<?php
// Single player: Mastermind. 4 pegs, 6 colors, 10 tries.
// State persisted in sp_games (game='mastermind').
require_once __DIR__ . '/../lib/bootstrap.php';
$me = require_login();

const MM_COLORS = ['1', '2', '3', '4', '5', '6'];
const MM_MAX_TRIES = 10;

function mm_load(int $uid): ?array {
    $s = db()->prepare("SELECT * FROM sp_games WHERE user_id=? AND game='mastermind'
                        AND status='active' ORDER BY id DESC LIMIT 1");
    $s->execute([$uid]);
    return $s->fetch() ?: null;
}
function mm_new(int $uid): array {
    $secret = [];
    foreach (range(0, 3)) $secret[] = MM_COLORS[array_rand(MM_COLORS)];
    $st = json_encode(['secret' => $secret, 'tries' => 0, 'log' => []]);
    $now = time();
    db()->prepare("INSERT INTO sp_games (game,user_id,state,created_at,updated_at)
                   VALUES ('mastermind',?,?,?,?)")->execute([$uid, $st, $now, $now]);
    return mm_load($uid);
}

function mm_feedback(array $secret, array $guess): array {
    $black = 0;
    $sCounts = [];
    $gCounts = [];
    for ($i = 0; $i < 4; $i++) {
        if ($guess[$i] === $secret[$i]) $black++;
        $sCounts[$secret[$i]] = ($sCounts[$secret[$i]] ?? 0) + 1;
        $gCounts[$guess[$i]] = ($gCounts[$guess[$i]] ?? 0) + 1;
    }
    $white = 0;
    foreach ($sCounts as $c => $n) {
        $white += min($n, $gCounts[$c] ?? 0);
    }
    return [$black, $white - $black];
}

$msg = ''; $done = false;
$g = mm_load((int)$me['id']);

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    require_csrf();
    $act = $_POST['act'] ?? '';
    if ($act === 'new') {
        if ($g) db()->prepare("UPDATE sp_games SET status='abandoned' WHERE id=?")->execute([$g['id']]);
        $g = mm_new((int)$me['id']);
        $msg = 'New game! I have chosen a sequence of 4 colors from 1-6.';
    } else {
        if (!$g) $g = mm_new((int)$me['id']);
        $st = json_decode($g['state'], true);
        $raw = (string)($_POST['guess'] ?? '');
        if (strlen($raw) !== 4 || !ctype_digit($raw) || !array_reduce(str_split($raw), function($carry, $c) { return $carry && in_array($c, MM_COLORS, true); }, true)) {
            $msg = 'Enter exactly 4 digits from 1-6 (e.g. 1234).';
        } else {
            $guess = str_split($raw);
            $st['tries']++;
            $st['log'][] = $guess;
            list($black, $white) = mm_feedback($st['secret'], $guess);
            if ($black === 4) {
                $score = max(1, 100 - 10 * (int)$st['tries']);
                db()->prepare("UPDATE sp_games SET status='won', state=?, updated_at=? WHERE id=?")
                    ->execute([json_encode($st), time(), $g['id']]);
                db()->prepare("INSERT INTO scores (game,user_id,score,detail,created_at)
                               VALUES ('mastermind',?,?,?,?)")
                    ->execute([$me['id'], $score, $st['tries'] . ' tries', time()]);
                $msg = "Correct! " . implode('', $st['secret']) . " in {$st['tries']} tries. Score: $score";
                $done = true; $g = null;
            } elseif ($st['tries'] >= MM_MAX_TRIES) {
                db()->prepare("UPDATE sp_games SET status='lost', state=?, updated_at=? WHERE id=?")
                    ->execute([json_encode($st), time(), $g['id']]);
                $msg = "Out of tries. The code was " . implode('', $st['secret']) . '.';
                $done = true; $g = null;
            } else {
                db()->prepare("UPDATE sp_games SET state=?, updated_at=? WHERE id=?")
                    ->execute([json_encode($st), time(), $g['id']]);
                $g['state'] = json_encode($st);
                $msg = "Feedback: $black Black, $white White. Tries: {$st['tries']}.";
            }
        }
    }
}

page_start('Mastermind', ['back' => '/games.php']);
if ($msg) p_para($msg);
if ($g) {
    $st = json_decode($g['state'], true);
    if ($st['log']) {
        $rows = [];
        foreach (array_slice($st['log'], -5) as $lg) {
            $rows[] = implode('', $lg);
        }
        p_para('Recent guesses: ' . implode(', ', $rows));
    }
    p_para('Guess a 4-digit code (digits 1-6).');
    p_form('/games/mastermind.php', [
        ['name' => 'guess', 'label' => 'Your guess (e.g. 1234)', 'maxlength' => 4,
         'format' => '*N'],
    ], 'Guess');
} else {
    if (!$done) p_para('Guess the secret 4-color sequence. Black = right color and position, White = right color only.');
}
p_form('/games/mastermind.php', [
    ['name' => 'act', 'type' => 'hidden', 'value' => 'new'],
], $g ? 'Restart' : 'New game');
p_links([['/games/scores.php', 'High scores', ['g' => 'mastermind']], ['/games.php', 'Games']]);
page_end();