sncf-bot/server.ss

109 lines
3.7 KiB
Scheme
Executable file

#!/usr/bin/env gxi
(export main)
(import :std/format
:std/getopt
:std/iter
:std/logger
:std/net/address
:std/net/httpd
:std/srfi/19
:std/sugar
:gerbil/gambit/threads
:dlozeve/sncf/api
:dlozeve/sncf/display)
(def (main . args)
(def gopt
(getopt (option 'address "-a" "--address"
help: "server address"
default: ":8080")))
(try
(let (opt (getopt-parse gopt args))
(parameterize ((current-logger-options 'DEBUG))
(start-logger!)
(run (hash-get opt 'address))))
(catch (getopt-error? exn)
(getopt-display-help exn "server" (current-error-port))
(exit 1))))
(def (run address)
(infof "Starting HTTP server on ~a" (inet-address->string address))
(let (httpd (start-http-server! address mux: (make-default-http-mux default-handler)))
(http-register-handler httpd "/" departures-handler)
(thread-join! httpd)))
;; /
(def (departures-handler req res)
(let/cc return
(def sncf-key (getenv "SNCF_AUTH_KEY" #f))
(unless sncf-key
(errorf "No SNCF API authentication key found. Set the SNCF_AUTH_KEY environment variable.")
(http-response-write res 500 '(("Content-Type" . "text/plain; charset=utf-8"))
"Missing SNCF API authentication key\n")
(return))
(def headers (http-request-headers req))
(def accept-header (assoc "Accept" headers))
(when accept-header (set! accept-header (cdr accept-header)))
(def params (parse-request-params (http-request-params req)))
(def datetime-str (assoc "datetime" params))
(def datetime (if datetime-str
(try
(string->date (cdr datetime-str) "~Y~m~dT~H~M~S")
(catch _
(warnf "Badly formatted date string: ~a" (cdr datetime-str))
(http-response-write res 400 '(("Content-Type" . "text/plain; charset=utf-8"))
(format "Badly formatted date string, expected %Y%m%dT%H%M%S: ~a\n"
(cdr datetime-str)))
(return)))
#f))
(def station (assoc "station" params))
(when station (set! station (cdr station)))
(define-values (station-name station-id)
(if (string? station)
(get-station-id sncf-key station)
(values "Vernon - Giverny (Vernon)" "stop_area:SNCF:87415604")))
(unless station-name
(set! station-name "Vernon - Giverny"))
(unless station-id
(set! station-id "stop_area:SNCF:87415604"))
(infof "~a ~a ~a ~a (\"~a\")~a"
(inet-address->string (http-request-client req))
(http-request-method req)
(http-request-path req)
station-name
station
(if datetime (string-append " at " (cdr datetime-str)) ""))
(define-values (departures disruptions) (get-departures sncf-key station-id datetime))
(def content
(cond
((or (assoc "markdown" params) (string-prefix? "text/markdown" accept-header))
(with-output-to-string
(lambda () (display-all departures disruptions station-name datetime
style: 'markdown))))
((string-prefix? "text/html" accept-header) ; TODO
(with-output-to-string
(lambda () (display-all departures disruptions station-name datetime
style: 'markdown))))
(#t
(with-output-to-string
(lambda () (display-all departures disruptions station-name datetime
style: 'unicode))))))
(http-response-write res 200 '(("Content-Type" . "text/plain; charset=utf-8"))
content)))
(def (parse-request-params params)
(if params
(for/collect ((param (string-split params #\&)))
(match (string-split param #\=)
([k] (cons k #t))
([k v] (cons k v))
([k . rest] (cons k rest))))
'()))
;; default
(def (default-handler req res)
(http-response-write res 404 '(("Content-Type" . "text/plain"))
"these aren't the droids you are looking for.\n"))