LR-LIB-RENAME: batch rename with templates, preview, safe on-disk renames and undo

Op::SetFile (catalog only; engine moves files + XMP sidecars first, never overwriting, rolling back on failure); undo/redo move files back and forth; virtual copies follow; photo.rename / photo.renamePreview; Rename Photos dialog (Photo menu, grid context menu). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-28 20:17:18 -06:00 · 2026-10-01 13:06:33 -04:00
parent 7fd21517ae
commit 53c4b295b9
14 changed files with 605 additions and 6 deletions
@@ -137,6 +137,13 @@ pub enum Op {
        photos: Vec<PhotoId>,
        collapsed: bool,
    },
+    /// Rename a photo: its file name and the source it points to. Applying the op never touches
+    /// the disk — the engine moves the file before it commits (and on undo/redo).
+    SetFile {
+        id: PhotoId,
+        file_name: String,
+        source: Source,
+    },
    /// Several ops as one step (undo applies the inverses in reverse).
    Batch {
        ops: Vec<Op>,
@@ -421,6 +428,14 @@ impl Catalog {
                s.collapsed = collapsed;
                old
            }
+            Op::SetFile { id, file_name, source } => {
+                if file_name.trim().is_empty() {
+                    return Err(CatalogError::Invalid("empty file name".into()));
+                }
+                let p = self.photo_mut(id)?;
+                let old_name = std::mem::replace(&mut p.file_name, file_name);
+                Op::SetFile { id, file_name: old_name, source: std::mem::replace(&mut p.source, source) }
+            }
            Op::Batch { ops } => {
                let mut inverses = Vec::with_capacity(ops.len());
                for op in ops {
@@ -67,6 +67,9 @@ fn op_for(c: &mut Catalog, kind: u8, a: u8, b: u8) -> Op {
        }
        13 => Op::Batch { ops: c.remove_from_stacks_ops(&[pid]) },
        14 => c.set_top_ops(pid).unwrap_or(Op::Batch { ops: vec![] }),
+        9 if b.is_multiple_of(2) => {
+            Op::SetFile { id: pid, file_name: format!("Renamed_{b}.jpg"), source: Source::File { path: format!("/p/Renamed_{b}.jpg") } }
+        }
        15 => match c.photo(pid).cloned() {
            // a virtual copy: same source, own id, copy_of/copy_name set
            Some(src) => {
@@ -0,0 +1,35 @@
+//! Photo management commands: batch rename, capture time, colour label names.
+
+use serde_json::{Value, json};
+
+use super::{CommandSpec, bad, cmd, has_selection, str_param};
+use crate::Result;
+
+fn rename_args(s: &crate::Session, p: &Value, c: &str) -> Result<(Vec<lightcraft_catalog::PhotoId>, String, usize)> {
+    let template = str_param(p, "template").ok_or_else(|| bad(c, "missing `template`"))?.to_string();
+    let start = p.get("start").and_then(Value::as_u64).unwrap_or(1) as usize;
+    Ok((s.targets(p), template, start))
+}
+
+pub fn specs() -> Vec<CommandSpec> {
+    vec![
+        cmd!(query "photo.renamePreview", "Rename Preview", [], None, "{template: e.g. `{date}_{name}`, `Trip-{seq:3}` (tokens: {name} {seq} {seq:N} {date} {date:%Y%m%d} {camera} {title} {ext}), start?: first sequence number (1), ids?} — renames the files on disk (sidecars too, never overwriting: collisions get -1, -2…); undoable", has_selection, |s, p| {
+            let (ids, template, start) = rename_args(s, p, "photo.renamePreview")?;
+            Ok(serde_json::to_value(s.plan_rename(&ids, &template, start)).unwrap_or_default())
+        }),
+        cmd!(
+            "photo.rename",
+            "Rename Photos",
+            [],
+            None,
+            "{template: e.g. `{date}_{name}`, `Trip-{seq:3}` (tokens: {name} {seq} {seq:N} {date} {date:%Y%m%d} {camera} {title} {ext}), start?: first sequence number (1), ids?} — renames the files on disk (sidecars too, never overwriting: collisions get -1, -2…); undoable",
+            has_selection,
+            |s, p| {
+                let (ids, template, start) = rename_args(s, p, "photo.rename")?;
+                let plans = s.plan_rename(&ids, &template, start);
+                let n = s.apply_rename(&plans)?;
+                Ok(json!({"renamed": n, "plans": plans}))
+            }
+        ),
+    ]
+}
@@ -9,6 +9,7 @@ mod develop;
 mod edit;
 mod keywords;
 mod library;
+mod manage;
 mod masks;
 mod merge;
 mod organize;
@@ -109,6 +110,7 @@ pub fn command_specs() -> &'static [CommandSpec] {
        v.extend(masks::specs());
        v.extend(organize::specs());
        v.extend(keywords::specs());
+        v.extend(manage::specs());
        v.extend(merge::specs());
        v.extend(query::specs());
        v.extend(xmp::specs());
@@ -20,6 +20,7 @@ pub mod library;
 pub mod media;
 pub mod merge;
 pub mod presets;
+pub mod rename;
 pub mod sidecar;
 mod view;

@@ -205,7 +206,13 @@ impl Session {

    pub fn undo_step(&mut self) -> Result<String> {
        let e = self.undo.pop().ok_or_else(|| EngineError::Other("nothing to undo".into()))?;
-        let redo = self.catalog.apply(e.op.clone())?;
+        let redo = match self.apply_with_files(&e.op) {
+            Ok(r) => r,
+            Err(err) => {
+                self.undo.push(e);
+                return Err(err);
+            }
+        };
        self.pending_log.push(e.op);
        self.redo.push(UndoEntry { label: e.label.clone(), op: redo });
        Ok(e.label)
@@ -213,12 +220,32 @@ impl Session {

    pub fn redo_step(&mut self) -> Result<String> {
        let e = self.redo.pop().ok_or_else(|| EngineError::Other("nothing to redo".into()))?;
-        let undo = self.catalog.apply(e.op.clone())?;
+        let undo = match self.apply_with_files(&e.op) {
+            Ok(r) => r,
+            Err(err) => {
+                self.redo.push(e);
+                return Err(err);
+            }
+        };
        self.pending_log.push(e.op);
        self.undo.push(UndoEntry { label: e.label.clone(), op: undo });
        Ok(e.label)
    }

+    /// Apply an undo/redo op, first moving the files its renames imply (all or nothing).
