(defun org-filetags-extract (content)
  "Extracts the list of tags from a #+FILETAGS: line."
  (let ((lines (uiop:split-string content :separator '(#\Newline))))
    (dolist (line lines)
      (when (uiop:string-prefix-p "#+FILETAGS:" (string-trim '(#\Space) line))
        (let ((tag-str (string-trim " :" (subseq (string-trim '(#\Space) line) 10))))
          (return-from org-filetags-extract
            (mapcar (lambda (tag) (format nil ":~a" (string-trim '(#\Space) tag)))
                    (uiop:split-string tag-str :separator '(#\space #\tab))))))))
  nil)

(defun org-privacy-tag-p (tags-list)
  "Returns T if any tag in TAGS-LIST matches bouncer-privacy-tags."
  (let ((privacy-tags (symbol-value (find-symbol "BOUNCER-PRIVACY-TAGS" :passepartout))))
    (when (and tags-list privacy-tags)
      (some (lambda (tag)
              (some (lambda (private-tag)
                      (string-equal (string-trim '(#\: #\space) tag)
                                    (string-trim '(#\: #\space) private-tag))
                    privacy-tags))
            tags-list)))))

(defun org-privacy-strip (content)
  "Removes Org headlines whose :TAGS: property contains a privacy-filtered tag.
Returns the filtered content as a string."
  (let* ((lines (uiop:split-string content :separator '(#\Newline)))
         (result-lines nil)
         (skip-depth nil)
         (current-tags nil)
         (in-properties nil))
    (dolist (line lines)
      (cond
        (skip-depth
         ;; We're inside a skipped subtree
         (when (and (uiop:string-prefix-p "*" (string-trim '(#\Space) line))
                    (<= (length (string-trim '(#\Space) line)) skip-depth))
           (setf skip-depth nil)))
        ((uiop:string-prefix-p ":PROPERTIES:" (string-trim '(#\Space) line))
         (setf in-properties t)
         (push line result-lines))
        ((uiop:string-prefix-p ":END:" (string-trim '(#\Space) line))
         (setf in-properties nil)
         (when current-tags
           (when (org-privacy-tag-p (reverse current-tags))
             (setf skip-depth
                   (length (car (last result-lines
                                      (1+ (position-if
                                           (lambda (l)
                                             (uiop:string-prefix-p "*" (string-trim '(#\Space) l)))
                                           (reverse result-lines))))))))
           (setf current-tags nil))
         (push line result-lines))
        ((and in-properties (uiop:string-prefix-p ":TAGS:" (string-trim '(#\Space) line)))
         (let ((tag-val (string-trim '(#\Space) (subseq (string-trim '(#\Space) line) 6))))
           (setf current-tags (uiop:split-string tag-val :separator '(#\space #\tab))))
         (push line result-lines))
        (t
         (push line result-lines))))
    (format nil "~{~a~%~}" (nreverse result-lines))))

(defun org-read-file (filepath)
  "Reads an Org file into a string, applying privacy filtering."
  (let* ((raw (uiop:read-file-string filepath))
         (filetags (org-filetags-extract raw)))
    (if (org-privacy-tag-p filetags)
        (progn
          (harness-log "UTILS-ORG: Blocked read of ~a — file-level privacy tag(s) ~a" filepath filetags)
          nil)
        (org-privacy-strip raw))))

(defun org-write-file (filepath content)
  "Writes content to an Org file."
  (uiop:with-output-file (s filepath :if-exists :supersede)
    (format s "~a" content)))

(defun org-id-generate ()
  "Generates a new UUID for an Org node."
  (string-downcase (format nil "~a" (uuid:make-v4-uuid))))

(defun org-id-format (id)
  "Ensures the ID has the 'id:' prefix."
  (if (uiop:string-prefix-p "id:" id)
      id
      (format nil "id:~a" id)))

