;; 
;; Author: David Krentzlin
;; 
;; Created: So Nov 14 13:22:34 2010 (CET)
;; Last-Updated: Sa Nov 20 09:19:45 2010 (CET)
;;           By:

(use nomads nomads-sql-de-lite numbers)

;; this file implements migrations with a timestamped versioning scheme
(versioner (lambda (max-version)
             (inexact->exact (current-seconds))))

(filename-partitioner      
 (lambda (filename)
   (let ((parts (string-split filename "-")))
     (cond
      ((null? parts) (cons #f ""))
      ((string->number (car parts))
       => (lambda (num)
            (cons (number->string (inexact->exact num)) (string-join (cdr parts) "-"))))
      (else (cons #f filename))))))

(filename-joiner           
 (lambda (version file)
   (sprintf "~A-~A" version file)))

;;we need to bind it to the number's version of those
(version? number?)

(define (->number what)
  (inexact->exact (if (string? what) (string->number what) what)))

(version-less?
 (lambda (l r)
   (< (->number l) (->number r))))

(version-equal?
 (lambda (l r)
   (equal? (->number l) (->number r))))

(database-credentials "./example.db")
(migration-directory "migrations")

(define (get-version)
  (let ((version (get-environment-variable "VERSION")))
    (if version
        (or (string->number version) (string->symbol version))
        'latest)))

(migrate version: (get-version))