#lang racket

(require net/url
         xml
         web-server/web-server
         web-server/servlet-dispatch
         web-server/dispatch
         (prefix-in files: web-server/dispatchers/dispatch-files)
         (prefix-in filter: web-server/dispatchers/dispatch-filter)
         (prefix-in sequencer: web-server/dispatchers/dispatch-sequencer)
         web-server/dispatchers/filesystem-map
         web-server/http)

(define (html-response content)
  (response/full
   200
   #"OK"
   (current-seconds)
   TEXT/HTML-MIME-TYPE
   '()
   (list content)))



(define (xexpr-file->xml file)
  (string->bytes/utf-8
   (xexpr->string (read (open-input-file file)))))

;;; httpx
;; sends only the requested resource
(define (about request)
  (html-response (xexpr-file->xml "source/about.txt")))

(define (home request)
  (html-response (xexpr-file->xml "source/index.txt")))

(define (404- request)
  (html-response (xexpr-file->xml "source/not-found.txt")))

(define (structures request structure-id)
  (html-response (xexpr-file->xml "source/not-found.txt")))

(define (index-structures request)
  (html-response (xexpr-file->xml "source/not-found.txt")))

(define (unstructures request structure-id)
  (html-response (xexpr-file->xml "source/not-found.txt")))

(define (index-unstructures request)
  (html-response (xexpr-file->xml "source/not-found.txt")))

(define-values (httpx-app reverse-httpx-uri)
  (dispatch-rules
   [("hx" "about") about]
   [("hx" "home") home]
   [("hx" "structures" (integer-arg)) structures]
   [("hx" "structures") index-structures]
   [("hx" "unstructures" (integer-arg)) unstructures]
   [("hx" "unstructures") index-unstructures]
   [else 404-]))

;;; page-app
;; constructs entire page for each response
(define (make-page resource)
  (string->bytes/utf-8
   (xexpr->string
    `(html ((lang "en"))
           ,(read (open-input-file "source/head.txt"))
           (body
            ,(read (open-input-file "source/header.txt"))
            ,(read (open-input-file resource)))))))

(define (homepage request)
  (html-response (make-page "source/index.txt")))
(define (about-page request)
  (html-response (make-page "source/about.txt")))

(define-values (page-app reverse-page-uri)
  (dispatch-rules
   [("") homepage]
   [("about") about-page]))
  

;;; from /static
(define url->path/static (make-url->path "static"))

(define static-dispatcher
  (files:make #:url->path (lambda (u)
                            (url->path/static
                             (struct-copy url u [path (cdr (url-path u))])))))


;;; 404
(define (not-found request)
  (html-response (make-page "source/not-found.txt")))


;;; server
(define stop
  (serve
   #:dispatch (sequencer:make
               (filter:make #rx"^/static/" static-dispatcher)
               (dispatch/servlet #:regexp #rx"^/hx/" httpx-app)
               (dispatch/servlet page-app)
               (dispatch/servlet not-found)
               )
   #:listen-ip "127.0.0.1"
   #:port 8000))

(with-handlers ([exn:break? (lambda (e)
                              (stop))])
  (sync/enable-break never-evt))