+    fn apply_with_files(&mut self, op: &Op) -> Result<Op> {
+        let moves = self.file_moves(op);
+        Session::move_files(&moves)?;
+        match self.catalog.apply(op.clone()) {
+            Ok(inv) => Ok(inv),
+            Err(e) => {
+                let back: Vec<(String, String)> = moves.iter().rev().map(|(a, b)| (b.clone(), a.clone())).collect();
+                let _ = Session::move_files(&back);
+                Err(e.into())
+            }
+        }
+    }
+
    /// Ops applied since the last call, for the op-log store.
    pub fn drain_log(&mut self) -> Vec<Op> {
        std::mem::take(&mut self.pending_log)
@@ -0,0 +1,351 @@
+//! Batch rename: a file-name template applied to the selected photos, renaming the files on
+//! disk (with their XMP sidecars) safely.
+//!
+//! Template tokens: `{name}` (current name without extension), `{seq}` / `{seq:3}` (sequence number,
+//! zero-padded to 3 digits), `{date}` / `{date:%Y%m%d}` (capture date; `%Y %y %m %d %H %M %S`),
+//! `{camera}`, `{title}`, `{ext}` (extension, without the dot). Characters that aren't allowed in
+//! file names become `-`. The original extension is always kept.
+//!
+//! Safety:
+//! - a target that exists on disk, or that another photo in the batch gets, receives a `-1`, `-2`…
+//!   suffix — no file is ever overwritten;
+//! - the moves happen before the catalog changes; if one fails, the ones already done are moved
+//!   back and nothing is committed;
+//! - the catalog op ([`Op::SetFile`]) is undoable: undo/redo move the files back and forth (see
+//!   [`crate::Session::undo_step`]);
+//! - virtual copies follow their master's file.
+
+use std::collections::{HashMap, HashSet};
+use std::path::{Path, PathBuf};
+
+use lightcraft_catalog::{Op, Photo, PhotoId, Source};
+use serde::Serialize;
+
+use crate::sidecar::SidecarNaming;
+use crate::{EngineError, Result, Session};
+
+/// One planned rename.
+#[derive(Clone, Debug, PartialEq, Serialize)]
+pub struct RenamePlan {
+    pub id: u64,
+    pub from: String,
+    pub to: String,
+    /// File sources: the old and new paths.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub from_path: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub to_path: Option<String>,
+}
+
+fn split_ext(name: &str) -> (&str, &str) {
+    match name.rsplit_once('.') {
+        Some((stem, ext)) if !stem.is_empty() => (stem, ext),
+        _ => (name, ""),
+    }
+}
+
+fn sanitize(s: &str) -> String {
+    let t: String =
+        s.chars().map(|c| if matches!(c, '/' | '\\' | ':' | '*' | '?' | '"' | '<' | '>' | '|') || c.is_control() { '-' } else { c }).collect();
+    t.trim().trim_matches('.').trim().to_string()
+}
+
+/// `%Y%m%d`-style formatting of an ISO local time.
+fn format_date(iso: &str, fmt: &str) -> String {
+    let part = |a: usize, b: usize| iso.get(a..b).unwrap_or("00").to_string();
+    let mut out = String::new();
+    let mut it = fmt.chars();
+    while let Some(c) = it.next() {
+        if c != '%' {
+            out.push(c);
+            continue;
+        }
+        match it.next() {
+            Some('Y') => out.push_str(&part(0, 4)),
+            Some('y') => out.push_str(&part(2, 4)),
+            Some('m') => out.push_str(&part(5, 7)),
+            Some('d') => out.push_str(&part(8, 10)),
+            Some('H') => out.push_str(&part(11, 13)),
+            Some('M') => out.push_str(&part(14, 16)),
+            Some('S') => out.push_str(&part(17, 19)),
+            Some('%') => out.push('%'),
+            Some(o) => {
+                out.push('%');
+                out.push(o);
+            }
+            None => out.push('%'),
+        }
+    }
+    out
+}
+
+/// Expand `template` for `p` (sequence number `seq`) into a file name with `p`'s extension.
