fix: TOC navigation and pagination improvements

- Fix recalculate_pages missing heading_top_spacing in page height calculation
- Improve build_toc path matching: extract filename first, fall back to substring
- Filter out EPUB3 nav.xhtml from content sections
- Skip Windows resource compilation when windres is not available
- Add unit tests for TOC filename matching and nav filtering

src/book.rs

@@ -248,7 +248,19 @@ pub fn load_epub(path: impl AsRef<Path>) -> Result<Book, String> {
     let title = doc.mdata("title").unwrap_or_else(|| "未知标题".to_string());
     let author = doc.mdata("creator").unwrap_or_else(|| "未知作者".to_string());
     let cover = doc.get_cover().ok();
-    let spine = doc.spine.clone();
+    let spine: Vec<String> = doc.spine.iter()
+        .filter(|id| {
+            if id.as_str() == "nav" { return false; }
+            if let Some((path, _)) = doc.resources.get(*id) {
+                let path_str = path.to_string_lossy().to_lowercase();
+                if path_str.ends_with("nav.xhtml") || path_str.ends_with("nav.html") {
+                    return false;
+                }
+            }
+            true
+        })
+        .cloned()
+        .collect();
 
     let mut sections = Vec::new();
     for (i, href) in spine.iter().enumerate() {
@@ -290,6 +302,11 @@ fn extract_title(html: &str) -> Option<String> {
     None
 }
 
+fn extract_filename(path: &str) -> &str {
+    let path = path.trim_end_matches('/');
+    path.rsplit('/').next().unwrap_or(path)
+}
+
 fn build_toc(
     entries: &[epub::doc::NavPoint],
     spine: &[String],
@@ -298,10 +315,15 @@ fn build_toc(
         .iter()
         .map(|e| {
             let content_str = e.content.to_string_lossy();
+            let content_file = extract_filename(&content_str);
             let section = spine
                 .iter()
-                .position(|s| content_str.contains(s.trim_end_matches('/')))
-                // unwrap_or(0) is safe: a real TOC entry should always match a spine item
+                .position(|s| {
+                    let spine_file = extract_filename(s);
+                    spine_file == content_file
+                        || content_str.contains(s.as_str())
+                        || s.contains(content_str.as_ref())
+                })
                 .unwrap_or(0);
             TocEntry {
                 label: e.label.clone(),
@@ -439,4 +461,66 @@ mod tests {
         let toc = build_toc(&[], &[]);
         assert!(toc.is_empty());
     }
+
+    #[test]
+    fn test_load_sample_epub_nav_filtered() {
+        let book = load_epub("sample-short.epub").expect("Failed to load sample epub");
+        // Nav document is filtered out, leaving only chapter_0 as the single section
+        assert_eq!(book.sections.len(), 1);
+        assert_eq!(book.sections[0].title, "Understanding Digital Formats");
+    }
+
+    #[test]
+    fn test_toc_section_bounds() {
+        let book = load_epub("sample-short.epub").expect("Failed to load sample epub");
+        // All TOC section indices should be within sections range
+        fn check_bounds(entries: &[TocEntry], max: usize) {
+            for e in entries {
+                assert!(e.section < max, "TOC entry '{}' maps to section {} but only {} sections exist", e.label, e.section, max);
+                check_bounds(&e.children, max);
+            }
+        }
+        check_bounds(&book.toc, book.sections.len());
+    }
+
+    #[test]
+    fn test_build_toc_filename_matching() {
+        use epub::doc::NavPoint;
+        let spine = vec![
+            "OEBPS/Text/chapter1.xhtml".to_string(),
+            "OEBPS/Text/chapter2.xhtml".to_string(),
+        ];
+        let nav_points = vec![
+            NavPoint {
+                label: "Chapter 2".to_string(),
+                content: std::path::PathBuf::from("Text/chapter2.xhtml"),
+                play_order: 1,
+                children: vec![],
+            },
+        ];
+        let toc = build_toc(&nav_points, &spine);
+        assert_eq!(toc.len(), 1);
+        assert_eq!(toc[0].section, 1); // maps to spine index 1
+        assert_eq!(toc[0].label, "Chapter 2");
+    }
+
+    #[test]
+    fn test_build_toc_exact_path_match() {
+        use epub::doc::NavPoint;
+        let spine = vec![
+            "chapter1.xhtml".to_string(),
+            "chapter2.xhtml".to_string(),
+        ];
+        let nav_points = vec![
+            NavPoint {
+                label: "Chapter 1".to_string(),
+                content: std::path::PathBuf::from("chapter1.xhtml"),
+                play_order: 1,
+                children: vec![],
+            },
+        ];
+        let toc = build_toc(&nav_points, &spine);
+        assert_eq!(toc.len(), 1);
+        assert_eq!(toc[0].section, 0);
+    }
 }