package main

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

const (
	DATABASE_USER       = "root"
	DATABASE_PASS       = "pass"
	DATABASE_CONNECTION = "" //e.g. "tcp(localhost:55555)
	DATABASE_NAME       = "netflow"
	MAXIMUM_ENTRIES     = 100
	TIMESPAN            = "day"
	EPSILON             = 1000
)

func cleanData() (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 1 day
	err = reprocess(db, time.Now().Add(-24*1*time.Hour))
	if err != nil {
		return
	}

	//Fetch data that should be cleaned
	rDat, err := fetchRawData(db, MAXIMUM_ENTRIES)
	if err != nil {
		log.Println("Faild to fetch raw data")
		return
	}

	cDat, err := clean(rDat)
	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, 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) (span time.Time, err error) {
	loc, err := time.LoadLocation("Local")
	switch {
	case TIMESPAN == "5min": //Round the date into 5 minutes
		y, m, d, h, min := t.Date()
		if err != nil {
			return
		}
		min = min / 5
		span = time.Date(y, m, d, h, min, 0, 0, loc)

	case TIMESPAN == "10min": //Round the date into 10 minutes
		y, m, d, h, min := t.Date()
		if err != nil {
			return
		}
		min = min / 10
		span = time.Date(y, m, d, h, min, 0, 0, loc)

	case TIMESPAN == "hour": //Round the date into hour
		y, m, d, h := t.Date()
		if err != nil {
			return
		}
		span = time.Date(y, m, d, h, 0, 0, 0, loc)

	case TIMESPAN == "day": //Round the date into day
		y, m, d := t.Date()
		if err != nil {
			return
		}
		span = time.Date(y, m, d, 0, 0, 0, 0, loc)
	default:
		err = errors.New("Bad timespan")
		return
	}
	return
}

func clean(rDat []RawData) (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]
	}

	for _, rd := range rDat {
		vol := rd.getVolSize()
		var tim time.Time
		tim, err = getTimespan(rd.time)
		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
}