package server

import (
	"crypto/rsa"
	"encoding/json"
	"github.com/s-rah/go-ricochet/utils"
	"io/ioutil"
	"log"
	"sync"
)

// Reporting is a struct for storing a the config a server needs to be a peer, and connect to a group to report
type Reporting struct {
	PeerPrivateKey      string `json:"privateKey"`
	ReportingGroupID    string `json:"reportingGroupId"`
	ReportingServerAddr string `json:"reportingServerAddr"`
}

// Config is a struct for storing basic server configuration
type Config struct {
	MaxBufferLines  int       `json:"maxBufferLines"`
	PrivateKeyBytes string    `json:"privateKey"`
	ServerReporting Reporting `json:"serverReporting"`
	lock            sync.Mutex
}

// PrivateKey returns an rsa.PrivateKey generated from the config's PrivateKeyBytes
func (config *Config) PrivateKey() *rsa.PrivateKey {
	pk, err := utils.ParsePrivateKey([]byte(config.PrivateKeyBytes))
	if err != nil {
		log.Println("Error parsing private key: ", err)
	}
	return pk
}

// Save dumps the latest version of the config to a json file given by filename
func (config *Config) Save(filename string) {
	config.lock.Lock()
	defer config.lock.Unlock()
	bytes, _ := json.MarshalIndent(config, "", "\t")
	ioutil.WriteFile(filename, bytes, 0600)
}

// LoadConfig loads a Config from a json file specified by filename
func LoadConfig(filename string) *Config {
	raw, err := ioutil.ReadFile(filename)
	if err != nil {
		log.Fatal("Could not read config: ", err)
	}

	config := Config{}
	err = json.Unmarshal(raw, &config)

	if err != nil {
		log.Fatal("Error reading config: ", err)
	}

	if config.PrivateKeyBytes == "" {
		config.generatePrivateKey()
		config.Save(filename)
	}
	if config.ServerReporting.PeerPrivateKey == "" {
		config.generatePeerPrivateKey()
		config.Save(filename)
	}

	return &config
}

func (config *Config) generatePrivateKey() {
	pk, err := utils.GeneratePrivateKey()
	if err != nil {
		log.Fatalf("error generating new private key: %v\n", err)
	}
	config.lock.Lock()
	config.PrivateKeyBytes = utils.PrivateKeyToString(pk)
	config.lock.Unlock()
}

func (config *Config) generatePeerPrivateKey() {
	pk, err := utils.GeneratePrivateKey()
	if err != nil {
		log.Fatalf("error generating new peer private key: %v\n", err)
	}
	config.lock.Lock()
	config.ServerReporting.PeerPrivateKey = utils.PrivateKeyToString(pk)
	config.lock.Unlock()
}