(require 'cl-lib)

(require 'mwheel)

(require 'pixel-scroll)

(require 'subr-x)

(require 'ai-code-session-link)

(declare-function ai-code-session-link--linkify-inhibited-p

"ai-code-session-link" (&optional buffer))

(declare-function ai-code-session-link--recent-output-tail-width

"ai-code-session-link" (output))

(declare-function ai-code-session-link--text-may-contain-image-reference-p

"ai-code-session-link" (text))

(declare-function ai-code-session-link--strict-image-candidate-bounds

"ai-code-session-link" (match-start match-end))

(declare-function ai-code-session-link--strict-image-candidates

"ai-code-session-link" (start end link-text))

(declare-function ai-code-session-link--image-preview-existing-local-file

"ai-code-session-link" (link-text))

(declare-function ai-code-session-link--image-preview-data

"ai-code-session-link" (file))

(declare-function ai-code-session-link--image-preview-file-signature

"ai-code-session-link" (file))

(declare-function ai-code-session-link--normalize-file

"ai-code-session-link" (filename))

(declare-function ai-code-session-link--linkify-strict-image-preview-region

"ai-code-session-link" (start end))

(declare-function ai-code-session-link--delete-image-preview-overlay

"ai-code-session-link" (overlay))

(declare-function ghostel--redraw-now "ghostel" (buffer &optional force))

(declare-function ghostel--viewport-start "ghostel" ())

(declare-function ultra-scroll "ultra-scroll" (event &optional arg))

(declare-function ultra-scroll-mac "ultra-scroll" (event &optional arg))

(defvar ai-code-session-link-image-preview-position-function)

(defvar ai-code-session-link-image-preview-source-function)

(defvar ai-code-session-link-image-preview-transaction-function)

(defvar ai-code-session-link--image-extension-regexp)

(defvar ai-code-backends-infra--session-directory)

(defvar ai-code-backends-infra--session-terminal-backend)

(defvar ghostel-inhibit-anchor-functions)

(defvar ghostel--cursor-char-pos)

(defconst ai-code-ghostel-image-preview--captured-source-limit 8

"Maximum number of temporary image sources retained per session.")

(defconst ai-code-ghostel-image-preview--output-tail-limit 8192

"Maximum raw process-output characters retained for split image paths.")

(defconst ai-code-ghostel-image-preview--output-probe-limit 4096

"Maximum recent output characters checked for a new image clue.")

(define-obsolete-variable-alias

'ai-code-backends-infra-ghostel-visible-image-linkify-delays

'ai-code-ghostel-image-preview-linkify-delays

"1.90")

(defcustom ai-code-ghostel-image-preview-linkify-delays '(0.15 0.5)

"Delays used to scan a newly displayed Ghostel viewport for previews."

:type '(repeat number)

:group 'ai-code-backends-infra)

(define-obsolete-variable-alias

'ai-code-backends-infra-ghostel-visible-image-linkify-max-chars

'ai-code-ghostel-image-preview-linkify-max-chars

"1.90")

(defcustom ai-code-ghostel-image-preview-linkify-max-chars 20000

"Fallback scan size when Ghostel or Emacs cannot report a viewport."

:type 'integer

:group 'ai-code-backends-infra)

(define-obsolete-variable-alias

'ai-code-backends-infra-ghostel-scroll-image-linkify-delay

'ai-code-ghostel-image-preview-scroll-linkify-delay

"1.90")

(defcustom ai-code-ghostel-image-preview-scroll-linkify-delay 0.08

"Debounce delay before scanning a Ghostel viewport after scrolling."

:type 'number

:group 'ai-code-backends-infra)

(defcustom ai-code-ghostel-image-preview-prefer-ultra-scroll t

"Use `ultra-scroll' for wheel events over local image previews.

:type 'boolean

:group 'ai-code-backends-infra)

(defvar-local ai-code-ghostel-image-preview--user-scrolled-windows nil

"Windows whose user explicitly entered terminal scrollback.")

(defvar-local ai-code-ghostel-image-preview--linkify-timers nil

"Alist of windows and their pending visible-preview scan timers.")

(defvar-local ai-code-ghostel-image-preview--transaction-active nil

"Non-nil while this buffer is reconciling an image-preview transaction.")

(defvar-local ai-code-ghostel-image-preview--captured-sources nil

"Recent temporary image source plists captured from process output.")

(defvar-local ai-code-ghostel-image-preview--output-tail ""

"Bounded process-output tail used to reconstruct split image references.")

(defvar ai-code-ghostel-image-preview-mode-map

(let ((map (make-sparse-keymap)))

(define-key map [remap pixel-scroll-precision]

#'ai-code-ghostel-image-preview-scroll)

map)

"Keymap used while Ghostel image-preview lifecycle management is active.")

