package main

import (
	"database/sql"
	"errors"
	"fmt"
	_ "github.com/go-sql-driver/mysql"
	"log"
	"time"
)

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

func cleanData(conf Config) (err error) {

	db, err := sql.Open("mysql", DATABASE_USER+":"+DATABASE_PASS+"@/"+DATABASE_NAME)
	if err != nil {
		log.Println("Failed to connect to db")
		return
	}
	defer db.Close()

	//Remove the processed mark on entries older than 6 hours
	err = reprocess(db, time.Now().Add(-6*time.Hour))
	if err != nil {
		return
	}

	var interval time.Duration
	switch conf.Interval {
	case "5min":
		interval = time.Minute * 5
	case "10min":
		interval = time.Minute * 10
	case "hour":
		interval = time.Hour
	case "day":
		interval = time.Hour * 24
	default:
		err = errors.New(fmt.Sprintf("Invalid interval: %s", conf.Interval))
		return
	}
	//Fetch data that should be cleaned
	rDat, err := fetchRawData(db, time.Now().Add(-2*interval))
	if err != nil {
		log.Println("Faild to fetch raw data")
		return
	}

	cDat, err := clean(rDat, conf)
	if err != nil {
		log.Println("Failed to clean data")
		return
	}

	//Add noise for differential privacy
	for i := range cDat {
		cDat[i].occurances = diffpriv(cDat[i].occurances, 1, conf.Epsilon)
	}

	//Begin transaction
	tx, err := db.Begin()
	if err != nil {
		log.Println("Failed to initialize transaction")
		return
	}

	//save cleaned data
	for _, cd := range cDat {
		err = insertCleanData(tx, cd.ipbSrc, cd.ipbDst, cd.volume, cd.time, cd.port, cd.occurances)
		if err != nil {
			tx.Rollback()
			log.Println("Failed to save cleaned data")
			return
		}
	}

	//remove old data
	err = purgeRawData(tx, rDat)
	if err != nil {
		tx.Rollback()
		log.Println("Failed to remove old data")
		return
	}

	tx.Commit()
	return
}

func getTimespan(t time.Time, conf Config) (span time.Time, err error) {
	loc, err := time.LoadLocation(TIMEZONE)
	if err != nil {
		return
	}
	switch {
	case conf.Interval == "5min": //Round the date into 5 minutes
		y, m, d := t.Date()
		h := t.Hour()
		min := t.Minute()
		min = (min / 5) * 5
		span = time.Date(y, m, d, h, min, 0, 0, loc)

	case conf.Interval == "10min": //Round the date into 10 minutes
		y, m, d := t.Date()
		h := t.Hour()
		min := t.Minute()
		min = (min / 10) * 10
		span = time.Date(y, m, d, h, min, 0, 0, loc)

	case conf.Interval == "hour": //Round the date into hour
		y, m, d := t.Date()
		h := t.Hour()
		span = time.Date(y, m, d, h, 0, 0, 0, loc)

	case conf.Interval == "day": //Round the date into day
		y, m, d := t.Date()
		span = time.Date(y, m, d, 0, 0, 0, 0, loc)
	default:
		err = errors.New(fmt.Sprintf("Bad interval in config %s", conf.Interval))
		return
	}
	return
}

func clean(rDat []RawData, conf Config) (cDat []CleanData, err error) {
	// collect all ips so we can query for their ip blocks
	ips := make(map[string]*asnipPair)
	for _, rd := range rDat {
		ips[rd.ipSrc] = nil
		ips[rd.ipDst] = nil
	}

	var iplist []string
	for ip := range ips {
		iplist = append(iplist, ip)
	}

	pairs, err := findASAndIPBlock(iplist...)
	if err != nil {
		return
	}
	for ix, p := range pairs {
		ips[p.ipAdr] = &pairs[ix]
	}

	var vol string
	for _, rd := range rDat {
		vol, err = rd.getVolSize(conf)
		if err != nil {
			return
		}
		var tim time.Time
		tim, err = getTimespan(rd.time, conf)
		if err != nil {
			return
		}
		cDat = append(cDat,
			CleanData{
				ipbSrc:     ips[rd.ipSrc].ipBlock,
				ipbDst:     ips[rd.ipDst].ipBlock,
				time:       tim,
				port:       rd.port,
				volume:     vol,
				occurances: 1,
			})
	}

	cDat = removeDups(cDat)

	return
}

func removeDups(cDat []CleanData) []CleanData {
	ret := make([]CleanData, 0)
	var found bool
	for ci := range cDat {
		found = false

		//Check if an equal struct already is appended
		for ri := range ret {
			if ret[ri].equals(&cDat[ci]) {
				//If found, increase it occurances instead of
				//appending a new struct
				ret[ri].occurances += cDat[ci].occurances
				found = true
				break
			}
		}

		if !found {
			//if no equal struct is found
			//append it
			ret = append(ret, cDat[ci])
		}
	}
	return ret
}