+pub fn expand(template: &str, p: &Photo, seq: usize) -> String {
+    let (stem, ext) = split_ext(&p.file_name);
+    let mut out = String::new();
+    let mut rest = template;
+    while let Some(i) = rest.find('{') {
+        out.push_str(&rest[..i]);
+        let Some(j) = rest[i..].find('}') else {
+            out.push_str(&rest[i..]);
+            rest = "";
+            break;
+        };
+        let tok = &rest[i + 1..i + j];
+        let (name, arg) = tok.split_once(':').map(|(a, b)| (a, Some(b))).unwrap_or((tok, None));
+        let v = match name.trim().to_ascii_lowercase().as_str() {
+            "name" | "filename" => stem.to_string(),
+            "seq" | "n" => {
+                let w: usize = arg.and_then(|a| a.parse().ok()).unwrap_or(1).min(9);
+                format!("{seq:0w$}")
+            }
+            "date" => format_date(p.date(), arg.unwrap_or("%Y%m%d")),
+            "camera" => p.meta.camera.clone(),
+            "title" => p.meta.title.clone(),
+            "ext" => ext.to_string(),
+            _ => format!("{{{tok}}}"),
+        };
+        out.push_str(&v);
+        rest = &rest[i + j + 1..];
+    }
+    out.push_str(rest);
+    let mut stem_out = sanitize(&out);
+    if stem_out.is_empty() {
+        stem_out = sanitize(stem);
+    }
+    if stem_out.is_empty() {
+        stem_out = "photo".into();
+    }
+    if ext.is_empty() { stem_out } else { format!("{stem_out}.{ext}") }
+}
+
+/// Every sidecar that may belong to `path` (both naming conventions, `.xmp` and `.XMP`).
+fn sidecars(path: &str) -> Vec<(PathBuf, SidecarNaming, bool)> {
+    let mut v = Vec::new();
+    for naming in [SidecarNaming::Stem, SidecarNaming::Full] {
+        let p = crate::sidecar::sidecar_path(path, naming);
+        v.push((p.with_extension("XMP"), naming, true));
+        v.push((p, naming, false));
+    }
+    v
+}
+
+/// Move `from` to `to` (never over an existing file) together with its sidecars. On error nothing
+/// is left moved.
+pub fn move_file(from: &str, to: &str) -> std::result::Result<(), String> {
+    if from == to {
+        return Ok(());
+    }
+    let (f, t) = (Path::new(from), Path::new(to));
+    // a case-only change on a case-insensitive file system "exists" already: that is this file
+    let case_only = from.to_lowercase() == to.to_lowercase();
+    if t.exists() && !case_only {
+        return Err(format!("{to} already exists"));
+    }
+    let mut done: Vec<(PathBuf, PathBuf)> = Vec::new();
+    let mv = |a: &Path, b: &Path| -> std::io::Result<()> {
+        if case_only {
+            // via a temporary name, so case-insensitive file systems see a real change
+            let tmp = a.with_file_name(format!(".lc-rename-{}", std::process::id()));
+            std::fs::rename(a, &tmp)?;
+            std::fs::rename(&tmp, b).inspect_err(|_| {
+                let _ = std::fs::rename(&tmp, a);
+            })
+        } else {
+            std::fs::rename(a, b)
+        }
+    };
+    mv(f, t).map_err(|e| format!("rename {from}: {e}"))?;
+    done.push((f.to_path_buf(), t.to_path_buf()));
+    for (sc, naming, upper) in sidecars(from) {
+        if !sc.is_file() {
+            continue;
+        }
+        let mut dst = crate::sidecar::sidecar_path(to, naming);
+        if upper {
+            dst = dst.with_extension("XMP");
+        }
+        if dst.exists() && !case_only {
+            continue; // never overwrite: the old sidecar stays where it was
+        }
+        if let Err(e) = mv(&sc, &dst) {
+            for (a, b) in done.iter().rev() {
+                let _ = std::fs::rename(b, a);
+            }
+            return Err(format!("rename {}: {e}", sc.display()));
+        }
+        done.push((sc, dst));
+    }
+    Ok(())
+}
+
+impl Session {
+    /// Plan renaming `ids` with `template` (sequence numbers from `start`), resolving collisions.
+    pub fn plan_rename(&self, ids: &[PhotoId], template: &str, start: usize) -> Vec<RenamePlan> {
+        // photos sharing one file (virtual copies) rename once
+        let mut seen_paths: HashSet<String> = HashSet::new();
+        let mut taken: HashSet<String> = HashSet::new(); // lower-case target paths/names claimed in this batch
+        let mut out = Vec::new();
+        let mut seq = start;
+        for id in ids {
+            let Some(p) = self.catalog.photo(*id) else { continue };
+            if let Source::File { path } = &p.source
+                && !seen_paths.insert(path.clone())
+            {
+                continue;
+            }
+            let want = expand(template, p, seq);
+            seq += 1;
+            let (stem, ext) = split_ext(&want);
+            let (stem, ext) = (stem.to_string(), ext.to_string());
+            let candidate = |k: usize| {
+                if k == 0 {
+                    want.clone()
+                } else if ext.is_empty() {
+                    format!("{stem}-{k}")
+                } else {
+                    format!("{stem}-{k}.{ext}")
+                }
+            };
+            let (to, to_path) = match &p.source {
+                Source::File { path } => {
+                    let dir = Path::new(path).parent().map(Path::to_path_buf).unwrap_or_default();
+                    let mut k = 0;
+                    loop {
+                        let name = candidate(k);
+                        let tp = dir.join(&name).to_string_lossy().to_string();
+                        let key = tp.to_lowercase();
+                        let same = key == path.to_lowercase();
+                        // free: not claimed in this batch and not on disk (unless it is this very file).