(define-minor-mode ai-code-ghostel-image-preview-mode

"Manage local image previews as one Ghostel render lifecycle."

:init-value nil

:lighter nil

:keymap ai-code-ghostel-image-preview-mode-map)

(defun ai-code-ghostel-image-preview--visible-region (window)

"Return the bounded visible buffer region for WINDOW."

(when (and (window-live-p window)

(buffer-live-p (window-buffer window)))

(with-current-buffer (window-buffer window)

(when ai-code-ghostel-image-preview-mode

(save-excursion

(save-restriction

(widen)

(let* ((start

(save-excursion

(goto-char (max (point-min) (window-start window)))

(forward-line -1)

(line-beginning-position)))

(window-end-position

(ignore-errors (window-end window t)))

(end

(min (point-max)

(or window-end-position

(+ start

ai-code-ghostel-image-preview-linkify-max-chars)))))

(goto-char start)

(setq start (line-beginning-position))

(goto-char end)

(setq end (min (point-max) (line-end-position)))

(when (and (not window-end-position)

(> (- end start)

ai-code-ghostel-image-preview-linkify-max-chars))

(setq end

(min (point-max)

(+ start

ai-code-ghostel-image-preview-linkify-max-chars))))

(and (< start end) (cons start end)))))))))

(defun ai-code-ghostel-image-preview--window-has-preview-p (window)

"Return non-nil when WINDOW intersects a local image preview."

(when-let* ((region

(ai-code-ghostel-image-preview--visible-region window)))

(with-current-buffer (window-buffer window)

(cl-some

(lambda (overlay)

(overlay-get overlay 'ai-code-session-image-preview))

(ai-code-ghostel-image-preview--overlays-in-region

(car region) (cdr region))))))

(defun ai-code-ghostel-image-preview--window-has-kitty-image-p (window)

"Return non-nil when WINDOW intersects a native Ghostel Kitty image."

(when-let* ((region

(ai-code-ghostel-image-preview--visible-region window)))

(with-current-buffer (window-buffer window)

(let ((start (car region))

(end (cdr region)))

(or (text-property-not-all start end 'ghostel-kitty nil)

(cl-some

(lambda (overlay)

(overlay-get overlay 'ghostel-kitty))

(delete-dups

(append (overlays-in start end)

(overlays-at start)

(overlays-at end)))))))))

(defun ai-code-ghostel-image-preview--window-has-image-p (window)

"Return non-nil when WINDOW intersects a local or Kitty image."

(or (ai-code-ghostel-image-preview--window-has-preview-p window)

(ai-code-ghostel-image-preview--window-has-kitty-image-p window)))

(defun ai-code-ghostel-image-preview--event-window (event)

"Return the target window of mouse EVENT, or nil."

(let ((target (ignore-errors (posn-window (event-start event)))))

(cond

((windowp target) target)

((framep target) (frame-selected-window target)))))

(defun ai-code-ghostel-image-preview--wheel-event-p (event)

"Return non-nil when EVENT represents mouse-wheel scrolling."

(memq (ignore-errors (event-basic-type event))

'(wheel-up wheel-down mouse-4 mouse-5)))

(defun ai-code-ghostel-image-preview--preview-at-window-start-p (window)

"Return non-nil when WINDOW starts inside a local preview overlay."

(when (and (window-live-p window)

(buffer-live-p (window-buffer window)))

(with-current-buffer (window-buffer window)

(cl-some

(lambda (overlay)

(overlay-get overlay 'ai-code-session-image-preview))

(overlays-at (window-start window))))))

(defun ai-code-ghostel-image-preview--clamp-up-event (event window)

"Clamp upward EVENT to WINDOW's partially hidden preview top."

(let* ((delta-pair (nth 4 event))

(delta (and (consp delta-pair) (cdr delta-pair)))

(vscroll (and (window-live-p window)

(window-vscroll window t))))

(if (and (numberp delta)

(> delta 0)

(numberp vscroll)

(> vscroll 0)

(> delta vscroll)

(ai-code-ghostel-image-preview--preview-at-window-start-p

window))

(let ((clamped (copy-tree event)))

(setcdr (nth 4 clamped) vscroll)

clamped)

event)))

(defun ai-code-ghostel-image-preview--note-user-scroll (window)

"Record that WINDOW is scrolling through image content."

(when (and (window-live-p window)

(ai-code-ghostel-image-preview--window-has-image-p window))

(with-current-buffer (window-buffer window)

(cl-pushnew window ai-code-ghostel-image-preview--user-scrolled-windows

:test #'eq))))

(defun ai-code-ghostel-image-preview--clear-user-scroll-at-live-end (window)

"Clear WINDOW's scrollback record after it visibly reaches live output."

