(ql:quickload '(:net.didierverna.clon :data-lens :yason))

(ql:quickload '(:net.didierverna.clon :data-lens :yason :local-time))

(defun format-stat-time (accessor stat)
  (local-time:format-timestring
   nil
   (local-time:unix-to-timestamp
    (funcall accessor
             stat))))

(defun decode-permissions (mode)
  (let* ((user (ash (logand #o700 mode) -6))
         (group (ash (logand #o70 mode) -3))
         (other (logand #o7 mode)))
    (list (list :user
                (when (= #o4 (logand #o4 user))
                  :read)
                (when (= #o2 (logand #o2 user))
                  :write)
                (when (= 1 (logand #o1 user))
                  :execute))
          (list :group
                (when (= #o4 (logand #o4 group))
                  :read)
                (when (= #o2 (logand #o2 group))
                  :write)
                (when (= 1 (logand #o1 group))
                  :execute))
          (list :other
                (when (= #o4 (logand #o4 other))
                  :read)
                (when (= #o2 (logand #o2 other))
                  :write)
                (when (= 1 (logand #o1 other))
                  :execute)))))

(defun list-directory (path)
  (handler-case (progn (let ((stat (sb-posix:lstat path)))
                         (if (directoryp stat)
                             (values (map-directory-entries path
                                                            (data-lens:juxt (constantly :name) 'sb-posix:dirent-name
                                                                            (constantly :path) (lambda (it)
                                                                                                 (format nil "~a/~a" path (sb-posix:dirent-name it)))
                                                                            (constantly :inode) 'sb-posix:dirent-ino))
                                     :directory)
                             (values (handle-non-directory path)
                                     (stat-file-type stat)))))

(defun prepend-path-component (prefix)
  (let ((prefix (if (eql #\/
                         (elt prefix (1- (length prefix))))
                    (subseq prefix 0 (1- (length prefix)))
                    prefix)))
    (lambda (suffix)
      (format nil "~a/~a" prefix suffix))))
(defun list-directory (path stat)
  (handler-case (if (directoryp stat)
                    (values (map-directory-entries
                             path
                             (data-lens:juxt
                              (constantly :name) 'sb-posix:dirent-name
                              (constantly :path) (data-lens:∘
                                                  (prepend-path-component path)
                                                  'sb-posix:dirent-name)
                              (constantly :inode) 'sb-posix:dirent-ino))
                            :directory
                            (decode-permissions (sb-posix:stat-mode stat)))
                    (values (handle-non-directory path)
                            (stat-file-type stat)
                            (decode-permissions (sb-posix:stat-mode stat))))

(defun name-or-dirname (pathname)
  (or (pathname-name pathname)
      (car (last (pathname-directory pathname)))))
(defun list-path (path)
  (yason:with-output (*standard-output*)
    (let ((yason:*symbol-key-encoder* 'yason:encode-symbol-as-lowercase)
          (yason:*symbol-encoder* 'yason:encode-symbol-as-lowercase)
          (stat (sb-posix:lstat path)))
      (yason:with-object ()
        (yason:encode-object-element
         "name"
         (name-or-dirname (uiop:parse-unix-namestring path)))
        (yason:encode-object-element "path" path)
        (yason:encode-object-element "atime" (format-stat-time 'sb-posix:stat-atime
                                                               stat))
        (yason:encode-object-element "mtime" (format-stat-time 'sb-posix:stat-atime
                                                               stat))
        (yason:encode-object-element "ctime" (format-stat-time 'sb-posix:stat-atime
                                                               stat))
        (multiple-value-bind (data type permissions) (list-directory path stat)
          (yason:encode-object-element "type" type)
          (yason:encode-object-element "mode" (alexandria:alist-hash-table
                                               permissions))
          (when (eql :directory type)
            (yason:with-object-element ("children")
              (yason:with-array ()
                (loop for it in data
                      do (yason:encode-array-element
                          (alexandria:plist-hash-table it))))))))
      (terpri *standard-output*))))

           (yason:with-output (*standard-output*)
             (let ((yason:*symbol-key-encoder* 'yason:encode-symbol-as-lowercase)
                   (yason:*symbol-encoder* 'yason:encode-symbol-as-lowercase))
               (yason:with-object ()
                 (yason:encode-object-element "path" path)
                 (multiple-value-bind (data type) (list-directory path)
                   (yason:encode-object-element "type" type)
                   (when (eql :directory type)
                     (yason:with-object-element ("children")
                       (yason:with-array ()
                         (loop for it in data
                               do (yason:encode-array-element (alexandria:plist-hash-table it))))))))
               (terpri *standard-output*)))))

           (list-path path)))