#!/usr/local/bin/sbcl --script


(defun foo (&key a b c) (list a b c))

(format t "~a~%" (foo :a 1 :b 2 :c 3))
(format t "~a~%" (foo :c 3 :b 2 :a 1))
(format t "~a~%" (foo :a 1 :c 3) )
(format t "~a~%" (foo))


(defun foo (&key a (b 20) (c 30 c-p)) (list a b c c-p))
(format t "~a~%" (foo :a 1 :b 2 :c 3))
(format t "~a~%" (foo :c 3 :b 2 :a 1))
(format t "~a~%" (foo :a 1 :c 3) )
(format t "~a~%" (foo))













(defun make-cd (title artist rating ripped)
  (list :title title :artist artist :rating rating :ripped ripped))

(defvar *db* nil)
(defun add-record (cd) (push cd *db*))

(add-record (make-cd "Roses" "Kathy Mattea" 7 t))
(add-record (make-cd "Fly" "Dixie Chicks" 8 t))
(add-record (make-cd "Home" "Dixie Chicks" 9 t))

(defun dump-db ()
  (dolist (cd *db*)
    (format t "~{~a:~10t~a~%~}~%" cd)))

;(dump-db)



;select
(format t "~a~%" "select")



(defun select-by-artist (artist)
  (remove-if-not
   #'(lambda (cd) (equal (getf cd :artist) artist))
   *db*))

(defun select (selector-fn)
  (remove-if-not selector-fn *db*))

(defun artist-selector (artist)
  #'(lambda (cd) (equal (getf cd :artist) artist)))

(format t "~a~%" (select (artist-selector "Dixie Chicks")))




;where
(format t "~a~%" "where")


(defun where (&key title artist rating (ripped nil ripped-p))
  #'(lambda (cd)
      (and
       (if title    (equal (getf cd :title)  title)  t)
       (if artist   (equal (getf cd :artist) artist) t)
       (if rating   (equal (getf cd :rating) rating) t)
       (if ripped-p (equal (getf cd :ripped) ripped) t))))






(format t "~a~%" (select (where :artist "Dixie Chicks")))

(format t "~a~%" (select (where :rating 10 :ripped nil)))






;update
(format t "~a~%" "update")


(defun update (selector-fn &key title artist rating (ripped nil ripped-p))
  (setf *db*
        (mapcar
         #'(lambda (row)
             (when (funcall selector-fn row)
               (if title    (setf (getf row :title) title))
               (if artist   (setf (getf row :artist) artist))
               (if rating   (setf (getf row :rating) rating))
               (if ripped-p (setf (getf row :ripped) ripped)))
             row) *db*)))




(format t "~a~%" (select (where :artist "Dixie Chicks")))

(update (where :artist "Dixie Chicks") :rating 11)

(format t "~a~%" (select (where :artist "Dixie Chicks")))



;delete
(format t "~a~%" "delete")

(dump-db)

(defun delete-rows (selector-fn)
  (setf *db* (remove-if selector-fn *db*)))

;(delete-rows (where :artist "Dixie Chicks"))
;(format t "~a~%" "deleted Dixie Chicks")

(delete-rows (where :rating 7 :ripped T))
(format t "~a~%" "deleted rating 7 ripped T")

(dump-db)



;defmacro
(format t "~a~%" '(1 2 3))
(format t "~a~%" (reverse '(1 2 3)))
(format t "~a~%" "hello, world")
(defmacro backwards (expr) (reverse expr))
(backwards ("hello, world" "~a~%" t format))

(defun make-comparison-expr (field value)
  (list 'equal (list 'getf 'cd field) value))

(make-comparison-expr :rating 10)
(make-comparison-expr :title "Give Us a Break")

(format t "~a~%" `(1 2 3))
(format t "~a~%" '(1 2 3))

(format t "~a~%" `(1 2 (+ 1 2)))
(format t "~a~%" `(1 2 ,(+ 1 2)))  

(defun make-comparison-expr (field value)
  `(equal (getf cd ,field) ,value))

(defun make-comparisons-list (fields)
  (loop while fields
     collecting (make-comparison-expr (pop fields) (pop fields))))

(defmacro where (&rest clauses)
  `#'(lambda (cd) (and ,@(make-comparisons-list clauses))))

`(and ,(list 1 2 3))
`(and ,@(list 1 2 3))
`(and ,@(list 1 2 3) 4)


(format t "~a~%" (macroexpand-1 '(where :title "Give Us a Break" :ripped t)))

;(format t "~a~%" (select (where :title "Give Us a Break" :ripped t)))
(format t "~a~%" (select (where :title "Give Us a Break" :ripped t)))