From 0ae25d22129c97af992b43af865d0cce898dc7cc Mon Sep 17 00:00:00 2001
From: SiriusXT <1160925501@qq.com>
Date: Thu, 4 Sep 2025 10:53:46 +0800
Subject: [PATCH] feat: show source diff between note and revision

---
 apps/client/src/services/utils.ts             | 49 +++++++++++++++
 .../src/translations/en/translation.json      |  5 ++
 apps/client/src/widgets/dialogs/revisions.tsx | 63 +++++++++++++++++--
 .../widgets/type_widgets/read_only_code.ts    | 51 +--------------
 4 files changed, 115 insertions(+), 53 deletions(-)

diff --git a/apps/client/src/services/utils.ts b/apps/client/src/services/utils.ts
index 77fec1366..bf3894474 100644
--- a/apps/client/src/services/utils.ts
+++ b/apps/client/src/services/utils.ts
@@ -297,6 +297,54 @@ function isHtmlEmpty(html: string) {
     );
 }
 
+function formatHtml(html: string) {
+    let indent = "\n";
+    const tab = "\t";
+    let i = 0;
+    let pre: { indent: string; tag: string }[] = [];
+
+    html = html
+        .replace(new RegExp("<pre>((.|\\t|\\n|\\r)+)?</pre>"), function (x) {
+            pre.push({ indent: "", tag: x });
+            return "<--TEMPPRE" + i++ + "/-->";
+        })
+        .replace(new RegExp("<[^<>]+>[^<]?", "g"), function (x) {
+            let ret;
+            const tagRegEx = /<\/?([^\s/>]+)/.exec(x);
+            let tag = tagRegEx ? tagRegEx[1] : "";
+            let p = new RegExp("<--TEMPPRE(\\d+)/-->").exec(x);
+
+            if (p) {
+                const pInd = parseInt(p[1]);
+                pre[pInd].indent = indent;
+            }
+
+            if (["area", "base", "br", "col", "command", "embed", "hr", "img", "input", "keygen", "link", "menuitem", "meta", "param", "source", "track", "wbr"].indexOf(tag) >= 0) {
+                // self closing tag
+                ret = indent + x;
+            } else {
+                if (x.indexOf("</") < 0) {
+                    //open tag
+                    if (x.charAt(x.length - 1) !== ">") ret = indent + x.substr(0, x.length - 1) + indent + tab + x.substr(x.length - 1, x.length);
+                    else ret = indent + x;
+                    !p && (indent += tab);
+                } else {
+                    //close tag
+                    indent = indent.substr(0, indent.length - 1);
+                    if (x.charAt(x.length - 1) !== ">") ret = indent + x.substr(0, x.length - 1) + indent + x.substr(x.length - 1, x.length);
+                    else ret = indent + x;
+                }
+            }
+            return ret;
+        });
+
+    for (i = pre.length; i--;) {
+        html = html.replace("<--TEMPPRE" + i + "/-->", pre[i].tag.replace("<pre>", "<pre>\n").replace("</pre>", pre[i].indent + "</pre>"));
+    }
+
+    return html.charAt(0) === "\n" ? html.substr(1, html.length - 1) : html;
+}
+
 export async function clearBrowserCache() {
     if (isElectron()) {
         const win = dynamicRequire("@electron/remote").getCurrentWindow();
@@ -855,6 +903,7 @@ export default {
     getNoteTypeClass,
     getMimeTypeClass,
     isHtmlEmpty,
+    formatHtml,
     clearBrowserCache,
     copySelectionToClipboard,
     dynamicRequire,
diff --git a/apps/client/src/translations/en/translation.json b/apps/client/src/translations/en/translation.json
index d76843a27..1fb32af95 100644
--- a/apps/client/src/translations/en/translation.json
+++ b/apps/client/src/translations/en/translation.json
@@ -263,6 +263,11 @@
     "confirm_delete_all": "Do you want to delete all revisions of this note?",
     "no_revisions": "No revisions for this note yet...",
     "restore_button": "Restore",
+    "diff_button": "Diff",
+    "content_button": "Content",
+    "diff_button_title": "Show note source diff",
+    "content_button_title": "Show revision content",
+    "diff_not_available": "Diff isn't available.",
     "confirm_restore": "Do you want to restore this revision? This will overwrite the current title and content of the note with this revision.",
     "delete_button": "Delete",
     "confirm_delete": "Do you want to delete this revision?",
diff --git a/apps/client/src/widgets/dialogs/revisions.tsx b/apps/client/src/widgets/dialogs/revisions.tsx
index 0fa4f956e..78f4468ae 100644
--- a/apps/client/src/widgets/dialogs/revisions.tsx
+++ b/apps/client/src/widgets/dialogs/revisions.tsx
@@ -18,12 +18,15 @@ import open from "../../services/open";
 import ActionButton from "../react/ActionButton";
 import options from "../../services/options";
 import { useTriliumEvent } from "../react/hooks";
+import { diffWords } from "diff";
 
