#!/usr/bin/env -S deno run --allow-read

import { assertExists } from "https://deno.land/std@0.224.0/assert/assert_exists.ts";

async function main() {
	const length = 6;
	const dict = await Dict.from_file("./data/liste_francais.txt", length);
	console.log(dict);
	const history = new History(dict);
	const game = Game.from_dict_rand(dict);
	console.log("Target is", game.word);
	let index = 0;
	while (true) {
		index += 1;
		const found = await history.next_guess((guess) => {
			console.log("Guessing", guess);
			const result = game.try_guess(guess);
			console.log(format_result(result));
			return result;
		});
		if (found !== undefined) {
			console.log("Found", found, "in", index);
			break;
		}
		await wait(500);
	}
}

type GuessResult = { kind: "success" } | { kind: "failure"; informations: Info[] };

function format_result(result: GuessResult) {
	if (result.kind === "success") return `success`;
	let line = "failure: ";
	for (const info of result.informations) line += info.kind === "abscent" ? "-" : info.kind === "somewhere" ? "+" : "#";
	return line;
}

class Dict {
	words;
	letters;
	length;

	constructor(words: Set<string>, length: number) {
		this.words = words;
		this.length = length;
		this.letters = new Set([...words.values()].map((w) => w.split("")).flat());
	}

	static async from_file(path: string, length: number) {
		const words = new Set<string>();
		const content = await Deno.readTextFile(path);
		for (const word of content.split("\n")) {
			const word_ = word.trim().toLowerCase();
			if (word_.length !== length) continue;
			for (const forbidden of [" ", "-", "."]) if (word_.includes(forbidden)) continue;
			words.add(remove_accent(word_));
		}
		return new Dict(words, length);
	}

	[Symbol.for("Deno.customInspect")]() {
		return `Dict { ${this.words.size} words }`;
	}
}

type Knowledge = {
	letter: string;
	at: Set<number>;
	not_at: Set<number>;
};

class History {
	length;
	dict;
	informations;

	constructor(dict: Dict) {
		this.length = dict.length;
		this.dict = dict;
		this.informations = new Map<string, Knowledge>();
		for (const letter of dict.letters.values()) {
			this.informations.set(letter, { letter, at: new Set(), not_at: new Set() });
		}
	}

	async next_guess(operation: (guess: string) => GuessResult | Promise<GuessResult>) {
		const res = this.expected_result();
		console.log("knows:  ", res.known);
		if (res.completed) return operation(res.known);

		const words = [...this.dict.words.values()];
		const scored = words.map((word) => [this.info_for(word), word] as const);
		const sorted = scored.toSorted(([sa], [sb]) => sb - sa);
		const [_score, guess] = sorted[0];

		const result = await operation(guess);
		if (result.kind === "success") return guess;

		for (const [letter, new_info] of zip(guess, result.informations)) {
			//
		}
	}

	learn_letter_at(letter: string, at: number) {
		const letter_info = this.informations.get(letter);
		assertExists(letter_info);
		letter_info.at.add(at);
		for (const l of this.informations.keys()) {
			if (letter === l) continue;
			this.learn_letter_not_at(l, at);
		}
	}

	learn_letter_not_at(letter: string, at: number) {
		const letter_info = this.informations.get(letter);
		assertExists(letter_info);
		letter_info.not_at.add(at);
	}

	info_for(word: string) {
		let total = 0;
		for (const [index, letter] of enumerate(word)) {
			const information = this.informations.get(letter);
			if (information === undefined) {
				total += 1;
				continue;
			}
            
            if ()

			if (information.kind === "abscent") {
				continue;
			}

			if (information.kind === "present") {
				const known_pos = information.not_at.has(index);
				if (!known_pos) total += this.length; // note : not 1 to priorize locating known letters.
				continue;
			}
		}
		return total;
	}

	expected_result() {
		const known_arr = [...range(0, this.length)].map(() => null as string | null);
		for (const [letter, info] of this.informations.entries()) {
			if (info.kind !== "known") continue;
			for (const i of info.at.values()) known_arr[i] = letter;
		}

		const known = known_arr.map((l) => l === null ? "." : l).join("");
		if (known.includes(".")) return { completed: false as const, known };
		const guess = known_arr as string[];
		return { completed: true as const, known, guess };
	}
}

type Info = { kind: "abscent" } | { kind: "somewhere" } | { kind: "there" };

function remove_accent(text: string) {
	const accents = [
		["à", "a"],
		["â", "a"],
		["ä", "a"],
		["é", "e"],
		["è", "e"],
		["ê", "e"],
		["ë", "e"],
		["î", "i"],
		["ï", "i"],
		["ô", "o"],
		["ö", "o"],
		["û", "u"],
	];
	let result = text;
	for (const [accent, alternative] of accents) result = result.replaceAll(accent, alternative);
	return result;
}

function* enumerate<T>(iterator: Iterable<T>) {
	let index = 0;
	for (const item of iterator) yield [index++, item] as const;
}

function* zip<A, B>(iterable_a: Iterable<A>, iterable_b: Iterable<B>) {
	const iter_a = iterable_a[Symbol.iterator]();
	const iter_b = iterable_b[Symbol.iterator]();
	while (true) {
		const next_a = iter_a.next().value;
		const next_b = iter_b.next().value;
		if (next_a === undefined) return;
		if (next_b === undefined) return;
		yield [next_a as A, next_b as B] as const;
	}
}

class Game {
	word;

	constructor(word: string) {
		this.word = word;
	}

	static from_dict_rand(dict: Dict) {
		const index = Math.floor(Math.random() * dict.words.size);
		const word = [...dict.words.values()][index];
		return new Game(word);
	}

	try_guess(guess: string): GuessResult {
		if (guess === this.word) return { kind: "success" };
		const rest_actual = [...this.word].map((letter) => letter as (string | null));
		const rest_guess = [...guess].map((letter) => letter as (string | null));
		const info = [...range(0, this.word.length)].map(() => null) as (Info | null)[];

		for (const [index, [guessed, actual]] of enumerate(zip(rest_guess, rest_actual))) {
			if (guessed !== actual) continue;
			rest_actual[index] = null;
			rest_guess[index] = null;
			info[index] = { kind: "known", at: new Set([index]) };
		}

		for (const [index, guessed] of enumerate(rest_guess)) {
			if (guessed === null) continue;
			if (!rest_actual.includes(guessed)) continue;
			info[index] = { kind: "present", not_at: new Set([index]) };
			rest_guess[index] = null;
			// note : removes only one.
			rest_actual[rest_actual.indexOf(guessed)] = null;
		}

		const informations = info.map((i) => i != undefined ? i : ({ kind: "abscent" }) as Info);
		return { kind: "failure", informations };
	}
}

function* range(from: number, to: number) {
	while (from < to) yield from++;
}

async function wait(ms: number) {
	await new Promise((resolver) => setTimeout(resolver, ms));
}

if (import.meta.main) await main();