From f41d6d6df7e21909eb50a56500e04b9b9b0995cb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hugo=20H=C3=B6rnquist?= <hugo@lysator.liu.se>
Date: Thu, 23 Jun 2022 01:41:30 +0200
Subject: Update fetch-liu-map to be runnable on files.

---
 scripts/fetch-liu-map-index.scm | 91 +++++++++++++++++++++++++++++------------
 1 file changed, 65 insertions(+), 26 deletions(-)

(limited to 'scripts')

diff --git a/scripts/fetch-liu-map-index.scm b/scripts/fetch-liu-map-index.scm
index eea2a63d..da012cf3 100755
--- a/scripts/fetch-liu-map-index.scm
+++ b/scripts/fetch-liu-map-index.scm
@@ -1,5 +1,5 @@
 #!/usr/bin/guile \
--s
+-e main -s
 !#
 
 ;;; Commentary:
@@ -15,39 +15,78 @@
              (web response)
              (ice-9 rdelim)
              (ice-9 format)
+             (ice-9 getopt-long)
              (sxml gumbo)
              (sxml match)
+             ((hnh util) :select (->))
              (json))
 
-(define-values (response body) (http-get "https://old.liu.se/karta/list?l=sv"))
 
-(unless (= 200 (response-code response))
-  (format #t "Fetching index failed with ~a ~a~%"
-          (response-code response)
-          (response-reason-phrase response))
-  (format #t "~{~s~%~}" (response-headers response))
-  (exit 1))
+;; Parse string as HTML, find all links which are "map links",
+;; and return them as an association list from name to url-fragments.
+(define (get-data string)
+  (define data (html->sxml string))
 
-(define data (html->sxml body))
+  (define rx (make-regexp "^karta\\?"))
 
-(define rx (make-regexp "^karta\\?"))
+  (define links
+    (map (lambda (node)
+           (sxml-match node
+                       [(a (@ (href ,href)) ,b0 ,body ...)
+                        (cons href b0)]))
+         (((@ (sxml xpath) sxpath) '(// a)) data)))
 
-(define links
-  (map (lambda (node)
-         (sxml-match node
-                     [(a (@ (href ,href)) ,b0 ,body ...)
-                      (cons href b0)]))
-       (((@ (sxml xpath) sxpath) '(// a)) data)))
+  (define map-links (filter (lambda (pair) (regexp-exec rx (car pair)))
+                            links))
 
-(define map-links (filter (lambda (pair) (regexp-exec rx (car pair)))
-                          links))
+  (define link-table (make-hash-table))
+  (for-each (lambda (pair) (hash-set! link-table (string-upcase (string-trim-both (cdr pair)))
+                                      (car pair)))
+            map-links)
 
-(define link-table (make-hash-table))
-(for-each (lambda (pair) (hash-set! link-table (string-upcase (string-trim-both (cdr pair)))
-                               (car pair)))
-          map-links)
+  (hash-map->list (lambda (name frag)
+                    `(,name . ,frag))
+                  link-table))
 
-(scm->json (hash-map->list (lambda (name frag)
-                             `(,name . ,frag))
-                           link-table))
-(newline)
+;; Open a HTTP request to the given URL, and return the
+;; response body as a port.
+(define (open-input-url url)
+  (define-values (response body) (http-get url #:streaming? #t))
+
+  (unless (= 200 (response-code response))
+    (format #t "Fetching index failed with ~a ~a~%"
+            (response-code response)
+            (response-reason-phrase response))
+    (throw 'misc-error "get-from-url" "~{~s~%~}" (response-headers response))
+    (exit 1))
+  body)
+
+
+(define (display-help)
+  (format #t "Usage: fetch-liu-map-index.scm [--url=url] [--file=file]~%")
+  (newline)
+  (for-each (lambda (line) (display line) (newline))
+   ((@ (text flow) flow-text)
+    "(Possibly) fetches, and parses Linköpings Universities list of locations. The return is a simple JSON-object where the keys are the location names, and the values are URL fragments. The --file flag exists since the TLS bindings in Guile are currently broken, and is mainly useful for taking input from a cURL pipe."))
+  (newline))
+
+(define option-spec
+  '((url (value #t))
+    (file (value #t))
+    (help (single-char #\h))))
+
+(define (main args)
+  (define options (getopt-long args option-spec))
+
+  (when (option-ref options 'help #f)
+    (display-help)
+    (exit 0))
+
+  (let ((port
+         (cond ((option-ref options 'url #f)  => open-input-url)
+               ((and=> (option-ref options 'file #f) (lambda (s) (string=? s "-")))
+                (current-input-port))
+               ((option-ref options 'file #f) => open-input-file)
+               (else (open-input-url "https://old.liu.se/karta/list?l=sv")))))
+    (-> port read-string get-data scm->json)
+    (newline)))
-- 
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