saving and loading library implemented

src/utils.rs

@@ -0,0 +1,60 @@
+use crate::structs::{Library, Shelf};
+use std::{env, fs, io, io::Read};
+use xdg::BaseDirectories;
+
+pub fn get_shelf_index(shelves: &Vec<Shelf>, id: &u8) -> Option<usize> {
+    shelves.iter().position(|shelf| shelf.id == *id)
+}
+
+pub fn deserialize_state_file() -> io::Result<Library> {
+    let xdg_dirs = get_xdg();
+    let state_file_path = xdg_dirs.place_state_file("shelf-state.json")?;
+
+    let state_file_content = match fs::read_to_string(state_file_path) {
+        Ok(content) => content,
+        Err(e) => {
+            eprintln!("Could not read state file: {}", e);
+            return Ok(initialize_library());
+        }
+    };
+
+    let state_file_decoded: Library = serde_json::from_str(&state_file_content)?;
+
+    Ok(state_file_decoded)
+}
+
+pub fn get_xdg() -> BaseDirectories {
+    let xdg_dirs = xdg::BaseDirectories::with_prefix("shelf");
+    return xdg_dirs;
+}
+
+pub fn get_state_file() -> io::Result<std::path::PathBuf> {
+    let xdg_dirs = get_xdg();
+    let state_file_path = xdg_dirs.place_state_file("shelf-state.json")?;
+    Ok(state_file_path)
+}
+
+pub fn save_library(library: Library) -> io::Result<()> {
+    let seralized_library = serde_json::to_string(&library).unwrap_or_default();
+    let state_file = get_state_file()?;
+
+    fs::write(state_file, seralized_library)?;
+
+    Ok(())
+}
+
+pub fn initialize_library() -> Library {
+    let default_shelf: Shelf = Shelf {
+        id: 0,
+        name: "default".to_string(),
+        content: Vec::new(),
+    };
+
+    let mut shelf_vec: Vec<Shelf> = Vec::new();
+    shelf_vec.push(default_shelf);
+    let default_library: Library = Library {
+        current_shelf: 0,
+        shelves: shelf_vec,
+    };
+    return default_library;
+}