wordle-analyzer/src/solve/naive/mod.rs

use libpt::log::{info, trace};

use crate::error::{SolverError, WResult};
use crate::wlist::word::{Word, WordData};
use crate::wlist::WordList;

use super::{AnyBuiltinSolver, Solver, Status};

#[derive(Debug, Clone)]
pub struct NaiveSolver<'wl, WL> {
    wl: &'wl WL,
}

impl<'wl, WL: WordList> Solver<'wl, WL> for NaiveSolver<'wl, WL> {
    fn build(wordlist: &'wl WL) -> crate::error::WResult<Self> {
        info!("using naive solver");
        Ok(Self { wl: wordlist })
    }
    /// Guess a word from the wordlist for the given game
    ///
    /// ## Algorithm
    ///
    /// * Look at the evaluation for the last response and keep the correct letters
    /// * Get all words that have these letters at the right position
    /// * Discard words that have already been tried
    /// * Discard all words that don't have the chars that we know from the last guess are in the
    ///   word, but don't know the position of.
    fn guess_for(&self, game: &crate::game::Game<WL>) -> WResult<Word> {
        // HACK: hardcoded length
        let mut pattern: String = String::from(".....");
        let mut other_chars: Vec<char> = Vec::new();
        let response = game.last_response();
        trace!(
            "guessing best guess for last response: {response:#?}\n{:#?}",
            response.map(|a| a.evaluation())
        );
        if response.is_some() {
            for (idx, p) in response
                .unwrap()
                .evaluation()
                .clone()
                .into_iter()
                .enumerate()
            {
                if p.1 == Status::Matched {
                    pattern.replace_range(idx..idx + 1, &p.0.to_string());
                } else if p.1 == Status::Exists {
                    other_chars.push(p.0)
                }
            }
        }
        trace!("other chars: {:?}", other_chars);
        let mut matches: Vec<WordData> = game.wordlist().get_words_matching(pattern)?;
        if matches.is_empty() {
            return Err(SolverError::NoMatches.into());
        }
        matches = matches
            .iter()
            // only words that have not been guessed yet
            .filter(|p| !game.made_guesses().contains(&&p.0))
            // only words that contain the letters we found earlier (that were not matched)
            .filter(|p| {
                // TODO: don't repeat unmatched contained chars on the same position twice #2
                let mut fits = true;
                for c in other_chars.iter() {
                    fits &= p.0.contains(*c);
                }
                fits
            })
            .map(|v| v.to_owned())
            .collect();
        if matches.is_empty() {
            return Err(SolverError::NoMatches.into());
        }
        Ok(matches[0].0.to_owned())
    }
}

impl<'wl, WL: WordList> From<NaiveSolver<'wl, WL>> for AnyBuiltinSolver<'wl, WL> {
    fn from(value: NaiveSolver<'wl, WL>) -> Self {
        Self::Naive(value)
    }
}