2025-12-03 19:54:16 -05:00

117 lines
3.1 KiB
Rust

use std::hint::unreachable_unchecked;
use crate::{generate_hint, Hint, HINT_EMPTY};
#[derive(PartialEq, Debug)]
pub enum Movement {
Complete,
#[allow(dead_code)]
Down,
#[allow(dead_code)]
Up,
None,
}
impl Movement {
pub const fn is_none(&self) -> bool {
matches!(&self, &Self::None)
}
pub const fn is_complete(&self) -> bool {
matches!(&self, &Self::Complete)
}
}
impl Default for Movement {
fn default() -> Self {
Self::None
}
}
#[derive(Clone, PartialEq)]
pub struct AutoComplete<'a> {
pub i: usize,
pub hint: &'a Hint<'a>,
pub string: String,
}
impl<'a> Default for AutoComplete<'a> {
fn default() -> AutoComplete<'a> {
AutoComplete::EMPTY
}
}
impl<'a> AutoComplete<'a> {
pub const EMPTY: AutoComplete<'a> = Self {
i: 0,
hint: &HINT_EMPTY,
string: String::new(),
};
#[allow(dead_code)]
pub fn update_string(&mut self, string: &str) {
if self.string != string {
// catch empty strings here to avoid call to `generate_hint` and unnecessary logic
if string.is_empty() {
*self = Self::EMPTY;
} else {
self.string = string.to_owned();
self.do_update_logic();
}
}
}
/// Runs update logic assuming that a change to `self.string` has been made
fn do_update_logic(&mut self) {
self.i = 0;
self.hint = generate_hint(&self.string);
}
#[allow(dead_code)]
pub fn register_movement(&mut self, movement: &Movement) {
if movement.is_none() | self.hint.is_none() {
return;
}
match self.hint {
Hint::Many(hints) => {
// Impossible for plural hints to be singular or non-existant
debug_assert!(hints.len() > 1); // check on debug
match movement {
Movement::Up => {
// Wrap self.i to maximum `i` value if needed
if self.i == 0 {
self.i = hints.len() - 1;
} else {
self.i -= 1;
}
}
Movement::Down => {
// Add one, if resulting value is above maximum `i` value, set `i` to 0
self.i += 1;
if self.i > (hints.len() - 1) {
self.i = 0;
}
}
Movement::Complete => {
self.apply_hint(unsafe { hints.get_unchecked(self.i) });
}
_ => unsafe { unreachable_unchecked() },
}
}
Hint::Single(hint) => {
if movement.is_complete() {
self.apply_hint(hint);
}
}
Hint::None => unsafe { unreachable_unchecked() },
}
}
pub fn apply_hint(&mut self, hint: &str) {
self.string.push_str(hint);
self.do_update_logic();
}
}