+                        // A file this batch moves away still counts as taken: simple and safe.
+                        let on_disk = Path::new(&tp).exists() && !same;
+                        if !taken.contains(&key) && !on_disk {
+                            taken.insert(key);
+                            break (name, Some(tp));
+                        }
+                        k += 1;
+                    }
+                }
+                Source::Demo { .. } => {
+                    let mut k = 0;
+                    loop {
+                        let name = candidate(k);
+                        if taken.insert(format!("demo:{}", name.to_lowercase())) {
+                            break (name, None);
+                        }
+                        k += 1;
+                    }
+                }
+            };
+            let from_path = match &p.source {
+                Source::File { path } => Some(path.clone()),
+                _ => None,
+            };
+            out.push(RenamePlan { id: id.0, from: p.file_name.clone(), to, from_path, to_path });
+        }
+        out
+    }
+
+    /// Carry out `plans`: move the files (rolled back on failure), then commit one undoable op
+    /// that updates the photos (and their virtual copies).
+    pub fn apply_rename(&mut self, plans: &[RenamePlan]) -> Result<usize> {
+        let mut moved: Vec<(String, String)> = Vec::new();
+        for pl in plans {
+            if let (Some(a), Some(b)) = (&pl.from_path, &pl.to_path)
+                && a != b
+            {
+                if let Err(e) = move_file(a, b) {
+                    for (a, b) in moved.iter().rev() {
+                        let _ = move_file(b, a);
+                    }
+                    return Err(EngineError::Other(e));
+                }
+                moved.push((a.clone(), b.clone()));
+            }
+        }
+        let mut ops = Vec::new();
+        let by_path: HashMap<&str, &RenamePlan> = plans.iter().filter_map(|p| p.from_path.as_deref().map(|f| (f, p))).collect();
+        for p in self.catalog.photos() {
+            let plan = match &p.source {
+                Source::File { path } => by_path.get(path.as_str()).copied(),
+                Source::Demo { .. } => plans.iter().find(|x| x.id == p.id.0 && x.from_path.is_none()),
+            };
+            let Some(plan) = plan else { continue };
+            let source = match &plan.to_path {
+                Some(t) => Source::File { path: t.clone() },
+                None => p.source.clone(),
+            };
+            if plan.to != p.file_name || source != p.source {
+                ops.push(Op::SetFile { id: p.id, file_name: plan.to.clone(), source });
+            }
+        }
+        let n = ops.len();
+        if n > 0
+            && let Err(e) = self.commit(&format!("Rename {n} Photo{}", if n == 1 { "" } else { "s" }), Op::Batch { ops })
+        {
+            for (a, b) in moved.iter().rev() {
+                let _ = move_file(b, a);
+            }
+            return Err(e);
+        }
+        Ok(n)
+    }
+
+    /// File moves an undo/redo op implies: `SetFile` ops whose source path differs from the photo's
+    /// current one.
+    pub(crate) fn file_moves(&self, op: &Op) -> Vec<(String, String)> {
+        fn rec(s: &Session, op: &Op, v: &mut Vec<(String, String)>) {
+            match op {
+                Op::Batch { ops } => ops.iter().for_each(|o| rec(s, o, v)),
+                Op::SetFile { id, source: Source::File { path: to }, .. } => {
+                    if let Some(Source::File { path: from }) = s.catalog.photo(*id).map(|p| &p.source)
+                        && from != to
+                        && !v.iter().any(|(f, _)| f == from)
+                    {
+                        v.push((from.clone(), to.clone()));
+                    }
+                }
+                _ => {}
+            }
+        }
+        let mut v = Vec::new();
+        rec(self, op, &mut v);
+        v
+    }
+
+    /// Move the files `moves` names; all or nothing.
