// 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 internal

import (
	"github.com/containernetworking/plugins/pkg/ns"
	"github.com/vishvananda/netlink"
)

// MockNetlinkOps provides a no-op implementation of the NetlinkOps interface
type MockNetlinkOps struct {
	// CreatedTap is the mock tap device object that will be returned by the mock methods
	CreatedTap netlink.Link

	// RedirectIface is the mock device object that will be returned by the mock methods as the
	// device with which the tap has a filter redirection with.
	RedirectIface netlink.Link

	// AddIngressQdiscErr is an error that will be returned from all AddIngressQdisc calls
	AddIngressQdiscErr error

	// GetIngressQdiscErr is an error that will be returned from all GetIngressQdisc calls
	GetIngressQdiscErr error

	// RemoveIngressQdiscErr is an error that will be returned from all RemoveIngressQdisc calls
	RemoveIngressQdiscErr error
	// RemoveIngressQdiscCalls records the args provided to each call to RemoveIngressQdisc
	RemoveIngressQdiscCalls []netlink.Link

	// AddRedirectFilterErr is an error that will be returned from all AddRedirectFilter calls
	AddRedirectFilterErr error

	// GetRedirectFilterErr is an error that will be returned from all GetRedirectFilter calls
	GetRedirectFilterErr error

	// CreateTapErr is an error that will be returned from all CreateTap calls
	CreateTapErr error

	// RemoveLinkErr is an error that will be returned from all RemoveLink calls
	RemoveLinkErr error
	// RemoveLinkCalls records the args provided to each call to RemoveLink
	RemoveLinkCalls []string

	// GetLinkErr is an error that will be returned from all GetLink calls
	GetLinkErr error
}

var _ NetlinkOps = &MockNetlinkOps{}

// AddIngressQdisc does nothing and returns an error if configured to do so (otherwise nil)
func (m *MockNetlinkOps) AddIngressQdisc(link netlink.Link) error {
	return m.AddIngressQdiscErr
}

// GetIngressQdisc does nothing and returns an error if configured to do so (otherwise nil)
func (m *MockNetlinkOps) GetIngressQdisc(sourceLink netlink.Link) (netlink.Qdisc, error) {
	return nil, m.GetIngressQdiscErr
}

// RemoveIngressQdisc does nothing and returns an error if configured to do so (otherwise nil)
func (m *MockNetlinkOps) RemoveIngressQdisc(sourceLink netlink.Link) error {
	m.RemoveIngressQdiscCalls = append(m.RemoveIngressQdiscCalls, sourceLink)
	return m.RemoveIngressQdiscErr
}

// AddRedirectFilter does nothing and returns an error if configured to do so (otherwise nil)
func (m *MockNetlinkOps) AddRedirectFilter(sourceLink netlink.Link, targetLink netlink.Link) error {
	return m.AddRedirectFilterErr
}

// GetRedirectFilter does nothing and returns an error if configured to do so (otherwise nil)
func (m *MockNetlinkOps) GetRedirectFilter(sourceLink netlink.Link, targetLink netlink.Link) (netlink.Filter, error) {
	return nil, m.GetRedirectFilterErr
}

// GetLink returns CreatedTap if provided the name of CreatedTap, RedirectIface if provided the name
// of RedirectIface or otherwise a netlink.LinkNotFoundError
func (m *MockNetlinkOps) GetLink(name string) (netlink.Link, error) {
	if m.GetLinkErr != nil {
		return nil, m.GetLinkErr
	}

	switch name {
	case m.RedirectIface.Attrs().Name:
		return m.RedirectIface, nil
	case m.CreatedTap.Attrs().Name:
		return m.CreatedTap, nil
	default:
		return nil, &LinkNotFoundError{}
	}
}

// RemoveLink returns a nil error if provided the name of CreatedTap or RedirectIface. Otherwise
// it returns a LinkNotFoundError.
func (m *MockNetlinkOps) RemoveLink(name string) error {
	if m.RemoveLinkErr != nil {
		return m.RemoveLinkErr
	}

	m.RemoveLinkCalls = append(m.RemoveLinkCalls, name)
	switch name {
	case m.RedirectIface.Attrs().Name:
		return nil
	case m.CreatedTap.Attrs().Name:
		return nil
	default:
		return &LinkNotFoundError{}
	}
}

// CreateTap returns the configured mock tap link and/or a configured error
func (m *MockNetlinkOps) CreateTap(name string, mtu int, ownerUID, ownerGID int) (netlink.Link, error) {
	return m.CreatedTap, m.CreateTapErr
}

// MockLink provides a mocked out netlink.Link implementation
type MockLink struct {
	netlink.Link
	netlink.LinkAttrs
}

var _ netlink.Link = &MockLink{}

// Attrs() returns the LinkAttrs configured in the MockLink object
func (l MockLink) Attrs() *netlink.LinkAttrs {
	return &l.LinkAttrs
}

// MockNetNS provides a mocked out ns.NetNS implementation that just executes callbacks
// in the host netns (to avoid permissions issues that require root to resolve).
type MockNetNS struct {
	ns.NetNS
	MockPath string
}

var _ ns.NetNS = &MockNetNS{}

// Do executes the provided callback in the host's netns (it does not actually switch ns)
func (m MockNetNS) Do(f func(ns.NetNS) error) error {
	return f(nil)
}

// Path returns the configured MockPath object in the MockNetNS object
func (m MockNetNS) Path() string {
	return m.MockPath
}