(require :uiop)

(defun input-string () (string-trim '(#\newline) (uiop:read-file-string "../../../data/2015/2/input.txt")))

(defun input-string-list () (uiop:split-string (input-string) :separator (list #\linefeed)))

(defun string-to-dimension-list (string)
  (mapcar #'parse-integer 
	  (uiop:split-string string :separator (list #\x))))

(defun dimension-list-to-surface-area (dimension-list)
  (let ((length (first dimension-list))
	(width (second dimension-list))
	(height (third dimension-list)))
    (+ (* 2 length width) (* 2 length height) (* 2 width height))))

(defun dimension-list-to-slack (dimension-list)
  (let ((length (first dimension-list))
	(width (second dimension-list))
	(height (third dimension-list)))
    (let ((top (* length width))
	  (front (* width height))
	  (side (* length height)))
      (min top front side))))

(defun dimension-list-to-bow (dimension-list)
  (let ((length (first dimension-list))
	(width (second dimension-list))
	(height (third dimension-list)))
    (* length width height)))

(defun dimension-list-to-wrap-ribbon (dimension-list)
  (let ((length (first dimension-list))
	(width (second dimension-list))
	(height (third dimension-list)))
    (let ((top-perim (* 2 (+ length width)))
	  (front-perim (* 2 (+ width height)))
	  (side-perim (* 2 (+ length height))))
      (min top-perim front-perim side-perim))))

(defun dimension-list-to-ribbon (dimension-list)
  (+ (dimension-list-to-wrap-ribbon dimension-list) (dimension-list-to-bow dimension-list)))

(defun dimension-list-to-paper (dimension-list)
  (+ (dimension-list-to-surface-area dimension-list) (dimension-list-to-slack dimension-list)))

(defun string-to-paper (string)
  (dimension-list-to-paper (string-to-dimension-list string)))

(defun string-to-ribbon (string)
  (dimension-list-to-ribbon (string-to-dimension-list string)))

(defun part-1 ()
  (reduce (lambda (sfp string)
	    (+ (string-to-paper string) sfp))
	  (input-string-list)
	  :initial-value 0))

(defun part-2 ()
  (reduce (lambda (sfp string)
	    (+ (string-to-ribbon string) sfp))
	  (input-string-list)
	  :initial-value 0))

(defun solution ()
  (format t "Part 1: ~a" (part-1))
  (terpri)
  (format t "Part 2: ~a" (part-2))
  (terpri))

(solution)