[REF] Port demo.py to elisp

demo/demo-server.el

@@ -0,0 +1,95 @@
+(defun demo-server-load-handlers ()
+  (let (handlers)
+    (dolist (item (directory-files "../testdata"))
+      (when (string-suffix-p ".json" item)
+        (with-temp-buffer
+          (insert-file-contents (file-name-concat ".." "testdata" item))
+          (let ((tmp (buffer-substring-no-properties
+                      (line-beginning-position) (1+ (line-end-position)))))
+            (delete-region (line-beginning-position) (1+ (line-end-position)))
+
+            (when (string-match (rx line-start (group (+? digit)) (literal "|")
+                                    (group (+? anychar)) line-end)
+                                tmp)
+              (push `(,(match-string 2 tmp)
+                      ,(string-to-number (match-string 1 tmp))
+                      ,(buffer-string))
+                    handlers))))))
+    handlers))
+
+(defun demo-server-eval-sexprs (data)
+  (with-temp-buffer
+    (insert data)
+    (goto-char (point-min))
+    (let ((last 0) tmp)
+      (while (string-match
+              (rx line-start (*? anychar)
+                  (group (literal "#(") (*? anychar) (literal ")"))
+                  (? ",") line-end)
+              (buffer-string) last)
+        (setq last (match-beginning 1))
+        (setq tmp (match-string 1 (buffer-string)))
+        (goto-char (1+ (match-beginning 1)))
+        (delete-region (1+ (match-beginning 1)) (1+ (match-end 1)))
+        (insert (format "%s" (eval (read (substring tmp 1)))))))
+    (buffer-string)))
+
+(defun demo-server-router (proc req-line)
+  (unwind-protect
+      (process-send-string
+       proc
+       ;; somewhat-(cond)
+       (let (default code)
+         (catch 'done
+           (dolist (handler (or (get 'demo-server-load-handlers 'cache)
+                                (progn
+                                  (put 'demo-server-load-handlers 'cache
+                                       (demo-server-load-handlers))
+                                  (get 'demo-server-load-handlers 'cache))))
+             (let ((path (nth 0 handler)) (data (nth 2 handler)))
+               (when (string-match path req-line)
+                 (setq code (nth 1 handler))
+                 (setq default
+                       (string-join `(,(format "HTTP/1.1 %s" code)
+                                      "Content-Type: application/json" ""
+                                      ;; re-eval per request
+                                      ,(demo-server-eval-sexprs data))
+                                    "\r\n"))
+                 (throw 'done t)))))
+         (message "%s %s %s"
+                  (format-time-string "[%d/%b/%Y %H:%M:%S]" (current-time))
+                  (when (string-match "\n" req-line)
+                    (substring req-line 0 (match-beginning 0)))
+                  (or code "404"))
+         (or default
+             (string-join '("HTTP/1.1 404 Not Found"
+                            "Content-Type: text/plain" ""
+                            "Page not found!\n") "\r\n"))))
+    (process-send-eof proc)))
+
+(defun demo-server-filter (proc string)
+  "Handle the incoming data from the network connection."
+  (let ((req-line (decode-coding-string string 'utf-8))
+        (handlers ))
+    (demo-server-router proc req-line)))
+
+(defun demo-server-sentinel (proc event)
+  "Handle the closing of a network connection."
+  (when (string-match "closed" event)
+    (message "Connection closed: %s" proc)))
+
+(let ((proc-name "syncthing-demo-server"))
+  (mapcar (lambda (proc)
+            (when (string= (process-name proc) proc-name)
+              (message "Restart!")
+              (delete-process proc)))
+          (process-list))
+  (put 'demo-server-load-handlers 'cache nil)
+  (make-network-process
+   :name proc-name
+   :server t
+   :host (or (getenv "DEMO_HOST") "127.0.0.1")
+   :service (string-to-number (or (getenv "DEMO_PORT") "5000"))
+   :family 'ipv4
+   :sentinel 'demo-server-sentinel
+   :filter 'demo-server-filter))