refactor: move block delete to history-safe commands

rust/spikes/leptos-tiptap-spike/src/editor_runtime/history_safe_commands.rs

@@ -1,4 +1,8 @@
-use leptos_tiptap::TiptapEditorHandle;
+use leptos_tiptap::{
+    TiptapContent, TiptapEditorHandle, TiptapInsertContentOptions, TiptapRange,
+};
+use serde_json::json;
+use serde_json::Value;
 
 use crate::editor_runtime::attachment_links;
 
@@ -18,3 +22,92 @@ pub(crate) fn delete_selected_attachment_link_with_history(
     // 继续走 Tiptap 命令路径，保留撤销/重做历史。
     editor.delete_selection().map_err(|error| error.to_string())
 }
+
+fn prosemirror_node_size(node: &Value) -> Option<u32> {
+    match node.get("type").and_then(Value::as_str) {
+        Some("text") => Some(
+            node.get("text")
+                .and_then(Value::as_str)
+                .map(|text| text.encode_utf16().count() as u32)
+                .unwrap_or(0),
+        ),
+        Some("hardBreak") | Some("horizontalRule") => Some(1),
+        _ => {
+            let Some(children) = node.get("content").and_then(Value::as_array) else {
+                return Some(match node.get("type").and_then(Value::as_str) {
+                    Some("paragraph") | Some("heading") | Some("blockquote")
+                    | Some("codeBlock") | Some("bulletList") | Some("orderedList")
+                    | Some("taskList") | Some("listItem") | Some("taskItem") | Some("table")
+                    | Some("tableRow") | Some("tableCell") | Some("tableHeader") => 2,
+                    _ => 1,
+                });
+            };
+
+            let content_size = children.iter().try_fold(0_u32, |acc, child| {
+                prosemirror_node_size(child).map(|size| acc + size)
+            })?;
+            Some(content_size + 2)
+        }
+    }
+}
+
+fn top_level_block_full_range(document: &Value, index: usize) -> Option<TiptapRange> {
+    let content = document.get("content").and_then(Value::as_array)?;
+    let mut position = 0_u32;
+
+    for (current_index, node) in content.iter().enumerate() {
+        let node_size = prosemirror_node_size(node)?;
+        if current_index == index {
+            return Some(TiptapRange {
+                from: position,
+                to: position + node_size,
+            });
+        }
+        position += node_size;
+    }
+
+    None
+}
+
+/// 通过 Tiptap `delete_range()` 删除顶层块，避免使用 `set_content()` 整文替换绕过 history。
+pub(crate) fn delete_top_level_block_with_history(
+    editor: &TiptapEditorHandle,
+    index: usize,
+) -> Result<(), String> {
+    let document = editor
+        .get_json()
+        .map_err(|err| format!("读取当前 JSON 失败：{err}"))?;
+    let content_len = document
+        .get("content")
+        .and_then(Value::as_array)
+        .map(Vec::len)
+        .unwrap_or(0);
+
+    if index >= content_len {
+        return Err(format!("找不到第 {index} 个块"));
+    }
+
+    let range = top_level_block_full_range(&document, index)
+        .ok_or_else(|| format!("找不到第 {} 个块的删除范围", index + 1))?;
+
+    if content_len <= 1 {
+        editor
+            .insert_content_at(
+                range,
+                TiptapContent::json(json!({ "type": "paragraph" })),
+                Some(TiptapInsertContentOptions {
+                    update_selection: Some(true),
+                    ..Default::default()
+                }),
+            )
+            .map_err(|err| format!("删除当前块失败：{err}"))?;
+    } else {
+        editor
+            .delete_range(range)
+            .map_err(|err| format!("删除当前块失败：{err}"))?;
+    }
+
+    editor
+        .focus()
+        .map_err(|err| format!("聚焦编辑器失败：{err}"))
+}