package main

import (
	"github.com/pterodactyl/wings/server"
	"gopkg.in/yaml.v2"
	"io/ioutil"
	"os"
)

type Configuration struct {
	// Determines if wings should be running in debug mode. This value is ignored
	// if the debug flag is passed through the command line arguments.
	Debug bool

	// Directory where the server data is stored at.
	Data string

	Api    *ApiConfiguration
	Docker *server.DockerConfiguration

	// Determines if permissions for a server should be set automatically on
	// daemon boot. This can take a long time on systems with many servers, or on
	// systems with servers containing thousands of files.
	SetPermissionsOnBoot bool `yaml:"set_permissions_on_boot"`

	// The amount of time in seconds that should elapse between disk usage checks
	// run by the daemon. Setting a higher number can result in better IO performance
	// at an increased risk of a malicious user creating a process that goes over
	// the assigned disk limits.
	DiskCheckTimeout int `yaml:"disk_check_timeout"`

	// Defines internal throttling configurations for server processes to prevent
	// someone from running an endless loop that spams data to logs.
	Throttles struct {
		// The number of data overage warnings (inclusive) that can accumulate
		// before a process is terminated.
		KillAtCount int `yaml:"kill_at_count"`

		// The number of seconds that must elapse before the internal counter
		// begins decrementing warnings assigned to a process that is outputting
		// too much data.
		DecaySeconds int `yaml:"decay"`

		// The total number of bytes allowed to be output by a server process
		// per interval.
		BytesPerInterval int `yaml:"bytes"`

		// The amount of time that should lapse between data output throttle
		// checks. This should be defined in milliseconds.
		CheckInterval int `yaml:"check_interval"`
	}

	// The location where the panel is running that this daemon should connect to
	// to collect data and send events.
	PanelLocation string `yaml:"remote"`

	// The token used when performing operations. Requests to this instance must
	// validate aganist it.
	AuthenticationToken string `yaml:"token"`
}

// Defines the configuration for the internal API that is exposed by the
// daemon webserver.
type ApiConfiguration struct {
	// The interface that the internal webserver should bind to.
	Host string

	// The port that the internal webserver should bind to.
	Port int

	// SSL configuration for the daemon.
	Ssl struct {
		Enabled         bool
		CertificateFile string `yaml:"cert"`
		KeyFile         string `yaml:"key"`
	}

	// The maximum size for files uploaded through the Panel in bytes.
	UploadLimit int `yaml:"upload_limit"`
}

// Configures the default values for many of the configuration options present
// in the structs. If these values are set in the configuration file they will
// be overridden. However, if they don't exist and we don't set these here, all
// of the places in the code using them will need to be doing checks, which is
// a tedious thing to have to do.
func (c *Configuration) SetDefaults() {
	// Set the default data directory.
	c.Data = "/srv/daemon-data"

	// By default the internal webserver should bind to all interfaces and
	// be served on port 8080.
	c.Api = &ApiConfiguration{
		Host: "0.0.0.0",
		Port: 8080,
	}

	// Setting this to true by default helps us avoid a lot of support requests
	// from people that keep trying to move files around as a root user leading
	// to server permission issues.
	//
	// In production and heavy use environments where boot speed is essential,
	// this should be set to false as servers will self-correct permissions on
	// boot anyways.
	c.SetPermissionsOnBoot = true

	// Configure the default throttler implementation. This should work fine
	// for 99% of people running servers on the platform. The occasional host
	// might need to tweak them to be less restrictive depending on their hardware
	// and target audience.
	c.Throttles.KillAtCount = 5
	c.Throttles.DecaySeconds = 10
	c.Throttles.BytesPerInterval = 4096
	c.Throttles.CheckInterval = 100

	// Configure the defaults for Docker connection and networks.
	c.Docker = &server.DockerConfiguration{}
	c.Docker.UpdateImages = true
	c.Docker.Socket = "/var/run/docker.sock"
	c.Docker.Network.Name = "pterodactyl_nw"
	c.Docker.Network.Interface = "172.18.0.1"
}

// Reads the configuration from the provided file and returns the configuration
// object that can then be used.
func ReadConfiguration(path string) (*Configuration, error) {
	b, err := ioutil.ReadFile(path)
	if err != nil {
		return nil, err
	}

	c := &Configuration{}
	c.SetDefaults()

	// Replace environment variables within the configuration file with their
	// values from the host system.
	b = []byte(os.ExpandEnv(string(b)))

	if err := yaml.Unmarshal(b, c); err != nil {
		return nil, err
	}

	return c, nil
}