<?php
declare(strict_types=1);

/**
 * Reads the shared campus configuration (config/campuses.json). The build
 * copies it to api/config/campuses.json; in local development we fall back to
 * the repo copy.
 */
final class Campuses
{
    /** @var array<string,array<string,mixed>>|null */
    private static ?array $byId = null;

    /** @return array<string,array<string,mixed>> */
    public static function all(): array
    {
        if (self::$byId !== null) {
            return self::$byId;
        }
        $candidates = [
            dirname(__DIR__) . '/config/campuses.json',
            dirname(__DIR__, 3) . '/config/campuses.json',
        ];
        foreach ($candidates as $file) {
            if (is_readable($file)) {
                $data = json_decode((string)file_get_contents($file), true);
                if (is_array($data) && isset($data['campuses'])) {
                    $out = [];
                    foreach ($data['campuses'] as $c) {
                        $out[$c['id']] = $c;
                    }
                    return self::$byId = $out;
                }
            }
        }
        throw new RuntimeException('campuses.json not found');
    }

    /** @return array<string,mixed>|null */
    public static function get(string $id): ?array
    {
        return self::all()[$id] ?? null;
    }

    /** @return string[] */
    public static function openIds(): array
    {
        return array_keys(array_filter(self::all(), static fn($c) => ($c['status'] ?? 'open') === 'open'));
    }

    /** "Sunday 9:30 AM" style summary of the first service day. */
    public static function timesSummary(array $campus): string
    {
        $parts = [];
        foreach ($campus['serviceTimes'] ?? [] as $st) {
            $parts[] = $st['day'] . ' ' . implode(', ', $st['times']);
        }
        return implode(' · ', $parts);
    }
}