main: Start command line option parsing

Include the 'unix-opts' library described in
http://lispcookbook.github.io/cl-cookbook/scripting.html#parsing-command-line-arguments
for command line option parsing.

Define the options I need. We want a `--socket-url` option, and a list
of extension IDs as free arguments.

Implement the `-V` version command line argument. Thanks to JJJ
(https://stackoverflow.com/users/1337941/jjj) on Stack Overflow for
describing how to get the version number of an ASDF system:
https://stackoverflow.com/questions/11084339/getting-the-version-of-an-asdf-system/11088022#11088022

Add a new `options.lisp` file where we'll add the option parsing restart
error handling functions required by 'unix-opts'.

3 files changed, 35 insertions, 4 deletions

diff --git a/l/extreload.asd b/l/extreload.asd
index 8a1cfc2..73402fb 100644
--- a/l/extreload.asd
+++ b/l/extreload.asd
@@ -1,12 +1,14 @@
 (asdf:defsystem extreload
   :version "0.0.1"
   :depends-on (:jsown
+                :unix-opts
                 :wait-group
                 :websocket-driver-client)
   :components ((:module "src"
                 :serial t
                 :components ((:file "package")
                              (:file "macro")
+                             (:file "option")
                              (:file "main"))))
 
   :build-operation "program-op"
diff --git a/l/src/main.lisp b/l/src/main.lisp
index 47e8eb1..5ea0384 100644
--- a/l/src/main.lisp
+++ b/l/src/main.lisp
@@ -4,13 +4,36 @@
 
 (defvar *wg* (wait-group:make-wait-group))
 
+(opts:define-opts
+  (:name :socket-url
+         :description "DevTools protocol WebSocket URL"
+         :long "socket-url"
+         :meta-var "SOCKET_URL")
+  (:name :help
+         :description "print this help menu"
+         :short #\h
+         :long "help")
+  (:name :version
+         :description "show the program version"
+         :short #\V
+         :long "version"))
+
 (defun main ()
-  (with-websocket-connection (*client*)
-    (wsd:on :message *client* #'ws-on-message)
+  (multiple-value-bind (options free-args) (opts:get-opts)
+    ; (when-option (options :help))
+    (when-option (options :version)
+      (format t "~a~%" (asdf:component-version (asdf:find-system :extreload)))
+
+      (opts:exit 0))
+
+    (let* ((socket-url (getf options :socket-url))
+           (client (wsd:make-client socket-url)))
+      (with-websocket-connection (*client*)
+        (wsd:on :message *client* #'ws-on-message)
 
-    (websocket-send *client* (target-get-targets-msg 1))
+        (websocket-send *client* (target-get-targets-msg 1))
 
-    (wait-group:wait *wg*)))
+        (wait-group:wait *wg*)))))
 
 (defun target-get-targets-msg (call-id)
   (jsown:to-json
diff --git a/l/src/option.lisp b/l/src/option.lisp
new file mode 100644
index 0000000..d828230
--- /dev/null
+++ b/l/src/option.lisp
@@ -0,0 +1,6 @@
+(in-package :extreload)
+
+(defmacro when-option ((options option) &body body)
+  `(let ((value (getf ,options ,option)))
+     (when value
+       ,@body)))