(when (and (window-live-p window)

(buffer-live-p (window-buffer window)))

(with-current-buffer (window-buffer window)

(when-let* ((end (ignore-errors (window-end window t)))

((>= end (point-max)))

((not

(ai-code-ghostel-image-preview--window-has-image-p

window))))

(setq ai-code-ghostel-image-preview--user-scrolled-windows

(delq window

ai-code-ghostel-image-preview--user-scrolled-windows))))))

(defun ai-code-ghostel-image-preview--user-scrolled-window-p (window)

"Return non-nil when WINDOW entered image scrollback by mouse wheel."

(when (and (window-live-p window)

(buffer-live-p (window-buffer window)))

(with-current-buffer (window-buffer window)

(setq ai-code-ghostel-image-preview--user-scrolled-windows

(cl-remove-if-not

(lambda (candidate)

(and (window-live-p candidate)

(eq (window-buffer candidate) (current-buffer))))

ai-code-ghostel-image-preview--user-scrolled-windows))

(memq window ai-code-ghostel-image-preview--user-scrolled-windows))))

(defun ai-code-ghostel-image-preview--input-row-bounds ()

"Return the bounds of Ghostel's live cursor row, or nil."

(when (and (boundp 'ghostel--cursor-char-pos)

(integer-or-marker-p ghostel--cursor-char-pos))

(save-excursion

(goto-char (max (point-min)

(min (point-max) ghostel--cursor-char-pos)))

(cons (line-beginning-position) (line-end-position)))))

(defun ai-code-ghostel-image-preview--position-allowed-p (start _end)

"Return non-nil when an image preview may begin at START."

(if-let* ((input-bounds

(ai-code-ghostel-image-preview--input-row-bounds)))

(not (<= (car input-bounds) start (cdr input-bounds)))

t))

(defun ai-code-ghostel-image-preview--overlays-in-region (start end)

"Return image preview overlays touching START through END."

(cl-remove-if-not

(lambda (overlay)

(overlay-get overlay 'ai-code-session-image-preview))

(delete-dups

(append (overlays-in start end)

(overlays-at start)

(overlays-at end)))))

(defun ai-code-ghostel-image-preview--render-region ()

"Return the terminal render region affected by a Ghostel redraw."

(let* ((end (point-max))

(viewport-start

(and (fboundp 'ghostel--viewport-start)

(ignore-errors (ghostel--viewport-start))))

(start

(if (integer-or-marker-p viewport-start)

(max (point-min) (min end viewport-start))

(max (point-min)

(- end ai-code-ghostel-image-preview-linkify-max-chars)))))

(save-excursion

(goto-char start)

(setq start (line-beginning-position))

(cons start end))))

(defun ai-code-ghostel-image-preview--layout-regions ()

"Return merged terminal and Emacs-visible image-layout regions."

(let ((regions

(cons

(ai-code-ghostel-image-preview--render-region)

(delq nil

(mapcar

#'ai-code-ghostel-image-preview--visible-region

(get-buffer-window-list (current-buffer) nil t)))))

merged)

(dolist (region (sort regions (lambda (left right)

(< (car left) (car right)))))

(if (and merged (<= (car region) (cdr (car merged))))

(setcdr (car merged) (max (cdr (car merged)) (cdr region)))

(push (cons (car region) (cdr region)) merged)))

(nreverse merged)))

(defun ai-code-ghostel-image-preview--capture-preview-state ()

"Capture semantic preview anchors before Ghostel rewrites terminal rows."

(let ((previews

(delete-dups

(apply

#'append

(mapcar

(lambda (region)

(ai-code-ghostel-image-preview--overlays-in-region

(car region) (cdr region)))

(ai-code-ghostel-image-preview--layout-regions))))))

(list

:signatures

(sort

(mapcar

(lambda (overlay)

(list (overlay-start overlay)

(overlay-end overlay)

(overlay-get overlay 'ai-code-session-image-display-end)

(overlay-get overlay 'ai-code-session-image-file)

(overlay-get overlay 'ai-code-session-image-file-signature)

(overlay-get overlay 'ai-code-session-image-display-text)

(overlay-get overlay 'before-string)

(overlay-get overlay 'ai-code-session-image-vertical-margin)

(overlay-get overlay 'ai-code-session-image-render-context)))

previews)

(lambda (left right)

(< (car left) (car right))))

:snapshots

(mapcar

(lambda (overlay)

(list :overlay overlay

:start (overlay-start overlay)

:end (overlay-end overlay)))

previews))))

(defun ai-code-ghostel-image-preview--preview-layout-changed-p (state)

"Return non-nil when final preview layout differs from captured STATE."

(not

(equal

(plist-get state :signatures)

(plist-get

(ai-code-ghostel-image-preview--capture-preview-state)

:signatures))))

(defun ai-code-ghostel-image-preview--preview-changed-p (snapshot)

"Return non-nil when the overlay in SNAPSHOT changed its anchor."

