Add desktop widgets and streamline documentation

shell/ferese-shell/src/note_store.rs

@@ -0,0 +1,131 @@
+//! Atomic, conflict-checked note edits; always called from a worker thread.
+use std::{fs, io::Write, path::Path};
+
+#[derive(Clone, Debug)]
+pub enum Edit {
+    Text(String, String),
+    Position(String, i32, i32),
+    ClockPosition(i32, i32),
+}
+
+pub fn save(path: &Path, edits: &[Edit]) -> Result<(), String> {
+    let canonical = path.canonicalize().map_err(|e| e.to_string())?;
+    let path = canonical.as_path();
+    let source = fs::read_to_string(path).map_err(|e| e.to_string())?;
+    let mut doc: toml_edit::DocumentMut = source
+        .parse()
+        .map_err(|e: toml_edit::TomlError| e.to_string())?;
+    for edit in edits {
+        if let Edit::ClockPosition(x, y) = edit {
+            let clock = doc
+                .get_mut("desktop_widgets")
+                .and_then(|item| item.get_mut("clock"))
+                .ok_or("Clock was removed from the config.")?;
+            clock["anchor"] = toml_edit::value("top_left");
+            clock["margin_x"] = toml_edit::value(i64::from(*x));
+            clock["margin_y"] = toml_edit::value(i64::from(*y));
+            continue;
+        }
+        let notes = doc
+            .get_mut("desktop_widgets")
+            .and_then(|item| item.get_mut("notes"))
+            .and_then(toml_edit::Item::as_array_of_tables_mut)
+            .ok_or("Notes were removed from the config.")?;
+        let id = match edit {
+            Edit::Text(id, _) | Edit::Position(id, _, _) => id,
+            Edit::ClockPosition(..) => unreachable!(),
+        };
+        let note = notes
+            .iter_mut()
+            .find(|note| {
+                note.get("id")
+                    .and_then(toml_edit::Item::as_str)
+                    .unwrap_or("note")
+                    == id
+            })
+            .ok_or("This note no longer exists in the config.")?;
+        match edit {
+            Edit::Text(_, value) => {
+                note["text"] = toml_edit::value(value);
+            }
+            Edit::Position(_, x, y) => {
+                note["anchor"] = toml_edit::value("top_left");
+                note["margin_x"] = toml_edit::value(i64::from(*x));
+                note["margin_y"] = toml_edit::value(i64::from(*y));
+            }
+            Edit::ClockPosition(..) => unreachable!(),
+        }
+    }
+    let updated = doc.to_string();
+    if updated.len() > 60 * 1024 {
+        return Err("Configuration exceeds 60 KiB.".into());
+    }
+    crate::config::parse_source(&updated).map_err(|e| e.to_string())?;
+    let parent = path.parent().ok_or("Config has no parent directory.")?;
+    let mut file = tempfile::NamedTempFile::new_in(parent).map_err(|e| e.to_string())?;
+    file.as_file()
+        .set_permissions(fs::metadata(path).map_err(|e| e.to_string())?.permissions())
+        .map_err(|e| e.to_string())?;
+    file.write_all(updated.as_bytes())
+        .map_err(|e| e.to_string())?;
+    file.as_file().sync_all().map_err(|e| e.to_string())?;
+    if fs::read_to_string(path).map_err(|e| e.to_string())? != source {
+        return Err(
+            "Config changed while saving; your note remains open. Edit again to retry.".into(),
+        );
+    }
+    file.persist(path).map_err(|e| e.to_string())?;
+    fs::File::open(parent)
+        .and_then(|dir| dir.sync_all())
+        .map_err(|e| e.to_string())?;
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn clock_position_saves_without_a_notes_table() {
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("config.toml");
+        fs::write(
+            &path,
+            "[desktop_widgets.clock]\nenabled = true\ntime_size = 80\n",
+        )
+        .unwrap();
+        save(&path, &[Edit::ClockPosition(120, 240)]).unwrap();
+        let config = crate::config::parse_source(&fs::read_to_string(path).unwrap()).unwrap();
+        assert_eq!(
+            (
+                config.desktop_widgets.clock.margin_x,
+                config.desktop_widgets.clock.margin_y
+            ),
+            (120, 240)
+        );
+        assert_eq!(config.desktop_widgets.clock.time_size, 80.);
+    }
+    #[test]
+    fn note_edits_preserve_unrelated_config_and_multiline_content() {
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("config.toml");
+        fs::write(&path, "# keep this\n[theme.colors]\naccent = '#123456'\n[[desktop_widgets.notes]]\nid = 'a'\ntext = 'old'\n").unwrap();
+        save(
+            &path,
+            &[
+                Edit::Text("a".into(), "one\ntwo".into()),
+                Edit::Position("a".into(), 50, 60),
+            ],
+        )
+        .unwrap();
+        let source = fs::read_to_string(&path).unwrap();
+        assert!(source.contains("# keep this"));
+        assert!(source.contains("#123456"));
+        let notes = crate::config::parse_source(&source)
+            .unwrap()
+            .desktop_widgets
+            .notes;
+        assert_eq!(notes[0].text, "one\ntwo");
+        assert_eq!((notes[0].margin_x, notes[0].margin_y), (50, 60));
+        assert_eq!(notes[0].anchor, ferese_core::desktop::Anchor::TopLeft);
+    }
+}