<?php
declare(strict_types=1);

/**
 * Shared helpers — lookup player account by jdPlayerKey (providerUserId).
 * รองรับทั้ง guest และ google (และ loginType อื่นในอนาคต)
 */
function valid_player_key(string $key): bool
{
    return (bool) preg_match('/^[a-zA-Z0-9_-]{8,128}$/', $key);
}

function find_account_index_by_player_key(array $accounts, string $key): int
{
    foreach ($accounts as $i => $a) {
        if (($a['providerUserId'] ?? '') === $key) {
            return (int) $i;
        }
    }
    return -1;
}

function find_account_by_player_key(array $accounts, string $key): ?array
{
    $idx = find_account_index_by_player_key($accounts, $key);
    return $idx >= 0 ? $accounts[$idx] : null;
}

function default_guest_account(string $key, string $notes = 'auto', array $extra = []): array
{
    $now = gmdate('c');
    return array_merge([
        'id' => new_id(),
        'email' => '',
        'displayName' => 'Guest',
        'loginType' => 'guest',
        'providerUserId' => $key,
        'notes' => $notes,
        'blocked' => false,
        'coins' => 0,
        'createdAt' => $now,
        'updatedAt' => $now,
    ], $extra);
}

function google_player_key(string $googleSub): string
{
    $sub = trim($googleSub);
    if ($sub === '') {
        return '';
    }
    if (str_starts_with($sub, 'g_')) {
        return $sub;
    }
    return 'g_' . $sub;
}

function merge_guest_account_into(array &$store, int $targetIdx, string $guestKey): void
{
    if ($guestKey === '' || !valid_player_key($guestKey)) {
        return;
    }
    $guestIdx = find_account_index_by_player_key($store['accounts'] ?? [], $guestKey);
    if ($guestIdx < 0 || $guestIdx === $targetIdx) {
        return;
    }
    $guest = $store['accounts'][$guestIdx];
    if (($guest['loginType'] ?? '') !== 'guest') {
        return;
    }

    $target = &$store['accounts'][$targetIdx];
    $target['coins'] = max(0, (int) ($target['coins'] ?? 0)) + max(0, (int) ($guest['coins'] ?? 0));
    $target['score'] = max(0, (int) ($target['score'] ?? 0)) + max(0, (int) ($guest['score'] ?? 0));

    if (isset($guest['scoreByCase']) && is_array($guest['scoreByCase'])) {
        if (!isset($target['scoreByCase']) || !is_array($target['scoreByCase'])) {
            $target['scoreByCase'] = [];
        }
        foreach ($guest['scoreByCase'] as $cid => $sc) {
            $target['scoreByCase'][$cid] = max(0, (int) ($target['scoreByCase'][$cid] ?? 0)) + max(0, (int) $sc);
        }
    }

    if (isset($guest['achievements']) && is_array($guest['achievements'])) {
        if (!isset($target['achievements']) || !is_array($target['achievements'])) {
            $target['achievements'] = [];
        }
        foreach ($guest['achievements'] as $aid => $cnt) {
            $target['achievements'][$aid] = max((int) ($target['achievements'][$aid] ?? 0), (int) $cnt);
        }
    }

    if (isset($guest['daily']) && is_array($guest['daily']) && empty($target['daily'])) {
        $target['daily'] = $guest['daily'];
    }

    if (!isset($target['lobbyColorThemeIndex']) && isset($guest['lobbyColorThemeIndex'])) {
        $target['lobbyColorThemeIndex'] = $guest['lobbyColorThemeIndex'];
    }
    if (!isset($target['lobbySkinToneIndex']) && isset($guest['lobbySkinToneIndex'])) {
        $target['lobbySkinToneIndex'] = $guest['lobbySkinToneIndex'];
    }

    if (($target['displayName'] ?? '') === '' || ($target['displayName'] ?? '') === 'Guest') {
        $gn = trim((string) ($guest['displayName'] ?? ''));
        if ($gn !== '' && $gn !== 'Guest') {
            $target['displayName'] = $gn;
        }
    }

    array_splice($store['accounts'], $guestIdx, 1);
    if ($guestIdx < $targetIdx) {
        $targetIdx--;
    }
}