#!/bin/sh
#| -*- scheme -*-
tmp="/tmp/path-compare-$$"
if [ -x "$PLTHOME/bin/racket" ]; then
  "$PLTHOME/bin/racket" -r "$0" "$@"
else
  "racket" -r "$0" "$@"
fi > "$tmp" || exit 1
cd "`dirname \"$0\"`"
if diff "paths-configure-snapshot" "$tmp"; then
     echo "PATHS OK"; rm "$tmp"; exit 0
else echo "*** PATHS DATA MISMATCH (see $tmp) ***"; exit 1
fi
|#

;; Extract path information from the configure script, so it can be compared
;; to a snapshot and generate an error each time things change

(define configure-path
  (simplify-path
   (build-path
    ;; (find-executable-path
    ;;  (find-system-path 'exec-file) (find-system-path 'collects-dir) #t)
    (find-system-path 'exec-file)
    'up 'up "src" "configure")))
(unless (file-exists? configure-path)
  (error "Cannot find `configure':" configure-path))

(define current-match (make-parameter #f))
(define (match? . bytess)
  (cond [(regexp-match (byte-regexp (apply bytes-append bytess))
                       (current-input-port))
         => (lambda (m) (current-match (car m)) #t)]
        [else #f]))
(define (show-match)
  (write-bytes (current-match)))

(with-input-from-file configure-path
  (lambda ()
    (if (match? #"\n# Installation directory options.\n"
                #"(?:#[^\n]*\n)+"
                #"(?:[a-z]+=[^\n]+\n)+"
                #"\n")
      (show-match)
      (error "Did not find first block"))
    (if (match? #"\n#+ Install targets #+\n\n"
                #"unixstyle=no\n"
                #"if (?:[^\n]+\n)+fi\n\n"
                #"MAKE_COPYTREE=no\n"
                #"if [^\n]+\n"
                #"(?: +[^\n]+\n)+"
                #"else\n"
                #"(?: +[^\n]+\n)+"
                #"fi\n\n")
      (show-match)
      (error "Did not find second block"))
    (if (match? #"\n +echo \">>> Installation targets:\"\n"
                #"(?: +echo [^\n]+\n)+")
      (show-match)
      (error "Did not find third block"))))
(exit)