// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License"). You may
// not use this file except in compliance with the License. A copy of the
// License is located at
//
//     http://aws.amazon.com/apache2.0/
//
// or in the "license" file accompanying this file. This file 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 ec2

import (
	"fmt"
	"testing"

	mock_api "github.com/aws/amazon-vpc-resource-controller-k8s/mocks/amazon-vcp-resource-controller-k8s/pkg/aws/ec2/api"
	"github.com/aws/amazon-vpc-resource-controller-k8s/pkg/utils"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/service/ec2"
	"github.com/golang/mock/gomock"
	"github.com/stretchr/testify/assert"
)

var (
	nodeName      = "name"
	os            = "linux"
	instanceID    = "i-000000000000000"
	subnetID      = "subnet-id"
	privateIPAddr = "192.168.1.0"

	securityGroup1 = "sg-1"
	securityGroup2 = "sg-2"

	securityGroup3 = "sg-3"

	instanceType    = "c5.large"
	subnetCidrBlock = "192.168.0.0/16"

	primaryInterfaceID = "192.168.0.2"

	deviceIndex0 = int64(0)
	deviceIndex2 = int64(2)

	nwInterfaces = &ec2.Instance{
		InstanceId:       &instanceID,
		InstanceType:     &instanceType,
		SubnetId:         &subnetID,
		PrivateIpAddress: &privateIPAddr,
		NetworkInterfaces: []*ec2.InstanceNetworkInterface{
			{
				NetworkInterfaceId: &primaryInterfaceID,
				PrivateIpAddress:   &privateIPAddr,
				Groups: []*ec2.GroupIdentifier{
					{
						GroupId: &securityGroup1,
					},
					{
						GroupId: &securityGroup2,
					},
				},
				Attachment: &ec2.InstanceNetworkInterfaceAttachment{DeviceIndex: &deviceIndex0},
			},
			{
				PrivateIpAddress: aws.String("192.168.1.2"),
				Groups: []*ec2.GroupIdentifier{
					{
						GroupId: &securityGroup3,
					},
				},
				Attachment: &ec2.InstanceNetworkInterfaceAttachment{DeviceIndex: &deviceIndex2},
			},
		},
	}

	subnet = &ec2.Subnet{
		CidrBlock: &subnetCidrBlock,
	}

	mockError = fmt.Errorf("mock error")
)

func getMockInstanceInterface() EC2Instance {
	return NewEC2Instance(nodeName, instanceID, os)
}

func getMockInstance(ctrl *gomock.Controller) (ec2Instance, *mock_api.MockEC2APIHelper) {
	mockEC2ApiHelper := mock_api.NewMockEC2APIHelper(ctrl)
	return ec2Instance{instanceID: instanceID, os: os, name: nodeName}, mockEC2ApiHelper
}

// TestNewEC2Instance tests that the returned instance is not nil and the passed information is initialized correctly
func TestNewEC2Instance(t *testing.T) {
	ec2Instance := getMockInstanceInterface()
	assert.NotNil(t, ec2Instance)
	assert.Equal(t, nodeName, ec2Instance.Name())
	assert.Equal(t, os, ec2Instance.Os())
	assert.Equal(t, instanceID, ec2Instance.InstanceID())
}

// TestEc2Instance_LoadDetails tests that load instance details loads all the instance details correctly by making calls
// to EC2 API Helper
func TestEc2Instance_LoadDetails(t *testing.T) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	ec2Instance, mockEC2ApiHelper := getMockInstance(ctrl)

	mockEC2ApiHelper.EXPECT().GetInstanceDetails(&instanceID).Return(nwInterfaces, nil)
	mockEC2ApiHelper.EXPECT().GetSubnet(&subnetID).Return(subnet, nil)

	err := ec2Instance.LoadDetails(mockEC2ApiHelper)
	assert.NoError(t, err)
	assert.Equal(t, subnetID, ec2Instance.SubnetID())
	assert.Equal(t, subnetCidrBlock, ec2Instance.SubnetCidrBlock())
	assert.Equal(t, instanceType, ec2Instance.Type())
	assert.Equal(t, []bool{true, false, true}, ec2Instance.deviceIndexes)
	assert.Equal(t, []string{securityGroup1, securityGroup2}, ec2Instance.CurrentInstanceSecurityGroups())
	assert.Equal(t, primaryInterfaceID, ec2Instance.PrimaryNetworkInterfaceID())
}