+    pub(crate) fn move_files(moves: &[(String, String)]) -> Result<()> {
+        let mut done: Vec<&(String, String)> = Vec::new();
+        for m in moves {
+            if let Err(e) = move_file(&m.0, &m.1) {
+                for (a, b) in done.iter().rev().map(|m| (&m.0, &m.1)) {
+                    let _ = move_file(b, a);
+                }
+                return Err(EngineError::Other(format!("can't undo the rename: {e}")));
+            }
+            done.push(m);
+        }
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn templates() {
+        let mut p = Photo::new(PhotoId(1), Source::Demo { scene: 1 }, "IMG_0042.CR2", "CR2", 1, 1, "2026-01-01T00:00:00");
+        p.captured = Some("2026-09-30T14:05:09".into());
+        p.meta.camera = "Model X/2".into();
+        p.meta.title = "Sunset: beach".into();
+        assert_eq!(expand("{name}", &p, 1), "IMG_0042.CR2");
+        assert_eq!(expand("Trip-{seq:3}", &p, 7), "Trip-007.CR2");
+        assert_eq!(expand("{date}_{name}", &p, 1), "20260930_IMG_0042.CR2");
+        assert_eq!(expand("{date:%Y-%m-%d %H.%M.%S}", &p, 1), "2026-09-30 14.05.09.CR2");
+        assert_eq!(expand("{camera} {title}", &p, 1), "Model X-2 Sunset- beach.CR2");
+        assert_eq!(expand("{unknown}-{seq}", &p, 12), "{unknown}-12.CR2");
+        assert_eq!(expand("  ", &p, 1), "IMG_0042.CR2", "empty template keeps the name");
+        assert_eq!(expand("../{name}", &p, 1), "-IMG_0042.CR2", "no path components");
+    }
+}
@@ -93,3 +93,96 @@ fn keyword_rename_merge_delete_undo_and_replay() {
    assert!(s.execute("keyword.merge", &json!({"from": [], "into": "x"})).is_err());
    let _ = std::fs::remove_dir_all(&dir);
 }
+
+fn write_png(path: &std::path::Path, seed: u8) {
+    let (w, h) = (24usize, 16usize);
+    let data: Vec<[u8; 4]> = (0..w * h).map(|i| [(i % w * 9) as u8, (i / w * 11) as u8, seed, 255]).collect();
+    let img = lightcraft_raster::Rgba8 { width: w, height: h, data };
+    let bytes = lightcraft_codecs::encode_png(&lightcraft_codecs::EncodeImage::rgba8(&img), &lightcraft_codecs::EncodeMeta::default()).unwrap();
+    std::fs::create_dir_all(path.parent().unwrap()).unwrap();
+    std::fs::write(path, bytes).unwrap();
+}
+
+fn path_of(s: &Session, id: u64) -> String {
+    match &s.catalog.photo(lightcraft_catalog::PhotoId(id)).unwrap().source {
+        lightcraft_catalog::Source::File { path } => path.clone(),
+        _ => panic!("not a file"),
+    }
+}
+
+/// Batch rename on disk: collisions with existing files and within the batch get suffixes, sidecars
+/// move along, virtual copies follow, undo/redo move the files back and forth, a failed move rolls
+/// the batch back, and the op log replays the new paths.
+#[test]
+fn batch_rename_files_collisions_undo_and_replay() {
+    let src = temp_dir("rename-src");
+    let lib = temp_dir("rename-lib");
+    write_png(&src.join("a.png"), 1);
+    write_png(&src.join("b.png"), 2);
+    std::fs::write(src.join("Trip-001.png"), b"not ours").unwrap();
+    std::fs::write(src.join("a.xmp"), b"<x:xmpmeta xmlns:x='adobe:ns:meta/'></x:xmpmeta>").unwrap();
+    let mut s = Session::new().with_fs();
+    s.open_library(&lib, false).unwrap();
+    let r = s.execute("library.import", &json!({"paths": [src.join("a.png").to_string_lossy(), src.join("b.png").to_string_lossy()]})).unwrap();
+    let ids: Vec<u64> = r["imported"].as_array().unwrap().iter().map(|v| v.as_u64().unwrap()).collect();
+    assert_eq!(ids.len(), 2, "{r}");
+    s.execute("library.select", &json!({"ids": [ids[0]]})).unwrap();
+    s.execute("photo.virtualCopy", &json!({})).unwrap();
+    let copy = s.catalog.photos().find(|p| p.copy_of.is_some()).unwrap().id.0;
+
+    // preview: the existing Trip-001.png is skipped, the copy shares its master's file
+    let pv = s.execute("photo.renamePreview", &json!({"ids": [ids[0], copy, ids[1]], "template": "Trip-{seq:3}"})).unwrap();
+    assert_eq!(pv.as_array().unwrap().len(), 2, "{pv}");
+    assert_eq!(pv[0]["to"], "Trip-001-1.png");
+    assert_eq!(pv[1]["to"], "Trip-002.png");
+    let r = s.execute("photo.rename", &json!({"ids": [ids[0], copy, ids[1]], "template": "Trip-{seq:3}"})).unwrap();
+    assert_eq!(r["renamed"], 3, "{r}");
+    assert!(src.join("Trip-001-1.png").is_file() && src.join("Trip-002.png").is_file());
+    assert!(!src.join("a.png").exists() && !src.join("b.png").exists());
+    assert_eq!(std::fs::read(src.join("Trip-001.png")).unwrap(), b"not ours", "never overwritten");
+    assert!(src.join("Trip-001-1.xmp").is_file() && !src.join("a.xmp").exists(), "sidecar moved");
+    assert_eq!(path_of(&s, copy), path_of(&s, ids[0]), "the virtual copy follows");
+    assert_eq!(s.catalog.photo(lightcraft_catalog::PhotoId(ids[1])).unwrap().file_name, "Trip-002.png");
+
+    // undo moves the files back; redo renames again
+    s.execute("edit.undo", &json!({})).unwrap();
+    assert!(src.join("a.png").is_file() && src.join("b.png").is_file() && src.join("a.xmp").is_file());
+    assert_eq!(path_of(&s, ids[0]), src.join("a.png").to_string_lossy());
+    s.execute("edit.redo", &json!({})).unwrap();
+    assert!(src.join("Trip-002.png").is_file() && !src.join("b.png").exists());
+
+    // collisions inside the batch
+    let r = s.execute("photo.rename", &json!({"ids": [ids[0], ids[1]], "template": "same"})).unwrap();
+    assert_eq!(r["plans"][0]["to"], "same.png");
+    assert_eq!(r["plans"][1]["to"], "same-1.png");
+
+    // a failing move rolls the whole batch back and changes nothing
+    std::fs::remove_file(src.join("same-1.png")).unwrap();
+    let before = s.catalog.to_snapshot();
+    assert!(s.execute("photo.rename", &json!({"ids": [ids[0], ids[1]], "template": "x-{seq}"})).is_err());
+    assert!(src.join("same.png").is_file() && !src.join("x-1.png").exists(), "rolled back");
+    assert_eq!(s.catalog.to_snapshot(), before);
+
+    // the op log replays the renames
+    let expect = s.catalog.to_snapshot();
+    drop(s);
+    let mut s = Session::new().with_fs();
+    s.open_library(&lib, false).unwrap();
+    assert_eq!(s.catalog.to_snapshot(), expect);
+    assert_eq!(path_of(&s, ids[0]), src.join("same.png").to_string_lossy());
+    let _ = std::fs::remove_dir_all(&src);
+    let _ = std::fs::remove_dir_all(&lib);
+}
+
+/// Demo photos (no file) rename in the catalog only.
