refactor(core): reorganize module structure

core/src/document/loader.rs

@@ -1,21 +1,56 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 // src/document/loader.rs
 //
-// Document loading: format dispatch and directory scanning.
+// Document loading: format detection, format dispatch, and directory scanning.
 
-use crate::document::format::{detect_format, DocumentFormat};
-use crate::document::portable::PortableModel;
-use crate::document::raster::RasterModel;
-use crate::document::session::{SessionData, SessionItem};
-use crate::document::vector::VectorModel;
-use crate::document::{core::PageLayout, DocumentContent};
+use crate::document::model::{PortableModel, RasterModel, VectorModel};
+use crate::document::session::data::{SessionData, SessionItem};
+use crate::document::types::PageLayout;
+use crate::document::DocumentContent;
 use crate::error::{Error, Result};
 use std::path::Path;
 
+/// The three document formats Noctua understands.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub(crate) enum DocumentFormat {
+    /// Raster images – anything the image crate can decode.
+    Raster,
+    /// Vector graphics (SVG).
+    Vector,
+    /// Portable documents (PDF).
+    Portable,
+}
+
+/// Detects the document format from the file extension.
+///
+/// Returns `None` for unknown extensions so directory scans can skip
+/// unsupported files early. At load time the underlying library
+/// (`ImageReader`, `usvg`, `pdfium`) is the final authority.
+fn detect_format(path: &Path) -> Option<DocumentFormat> {
+    match path
+        .extension()
+        .and_then(|e| e.to_str())
+        .map(str::to_lowercase)
+        .as_deref()
+    {
+        Some("pdf") => Some(DocumentFormat::Portable),
+        Some("svg") => Some(DocumentFormat::Vector),
+        Some("png" | "jpg" | "jpeg" | "webp" | "gif" | "bmp" | "tiff" | "tif") => {
+            Some(DocumentFormat::Raster)
+        }
+        _ => None,
+    }
+}
+
 /// Loads a document from a path and returns its content.
-pub fn load_document(path: &Path) -> Result<DocumentContent> {
+///
+/// # Errors
+///
+/// Returns [`Error::NotFound`] if the path does not exist.
+/// Returns [`Error::Unsupported`] if the file extension is not recognised.
+pub(crate) fn load_document(path: &Path) -> Result<DocumentContent> {
     if !path.exists() {
-        return Err(Error::NotFound(format!("{:?}", path)));
+        return Err(Error::NotFound(format!("{}", path.display())));
     }
 
     match detect_format(path) {
@@ -51,10 +86,10 @@ pub fn load_document(path: &Path) -> Result<DocumentContent> {
 }
 
 /// Scans a directory for supported files and populates the session.
-pub fn scan_directory_into(session: &mut SessionData, dir: &Path) {
+pub(crate) fn scan_directory_into(session: &mut SessionData, dir: &Path) {
     if let Ok(entries) = std::fs::read_dir(dir) {
         let mut paths: Vec<_> = entries
-            .filter_map(|e| e.ok())
+            .filter_map(std::result::Result::ok)
             .map(|e| e.path())
             .filter(|p| p.is_file() && detect_format(p).is_some())
             .collect();