								Headers: map[string]string{checkHeader: tc.header},
							},
						},
					},
				})
				if err != nil {
					t.Error(err)
				} else {
					got = int(resp.Status.Code)
				}
			} else {
				httpReq.Header.Set(checkHeader, tc.header)
				resp, err := httpClient.Do(httpReq)
				if err != nil {
					t.Error(err)
				} else {
					got = resp.StatusCode
					resp.Body.Close()
				}
			}
			if got != tc.want {
				t.Errorf("want %d but got %d", tc.want, got)
			}
		})
	}
}