(let ((overlay (plist-get snapshot :overlay)))

(or (not (overlay-buffer overlay))

(/= (overlay-start overlay) (plist-get snapshot :start))

(/= (overlay-end overlay) (plist-get snapshot :end)))))

(defun ai-code-ghostel-image-preview--reconcile-preview-state (state)

"Reconcile previews from pre-render STATE against final terminal text."

(dolist (snapshot (plist-get state :snapshots))

(when (ai-code-ghostel-image-preview--preview-changed-p snapshot)

(ai-code-session-link--delete-image-preview-overlay

(plist-get snapshot :overlay)))))

(defun ai-code-ghostel-image-preview--linkify-region (start end)

"Rebuild strict local image previews between START and END."

(when (and (< start end)

(not (ai-code-session-link--linkify-inhibited-p)))

(ai-code-session-link--linkify-strict-image-preview-region start end)))

(defun ai-code-ghostel-image-preview--plain-output (output)

"Return OUTPUT without terminal controls, preserving hard line breaks."

(let* ((text (or output ""))

(text (replace-regexp-in-string

"\x1b\\][^\x07\x1b]*\\(?:\x07\\|\x1b\\\\\\)" "" text))

(text (replace-regexp-in-string

"\x1b\\[[0-9;?]*[ -/]*[@-~]" "" text)))

(replace-regexp-in-string "[\x00-\x09\x0b-\x1f\x7f]" "" text)))

(defun ai-code-ghostel-image-preview--remember-source

(file data signature)

"Remember captured FILE with DATA and SIGNATURE in the current session."

(let ((source (list :file (expand-file-name file)

:data data

:signature signature)))

(setq ai-code-ghostel-image-preview--captured-sources

(cons

source

(cl-remove-if

(lambda (entry)

(equal (plist-get entry :file) (plist-get source :file)))

ai-code-ghostel-image-preview--captured-sources)))

(when (> (length ai-code-ghostel-image-preview--captured-sources)

ai-code-ghostel-image-preview--captured-source-limit)

(setcdr

(nthcdr

(1- ai-code-ghostel-image-preview--captured-source-limit)

ai-code-ghostel-image-preview--captured-sources)

nil))))

(defun ai-code-ghostel-image-preview--capture-sources-in-tail ()

"Capture readable local image sources from the current output tail."

(let ((source-buffer (current-buffer))

(session-directory ai-code-backends-infra--session-directory)

(tail ai-code-ghostel-image-preview--output-tail))

(with-temp-buffer

(setq default-directory

(file-name-as-directory

(expand-file-name (or session-directory default-directory))))

(setq-local ai-code-backends-infra--session-directory session-directory)

(setq-local ai-code-backends-infra--session-terminal-backend 'ghostel)

(insert tail)

(let ((case-fold-search t)

(extension-regexp

(concat "\\.\\(?:"

ai-code-session-link--image-extension-regexp

"\\)")))

(goto-char (point-min))

(while (re-search-forward extension-regexp nil t)

(when-let* ((bounds

(ai-code-session-link--strict-image-candidate-bounds

(match-beginning 0) (match-end 0)))

(link-text

(buffer-substring-no-properties

(car bounds) (cdr bounds))))

(catch 'captured

(dolist (candidate

(ai-code-session-link--strict-image-candidates

(car bounds) (cdr bounds) link-text))

(when-let* ((candidate-text

(plist-get candidate :link-text))

(file

(ai-code-session-link--image-preview-existing-local-file

candidate-text))

(signature

(ai-code-session-link--image-preview-file-signature

file)))

(let ((existing

(with-current-buffer source-buffer

(cl-find-if

(lambda (source)

(equal (plist-get source :file)

(expand-file-name file)))

ai-code-ghostel-image-preview--captured-sources))))

(if (equal (plist-get existing :signature) signature)

(throw 'captured t)

(when-let* ((data

(ignore-errors

(ai-code-session-link--image-preview-data

file))))

(with-current-buffer source-buffer

(ai-code-ghostel-image-preview--remember-source

file data signature))

(throw 'captured t)))))))))))))

(defun ai-code-ghostel-image-preview--capture-output-sources (output)

"Capture local image bytes referenced across recent process OUTPUT chunks."

