cloudfoundry-incubator/stratos

package goosedbversion

import (
    "database/sql"
    "errors"
    "fmt"

    log "github.com/sirupsen/logrus"

    "github.com/cloudfoundry-incubator/stratos/src/jetstream/repository/interfaces"
)

const (
    getCurrentVersion = `SELECT version_id FROM goose_db_version WHERE is_applied = '1' ORDER BY id DESC LIMIT 1`

    listVersions = `SELECT id, version_id, is_applied, tstamp FROM goose_db_version WHERE is_applied = '1' ORDER BY id DESC`
)

// PostgresGooseDBVersionRepository is a PostgreSQL-backed Goose DB Version repository
type PostgresGooseDBVersionRepository struct {
    db *sql.DB
}

// NewPostgresGooseDBVersionRepository will create a new instance of the PostgresInstanceRepository
func NewPostgresGooseDBVersionRepository(dcp *sql.DB) (Repository, error) {
    log.Debug("NewPostgresGooseDBVersionRepository")
    return &PostgresGooseDBVersionRepository{db: dcp}, nil
}

// GetCurrentVersion - Returns the latest GooseDBVersionRecord
func (p *PostgresGooseDBVersionRepository) GetCurrentVersion() (interfaces.GooseDBVersionRecord, error) {
    log.Debug("GetCurrentVersion")

    dbVersion := new(interfaces.GooseDBVersionRecord)

    err := p.db.QueryRow(getCurrentVersion).Scan(&dbVersion.VersionID)

    switch {
    case err == sql.ErrNoRows:
        return interfaces.GooseDBVersionRecord{}, errors.New("No database versions found")
    case err != nil:
        return interfaces.GooseDBVersionRecord{}, fmt.Errorf("Error trying to get current database version: %v", err)
    default:
        // do nothing
    }

    return *dbVersion, nil
}

// List - Returns a list of all versions
func (p *PostgresGooseDBVersionRepository) List() ([]*interfaces.GooseDBVersionRecord, error) {
    log.Debug("List")
    rows, err := p.db.Query(listVersions)
    if err != nil {
        return nil, fmt.Errorf("Unable to retrieve Goose Version records: %v", err)
    }
    defer rows.Close()

    var versionList []*interfaces.GooseDBVersionRecord
    versionList = make([]*interfaces.GooseDBVersionRecord, 0)

    for rows.Next() {
        version := new(interfaces.GooseDBVersionRecord)
        err := rows.Scan(&version.ID, &version.VersionID, &version.IsApplied, &version.Timestamp)
        if err != nil {
            return nil, fmt.Errorf("Unable to scan Goose Version records: %v", err)
        }
        versionList = append(versionList, version)
    }

    if err = rows.Err(); err != nil {
        return nil, fmt.Errorf("Unable to List Goose Version records: %v", err)
    }

    return versionList, nil
}