package main

import (
	"bufio"
	"database/sql"
	_ "github.com/go-sql-driver/mysql"
	"log"
	"os"
	"time"
	//"strings"
)

const (
	DATABASE_USER       = "flowcleaner"
	DATABASE_PASS       = "nil"
	DATABASE_CONNECTION = "" //e.g. "tcp(localhost:55555)
	DATABASE_NAME       = "pmacct"
)

func main() {
	log.Println("Reading config...")
	conf, err := readConfig()
	if err != nil {
		log.Println("Could not read config")
		return
	}
	log.Println("Done!")

	/*
		stdin := readFromStdin()
		for line := range stdin {
			strs := strings.Split(line, ",")
			for _, str := range strs {
				log.Println(str)
			}
		}
	*/
	log.Print("Cleaning data...")
	starttime := time.Now()
	numOfRowsNotCleaned, err := cleanData(conf, DATABASE_USER, DATABASE_PASS, DATABASE_CONNECTION, DATABASE_NAME)
	if err != nil {
		log.Println(err)
		log.Println("Exiting...")
		return
	}
	log.Println("Done!")

	// If  either all rows are processed or if there is no limit for the processing
	// we can safely add noise to the cleaned data
	if (numOfRowsNotCleaned == 0 || conf.Limit == 0) && conf.Epsilon >= 0 {
		log.Println("Adding differential privacy noise to processed data...")
		db, err := sql.Open("mysql", DATABASE_USER+":"+DATABASE_PASS+"@"+DATABASE_CONNECTION+"/"+DATABASE_NAME)
		if err != nil {
			log.Println("Failed to connect to db:", err)
			return
		}
		defer db.Close()

		ival, err := conf.getInterval()
		if err != nil {
			log.Println("erronous interval in conf prevents the privatization of data:", err)
			return
		}

		err = privatizeCleaned(db, starttime.Add(-2*ival), conf)
		if err != nil {
			log.Println("Failed to privatize data:", err)
		}
		log.Println("Done!")
	}
	log.Println("Finished processing, now exiting")
}

//Starts a process that reads from stdin and
//puts the strings read on the returned channel
func readFromStdin() <-chan string {

	out := make(chan string)
	go func() {
		scanner := bufio.NewScanner(os.Stdin)
		for scanner.Scan() {
			out <- scanner.Text()
		}
		close(out)
	}()
	return out
}