 export default function RevisionsDialog() {
     const [ note, setNote ] = useState<FNote>();
+    const [ noteContent, setNoteContent ] = useState<string>();
     const [ revisions, setRevisions ] = useState<RevisionItem[]>();
     const [ currentRevision, setCurrentRevision ] = useState<RevisionItem>();
     const [ shown, setShown ] = useState(false);
+    const [ showDiff, setShowDiff ] = useState(false);
     const [ refreshCounter, setRefreshCounter ] = useState(0);
 
     useTriliumEvent("showRevisions", async ({ noteId }) => {
@@ -37,8 +40,10 @@ export default function RevisionsDialog() {
     useEffect(() => {
         if (note?.noteId) {
             server.get<RevisionItem[]>(`notes/${note.noteId}/revisions`).then(setRevisions);
+            note.getContent().then(setNoteContent);
         } else {
             setRevisions(undefined);
+            setNoteContent(undefined);
         }
     }, [ note?.noteId, refreshCounter ]);
 
@@ -70,6 +75,7 @@ export default function RevisionsDialog() {
             footerStyle={{ paddingTop: 0, paddingBottom: 0 }}
             onHidden={() => {
                 setShown(false);
+                setShowDiff(false);
                 setNote(undefined);
                 setCurrentRevision(undefined);
                 setRevisions(undefined);
@@ -92,11 +98,15 @@ export default function RevisionsDialog() {
                     marginLeft: "20px",
                     display: "flex",
                     flexDirection: "column",
+                    maxWidth: "calc(100% - 150px)",
                     minWidth: 0                    
                 }}>
                     <RevisionPreview 
+                        noteContent={noteContent}
                         revisionItem={currentRevision} 
                         setShown={setShown}
+                        showDiff={showDiff}
+                        setShowDiff={setShowDiff}
                         onRevisionDeleted={() => {
                             setRefreshCounter(c => c + 1);
                             setCurrentRevision(undefined);
@@ -121,9 +131,12 @@ function RevisionsList({ revisions, onSelect, currentRevision }: { revisions: Re
         </FormList>);
 }
 
-function RevisionPreview({ revisionItem, setShown, onRevisionDeleted }: { 
+function RevisionPreview({noteContent, revisionItem, setShown, showDiff, setShowDiff, onRevisionDeleted }: {
+    noteContent?: string,
     revisionItem?: RevisionItem, 
-    setShown: Dispatch<StateUpdater<boolean>>,
+    setShown: Dispatch<StateUpdater<boolean>>, 
+    showDiff: boolean,
+    setShowDiff: Dispatch<StateUpdater<boolean>>, 
     onRevisionDeleted?: () => void
 }) {
     const [ fullRevision, setFullRevision ] = useState<RevisionPojo>();
@@ -143,6 +156,17 @@ function RevisionPreview({ revisionItem, setShown, onRevisionDeleted }: {
                 {(revisionItem && <div className="revision-title-buttons">
                     {(!revisionItem.isProtected || protected_session_holder.isProtectedSessionAvailable()) &&
                         <>
+                            {["text", "code", "mermaid"].includes(revisionItem.type) && (
+                                <Button
+                                    icon={showDiff ? "bx bx-detail" : "bx bx-outline"}
+                                    text={showDiff ? t("revisions.content_button") : t("revisions.diff_button")}
+                                    title={showDiff ? t("revisions.content_button_title") : t("revisions.diff_button_title")}
+                                    onClick={async () => {
+                                        setShowDiff(!showDiff);
+                                    }}
+                                />
+                            )}
+                            &nbsp;
                             <Button
                                 icon="bx bx-history"
                                 text={t("revisions.restore_button")}
@@ -179,7 +203,7 @@ function RevisionPreview({ revisionItem, setShown, onRevisionDeleted }: {
                 </div>)}
             </div>
             <div className="revision-content use-tn-links" style={{ overflow: "auto", wordBreak: "break-word" }}>
-                <RevisionContent revisionItem={revisionItem} fullRevision={fullRevision} />
+                <RevisionContent noteContent={noteContent} revisionItem={revisionItem} fullRevision={fullRevision} showDiff={showDiff}/>
             </div>
         </>
     );
@@ -197,12 +221,15 @@ const CODE_STYLE: CSSProperties = {
     whiteSpace: "pre-wrap"
 };
 
-function RevisionContent({ revisionItem, fullRevision }: { revisionItem?: RevisionItem, fullRevision?: RevisionPojo }) {
+function RevisionContent({ noteContent, revisionItem, fullRevision, showDiff }: { noteContent?:string, revisionItem?: RevisionItem, fullRevision?: RevisionPojo, showDiff: boolean}) {
     const content = fullRevision?.content;
     if (!revisionItem || !content) {
         return <></>;
     }
 
+    if (showDiff) {
+        return <RevisionContentDiff noteContent={noteContent} itemContent={content} itemType={revisionItem.type}/>
+    }
     switch (revisionItem.type) {
         case "text":
             return <RevisionContentText content={content} />
@@ -267,6 +294,34 @@ function RevisionContentText({ content }: { content: string | Buffer<ArrayBuffer
     return <div ref={contentRef} className="ck-content" dangerouslySetInnerHTML={{ __html: content as string }}></div>
 }
 
