/*
Copyright © 2021-2022 Ettore Di Giacinto <mudler@mocaccino.org>
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 vpn

import (
	"time"

	"github.com/ipfs/go-log"
	"github.com/mudler/water"
)

type Config struct {
	Interface        *water.Interface
	InterfaceName    string
	InterfaceAddress string
	RouterAddress    string
	InterfaceMTU     int
	MTU              int
	DeviceType       water.DeviceType

	LedgerAnnounceTime time.Duration
	Logger             log.StandardLogger

	NetLinkBootstrap bool

	// Frame timeout
	Timeout time.Duration

	Concurrency       int
	ChannelBufferSize int
	MaxStreams        int
	lowProfile        bool
}

type Option func(cfg *Config) error

// Apply applies the given options to the config, returning the first error
// encountered (if any).
func (cfg *Config) Apply(opts ...Option) error {
	for _, opt := range opts {
		if opt == nil {
			continue
		}
		if err := opt(cfg); err != nil {
			return err
		}
	}
	return nil
}

func WithMaxStreams(i int) func(cfg *Config) error {
	return func(cfg *Config) error {
		cfg.MaxStreams = i
		return nil
	}
}

var LowProfile Option = func(cfg *Config) error {
	cfg.lowProfile = true

	return nil
}

func WithInterface(i *water.Interface) func(cfg *Config) error {
	return func(cfg *Config) error {
		cfg.Interface = i
		return nil
	}
}

func NetLinkBootstrap(b bool) func(cfg *Config) error {
	return func(cfg *Config) error {
		cfg.NetLinkBootstrap = b
		return nil
	}
}

func WithTimeout(s string) Option {
	return func(cfg *Config) error {
		d, err := time.ParseDuration(s)
		cfg.Timeout = d
		return err
	}
}

func Logger(l log.StandardLogger) func(cfg *Config) error {
	return func(cfg *Config) error {
		cfg.Logger = l
		return nil
	}
}
func WithRouterAddress(i string) func(cfg *Config) error {
	return func(cfg *Config) error {
		cfg.RouterAddress = i
		return nil
	}
}

func WithLedgerAnnounceTime(t time.Duration) func(cfg *Config) error {
	return func(cfg *Config) error {
		cfg.LedgerAnnounceTime = t
		return nil
	}
}

func WithConcurrency(i int) Option {
	return func(cfg *Config) error {
		cfg.Concurrency = i
		return nil
	}
}

func WithChannelBufferSize(i int) Option {
	return func(cfg *Config) error {
		cfg.ChannelBufferSize = i
		return nil
	}
}

func WithInterfaceMTU(i int) func(cfg *Config) error {
	return func(cfg *Config) error {
		cfg.InterfaceMTU = i
		return nil
	}
}

func WithPacketMTU(i int) func(cfg *Config) error {
	return func(cfg *Config) error {
		cfg.MTU = i
		return nil
	}
}

func WithInterfaceType(d water.DeviceType) func(cfg *Config) error {
	return func(cfg *Config) error {
		cfg.DeviceType = d
		return nil
	}
}

func WithInterfaceName(i string) func(cfg *Config) error {
	return func(cfg *Config) error {
		cfg.InterfaceName = i
		return nil
	}
}

func WithInterfaceAddress(i string) func(cfg *Config) error {
	return func(cfg *Config) error {
		cfg.InterfaceAddress = i
		return nil
	}
}