// TODO: Define a function named `lowercase` that converts all characters in a string to lowercase,
// modifying the input in place.
// Does it need to take a `&mut String`? Does a `&mut str` work? Why or why not?

#[cfg(test)]
mod tests {
 use super::*;

 #[test]
 fn empty() {
 let mut s = String::from("");
 lowercase(&mut s);
 assert_eq!(s, "");
 }

 #[test]
 fn one_char() {
 let mut s = String::from("A");
 lowercase(&mut s);
 assert_eq!(s, "a");
 }

 #[test]
 fn multiple_chars() {
 let mut s = String::from("Hello, World!");
 lowercase(&mut s);
 assert_eq!(s, "hello, world!");
 }

 #[test]
 fn mut_slice() {
 let mut s = "Hello, World!".to_string();
 lowercase(s.as_mut_str());
 assert_eq!(s, "hello, world!");
 }
}

fn lowercase(s: &mut str) {
// fn lowercase(s: &mut String) { // どっち？という問題でこちらは選ばなかった
 s.make_ascii_lowercase();
}

// TODO: Update `add_ticket`'s signature: it should take a `TicketDraft` as input
// and return a `TicketId` as output.
// Each ticket should have a unique id, generated by `TicketStore`.
// Feel free to modify `TicketStore` fields, if needed.
//
// You also need to add a `get` method that takes as input a `TicketId`
// and returns an `Option<&Ticket>`.

use ticket_fields::{TicketDescription, TicketTitle};

#[derive(Clone)]
pub struct TicketStore {
 tickets: Vec<Ticket>,
}

#[derive(Clone, Copy, Debug, PartialEq)]
pub struct TicketId(u64);

#[derive(Clone, Debug, PartialEq)]
pub struct Ticket {
 pub id: TicketId,
 pub title: TicketTitle,
 pub description: TicketDescription,
 pub status: Status,
}

#[derive(Clone, Debug, PartialEq)]
pub struct TicketDraft {
 pub title: TicketTitle,
 pub description: TicketDescription,
}

#[derive(Clone, Debug, Copy, PartialEq)]
pub enum Status {
 ToDo,
 InProgress,
 Done,
}

impl TicketStore {
 pub fn new() -> Self {
 Self {
 tickets: Vec::new(),
 }
 }

 // ここに改変が必要
 pub fn add_ticket(&mut self, ticket: Ticket) {
 self.tickets.push(ticket);
 }
}

#[cfg(test)]
mod tests {
 use crate::{Status, TicketDraft, TicketStore};
 use ticket_fields::test_helpers::{ticket_description, ticket_title};

 #[test]
 fn works() {
 let mut store = TicketStore::new();

 let draft1 = TicketDraft {
 title: ticket_title(),
 description: ticket_description(),
 };
 let id1 = store.add_ticket(draft1.clone());
 let ticket1 = store.get(id1).unwrap();
 assert_eq!(draft1.title, ticket1.title);
 assert_eq!(draft1.description, ticket1.description);
 assert_eq!(ticket1.status, Status::ToDo);

 let draft2 = TicketDraft {
 title: ticket_title(),
 description: ticket_description(),
 };
 let id2 = store.add_ticket(draft2);
 let ticket2 = store.get(id2).unwrap();

 assert_ne!(id1, id2);
 }
}

impl TicketStore {
 // ...省略...

 pub fn add_ticket(&mut self, ticket_draft: TicketDraft) -> TicketId {
 let TicketDraft { title, description } = ticket_draft;

 let id = TicketId(self.tickets.len() as _);

 let ticket = Ticket {
 title,
 id,
 description,
 status: Status::ToDo,
 };

 self.tickets.push(ticket);

 id
 }

 fn get(&self, id: TicketId) -> Option<&Ticket> {
 self.tickets.iter().find(|t| t.id == id)
 }
}