// TestEc2Instance_LoadDetails_InstanceDetailsIsNull tests error is returned if the instance details
// response from EC2 API is null
func TestEc2Instance_LoadDetails_InstanceDetailsIsNull(t *testing.T) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	ec2Instance, mockEC2ApiHelper := getMockInstance(ctrl)

	mockEC2ApiHelper.EXPECT().GetInstanceDetails(&instanceID).Return(nil, nil)

	err := ec2Instance.LoadDetails(mockEC2ApiHelper)
	assert.NotNil(t, err)
}

// TestEc2Instance_LoadDetails_InstanceDetails_SubnetID_IsNull tests error is returned if the instance
// is not details null but the subnet is nil
func TestEc2Instance_LoadDetails_InstanceDetails_SubnetID_IsNull(t *testing.T) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	ec2Instance, mockEC2ApiHelper := getMockInstance(ctrl)

	mockEC2ApiHelper.EXPECT().GetInstanceDetails(&instanceID).Return(&ec2.Instance{}, nil)

	err := ec2Instance.LoadDetails(mockEC2ApiHelper)
	assert.NotNil(t, err)
}

// TestEc2Instance_LoadDetails_InstanceSubnet_IsNull tests error is returned if the instance subnet
// response from EC2 API is null
func TestEc2Instance_LoadDetails_InstanceSubnet_IsNull(t *testing.T) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	ec2Instance, mockEC2ApiHelper := getMockInstance(ctrl)

	mockEC2ApiHelper.EXPECT().GetInstanceDetails(&instanceID).Return(nwInterfaces, nil)
	mockEC2ApiHelper.EXPECT().GetSubnet(&subnetID).Return(nil, nil)

	err := ec2Instance.LoadDetails(mockEC2ApiHelper)
	assert.NotNil(t, err)
}

// TestEc2Instance_LoadDetails_InstanceSubnet_CidrBlock_IsNull tests error is returned if the instance
// subnet CIDR Block from GetSubnet response from EC2 API is null
func TestEc2Instance_LoadDetails_InstanceSubnet_CidrBlock_IsNull(t *testing.T) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	ec2Instance, mockEC2ApiHelper := getMockInstance(ctrl)

	mockEC2ApiHelper.EXPECT().GetInstanceDetails(&instanceID).Return(nwInterfaces, nil)
	mockEC2ApiHelper.EXPECT().GetSubnet(&subnetID).Return(&ec2.Subnet{}, nil)

	err := ec2Instance.LoadDetails(mockEC2ApiHelper)
	assert.NotNil(t, err)
}

// TestEc2Instance_LoadDetails_SubnetPreLoaded if the subnet is already loaded it's not set to the value of the instance's
// subnet
func TestEc2Instance_LoadDetails_SubnetPreLoaded(t *testing.T) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	ec2Instance, mockEC2ApiHelper := getMockInstance(ctrl)
	customNWSubnetID := "custom-networking"
	customNWSecurityGroups := []string{"sg-1"}
	customNWSubnetCidr := "192.2.0.0/24"

	// Set the instance subnet ID and CIDR block
	ec2Instance.instanceSubnetID = subnetID
	ec2Instance.instanceSubnetCidrBlock = subnetCidrBlock

	// Set the custom networking subnet ID and CIDR block
	ec2Instance.newCustomNetworkingSubnetID = customNWSubnetID
	ec2Instance.newCustomNetworkingSecurityGroups = customNWSecurityGroups

	customSubnet := &ec2.Subnet{CidrBlock: &customNWSubnetCidr}

	mockEC2ApiHelper.EXPECT().GetInstanceDetails(&instanceID).Return(nwInterfaces, nil)
	mockEC2ApiHelper.EXPECT().GetSubnet(&subnetID).Return(subnet, nil)
	mockEC2ApiHelper.EXPECT().GetSubnet(&customNWSubnetID).Return(customSubnet, nil)

	err := ec2Instance.LoadDetails(mockEC2ApiHelper)
	assert.NoError(t, err)
	assert.Equal(t, customNWSubnetID, ec2Instance.currentSubnetID)
	assert.Equal(t, customNWSecurityGroups, ec2Instance.currentInstanceSecurityGroups)
	assert.Equal(t, customNWSubnetCidr, ec2Instance.currentSubnetCIDRBlock)
}

// TestEc2Instance_LoadDetails_ErrInstanceDetails tests that if error is returned in loading instance details then the
// operation fails
func TestEc2Instance_LoadDetails_ErrInstanceDetails(t *testing.T) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	ec2Instance, mockEC2ApiHelper := getMockInstance(ctrl)

	mockEC2ApiHelper.EXPECT().GetInstanceDetails(&instanceID).Return(nil, mockError)

	err := ec2Instance.LoadDetails(mockEC2ApiHelper)
	assert.Error(t, mockError, err)
}

// TestEc2Instance_LoadDetails_ErrGetSubnet tests that if error is returned in loading subnet details then the
// operation fails
func TestEc2Instance_LoadDetails_ErrGetSubnet(t *testing.T) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	ec2Instance, mockEC2ApiHelper := getMockInstance(ctrl)

	mockEC2ApiHelper.EXPECT().GetInstanceDetails(&instanceID).Return(nwInterfaces, nil)
	mockEC2ApiHelper.EXPECT().GetSubnet(&subnetID).Return(nil, mockError)

	err := ec2Instance.LoadDetails(mockEC2ApiHelper)
	assert.Error(t, mockError, err)
}

