;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; Base: 10 -*-
(declaim (optimize (speed 0) (safety 3) (debug 3)))

(in-package #:music-dispensary)

;; ========================================================================== ;;

(defclass file-browser ()
  ((document-root :initarg :document-root
                  :initform nil
                  :accessor document-root
                  :documentation "The highest level directory that the
user is allowed to navigate to. Ends in a slash.")
   (relative-path :initarg :relative-path
                  :initform nil
                  :accessor relative-path
                  :documentation "Add this to `document-root'
to get to the current directory, whose contents are to be
displayed.")
   (mime-extensions :initarg :mime-extensions
                    :initform nil
                    :accessor mime-extensions
                    :documentation "A list of MIME file extensions
that, if not `nil', will limit directory listings to show only those
files that contain these extensions.")
   (nodes :initarg :nodes
          :initform ()
          :accessor nodes
          :documentation "The nodes of the current directory. A list
of dotted pairs in the form '(([:directory|:file|:symlink] . <node-name>))."))
   (:documentation "Used for directory-browsing. Keeps track of
directory-navigating state in the `user-session'."))

(defmethod absolute-path ((file-browser file-browser))
  (ppcre:regex-replace-all "//"
                           (format nil "~a/~a" (or (document-root file-browser) "") (or (relative-path file-browser) ""))
                           "/"))

(defmethod update-relative-path ((file-browser file-browser) node)
  (when (not (null-or-empty-p node))
    (if (equal node "..")
        (if (null-or-empty-p (relative-path file-browser))
            (setf (relative-path file-browser) "")
            (setf (relative-path file-browser) (let ((path-list (nreverse (remove-if 'null-or-empty-p (ppcre:split "/" (relative-path file-browser)))))
                                                     (new-path ""))
                                                 (pop path-list)
                                                 (loop for path-part in (nreverse path-list) do
                                                      (setf new-path (format nil "~a~a/" new-path path-part)))
                                                 (ppcre:regex-replace-all "/$" new-path ""))))
        (if (null-or-empty-p (relative-path file-browser))
            (setf (relative-path file-browser) node)
            (setf (relative-path file-browser) (format nil "~a/~a" (relative-path file-browser) node))))))

(defmethod directory-list ((file-browser file-browser))
  (labels ((finder (type)
             (remove-if 'null (mapcar (lambda (line)
                                        (when (not (or (equal line ".")))
                                          (let ((item (ppcre:regex-replace-all "\\./" line "")))
                                            (when (or (null (mime-extensions file-browser))
                                                      (equal type "d")
                                                      (remove-if-not (lambda (x)
                                                                       (match-it (format nil "~a$" x) item))
                                                                     (mime-extensions file-browser)))
                                              (cons (cond ((equal type "d") :directory)
                                                          ((equal type "f") :file)
                                                          ((equal type "l") :symlink))
                                                    item)))))
                                      (shell-wrapper (format nil
                                                             "pushd '~a' >/dev/null ; find -maxdepth 1 -type ~a | sort ; popd >/dev/null"
                                                             (absolute-path file-browser)
                                                             type))))))
    (setf (nodes file-browser) (remove-if 'null (append `((:directory . "..")) (finder "d") (finder "f") (finder "l"))))))