+#[test]
+fn rename_demo_photos_in_catalog() {
+    let mut s = Session::with_demo();
+    let ids: Vec<u64> = s.visible_cloned().iter().take(3).map(|p| p.0).collect();
+    let r = s.execute("photo.rename", &json!({"ids": ids, "template": "{date:%Y-%m-%d}_{seq:2}", "start": 7})).unwrap();
+    assert_eq!(r["renamed"], 3);
+    let name = &s.catalog.photo(lightcraft_catalog::PhotoId(ids[0])).unwrap().file_name;
+    assert!(name.ends_with("_07.jpg") || name.contains("_07."), "{name}");
+    s.execute("edit.undo", &json!({})).unwrap();
+    assert!(s.catalog.photo(lightcraft_catalog::PhotoId(ids[0])).unwrap().file_name.starts_with("LC"));
+}
@@ -437,6 +437,25 @@ mod tests {
        h.settle(SETTLE);
    }

+    /// Photo > Rename Photos…: the dialog previews and renames the selection.
+    #[test]
+    fn rename_dialog_renames_the_selection() {
+        let mut h = demo([1200.0, 800.0]);
+        let t = Duration::from_secs(10);
+        let vis: Vec<u64> = h.app.session.visible_cloned().iter().take(2).map(|p| p.0).collect();
+        h.request("engine.execute", json!({"command": "library.select", "params": {"ids": vis}}), t);
+        let tree = h.request("ui.menu.tree", json!({}), t);
+        assert!(tree.to_string().contains("Rename 2 Photos…"), "live menu label");
+        h.request("engine.execute", json!({"command": "dialog.rename", "params": {"template": "Trip-{seq:2}", "start": 5}}), t);
+        h.settle(SETTLE);
+        let r = h.request("ui.dialog.confirm", json!({}), t);
+        assert_eq!(r["ok"], true, "{r}");
+        let name = |id: u64| h.app.session.catalog.photo(lightcraft_catalog::PhotoId(id)).unwrap().file_name.clone();
+        assert!(name(vis[0]).starts_with("Trip-05."), "{}", name(vis[0]));
+        assert!(name(vis[1]).starts_with("Trip-06."), "{}", name(vis[1]));
+        h.settle(SETTLE);
+    }
+
    #[test]
    fn screenshot_request_is_answered_without_a_window() {
        let mut h = demo([800.0, 500.0]);
@@ -136,6 +136,7 @@ const LAYOUT: &[(&str, &[&str])] = &[
            "photo.saveMetadataToFile",
            "photo.readMetadataFromFile",
            "app.showInFinder",
+            "dialog.rename",
            "---",
            "photo.delete",
        ],
@@ -225,6 +226,7 @@ fn live_label(app: &LightcraftApp, id: &str, label: &str) -> String {
        "edit.redo" => app.session.redo.last().map(|e| format!("Redo {}", e.label)).unwrap_or_else(|| "Redo".into()),
        "photo.delete" if n > 1 => format!("Delete {n} Photos"),
        "photo.virtualCopy" if n > 1 => format!("Create {n} Virtual Copies"),
+        "dialog.rename" if n > 1 => format!("Rename {n} Photos…"),
        _ => label.to_string(),
    }
 }
@@ -76,6 +76,7 @@ pub const UI_COMMANDS: &[UiCommand] = &[
    ("app.shortcuts", "Keyboard Shortcuts", Some("Cmd+/"), "Help"),
    ("app.export", "Export Now", None, ""),
    ("app.showInFinder", "Show in Finder", Some("Cmd+R"), "Photo"),
+    ("dialog.rename", "Rename Photos…", None, "Photo"),
    ("app.exportPrevious", "Export with Previous", Some("Cmd+Alt+Shift+E"), "File"),
 ];

@@ -329,6 +330,11 @@ pub fn run_ui_command(app: &mut LightcraftApp, id: &str, p: &Value) -> Option<Re
            app.ui.dialog = Some(Dialog::NewSmartAlbum { name: p.get("name").and_then(Value::as_str).unwrap_or("").into() });
            Ok(Value::Null)
        }
+        "dialog.rename" => {
+            let template = p.get("template").and_then(Value::as_str).unwrap_or("{name}").to_string();
+            app.ui.dialog = Some(Dialog::Rename { template, start: p.get("start").and_then(Value::as_u64).unwrap_or(1) as u32 });
+            Ok(Value::Null)
+        }
        "dialog.createPreset" => {
            app.ui.dialog = Some(Dialog::CreatePreset { name: String::new(), group: "User Presets".into() });
            Ok(Value::Null)
@@ -439,7 +445,7 @@ pub fn run_ui_command(app: &mut LightcraftApp, id: &str, p: &Value) -> Option<Re
 pub fn ui_enabled(app: &LightcraftApp, id: &str) -> bool {
    match id {
        s if s.starts_with("panel.") || s.starts_with("tool.") || s.starts_with("section.") => app.session.active().is_some() || s == "panel.close",
-        "app.export" | "dialog.export" | "dialog.createPreset" | "dialog.copySettings" => app.session.active().is_some(),
+        "app.export" | "dialog.export" | "dialog.createPreset" | "dialog.rename" | "dialog.copySettings" => app.session.active().is_some(),
        "app.exportPrevious" => app.session.active().is_some() && app.session.last_export.is_some(),
        "app.showInFinder" => {
            app.services.reveal.is_some()
@@ -22,6 +22,7 @@ pub fn show(app: &mut LightcraftApp, ctx: &egui::Context) {
        Dialog::NewAlbum { folder: true, .. } => "Create Folder",
