package app

import (
	"crypto/rand"
	"cwtch.im/cwtch/connectivity/tor"
	"cwtch.im/cwtch/peer"
	"cwtch.im/cwtch/storage"
	"encoding/hex"
	"fmt"

	"io/ioutil"
	"log"
	"os"
	"path"
	"path/filepath"
	"sync"
)

type application struct {
	peers        map[string]peer.CwtchPeer
	torManager   *tor.Manager
	directory    string
	mutex        sync.Mutex
	primaryonion string
	storage      map[string]storage.ProfileStore
}

// Application is a full cwtch peer application. It allows management, usage and storage of multiple peers
type Application interface {
	SaveProfile(cwtchPeer peer.CwtchPeer)
	LoadProfiles(password string) error
	CreatePeer(name string, password string) (peer.CwtchPeer, error)

	PrimaryIdentity() peer.CwtchPeer
	GetPeer(onion string) peer.CwtchPeer
	ListPeers() map[string]string

	GetTorStatus() (map[string]string, error)

	Shutdown()
}

// NewApp creates a new app with some environment awareness and initializes a Tor Manager
func NewApp(appDirectory string, torPath string) (Application, error) {
	log.Printf("NewApp(%v, %v)\n", appDirectory, torPath)
	app := &application{peers: make(map[string]peer.CwtchPeer), storage: make(map[string]storage.ProfileStore), directory: appDirectory}
	os.MkdirAll(path.Join(appDirectory, "tor"), 0700)
	os.Mkdir(path.Join(app.directory, "profiles"), 0700)

	err := app.startTor(torPath)
	if err != nil {
		return nil, err
	}
	return app, nil
}

func generateRandomFilename() string {
	randBytes := make([]byte, 16)
	rand.Read(randBytes)
	return filepath.Join(hex.EncodeToString(randBytes))
}

func (app *application) SaveProfile(p peer.CwtchPeer) {
	app.mutex.Lock()
	defer app.mutex.Unlock()
	app.peers[p.GetProfile().Onion] = p
	app.storage[p.GetProfile().Onion].Save(p)
}

// NewProfile creates a new cwtchPeer with a given name.
func (app *application) CreatePeer(name string, password string) (peer.CwtchPeer, error) {
	log.Printf("CreatePeer(%v)\n", name)

	randomFileName := generateRandomFilename()
	fileStore := storage.CreateFileProfileStore(path.Join(app.directory, "profiles", randomFileName), password)
	p := peer.NewCwtchPeer(name)
	err := fileStore.Save(p)
	if err != nil {
		return nil, err
	}
	app.startPeer(p)
	_, exists := app.peers[p.GetProfile().Onion]
	if exists {
		p.Shutdown()
		return nil, fmt.Errorf("Error: profile for onion %v already exists", p.GetProfile().Onion)
	}
	app.mutex.Lock()
	app.peers[p.GetProfile().Onion] = p
	app.storage[p.GetProfile().Onion] = fileStore
	app.mutex.Unlock()

	return p, nil
}

func (app *application) LoadProfiles(password string) error {
	files, err := ioutil.ReadDir(path.Join(app.directory, "profiles"))
	if err != nil {
		return fmt.Errorf("Error: cannot read profiles directory: %v", err)
	}

	for _, file := range files {

		fileStore := storage.CreateFileProfileStore(path.Join(app.directory, "profiles", file.Name()), password)

		p, err := fileStore.Load()
		if err != nil {

			continue
		}

		_, exists := app.peers[p.GetProfile().Onion]
		if exists {
			p.Shutdown()
			log.Printf("Error: profile for onion %v already exists", p.GetProfile().Onion)
			continue
		}
		app.startPeer(p)
		app.mutex.Lock()
		app.peers[p.GetProfile().Onion] = p
		app.storage[p.GetProfile().Onion] = fileStore
		if app.primaryonion == "" {
			app.primaryonion = p.GetProfile().Onion
		}
		app.mutex.Unlock()
	}
	return nil
}

// startTor will create a local torrc if needed
func (app *application) startTor(torPath string) error {
	// Creating a local cwtch tor server config for the user
	// creating $app.directory/torrc file
	// SOCKSPort  socksPort
	// ControlPort controlPort
	torrc := path.Join(app.directory, "tor", "torrc")
	if _, err := os.Stat(torrc); os.IsNotExist(err) {
		log.Printf("writing torrc to: %v\n", torrc)
		file, err := os.Create(torrc)
		if err != nil {
			return err
		}
		fmt.Fprintf(file, "SOCKSPort %d\nControlPort %d\nCookieAuthentication 0\nSafeSocks 1\n", 9050, 9051)
		file.Close()
	}

	tm, err := tor.NewTorManager(9050, 9051, torPath, torrc)
	if err != nil {
		return err
	}
	app.torManager = tm
	return nil
}

func (app *application) startPeer(peer peer.CwtchPeer) {
	go func() {
		e := peer.Listen()
		if e != nil {
			log.Fatalf("ERROR: peer %v has crashed with: %v\n", peer.GetProfile().Onion, e)
		}
	}()
}

// ListPeers returns a map of onions to their profile's Name
func (app *application) ListPeers() map[string]string {
	keys := map[string]string{}
	for k, p := range app.peers {
		keys[k] = p.GetProfile().Name
	}
	return keys
}

// PrimaryIdentity returns a cwtchPeer for a given onion address
func (app *application) PrimaryIdentity() peer.CwtchPeer {
	return app.peers[app.primaryonion]
}

// GetPeer returns a cwtchPeer for a given onion address
func (app *application) GetPeer(onion string) peer.CwtchPeer {
	if peer, ok := app.peers[onion]; ok {
		return peer
	}
	return nil
}

// GetTorStatus returns tor control port bootstrap-phase status info in a map
func (app *application) GetTorStatus() (map[string]string, error) {
	return app.torManager.GetStatus()
}

// Shutdown shutsdown all peers of an app and then the tormanager
func (app *application) Shutdown() {
	for _, peer := range app.peers {
		peer.Shutdown()
	}
	app.torManager.Shutdown()
}