package main

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

var (
	flogger *log.Logger
)

func init() {
	flogger = log.New(os.Stdout, "[ Flow-cleaner ]", log.LstdFlags)
}

func main() {
	cfg, err := readConfig()
	if err != nil {
		flogger.Println("Could not read config")
		return
	}

	switch cfg.DataSource {
	case "stdin":
		processFromStdin(cfg)
	case "mysq":
		processFromDB(cfg)
	default:
		flogger.Println("Invalid dataSource in config. Needs to be either 'stdin' or 'mysql'.")
	}

	flogger.Println("Finished processing, now exiting")
}

func processFromStdin(cfg *Config) {
	flogger.Println("Starting to process from stdin...")
	input := readFromStdin()
	rDatChan := parseRawData(input, cfg)
	err := cleanFromStdin(rDatChan, cfg)
	if err != nil {
		flogger.Println("Failed to clean data:", err)
	}
	flogger.Println("Finished processing from stdin!")
}

func processFromDB(cfg *Config) {
	flogger.Print("Starting to process from db...")
	starttime := time.Now()
	numOfRowsNotCleaned, err := cleanFromDB(cfg)
	if err != nil {
		flogger.Println(err)
		flogger.Println("Exiting...")
		return
	}
	flogger.Println("Finished processing from db!")

	// 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 || cfg.Limit == 0) && cfg.Epsilon >= 0 {
		flogger.Println("Adding differential privacy noise to processed data...")
		db, err := sql.Open("mysql", cfg.DBUser+":"+cfg.DBPass+"@"+cfg.DBConn+"/"+cfg.DBName)
		if err != nil {
			flogger.Println("Failed to connect to db:", err)
			return
		}
		defer db.Close()

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

		err = privatizeCleaned(db, starttime.Add(-2*ival), cfg)
		if err != nil {
			flogger.Println("Failed to privatize data:", err)
		}
		flogger.Println("Done!")
	}
}