;;; -*- lexical-binding: t -*-
;;
;; --------------------------------------------------------------------------

(require 'cl-lib)
(cl-pushnew "." load-path :test #'string=)
(require 'luki-lisp)

;; --------------------------------------------------------------------------

(-> 'bad-elem)

;; --------------------------------------------------------------------------

(defconst bad-solid    ?\s)
(defconst bad-nonsolid ?\{)

;; --------------------------------------------------------------------------

(cl-defmethod bad-write-replace ((dst elem) (src elem) &optional read)
  (~ (data w h) dst
     (~ ((src-data data)
         (src-len len)
         (src-w w)
         (src-h h)
         (src-x x)
         (src-y y)
         (src-visible visible))
        src
        (when (& data src-data src-visible)
          (cl-loop
           with read-data
           with loop-data = (take (* src-h src-w) src-data)
           for i from 0 to (1- src-len)
           for s in loop-data do
           (let* ((pos-x (+ src-x (m i src-w)))
                  (pos-y (* (+ src-y (/ i src-w))))
                  (pos   (+ pos-x (* pos-y w))))
             (when (& (< pos-x (1- w))
                      (< pos-y (1- h)))
               (if read
                   (when (= s bad-nonsolid)
                     (push (nth pos data) read-data))
                 (unless (= s bad-nonsolid)
                   (setf (nth pos data) s)))))
           finally return (when read
                            (nreverse read-data)))))))

;; --------------------------------------------------------------------------

(<- 'bad-write)