<?php
declare(strict_types=1);

namespace App;

final class SystemSettings
{
    private array $tableCache = [];

    private const DEFAULTS = [
        'google_places_enabled' => '0',
        'azure_maps_enabled' => '0',
        'osm_places_enabled' => '1',
        'forum_maintenance_mode' => '0',
        'site_maintenance_mode' => '0',
        'site_maintenance_message' => 'Papa-Kind-Treff ist gerade kurz in Wartung. Bitte versuche es in Kürze erneut.',
        'place_data_provider' => 'osm',
        'community_levels_json' => '',
    ];

    public function __construct(private \PDO $pdo)
    {
    }

    public function ensureSchema(): void
    {
        $this->pdo->exec(
            'CREATE TABLE IF NOT EXISTS system_settings (
                `key` VARCHAR(120) NOT NULL PRIMARY KEY,
                `value` TEXT NULL,
                updated_by BIGINT UNSIGNED NULL,
                updated_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                CONSTRAINT fk_system_settings_updated_by FOREIGN KEY (updated_by) REFERENCES users(id) ON DELETE SET NULL
            ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci'
        );

        $stmt = $this->pdo->prepare(
            'INSERT INTO system_settings (`key`, `value`, updated_by)
             VALUES (:key, :value, NULL)
             ON DUPLICATE KEY UPDATE `value` = `value`'
        );
        foreach (self::DEFAULTS as $key => $value) {
            $stmt->execute([
                'key' => $key,
                'value' => $value,
            ]);
        }
    }

    public function getAll(): array
    {
        $this->ensureSchema();
        $settings = self::DEFAULTS;
        $stmt = $this->pdo->query('SELECT `key`, `value` FROM system_settings');
        foreach ($stmt->fetchAll(\PDO::FETCH_ASSOC) ?: [] as $row) {
            $settings[(string)$row['key']] = (string)($row['value'] ?? '');
        }
        return $settings;
    }

    public function get(string $key, ?string $default = null): ?string
    {
        $this->ensureSchema();
        $stmt = $this->pdo->prepare('SELECT `value` FROM system_settings WHERE `key` = :key LIMIT 1');
        $stmt->execute(['key' => $key]);
        $value = $stmt->fetchColumn();
        if ($value === false) {
            return $default ?? (self::DEFAULTS[$key] ?? null);
        }
        return (string)$value;
    }

    public function getBool(string $key, bool $default = false): bool
    {
        $value = $this->get($key, $default ? '1' : '0');
        return in_array((string)$value, ['1', 'true', 'yes', 'on'], true);
    }

    public function set(string $key, string $value, ?int $updatedBy = null): void
    {
        $this->ensureSchema();
        $stmt = $this->pdo->prepare(
            'INSERT INTO system_settings (`key`, `value`, updated_by)
             VALUES (:key, :value, :updatedBy)
             ON DUPLICATE KEY UPDATE `value` = VALUES(`value`), updated_by = VALUES(updated_by), updated_at = CURRENT_TIMESTAMP'
        );
        $stmt->execute([
            'key' => $key,
            'value' => $value,
            'updatedBy' => $updatedBy,
        ]);
    }

    public function updateMany(array $values, ?int $updatedBy = null): void
    {
        $this->ensureSchema();
        $stmt = $this->pdo->prepare(
            'INSERT INTO system_settings (`key`, `value`, updated_by)
             VALUES (:key, :value, :updatedBy)
             ON DUPLICATE KEY UPDATE `value` = VALUES(`value`), updated_by = VALUES(updated_by), updated_at = CURRENT_TIMESTAMP'
        );
        foreach ($values as $key => $value) {
            $stmt->execute([
                'key' => (string)$key,
                'value' => (string)$value,
                'updatedBy' => $updatedBy,
            ]);
        }
    }
}