(let* ((output (or output ""))

(output-start

(max 0

(- (length output)

ai-code-ghostel-image-preview--output-tail-limit)))

(old-tail ai-code-ghostel-image-preview--output-tail)

(plain-output

(ai-code-ghostel-image-preview--plain-output

(substring output output-start)))

(probe

(concat

(substring old-tail (max 0 (- (length old-tail) 64)))

(substring plain-output

(max 0

(- (length plain-output)

ai-code-ghostel-image-preview--output-probe-limit))))))

(setq ai-code-ghostel-image-preview--output-tail

(concat old-tail plain-output))

(when (> (length ai-code-ghostel-image-preview--output-tail)

ai-code-ghostel-image-preview--output-tail-limit)

(setq ai-code-ghostel-image-preview--output-tail

(substring ai-code-ghostel-image-preview--output-tail

(- ai-code-ghostel-image-preview--output-tail-limit))))

(when (ai-code-session-link--text-may-contain-image-reference-p probe)

(ai-code-ghostel-image-preview--capture-sources-in-tail)

t)))

(defun ai-code-ghostel-image-preview--cached-source (link-text)

"Return captured source bytes matching rendered LINK-TEXT, or nil."

(when-let* ((normalized

(ai-code-session-link--normalize-file link-text))

((not (file-remote-p normalized)))

(root

(file-name-as-directory

(expand-file-name

(or ai-code-backends-infra--session-directory

default-directory))))

(candidate

(expand-file-name normalized root)))

(cl-find-if

(lambda (source)

(equal (plist-get source :file) candidate))

ai-code-ghostel-image-preview--captured-sources)))

(defun ai-code-ghostel-image-preview-capture-output (output)

"Capture temporary images from OUTPUT and schedule post-redraw recovery."

(when (and ai-code-ghostel-image-preview-mode

(ai-code-session-link--image-preview-enabled-p))

(let* ((output (or output ""))

(tail-width

(min ai-code-ghostel-image-preview--output-probe-limit

(ai-code-session-link--recent-output-tail-width output)))

(output-tail

(substring output (max 0 (- (length output) tail-width))))

(image-output-p

(or (ai-code-ghostel-image-preview--capture-output-sources output)

(ai-code-session-link--text-may-contain-image-reference-p

output-tail))))

(when image-output-p

(save-restriction

(widen)

(let* ((end (point-max))

(start (max (point-min) (- end tail-width))))

(save-excursion

(goto-char start)

(ai-code-ghostel-image-preview--linkify-region

(line-beginning-position) end))))

;; Ghostel's process filter updates its terminal model immediately but

;; materializes that model in the Emacs buffer on a later redraw. The

;; first scan can therefore see either stale text or the live cursor

;; row, where previews are deliberately suppressed. Retry against

;; the visible post-redraw buffer so a completed output path is not

;; stranded as a text-only link after the cursor moves to the input.

(ai-code-ghostel-image-preview-schedule-buffer

(current-buffer))))))

(defun ai-code-ghostel-image-preview--refresh-render-region ()

"Rebuild image layout in final terminal and Emacs-visible regions."

(dolist (region (ai-code-ghostel-image-preview--layout-regions))

(ai-code-ghostel-image-preview--linkify-region

(car region) (cdr region))))

(defun ai-code-ghostel-image-preview--window-pixel-anchor-state (window)

"Return WINDOW's pixel follow state as `following' or `preserve'."

(let* ((body-height (window-body-height window t))

(line-height (with-selected-window window (default-line-height)))

(vscroll (max 0 (or (window-vscroll window t) 0)))

(limit (and (> body-height 0) (> line-height 0)

(+ body-height line-height vscroll)))

(size

(and limit

(ignore-errors

(window-text-pixel-size

window (window-start window) (point-max) nil (1+ limit))))))

(if (and (consp size)

(numberp (cdr size))

(<= (cdr size) limit))

'following

'preserve)))

(defun ai-code-ghostel-image-preview--window-at-live-cursor-p (window)

"Return non-nil when WINDOW point tracks Ghostel's live cursor."

(when (and (window-live-p window)

(boundp 'ghostel--cursor-char-pos)

(integer-or-marker-p ghostel--cursor-char-pos))

(let ((cursor (if (markerp ghostel--cursor-char-pos)

(marker-position ghostel--cursor-char-pos)

ghostel--cursor-char-pos)))

(and cursor

(= (window-point window)

(max (point-min) (min (point-max) cursor)))))))

(defun ai-code-ghostel-image-preview--capture-window-state (window)

"Capture semantic and pixel state for WINDOW."

(let ((intent

(cond

((memq window ai-code-ghostel-image-preview--user-scrolled-windows)

'user-scroll)

((ai-code-ghostel-image-preview--window-at-live-cursor-p window)

'following)

(t

(ai-code-ghostel-image-preview--window-pixel-anchor-state window)))))

(list :window window

:start (copy-marker (window-start window))

:point (copy-marker (window-point window))

:vscroll (window-vscroll window t)

;; Only following windows use this extent check. Avoid traversing

;; a large scrollback tail for a window the user asked us to freeze.

:tail-lines (and (eq intent 'following)

(count-lines (window-start window) (point-max)))

:intent intent)))

(defun ai-code-ghostel-image-preview--set-window-vscroll

(window vscroll)

"Set WINDOW pixel VSCROLL while preserving it when Emacs supports that."

