// Copyright (c) 2017-2019 Tigera, Inc. 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.
// 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 proxy

import (
	"fmt"
	"time"

	log "github.com/sirupsen/logrus"
	"k8s.io/kubernetes/pkg/proxy/healthcheck"

	"github.com/projectcalico/calico/felix/ip"
)

// Option defines Proxy options
type Option func(Proxy) error

func makeOption(f func(*proxy) error) Option {
	return func(P Proxy) error {
		p, ok := P.(*proxy)
		if !ok {
			return nil
		}

		return f(p)
	}
}

func makeKubeProxyOption(f func(*KubeProxy) error) Option {
	return func(P Proxy) error {
		p, ok := P.(*KubeProxy)
		if !ok {
			return nil
		}
		return f(p)
	}

}

// WithMinSyncPeriod sets the minimum duration between two attempts to sync with
// the dataplane
func WithMinSyncPeriod(min time.Duration) Option {
	return makeOption(func(p *proxy) error {
		p.minDPSyncPeriod = min
		log.Infof("proxy.WithMinSyncPeriod(%s)", min)
		return nil
	})
}

// WithImmediateSync triggers sync with dataplane on immediately on every update
func WithImmediateSync() Option {
	return WithMinSyncPeriod(0)
}

// WithDSREnabled sets the DSR mode
func WithDSREnabled() Option {
	return makeKubeProxyOption(func(kp *KubeProxy) error {
		kp.dsrEnabled = true
		return nil
	})
}

// WithTopologyNodeZone sets the topology node zone
func WithTopologyNodeZone(nodeZone string) Option {
	return makeOption(func(p *proxy) error {
		p.nodeZone = nodeZone
		return nil
	})
}

func WithIPFamily(ipFamily int) Option {
	return func(p Proxy) error {
		p.setIpFamily(ipFamily)
		return nil
	}
}

var excludeCIDRsMatch = 1

func WithExcludedCIDRs(cidrs []string) Option {
	return makeKubeProxyOption(func(kp *KubeProxy) error {
		if kp.ipFamily == 0 {
			return fmt.Errorf("ip family is not set")
		}

		kp.excludedCIDRs = ip.NewCIDRTrie()

		for _, c := range cidrs {
			cidr, err := ip.CIDRFromString(c)
			if err != nil {
				return fmt.Errorf("bad CIDR %s: %w", c, err)
			}

			if int(cidr.Version()) != kp.ipFamily {
				continue
			}

			kp.excludedCIDRs.Update(cidr, &excludeCIDRsMatch)
		}

		return nil
	})
}

func WithHealthzServer(hs *healthcheck.ProxyHealthServer) Option {
	return makeOption(func(p *proxy) error {
		p.healthzServer = hs
		return nil
	})
}
