elevation-profile-client.scm

;;;
;;; elevation profile web-service client
;;;
;;;   Copyright (c) 2012,2013,2020 Jens Thiele <karme@karme.de>
;;;   
;;;   Redistribution and use in source and binary forms, with or without
;;;   modification, are permitted provided that the following conditions
;;;   are met:
;;;   
;;;   1. Redistributions of source code must retain the above copyright
;;;      notice, this list of conditions and the following disclaimer.
;;;  
;;;   2. Redistributions in binary form must reproduce the above copyright
;;;      notice, this list of conditions and the following disclaimer in the
;;;      documentation and/or other materials provided with the distribution.
;;;  
;;;   3. Neither the name of the authors nor the names of its contributors
;;;      may be used to endorse or promote products derived from this
;;;      software without specific prior written permission.
;;;  
;;;   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
;;;   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
;;;   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
;;;   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
;;;   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
;;;   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
;;;   TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
;;;   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
;;;   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
;;;   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
;;;   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
;;;  
(define-module elevation-profile-client
  (use rfc.uri)
  (use rfc.http)
  (use util.list)
  (use gauche.sequence)
  (use gauche.time)
  (export polyline->3d
          upsample-polyline->4d
          sample-polyline->4d))

(select-module elevation-profile-client)

(define (encode-polyline pl)
  (string-join (map (lambda(p)
		      (string-join (map x->string
					(permute p '(1 0)))
                                   ","))
		    pl)
               "|"))

;; todo: temporarily ignore or block sigpipe?!
(define (elevation-profile-http-request server request-uri method params reader . args)
  (let1 tc (make <real-time-counter>)
    (receive (status headers body)
        (with-time-counter tc (case method
                                [(post)
                                 (apply http-post (append (list server
                                                                request-uri
                                                                ;; ugly workaround for server side bug!
                                                                ;; now using workaround on server side => disabled
                                                                ;; (subseq (http-compose-query "" params) 1))
                                                                params)
                                                          args))]
                                [(get)
                                 (apply http-get (append (list server
                                                               (http-compose-query request-uri params))
                                                         args))]
                                [else
                                 (error "todo")]))
      (case (x->number status)
        [(200)
         (reader body)]
        [else
         (error status headers body (time-counter-value tc))]))))

(define (my-read-from-string s)
  (guard (e [else
             #?=s
             (raise e)  ;; todo: embed s?
             ])
         ;; todo:
         ;; - better error protection?
         ;; - dangerous / cyclic structures...
         (read-from-string s)))

(define (sexpr-http-request service params)
  (apply elevation-profile-http-request (append (list (car service)
                                                      (cadr service)
                                                      'post
                                                      (append params '((format sexpr)))
                                                      my-read-from-string)
                                                (cddr service))))

(define (polyline->3d service pl . args)
  (sexpr-http-request service (append args
                                      `((locations ,(encode-polyline pl))))))

(define (upsample-polyline->4d service pl upsample . args)
  (sexpr-http-request service
                      (append args
                              `((path ,(encode-polyline pl))
                                (upsample ,upsample)))))

(define (sample-polyline->4d service pl samples . args)
  (sexpr-http-request service
                      (append args
                              `((path ,(encode-polyline pl))
                                (samples ,samples)))))