(defun org-property-set (ast target-id property value)
  "Recursively sets a property on a headline with a matching ID in the AST."
  (let ((type (getf ast :type))
        (props (getf ast :properties))
        (contents (getf ast :contents)))
    (when (and (eq type :HEADLINE) (string= (getf props :ID) target-id))
      (setf (getf (getf ast :properties) property) value)
      (return-from org-property-set t))
    (dolist (child contents)
      (when (listp child)
        (when (org-property-set child target-id property value)
          (return-from org-property-set t)))))
  nil)

(defun org-todo-set (ast target-id status)
  "Sets the TODO status of a headline in the AST."
  (org-property-set ast target-id :TODO status))

(defun org-headline-add (ast parent-id title)
  "Adds a new headline as a child of the parent-id in the AST."
  (let* ((type (getf ast :type))
         (props (getf ast :properties))
         (id (getf props :ID))
         (contents (getf ast :contents)))
    (when (and (eq type :HEADLINE) (string= id parent-id))
      (let ((new-node (list :type :HEADLINE
                           :properties (list :ID (org-id-format (org-id-generate))
                                            :TITLE title)
                           :contents nil)))
        (setf (getf ast :contents) (append contents (list new-node)))
        (return-from org-headline-add t)))
    (dolist (child contents)
      (when (listp child)
        (when (org-headline-add child parent-id title)
          (return-from org-headline-add t)))))
  nil)

(defun org-headline-find-by-id (ast id)
  "Finds a headline by its ID in the AST."
  (let ((props (getf ast :properties)))
    (when (string= (getf props :ID) id)
      (return-from org-headline-find-by-id ast))
    (dolist (child (getf ast :contents))
      (when (listp child)
        (let ((found (org-headline-find-by-id child id)))
          (when found (return-from org-headline-find-by-id found)))))
    nil))

(defun org-headline-find-by-title (ast title)
  "Finds a headline by its title in the AST."
  (let ((props (getf ast :properties)))
    (when (string-equal (getf props :TITLE) title)
      (return-from org-headline-find-by-title ast))
    (dolist (child (getf ast :contents))
      (when (listp child)
        (let ((found (org-headline-find-by-title child title)))
          (when found (return-from org-headline-find-by-title found)))))
    nil))

(defun org-modify (filepath id changes)
  "Placeholder for Emacs-driven modification of a specific node."
  (declare (ignore changes))
  (harness-log "UTILS-ORG: Applying changes to ~a in ~a" id filepath)
  t)

(defun org-ast-render (ast)
  "Minimal converter from AST back to Org text (Placeholder)."
  (declare (ignore ast))
  "* TITLE (Placeholder)")

(defskill :passepartout-programming-org
  :priority 100
  :trigger (lambda (ctx) (declare (ignore ctx)) nil))

(defpackage :passepartout-utils-org-tests
  (:use :cl :fiveam :passepartout)
  (:export #:utils-org-suite))

(in-package :passepartout-utils-org-tests)

(def-suite utils-org-suite
  :description "Tests for Utils Org skill.")

(in-suite utils-org-suite)

(test id-generation
  (let ((id1 (org-id-generate))
        (id2 (org-id-generate)))
    (is (plusp (length id1)))
    (is (not (string= id1 id2)))))

(test id-format
  (let ((formatted (org-id-format "abc12345")))
    (is (search "id:" formatted))))

(test property-setter
  (let ((ast (list :type :HEADLINE
                  :properties (list :ID "id:test123" :TITLE "Test")
                  :contents nil)))
    (org-property-set ast "id:test123" :STATUS "ACTIVE")
    (is (string= (getf (getf ast :properties) :STATUS) "ACTIVE"))))

(test todo-setter
  (let ((ast (list :type :HEADLINE
                  :properties (list :ID "id:todo001" :TITLE "Task")
                  :contents nil)))
    (org-todo-set ast "id:todo001" "DONE")
    (is (string= (getf (getf ast :properties) :TODO) "DONE"))))