(let ((max-args (cdr (subr-arity (symbol-function 'set-window-vscroll)))))

(if (or (eq max-args 'many)

(and (integerp max-args) (>= max-args 4)))

(set-window-vscroll window vscroll t t)

(set-window-vscroll window vscroll t))))

(defun ai-code-ghostel-image-preview--anchor-window (window)

"Anchor WINDOW to the final display geometry at live terminal output."

(let* ((target (point-max))

(body-height (window-body-height window t))

(max-args

(cdr (subr-arity (symbol-function 'window-text-pixel-size))))

(size

(and (> body-height 0)

(integerp max-args)

(>= max-args 7)

(ignore-errors

(window-text-pixel-size

window (cons target (- body-height)) target nil nil))))

(start (and (consp size) (nth 2 size))))

(if (integer-or-marker-p start)

(progn

(set-window-start window start)

(ai-code-ghostel-image-preview--set-window-vscroll

window (max 0 (- (nth 1 size) body-height))))

(with-selected-window window

(goto-char target)

(forward-line (- (floor (window-screen-lines))))

(set-window-start window (point))

(ai-code-ghostel-image-preview--set-window-vscroll window 0)))))

(defun ai-code-ghostel-image-preview--restore-exact-window-state (state)

"Restore the exact viewport captured in window STATE."

(let ((window (plist-get state :window)))

(when-let* ((start (marker-position (plist-get state :start))))

(set-window-start window start))

(ai-code-ghostel-image-preview--set-window-vscroll

window (or (plist-get state :vscroll) 0))))

(defun ai-code-ghostel-image-preview--restore-window-state

(state layout-changed)

"Restore a window from transaction STATE.

(let ((window (plist-get state :window)))

(when (and (window-live-p window)

(eq (window-buffer window) (current-buffer)))

(pcase (plist-get state :intent)

('following

(if (or layout-changed

(/= (plist-get state :tail-lines)

(count-lines

(or (marker-position (plist-get state :start))

(point-min))

(point-max))))

(ai-code-ghostel-image-preview--anchor-window window)

;; In-place terminal animation did not change vertical extent.

;; Re-anchoring a jumbo display line here can round to a slightly

;; different pixel offset and create the visible 2-3px shimmer.

(ai-code-ghostel-image-preview--restore-exact-window-state state)))

(_

(ai-code-ghostel-image-preview--restore-exact-window-state state)))

;; Set the point after geometry restoration because the pixel-anchor

;; fallback temporarily moves point while calculating WINDOW's start.

(when-let* ((point (marker-position (plist-get state :point))))

(set-window-point window point)))))

(defun ai-code-ghostel-image-preview--capture-final-window-points (states)

"Retarget window point markers in STATES to their current positions."

(dolist (state states)

(let ((window (plist-get state :window)))

(when (and (window-live-p window)

(eq (window-buffer window) (current-buffer)))

(when-let* ((marker (plist-get state :point))

((markerp marker)))

(set-marker marker (window-point window)))))))

(defun ai-code-ghostel-image-preview--release-window-state (state)

"Release marker resources held by window transaction STATE."

(dolist (key '(:start :point))

(when-let* ((marker (plist-get state key))

((markerp marker)))

(set-marker marker nil))))

(defun ai-code-ghostel-image-preview--call-atomic

(buffer function &optional refresh keep-final-window-points)

"Call FUNCTION as BUFFER's single image-layout transaction.

(if (not (buffer-live-p buffer))

(funcall function)

(with-current-buffer buffer

(if ai-code-ghostel-image-preview--transaction-active

(funcall function)

(let* ((ai-code-ghostel-image-preview--transaction-active t)

(preview-state

(ai-code-ghostel-image-preview--capture-preview-state))

(window-states

(mapcar #'ai-code-ghostel-image-preview--capture-window-state

(get-buffer-window-list buffer nil t)))

(inhibit-redisplay t)

completed layout-changed result)

(unwind-protect

(progn

(setq result (funcall function))

(when keep-final-window-points

(ai-code-ghostel-image-preview--capture-final-window-points

window-states))

(setq completed t))

(when completed

(with-demoted-errors "AI Code image reconciliation error: %S"

(when preview-state

(ai-code-ghostel-image-preview--reconcile-preview-state

preview-state))

(when refresh

(ai-code-ghostel-image-preview--refresh-render-region))

(setq layout-changed

(ai-code-ghostel-image-preview--preview-layout-changed-p

preview-state))))

(dolist (state window-states)

(unwind-protect

(with-demoted-errors "AI Code image window restore error: %S"

(ai-code-ghostel-image-preview--restore-window-state

state layout-changed))

(ai-code-ghostel-image-preview--release-window-state state))))

result)))))

(defun ai-code-ghostel-image-preview--call-transaction

(_start _end function)

"Call FUNCTION inside the current preview transaction."