        Dialog::NewAlbum { .. } => "Create Album",
        Dialog::RenameAlbum { .. } => "Rename Album",
+        Dialog::Rename { .. } => "Rename Photos",
        Dialog::RenameKeyword { .. } => "Rename Keyword",
        Dialog::MergeKeywords { .. } => "Merge Keywords",
        Dialog::NewSmartAlbum { .. } => "Create Smart Album",
@@ -72,6 +73,42 @@ pub fn show(app: &mut LightcraftApp, ctx: &egui::Context) {
                            .color(t.text_dim),
                    );
                }
+                Dialog::Rename { template, start } => {
+                    let n = app.session.targets(&json!({})).len();
+                    ui.label(egui::RichText::new(format!("{n} photo{}", if n == 1 { "" } else { "s" })).color(t.text_dim));
+                    field(ui, "Template", |ui| {
+                        let r = ui.add(egui::TextEdit::singleline(template).hint_text("{name}").desired_width(f32::INFINITY));
+                        crate::widgets::register(ui.ctx(), "field:renameTemplate", r.rect);
+                    });
+                    field(ui, "Presets", |ui| {
+                        ui.spacing_mut().item_spacing.x = 4.0;
+                        for (i, (label, tpl)) in
+                            [("Name", "{name}"), ("Date–Name", "{date}_{name}"), ("Title–Seq", "{title}-{seq:3}"), ("Custom–Seq", "Photo-{seq:3}")].iter().enumerate()
+                        {
+                            if crate::widgets::text_button(ui, &format!("renamePreset-{i}"), label, template == tpl).clicked() {
+                                *template = tpl.to_string();
+                            }
+                        }
+                    });
+                    field(ui, "Start at", |ui| ui.add(egui::DragValue::new(start).range(0..=999_999)));
+                    ui.label(
+                        egui::RichText::new("Tokens: {name} {seq} {seq:3} {date} {date:%Y-%m-%d} {camera} {title}. Files are renamed on disk (with their XMP sidecars); existing names get -1, -2…")
+                            .color(t.text_dim),
+                    );
+                    let preview = app.session.execute("photo.renamePreview", &json!({"template": template, "start": start})).unwrap_or_default();
+                    egui::Grid::new("rename-preview").num_columns(3).spacing([8.0, 2.0]).show(ui, |ui| {
+                        for pl in preview.as_array().into_iter().flatten().take(6) {
+                            ui.label(egui::RichText::new(pl["from"].as_str().unwrap_or("")).color(t.text_dim));
+                            ui.label(egui::RichText::new("→").color(t.text_dim));
+                            ui.label(egui::RichText::new(pl["to"].as_str().unwrap_or("")).color(t.text));
+                            ui.end_row();
+                        }
+                    });
+                    let more = preview.as_array().map_or(0, Vec::len).saturating_sub(6);
+                    if more > 0 {
+                        ui.label(egui::RichText::new(format!("… and {more} more")).color(t.text_dim));
+                    }
+                }
                Dialog::RenameKeyword { from, to } => {
                    let n = app.session.catalog.photos().filter(|p| p.meta.keywords.iter().any(|k| lightcraft_catalog::keywords::is_under(k, from))).count();
                    let r = ui.add(egui::TextEdit::singleline(to).hint_text("New name").desired_width(f32::INFINITY));
@@ -321,6 +358,7 @@ pub fn confirm_dialog(app: &mut LightcraftApp, dlg: &Dialog) -> Result<serde_jso
    match dlg {
        Dialog::NewAlbum { name, folder } => app.run("album.create", json!({"name": name, "folder": folder, "addSelected": !folder})),
        Dialog::RenameAlbum { id, name } => app.run("album.rename", json!({"id": id, "name": name})),
+        Dialog::Rename { template, start } => app.run("photo.rename", json!({"template": template, "start": start})),
        Dialog::RenameKeyword { from, to } => app.run("keyword.rename", json!({"from": from, "to": to})),
        Dialog::MergeKeywords { from, into } => app.run("keyword.merge", json!({"from": from, "into": into})),
        Dialog::AutoStack { gap } => app.run("stack.auto", json!({"gap": gap})),
@@ -431,6 +431,9 @@ pub fn context_menu(app: &mut LightcraftApp, ui: &mut egui::Ui, id: PhotoId) {
            }
        }
    });
+    if ui.button("Rename…").clicked() {
+        let _ = app.run("dialog.rename", json!({}));
+    }
    if ui.button("Create Virtual Copy").clicked() {
        let _ = app.run("photo.virtualCopy", json!({}));
    }
@@ -151,6 +151,11 @@ pub enum Dialog {
        id: u64,
        name: String,
    },
+    /// Batch rename the selected photos with a file-name template.