+function RevisionContentDiff({ noteContent, itemContent, itemType }: { noteContent?: string, itemContent: string | Buffer<ArrayBufferLike> | undefined, itemType: string }) {
+    let diffHtml: string;
+
+    if (noteContent && typeof itemContent === "string") {
+        if (itemType === "text") {
+            noteContent = utils.formatHtml(noteContent);
+            itemContent = utils.formatHtml(itemContent);
+        }
+        const diff = diffWords(noteContent, itemContent);
+        diffHtml = diff.map(part => {
+            if (part.added) {
+                return `<span style="background:#d4fcbc">${utils.escapeHtml(part.value)}</span>`;
+            } else if (part.removed) {
+                return `<span style="background:#ffe6e6;text-decoration:line-through;">${utils.escapeHtml(part.value)}</span>`;
+            } else {
+                return utils.escapeHtml(part.value);
+            }
+        }).join("");
+    } else {
+        return <>{t("revisions.diff_not_available")}</>
+    }
+    
+    return (
+        <div className="ck-content" style={{ whiteSpace: "pre-wrap" }}
+            dangerouslySetInnerHTML={{ __html: diffHtml }}></div>
+    );
+}
+
 function RevisionFooter({ note }: { note?: FNote }) {
     if (!note) {
         return <></>;
diff --git a/apps/client/src/widgets/type_widgets/read_only_code.ts b/apps/client/src/widgets/type_widgets/read_only_code.ts
index fd74aaa5a..cdae4565e 100644
--- a/apps/client/src/widgets/type_widgets/read_only_code.ts
+++ b/apps/client/src/widgets/type_widgets/read_only_code.ts
@@ -1,6 +1,7 @@
 import type { EventData } from "../../components/app_context.js";
 import type FNote from "../../entities/fnote.js";
 import AbstractCodeTypeWidget from "./abstract_code_type_widget.js";
+import utils from "../../services/utils.js";
 
 const TPL = /*html*/`
 <div class="note-detail-readonly-code note-detail-printable">
@@ -33,7 +34,7 @@ export default class ReadOnlyCodeTypeWidget extends AbstractCodeTypeWidget {
         if (!blob) return;
 
         const isFormattable = note.type === "text" && this.noteContext?.viewScope?.viewMode === "source";
-        const content = isFormattable ? this.format(blob.content) : blob.content;
+        const content = isFormattable ? utils.formatHtml(blob.content) : blob.content;
 
         this._update(note, content);
         this.show();
@@ -54,52 +55,4 @@ export default class ReadOnlyCodeTypeWidget extends AbstractCodeTypeWidget {
 
         resolve(this.$editor);
     }
-
-    format(html: string) {
-        let indent = "\n";
-        const tab = "\t";
-        let i = 0;
-        let pre: { indent: string; tag: string }[] = [];
-
-        html = html
-            .replace(new RegExp("<pre>((.|\\t|\\n|\\r)+)?</pre>"), function (x) {
-                pre.push({ indent: "", tag: x });
-                return "<--TEMPPRE" + i++ + "/-->";
-            })
-            .replace(new RegExp("<[^<>]+>[^<]?", "g"), function (x) {
-                let ret;
-                const tagRegEx = /<\/?([^\s/>]+)/.exec(x);
-                let tag = tagRegEx ? tagRegEx[1] : "";
-                let p = new RegExp("<--TEMPPRE(\\d+)/-->").exec(x);
-
-                if (p) {
-                    const pInd = parseInt(p[1]);
-                    pre[pInd].indent = indent;
-                }
-
-                if (["area", "base", "br", "col", "command", "embed", "hr", "img", "input", "keygen", "link", "menuitem", "meta", "param", "source", "track", "wbr"].indexOf(tag) >= 0) {
-                    // self closing tag
-                    ret = indent + x;
-                } else {
-                    if (x.indexOf("</") < 0) {
-                        //open tag
-                        if (x.charAt(x.length - 1) !== ">") ret = indent + x.substr(0, x.length - 1) + indent + tab + x.substr(x.length - 1, x.length);
-                        else ret = indent + x;
-                        !p && (indent += tab);
-                    } else {
-                        //close tag
-                        indent = indent.substr(0, indent.length - 1);
-                        if (x.charAt(x.length - 1) !== ">") ret = indent + x.substr(0, x.length - 1) + indent + x.substr(x.length - 1, x.length);
-                        else ret = indent + x;
-                    }
-                }
-                return ret;
-            });
-
-        for (i = pre.length; i--;) {
-            html = html.replace("<--TEMPPRE" + i + "/-->", pre[i].tag.replace("<pre>", "<pre>\n").replace("</pre>", pre[i].indent + "</pre>"));
-        }
-
-        return html.charAt(0) === "\n" ? html.substr(1, html.length - 1) : html;
-    }
 }