#!/usr/bin/gosh

(use file.util)

(define (rounded-number->string x . digits-of-precision)
  (if (null? digits-of-precision)
      (number->string (inexact->exact (round x)))
      (let* ((digits (car digits-of-precision))
             (factor (expt 10.0 digits))
             (n (abs (inexact->exact (round (* x factor)))))
             (s (number->string n))
             (l (string-length s))
             (rs (if (< n factor)
                     (string-append "0." (make-string (- digits l) #\0) s)
                     (string-append
                      (substring s 0 (- l digits)) "."
                      (substring s (- l digits) l)))))
        (if (< x 0) (string-append "-" rs) rs))))

(define (format-size size)
  ;; TODO print decimals in k & M notations
  ;; - with format: does ~d support this? doesn't look like it
  ;; - with quotient&remainder: repeated simplification
  ;;    (q&r 1234567 (expt 2 20)) => (1 185991)
  ;;    (q&r 185991 (expt 2 10)) => (181 647)
  ;;    so: 1M, 181k and 647 bytes
  ;;   or determine single decimal after first quotient:
  ;;    (q&r 1234567 (expt 2 20)) => (1 185991)
  ;;    and round off (/ 185991 (expt 2 20)) using integer arithmetic
  ;;    so: 1.2M
  (cond
   ;;((< size (expt 2 10)) (format "~4d " size))
   ((< size (expt 2 20))
    ;;(format "~4dk" (round (/ size (expt 2 10)))))
    (format "~6@ak" (rounded-number->string (/ size (expt 2 10)) 1)))
   ((< size (expt 2 30))
    (format "~6@aM" (rounded-number->string (/ size (expt 2 20)) 1)))
   (else "moby")))

;; TODO list the following fields:
;; mode       size   mtime        name
;; -rw-r--r--   1.4k Nov 21 15:34 snarf.scm

(define (print-entry/1 name)
  (let ((st (sys-stat name)))
    (format #t "~o ~s ~a\n"
            (slot-ref st 'perm)
            (slot-ref st 'mtime)
            name)))

(define (print-entry name)
  (let1 st (sys-stat name)
    (format #t "~o ~6@a ~a ~a\n"
            (slot-ref st 'perm)
            (format-size (slot-ref st 'size))
            (sys-strftime "%Y%m%d %H:%M" (sys-localtime (slot-ref st 'mtime)))
            (if (file-is-directory? name)
                (string-append name "/")
                name))))

(define (main args)
  (let ((args (cdr args)))
    (cond
     ((null? args)
      (map print-entry (directory-list ".")))
        ;; XXX invoke directory-list when an arg is-a directory.
     ((file-is-directory? (car args))
      (map print-entry (directory-list (car args))))
     (else
      (map print-entry args)))))

;; Local Variables:
;; mode: gauche
;; end: