;; Parenscript shortcut
(defmacro script (&rest body)
  "Macro expanding to (:script (:raw (ps body))). Great for embedding JS inside page."
  `(list :script 
         (list :raw 
               (ps ,@body))))

;; Templating macros
(defmacro mu (&rest body)
  "Macro writing Mustache syntax, namely the '{{ mustache }}'"
  `(list :raw (concatenate 'string "{{ " ,@body " }}")))

(defun keyword-to-chain (string-or-keyword)
  (if (keywordp string-or-keyword)
    (concatenate 'string "."
                 (-> string-or-keyword
                     symbol-name
                     string-downcase))
    string-or-keyword))

(defun muc (&rest chain-of-props)
  "Shortcut chaining props in a mustache"
  (mu (reduce (lambda (a b) 
                (concatenate 'string 
                             (keyword-to-chain a) 
                             (keyword-to-chain b)))
        chain-of-props)))

(defmacro mublock (name attrs &rest body)
  "Macro writing a block where a '{{ end }}' is followed."
  `(list
    (mu ,name " " ,attrs)
    ,@(mapcar (lambda (x) `',x) body)
    (mu "end")))

(defmacro muwhen (condition &rest body)
  `(mublock "if" ,condition ,@body))

(defmacro muif (condition do do-else)
  `(muwhen ,condition 
           (values ,do)
           (list :RAW (mu "else"))
           (values ,do-else)))

(defun quote-if-string (str)
  (if (stringp str) 
    (concatenate 'string "\"" str "\"")
    (write-to-string str)))

;; TODO support function calls as values
(defmacro mudefvar (var val)
  `(mu "$" 
       (string-downcase (symbol-name ',var)) 
       " := " 
       (quote-if-string ,val)))