#!/usr/bin/guile \
-e main -s
!#

;; (add-to-load-path ".")
(add-to-load-path (dirname (current-filename)))
(add-to-load-path "/home/hugo/code/calp/module")

(use-modules
 (web client)
 (web response)
 (sxml simple)
 (sxml xpath)

 (ice-9 getopt-long)
 (ice-9 curried-definitions)
 (ice-9 format)

 ;; following are from calp
 (sxml namespace)
 ((calp util) :select (path-append))

 (feed-handler)
 )



(define option-spec
  `((output (single-char #\o)
            (required? #f)
            (value #t))))

(define ((handle-feed output-directory) feed)
  (define response
    ;; TODO follow redirects
    (http-get (feed-url feed)
              #:streaming? #t))

  (unless (= 200 (response-code response))
    (format (current-error-port) "HTTP error ~a"
            (response-code response))
    (exit 1))

  (let* ((feed-content (move-to-namespace (parse-rss (response-body-port response))
                                          '((#f . rss))))
         (feed-title (car ((sxpath '(// rss:channel rss:title *text*)) feed-content)))
         (safe-title (string-map (lambda (c) (if (char-set-contains? char-set:letter+digit c)
                                            c #\_))
                                 feed-title)))


    (let ((output (filter-tree (feed-transformer feed)
                               feed-content))
          (filename (string-append
                     (path-append output-directory safe-title)
                     ".rss")))
      (with-output-to-file filename
        (lambda ()
          (sxml->xml
           ;; Removing the rss prefix should be fine, but at least NewNewsWire
           ;; (for iPad) expects all rss elements to be un-namespaced.
           (move-to-namespace output '((rss . #f)))))))))

(define (main args)

  (define opts (getopt-long args option-spec))
  (define output-directory (option-ref opts 'output "."))

  (for-each (handle-feed output-directory) (@ (config) feeds)))