// 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 service

import (
	"fmt"
	"time"

	"github.com/EtixLabs/cameradar"
	"github.com/pkg/errors"
)

// Cameradar is the service in charge of communicating with the GUI
type Cameradar struct {
	Streams []cmrdr.Stream

	options *Options
}

// Options contains all options needed to launch a complete cameradar scan
type Options struct {
	Target      string
	Ports       string
	OutputFile  string
	Routes      cmrdr.Routes
	Credentials cmrdr.Credentials
	Speed       int
	Timeout     time.Duration
}

// NewCameradar instanciates a new Cameradar service
func NewCameradar(routesFilePath, credentialsFilePath string) (*Cameradar, error) {
	routes, err := cmrdr.LoadRoutes(routesFilePath)
	if err != nil {
		return nil, errors.Wrap(err, "can't load routes dictionary")
	}

	credentials, err := cmrdr.LoadCredentials(credentialsFilePath)
	if err != nil {
		return nil, errors.Wrap(err, "can't load credentials dictionary")
	}

	return &Cameradar{
		Streams: nil,
		options: &Options{
			Ports:       "554,8554",
			Routes:      routes,
			Credentials: credentials,
			Speed:       4,
			Timeout:     2000,
		},
	}, nil
}

// Discover launches a Cameradar scan using the service's options
func (c *Cameradar) Discover() error {
	streams, err := cmrdr.Discover(c.options.Target, c.options.Ports, c.options.OutputFile, c.options.Speed, true)
	if err != nil {
		return errors.Wrap(err, "could not discover streams")
	}
	c.Streams = streams
	return nil
}

// AttackRoute launches a Cameradar route attack using the service's options
func (c *Cameradar) AttackRoute() error {
	streams, err := cmrdr.AttackRoute(c.Streams, c.options.Routes, c.options.Timeout, true)
	if err != nil {
		return errors.Wrap(err, "could not discover streams")
	}
	c.Streams = streams
	return nil
}

// AttackCredentials launches a Cameradar credential attack using the service's options
func (c *Cameradar) AttackCredentials() error {
	streams, err := cmrdr.AttackCredentials(c.Streams, c.options.Credentials, c.options.Timeout, true)
	if err != nil {
		return errors.Wrap(err, "could not discover streams")
	}
	c.Streams = streams
	return nil
}

// SetNmapOutputFile sets the OutputFile option
func (c *Cameradar) SetNmapOutputFile(path string) {
	c.options.OutputFile = path
}

// SetRoutes overwrites the routes dictionary with new values
func (c *Cameradar) SetRoutes(routes string) {
	c.options.Routes = cmrdr.ParseRoutesFromString(routes)
}

// SetCredentials overwrites the routes dictionary with new values
func (c *Cameradar) SetCredentials(credentials string) error {
	newCredentials, err := cmrdr.ParseCredentialsFromString(credentials)
	if err != nil {
		return errors.Wrap(err, "could not decode credentials")
	}
	c.options.Credentials = newCredentials
	return nil
}

// SetSpeed sets the Speed option
func (c *Cameradar) SetSpeed(speed int) error {
	if speed < cmrdr.PARANOIAC || speed > cmrdr.INSANE {
		return fmt.Errorf("invalid speed value '%d'. should be between '%d' and '%d'", speed, cmrdr.PARANOIAC, cmrdr.INSANE)
	}
	c.options.Speed = speed
	return nil
}

// SetTimeout sets the Timeout option
func (c *Cameradar) SetTimeout(timeout int) error {
	if timeout < 0 {
		return fmt.Errorf("invalid timeout value '%d'. should be superior to 0", timeout)
	}
	c.options.Timeout = time.Millisecond * time.Duration(timeout)
	return nil
}