package main

import (
	"flag"
	"fmt"
	"local/watchman/client/remote"
	"local/watchman/client/watchman"
	"log"
	"os"
	"os/signal"
)

func envOrDefault(key, alt string) string {
	if v := os.Getenv(key); v != "" {
		return v
	}
	log.Printf("ENV variable %q not set, defaulting to %q", key, alt)
	return alt
}

var defaultKey = envOrDefault("WATCHMANKEY", "key")
var defaultID = envOrDefault("WATCHMANID", "ID")

type empty struct{}

func catchInterrupt() chan os.Signal {
	stop := make(chan os.Signal)
	signal.Notify(stop, os.Interrupt)
	return stop
}

func main() {
	stopWatch := make(chan empty)
	fnames := make(chan string)
	packs := make(chan *watchman.Package)

	pullPath := flag.String("path", "", "path to pull")
	flag.Parse()
	if *pullPath != "" {
		go packPuller(packs, stopWatch)
		packs <- &watchman.Package{Path: *pullPath}
		stopWatch <- empty{}
		return
	}

	log.Print("Watching for changes...")
	go watchFiles("testdir", fnames, stopWatch)

	log.Print("Packing changes...")
	go filePacker(packs, fnames, stopWatch)

	log.Print("Pushing changes...")
	go packPusher(packs, stopWatch)

	log.Print("Waiting for signal...")
	<-catchInterrupt()
	for i := 0; i < 3; i++ {
		stopWatch <- empty{}
	}

	fmt.Println()
	log.Print("Exiting")
}

func packPuller(packs <-chan *watchman.Package, stop <-chan empty) {
	rem, err := remote.New()
	if err != nil {
		log.Fatal("can't connect to remote:", err)
	}
	exiting := false
	for !exiting {
		select {
		case pack := <-packs:
			pack.ID = defaultID
			backpack, err := rem.Pull(pack)
			if err != nil {
				log.Print("error pulling:", err)
				break
			}
			if backpack == nil {
				break
			}
			decrypted, err := watchman.UnpackNDecrypt(backpack, defaultKey)
			if err != nil {
				log.Print("error unpacking and decrypting:", err)
				break
			}
			log.Print(string(decrypted))
		case <-stop:
			exiting = true
		}
	}
}

func packPusher(packs <-chan *watchman.Package, stop <-chan empty) {
	rem, err := remote.New()
	if err != nil {
		log.Fatal("can't connect to remote:", err)
	}
	exiting := false
	for !exiting {
		select {
		case pack := <-packs:
			if err := rem.Push(pack); err != nil {
				log.Print("error pushing:", err)
			}
		case <-stop:
			exiting = true
		}
	}
}

func filePacker(packs chan<- *watchman.Package, fnames <-chan string, stop <-chan empty) {
	exiting := false
	for !exiting {
		select {
		case fname := <-fnames:
			pack, err := watchman.EncryptNPack(fname, defaultKey, defaultID)
			if err != nil {
				log.Printf("err packingNencrypting file %q: %v", fname, err)
				break
			}
			packs <- pack
		case <-stop:
			exiting = true
		}
	}
}

func watchFiles(path string, fnames chan<- string, stop <-chan empty) {
	watcher := watchman.NewWatcher(path)
	if err := watcher.Start(); err != nil {
		panic(err)
	}
	exiting := false
	for !exiting {
		select {
		case fname := <-watcher.Files:
			fnames <- fname
		case <-stop:
			exiting = true
			watcher.Stop()
			return
		}
	}
}