+    Rename {
+        template: String,
+        start: u32,
+    },
    /// Rename a keyword on every photo (children included).
    RenameKeyword {
        from: String,
@@ -75,7 +75,7 @@ Ordered by tier, then user value, then (low) effort. Take the first one nobody i
 12. **LR-IMP-FORMATS** (P0) — CR3, compressed NEF/RAF/ORF, RW2 v4 (preview only today); HEIC/AVIF decode (no
    permissive pure-Rust decoder yet). High value, high effort (clean sources needed).
 13. **LR-VIEW-FULLSCREEN + LR-VIEW-NAVIGATOR + LR-VIEW-INFOOVERLAY** (P1) — view modes. Medium effort.
-14. **LR-LIB-RENAME + LR-LIB-CAPTURETIME + LR-LIB-LABEL UI** (P1) — batch rename, capture-time edit, label menu/names.
+14. **LR-LIB-CAPTURETIME + LR-LIB-LABEL UI** (P1) — capture-time edit, label menu/names.
 15. **LR-EXP-BITDEPTH + LR-EXP-COMPRESSION** (P1) — 16-bit TIFF/PNG and TIFF compression choice.
 16. **LR-EDIT-OPTICS-PROFILE** (P1) — a lens-profile database of our own (embedded DNG/maker corrections work today).

@@ -156,7 +156,7 @@ under the UI command that wraps it (a no-op error); the UI command now wins.
 | LR-LIB-DELETE | Delete / Recently Deleted | P0 | ✅ | `cmd:photo.delete`, `cmd:photo.restore`, `cmd:photo.deletePermanently` | no confirmation dialog, no auto-purge after N days, no "Empty" |
 | LR-LIB-REMOVE-ALBUM | Remove from album | P0 | ✅ | `cmd:album.removePhotos` | |
 | LR-LIB-DUPLICATE | Duplicate a photo | P2 | ⬜ | | |
-| LR-LIB-RENAME | Batch rename | P1 | ⬜ | | |
+| LR-LIB-RENAME | Batch rename | P1 | ✅ | `cmd:photo.rename`, `cmd:photo.renamePreview`, `cmd:dialog.rename`, `crates/engine/src/rename.rs` | template tokens {name} {seq:N} {date:%Y%m%d} {camera} {title}; preview; renames files on disk with their XMP sidecars, never overwriting (-1, -2… suffixes), rolls back on failure; undo/redo move the files; virtual copies follow |
 | LR-LIB-CAPTURETIME | Edit capture time | P1 | ⬜ | | `photo.setMeta` has no capture-time field |
 | LR-LIB-SHOWFINDER | Reveal original in file manager | P0 | ⬜ | | |
 | LR-LIB-COVER | Album cover | P2 | ✅ | `cmd:album.setCover` | |
@@ -587,7 +587,7 @@ visible menu bar yet: the menu model is only exposed through the control channel
 | MENU-PHOTO-BW | Convert to B&W | P0 | ✅ | `cmd:develop.treatment` | |
 | MENU-PHOTO-RESET | Reset edits / crop | P0 | ✅ | `cmd:develop.reset`, `cmd:crop.reset` | |
 | MENU-PHOTO-UPDATEAI | Update AI settings | P2 | ⬜ | | |
-| MENU-PHOTO-RENAME | Rename N photos… | P1 | ⬜ | | |
+| MENU-PHOTO-RENAME | Rename N photos… | P1 | ✅ | `cmd:dialog.rename` | live “Rename N Photos…” label |
 | MENU-PHOTO-CAPTURETIME | Edit capture time… | P1 | ⬜ | | |
 | MENU-PHOTO-COVER | Set as album cover | P2 | ✅ | `cmd:album.setCover` | |
 | MENU-PHOTO-DELETE | Delete N photos… | P0 | ✅ | `cmd:photo.delete` | no confirmation; static label |