(ai-code-ghostel-image-preview--call-atomic

(current-buffer) function))

(defun ai-code-ghostel-image-preview--redraw-now-around

(original buffer &rest args)

"Call ORIGINAL for BUFFER inside one atomic image transaction.

(if (and (buffer-live-p buffer)

(buffer-local-value 'ai-code-ghostel-image-preview-mode buffer))

(ai-code-ghostel-image-preview--call-atomic

buffer (lambda () (apply original buffer args)) t t)

(apply original buffer args)))

(defun ai-code-ghostel-image-preview--install-redraw-advice ()

"Install the single Ghostel private redraw adapter."

(when (and (fboundp 'ghostel--redraw-now)

(not

(advice-member-p

#'ai-code-ghostel-image-preview--redraw-now-around

'ghostel--redraw-now)))

(advice-add 'ghostel--redraw-now :around

#'ai-code-ghostel-image-preview--redraw-now-around)))

(defun ai-code-ghostel-image-preview--inhibit-anchor-p (window force)

"Return non-nil when Ghostel should not anchor WINDOW.

(if force

(progn

(setq ai-code-ghostel-image-preview--user-scrolled-windows

(delq window

ai-code-ghostel-image-preview--user-scrolled-windows))

nil)

(ai-code-ghostel-image-preview--user-scrolled-window-p window)))

(defun ai-code-ghostel-image-preview--cancel-linkify-timers (window)

"Cancel pending visible-preview scan timers for WINDOW."

(when-let* ((entry

(assq window ai-code-ghostel-image-preview--linkify-timers)))

(dolist (timer (cdr entry))

(when (timerp timer)

(cancel-timer timer)))

(setq ai-code-ghostel-image-preview--linkify-timers

(assq-delete-all

window ai-code-ghostel-image-preview--linkify-timers))))

(defun ai-code-ghostel-image-preview--cancel-all-linkify-timers ()

"Cancel every visible-preview scan timer in the current buffer."

(dolist (entry ai-code-ghostel-image-preview--linkify-timers)

(dolist (timer (cdr entry))

(when (timerp timer)

(cancel-timer timer))))

(setq ai-code-ghostel-image-preview--linkify-timers nil))

(defun ai-code-ghostel-image-preview--prune-linkify-timers ()

"Discard pending scan entries belonging to dead windows."

(setq ai-code-ghostel-image-preview--linkify-timers

(cl-remove-if-not

(lambda (entry)

(and (consp entry) (window-live-p (car entry))))

ai-code-ghostel-image-preview--linkify-timers)))

(defun ai-code-ghostel-image-preview--linkify-visible (buffer window)

"Linkify the visible image-layout region of BUFFER in WINDOW."

(when (and (buffer-live-p buffer)

(window-live-p window)

(eq (window-buffer window) buffer))

(with-current-buffer buffer

(ai-code-ghostel-image-preview--prune-linkify-timers)

(when ai-code-ghostel-image-preview-mode

(if (ai-code-session-link--linkify-inhibited-p buffer)

(ai-code-ghostel-image-preview-schedule-visible-linkify

window

(list ai-code-session-link--linkify-inhibited-retry-delay))

(when-let* ((region

(ai-code-ghostel-image-preview--visible-region window)))

(ai-code-ghostel-image-preview--call-atomic

buffer

(lambda ()

(ai-code-ghostel-image-preview--linkify-region

(car region) (cdr region))))))))))

(defun ai-code-ghostel-image-preview-schedule-visible-linkify

(window &optional delays)

"Schedule image-layout linkification for WINDOW.

(when (and (window-live-p window)

(buffer-live-p (window-buffer window)))

(let ((buffer (window-buffer window)))

(with-current-buffer buffer

(when ai-code-ghostel-image-preview-mode

(ai-code-ghostel-image-preview--prune-linkify-timers)

(ai-code-ghostel-image-preview--cancel-linkify-timers window)

(let ((timers

(mapcar

(lambda (delay)

(run-at-time

delay nil

#'ai-code-ghostel-image-preview--linkify-visible

buffer window))

(or delays

ai-code-ghostel-image-preview-linkify-delays))))

(push (cons window timers)

ai-code-ghostel-image-preview--linkify-timers)))))))

(defun ai-code-ghostel-image-preview-schedule-buffer

(&optional buffer delays)

"Schedule visible image-layout scans for BUFFER.

(let ((buffer (or buffer (current-buffer))))

(when (buffer-live-p buffer)

(dolist (window (get-buffer-window-list buffer nil t))

(ai-code-ghostel-image-preview-schedule-visible-linkify

window delays)))))

(defun ai-code-ghostel-image-preview--window-scroll (window _display-start)

"Record wheel intent and schedule image-layout recovery for WINDOW."

