af83/edwig

package model

import (
    "fmt"

    "bitbucket.org/enroute-mobi/ara/clock"
    "bitbucket.org/enroute-mobi/ara/logger"
)

type Purifier struct {
    date string
}

func NewPurifier(days int) *Purifier {
    return &Purifier{
        date: clock.DefaultClock().Now().AddDate(0, 0, -days).Format("2006-01-02"),
    }
}

func (p *Purifier) Purge() error {
    if p.date == "" {
        return fmt.Errorf("purifier date is empty")
    }

    tx, err := Database.Begin()
    if err != nil {
        return fmt.Errorf("database error: %v", err)
    }

    table_names := []string{"stop_areas", "lines", "vehicle_journeys", "stop_visits", "operators"}
    for i := range table_names {
        r, err := tx.Exec(p.query(table_names[i]))
        if err != nil {
            tx.Rollback()
            return fmt.Errorf("database error: %v", err)
        }
        ra, err := r.RowsAffected()
        if err != nil {
            logger.Log.Debugf("Error with Result.RowsAffected: %v", err)
        }
        logger.Log.Printf("Purged %v %v from database", ra, table_names[i])
    }

    // Commit transaction
    err = tx.Commit()
    if err != nil {
        return fmt.Errorf("database error: %v", err)
    }

    return nil
}

func (p Purifier) query(table_name string) string {
    return fmt.Sprintf("delete from %v where model_name < '%v';", table_name, p.date)
}