feat(library): app-managed book storage commands

src-tauri/src/lib.rs

@@ -1,4 +1,5 @@
 mod epub;
+mod library;
 mod pdf;
 mod project;
 
@@ -12,7 +13,11 @@ pub fn run() {
             pdf::compile_pdf,
             project::read_file,
             project::write_file,
-            project::write_bytes
+            project::write_bytes,
+            library::list_books,
+            library::load_book,
+            library::save_book,
+            library::delete_book
         ])
         .run(tauri::generate_context!())
         .expect("error while running margin");

src-tauri/src/library.rs

@@ -0,0 +1,85 @@
+use std::fs;
+use std::path::PathBuf;
+use tauri::Manager;
+
+#[derive(serde::Serialize)]
+pub struct BookSummary {
+    id: String,
+    title: String,
+    author: String,
+}
+
+fn library_dir(app: &tauri::AppHandle) -> Result<PathBuf, String> {
+    let dir = app
+        .path()
+        .app_data_dir()
+        .map_err(|e| e.to_string())?
+        .join("library");
+    fs::create_dir_all(&dir).map_err(|e| e.to_string())?;
+    Ok(dir)
+}
+
+#[tauri::command]
+pub fn list_books(app: tauri::AppHandle) -> Result<Vec<BookSummary>, String> {
+    let dir = library_dir(&app)?;
+    let mut books = Vec::new();
+    for entry in fs::read_dir(&dir).map_err(|e| e.to_string())? {
+        let path = match entry {
+            Ok(entry) => entry.path(),
+            Err(_) => continue,
+        };
+        if path.extension().and_then(|e| e.to_str()) != Some("margin") {
+            continue;
+        }
+        let contents = match fs::read_to_string(&path) {
+            Ok(contents) => contents,
+            Err(_) => continue,
+        };
+        let value: serde_json::Value = match serde_json::from_str(&contents) {
+            Ok(value) => value,
+            Err(_) => continue,
+        };
+        let id = value.get("id").and_then(|v| v.as_str()).unwrap_or("");
+        if id.is_empty() {
+            continue;
+        }
+        let metadata = value.get("metadata");
+        let title = metadata
+            .and_then(|m| m.get("title"))
+            .and_then(|v| v.as_str())
+            .unwrap_or("Untitled")
+            .to_string();
+        let author = metadata
+            .and_then(|m| m.get("author"))
+            .and_then(|v| v.as_str())
+            .unwrap_or("")
+            .to_string();
+        books.push(BookSummary {
+            id: id.to_string(),
+            title,
+            author,
+        });
+    }
+    Ok(books)
+}
+
+#[tauri::command]
+pub fn load_book(app: tauri::AppHandle, id: String) -> Result<String, String> {
+    let path = library_dir(&app)?.join(format!("{id}.margin"));
+    fs::read_to_string(&path).map_err(|e| e.to_string())
+}
+
+#[tauri::command]
+pub fn save_book(app: tauri::AppHandle, id: String, contents: String) -> Result<(), String> {
+    let path = library_dir(&app)?.join(format!("{id}.margin"));
+    fs::write(&path, contents).map_err(|e| e.to_string())
+}
+
+#[tauri::command]
+pub fn delete_book(app: tauri::AppHandle, id: String) -> Result<(), String> {
+    let path = library_dir(&app)?.join(format!("{id}.margin"));
+    if path.exists() {
+        fs::remove_file(&path).map_err(|e| e.to_string())?;
+    }
+    Ok(())
+}