(define-module (hnh module-introspection all-modules)
  :use-module (ice-9 regex)
  :use-module (srfi srfi-1)
  :use-module (ice-9 ftw)
  :use-module (ice-9 match)
  :use-module (hnh util path)
  :use-module (hnh module-introspection)
  :use-module ((hnh module-introspection static-util) :select (get-forms))
  :export (all-files-and-modules-under-directory
           all-files-under-directory
           all-modules-under-directory
           fs-find-base fs-find
           module-file-mapping
           ))

(define (fs-find dir)
  (define files '())
  (ftw dir (lambda args (set! files (cons args files)) #t))
  files)

;; (define (fs-find proc dir)
;;   (filter proc (fs-find-base dir)))

(define* (all-files-under-directory dir extension)
  (define extension-rx ((@ (texinfo string-utils) escape-special-chars)
                        extension "[](){}+*?.^$" #\\))
  (define re (make-regexp (string-append extension-rx "$")))

  (map car
       (filter (match-lambda ((filename _ 'regular)
                              (and (regexp-exec re filename)
                                   (not (file-hidden? filename))))
                             (_ #f))
               (fs-find dir))))

(define (all-files-and-modules-under-directory dir)
  (map (lambda (file)
         (list file
               (call-with-input-file file
                 (compose find-module-declaration get-forms))))
       (all-files-under-directory dir ".scm")))

(define (all-modules-under-directory dir)
  "Returns two values, all scm files in dir, and all top
level modules in those files"

  (define pairs (all-files-and-modules-under-directory dir))
  (values
   (map car pairs)
   (filter identity (map cadr pairs))))

;; Returns an association list from module names the modules
;; containing filename
(define (module-file-mapping dir)
  (filter
   car
   (map (lambda (pair) (cons (cadr pair) (car pair)))
        (all-files-and-modules-under-directory dir))))