(when (ai-code-ghostel-image-preview--wheel-event-p last-command-event)

(if (ai-code-ghostel-image-preview--window-has-image-p window)

(ai-code-ghostel-image-preview--note-user-scroll window)

(ai-code-ghostel-image-preview--clear-user-scroll-at-live-end window)))

(ai-code-ghostel-image-preview-schedule-visible-linkify

window (list ai-code-ghostel-image-preview-scroll-linkify-delay)))

(defun ai-code-ghostel-image-preview-scroll (event)

"Handle precision scroll EVENT in an enabled Ghostel session."

(interactive "e")

(let ((window (or (ai-code-ghostel-image-preview--event-window event)

(selected-window))))

(when (window-live-p window)

(ai-code-ghostel-image-preview--note-user-scroll window))

(if (and window

ai-code-ghostel-image-preview-prefer-ultra-scroll

(ai-code-ghostel-image-preview--window-has-preview-p window)

(or (fboundp 'ultra-scroll)

(require 'ultra-scroll nil t)))

(let ((event

(ai-code-ghostel-image-preview--clamp-up-event event window)))

(if (and (featurep 'mac-win)

(fboundp 'ultra-scroll-mac))

(ultra-scroll-mac event)

(ultra-scroll event)))

(if (fboundp 'pixel-scroll-precision)

(pixel-scroll-precision event)

(mwheel-scroll event)))

(when (window-live-p window)

(ai-code-ghostel-image-preview-schedule-visible-linkify

window (list ai-code-ghostel-image-preview-scroll-linkify-delay)))))

(defun ai-code-ghostel-image-preview-enable ()

"Enable stable Ghostel image previews in the current AI Code session."

(ai-code-ghostel-image-preview--install-redraw-advice)

(setq-local ai-code-session-link-image-preview-position-function

#'ai-code-ghostel-image-preview--position-allowed-p)

(setq-local ai-code-session-link-image-preview-source-function

#'ai-code-ghostel-image-preview--cached-source)

(setq-local ai-code-session-link-image-preview-transaction-function

#'ai-code-ghostel-image-preview--call-transaction)

(setq ai-code-ghostel-image-preview--captured-sources nil

ai-code-ghostel-image-preview--output-tail "")

(add-hook 'ghostel-inhibit-anchor-functions

#'ai-code-ghostel-image-preview--inhibit-anchor-p nil t)

(add-hook 'window-scroll-functions

#'ai-code-ghostel-image-preview--window-scroll nil t)

(add-hook 'kill-buffer-hook

#'ai-code-ghostel-image-preview-disable nil t)

(ai-code-ghostel-image-preview-mode 1)

(ai-code-ghostel-image-preview-schedule-buffer

(current-buffer)))

(defun ai-code-ghostel-image-preview-disable ()

"Disable stable Ghostel image previews in the current buffer."

(ai-code-ghostel-image-preview--cancel-all-linkify-timers)

(remove-hook 'ghostel-inhibit-anchor-functions

#'ai-code-ghostel-image-preview--inhibit-anchor-p t)

(remove-hook 'window-scroll-functions

#'ai-code-ghostel-image-preview--window-scroll t)

(remove-hook 'kill-buffer-hook

#'ai-code-ghostel-image-preview-disable t)

(setq-local ai-code-session-link-image-preview-position-function nil)

(setq-local ai-code-session-link-image-preview-source-function nil)

(setq-local ai-code-session-link-image-preview-transaction-function nil)

(setq ai-code-ghostel-image-preview--user-scrolled-windows nil

ai-code-ghostel-image-preview--captured-sources nil

ai-code-ghostel-image-preview--output-tail "")

(ai-code-ghostel-image-preview-mode -1))

(defun ai-code-ghostel-image-preview-unload-function ()

"Remove global integration installed by this module."

(dolist (buffer (buffer-list))

(with-current-buffer buffer

(when ai-code-ghostel-image-preview-mode

(ai-code-ghostel-image-preview-disable))))

(when (and (fboundp 'ghostel--redraw-now)

(advice-member-p

#'ai-code-ghostel-image-preview--redraw-now-around

'ghostel--redraw-now))

(advice-remove 'ghostel--redraw-now

#'ai-code-ghostel-image-preview--redraw-now-around))

t)

(define-obsolete-function-alias

'ai-code-backends-infra-ghostel-schedule-visible-image-linkify

#'ai-code-ghostel-image-preview-schedule-visible-linkify

"1.90")

(define-obsolete-function-alias

'ai-code-backends-infra-ghostel-schedule-visible-image-linkify-for-buffer

#'ai-code-ghostel-image-preview-schedule-buffer

"1.90")

(provide 'ai-code-ghostel-image-preview)