// TestEc2Instance_LoadDetails_InstanceENILimitNotFound tests that the instance ENI limit is not found then the operation
// fails
func TestEc2Instance_LoadDetails_InstanceENILimitNotFound(t *testing.T) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	ec2Instance, mockEC2ApiHelper := getMockInstance(ctrl)

	unsupportedInstance := "c5.xlarge-2"

	nwInterfaces.InstanceType = &unsupportedInstance

	mockEC2ApiHelper.EXPECT().GetInstanceDetails(&instanceID).Return(nwInterfaces, nil)
	mockEC2ApiHelper.EXPECT().GetSubnet(&subnetID).Return(subnet, nil)

	err := ec2Instance.LoadDetails(mockEC2ApiHelper)
	assert.NotNil(t, err)
	// ensure the expected error is returned to trigger a node event
	assert.ErrorIs(t, err, utils.ErrNotFound)

	// Clean up
	nwInterfaces.InstanceType = &instanceType
}

// TestEc2Instance_GetHighestUnusedDeviceIndex tests that if a free index exists, it is returned
func TestEc2Instance_GetHighestUnusedDeviceIndex(t *testing.T) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	ec2Instance, _ := getMockInstance(ctrl)
	ec2Instance.deviceIndexes = []bool{true, false, true}

	index, err := ec2Instance.GetHighestUnusedDeviceIndex()
	assert.NoError(t, err)
	assert.Equal(t, int64(1), index)
}

// TestEc2Instance_GetHighestUnusedDeviceIndex_NoFreeIndex tests that error is returned if no free index exists
func TestEc2Instance_GetHighestUnusedDeviceIndex_NoFreeIndex(t *testing.T) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	ec2Instance, _ := getMockInstance(ctrl)
	ec2Instance.deviceIndexes = []bool{true, true, true}

	_, err := ec2Instance.GetHighestUnusedDeviceIndex()
	assert.NotNil(t, err)
}

// TestEc2Instance_FreeDeviceIndex tests that index is freed after making the call
func TestEc2Instance_FreeDeviceIndex(t *testing.T) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	ec2Instance, _ := getMockInstance(ctrl)
	ec2Instance.deviceIndexes = []bool{true, true, true}

	indexToFree := int64(2)
	ec2Instance.FreeDeviceIndex(indexToFree)

	assert.False(t, ec2Instance.deviceIndexes[2])
}

// TestEc2Instance_E2E tests end to end workflow of loading the instance details and then assigning a free index and
// finally releasing a used device index
func TestEc2Instance_E2E(t *testing.T) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	ec2Instance, mockEC2ApiHelper := getMockInstance(ctrl)

	mockEC2ApiHelper.EXPECT().GetInstanceDetails(&instanceID).Return(nwInterfaces, nil)
	mockEC2ApiHelper.EXPECT().GetSubnet(&subnetID).Return(subnet, nil)

	// Assert no error on loading the instance details
	err := ec2Instance.LoadDetails(mockEC2ApiHelper)
	assert.NoError(t, err)

	// Check index is not used, assign index and verify index is used now
	assert.False(t, ec2Instance.deviceIndexes[1])
	index, err := ec2Instance.GetHighestUnusedDeviceIndex()
	assert.NoError(t, err)
	assert.Equal(t, int64(1), index)
	assert.True(t, ec2Instance.deviceIndexes[1])

	// Check index is used and then free that index
	assert.True(t, ec2Instance.deviceIndexes[1])
	ec2Instance.FreeDeviceIndex(deviceIndex0)
	assert.False(t, ec2Instance.deviceIndexes[deviceIndex0])
}

// Tests instance details when custom networking is incorrectly configured- missing security groups
func TestEc2Instance_LoadDetails_InvalidCustomNetworkingConfiguration(t *testing.T) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	ec2Instance, mockEC2ApiHelper := getMockInstance(ctrl)

	// Set the instance subnet ID and CIDR block
	ec2Instance.instanceSubnetID = subnetID
	ec2Instance.instanceSubnetCidrBlock = subnetCidrBlock

	// Set the custom networking subnet ID and CIDR block
	customNWSubnetID := "custom-networking"
	ec2Instance.newCustomNetworkingSubnetID = customNWSubnetID
	ec2Instance.newCustomNetworkingSecurityGroups = []string{}

	customNWSubnetCidr := "192.2.0.0/24"
	customSubnet := &ec2.Subnet{CidrBlock: &customNWSubnetCidr}

	mockEC2ApiHelper.EXPECT().GetInstanceDetails(&instanceID).Return(nwInterfaces, nil)
	mockEC2ApiHelper.EXPECT().GetSubnet(&subnetID).Return(subnet, nil)
	mockEC2ApiHelper.EXPECT().GetSubnet(&customNWSubnetID).Return(customSubnet, nil)

	err := ec2Instance.LoadDetails(mockEC2ApiHelper)
	assert.NoError(t, err)
	assert.Equal(t, customNWSubnetID, ec2Instance.currentSubnetID)
	// Expect the primary network interface security groups when ENIConfig SG is missing
	assert.Equal(t, []string{securityGroup1, securityGroup2}, ec2Instance.currentInstanceSecurityGroups)
	assert.Equal(t, customNWSubnetCidr, ec2Instance.currentSubnetCIDRBlock)
}