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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
use std::sync::{Arc, RwLock};
use once_cell::sync::Lazy;
#[derive(Debug, Clone)]
pub struct TodoEntry {
text: String,
}
// There is a single "default" TodoList that can be shared
// by all consumers of this component. Depending on requirements,
// a real app might like to use a `Weak<>` rather than an `Arc<>`
// here to reduce the risk of circular references.
static DEFAULT_LIST: Lazy<RwLock<Option<Arc<TodoList>>>> = Lazy::new(|| RwLock::new(None));
#[derive(Debug, thiserror::Error)]
pub enum TodoError {
#[error("The todo does not exist!")]
TodoDoesNotExist,
#[error("The todolist is empty!")]
EmptyTodoList,
#[error("That todo already exists!")]
DuplicateTodo,
#[error("Empty String error!: {0}")]
EmptyString(String),
#[error("I am a delegated Error: {0}")]
DeligatedError(#[from] std::io::Error),
}
/// Get a reference to the global default TodoList, if set.
///
fn get_default_list() -> Option<Arc<TodoList>> {
DEFAULT_LIST.read().unwrap().clone()
}
/// Set the global default TodoList.
///
/// This will silently drop any previously set value.
///
fn set_default_list(list: Arc<TodoList>) {
*DEFAULT_LIST.write().unwrap() = Some(list);
}
/// Create a new TodoEntry from the given string.
///
fn create_entry_with<S: Into<String>>(item: S) -> Result<TodoEntry> {
let text = item.into();
if text.is_empty() {
return Err(TodoError::EmptyString(
"Cannot add empty string as entry".to_string(),
));
}
Ok(TodoEntry { text })
}
type Result<T, E = TodoError> = std::result::Result<T, E>;
// A simple Todolist.
// UniFFI requires that we use interior mutability for managing mutable state, so we wrap our `Vec` in a RwLock.
// (A Mutex would also work, but a RwLock is more appropriate for this use-case, so we use it).
#[derive(Debug)]
pub struct TodoList {
items: RwLock<Vec<String>>,
}
impl TodoList {
fn new() -> Self {
Self {
items: RwLock::new(Vec::new()),
}
}
fn add_item<S: Into<String>>(&self, item: S) -> Result<()> {
let item = item.into();
if item.is_empty() {
return Err(TodoError::EmptyString(
"Cannot add empty string as item".to_string(),
));
}
let mut items = self.items.write().unwrap();
if items.contains(&item) {
return Err(TodoError::DuplicateTodo);
}
items.push(item);
Ok(())
}
fn get_last(&self) -> Result<String> {
let items = self.items.read().unwrap();
items.last().cloned().ok_or(TodoError::EmptyTodoList)
}
fn get_first(&self) -> Result<String> {
let items = self.items.read().unwrap();
items.first().cloned().ok_or(TodoError::EmptyTodoList)
}
fn add_entries(&self, entries: Vec<TodoEntry>) {
let mut items = self.items.write().unwrap();
items.extend(entries.into_iter().map(|e| e.text))
}
fn add_entry(&self, entry: TodoEntry) -> Result<()> {
self.add_item(entry.text)
}
fn add_items<S: Into<String>>(&self, items: Vec<S>) {
let mut my_items = self.items.write().unwrap();
my_items.extend(items.into_iter().map(Into::into))
}
fn get_items(&self) -> Vec<String> {
let items = self.items.read().unwrap();
items.clone()
}
fn get_entries(&self) -> Vec<TodoEntry> {
let items = self.items.read().unwrap();
items
.iter()
.map(|text| TodoEntry { text: text.clone() })
.collect()
}
fn get_last_entry(&self) -> Result<TodoEntry> {
let text = self.get_last()?;
Ok(TodoEntry { text })
}
fn clear_item<S: Into<String>>(&self, item: S) -> Result<()> {
let item = item.into();
let mut items = self.items.write().unwrap();
let idx = items
.iter()
.position(|s| s == &item)
.ok_or(TodoError::TodoDoesNotExist)?;
items.remove(idx);
Ok(())
}
fn make_default(self: Arc<Self>) {
set_default_list(self);
}
}
uniffi::include_scaffolding!("todolist");
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