<?php
/**
 * Plugin-wide settings (CAPTCHA provider and keys, spam options).
 *
 * @package TFlexForms
 */

declare( strict_types = 1 );

namespace TFlexForms;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Stored in one option. Secret keys are write-only in the UI and can instead
 * be defined in wp-config.php, e.g. define( 'TFLEXFORMS_TURNSTILE_SECRET_KEY', '...' );
 */
final class Settings {

	public const OPTION = 'tflexforms_settings';

	/**
	 * Defaults.
	 *
	 * @return array<string,mixed>
	 */
	public static function defaults(): array {
		return array(
			'captcha_provider'         => '',
			'keys'                     => array(), // provider id => [ site_key, secret_key ].
			'recaptcha_threshold'      => 0.5,
			'use_disallowed_list'      => true,
			'store_ip'                 => false, // IP addresses are personal data: opt-in.
			'retention_days'           => 0,     // 0 = keep entries until deleted.
			'delete_data_on_uninstall' => false, // Read by uninstall.php: keep data unless chosen.
		);
	}

	/**
	 * All settings merged with defaults.
	 *
	 * @return array<string,mixed>
	 */
	public static function all(): array {
		$stored = get_option( self::OPTION, array() );
		return array_merge( self::defaults(), is_array( $stored ) ? $stored : array() );
	}

	/**
	 * One setting.
	 *
	 * @param string $key Setting key.
	 */
	public static function get( string $key ): mixed {
		return self::all()[ $key ] ?? null;
	}

	/**
	 * A provider key ('site_key' or 'secret_key'). wp-config.php constants win.
	 *
	 * @param string $provider Provider id.
	 * @param string $which    'site_key' or 'secret_key'.
	 */
	public static function key( string $provider, string $which ): string {
		$constant = self::constant_name( $provider, $which );
		if ( defined( $constant ) ) {
			return (string) constant( $constant );
		}
		$keys = self::get( 'keys' );
		return is_array( $keys ) && isset( $keys[ $provider ][ $which ] ) ? (string) $keys[ $provider ][ $which ] : '';
	}

	/**
	 * Name of the wp-config.php constant for a key.
	 *
	 * @param string $provider Provider id.
	 * @param string $which    'site_key' or 'secret_key'.
	 */
	public static function constant_name( string $provider, string $which ): string {
		return 'TFLEXFORMS_' . strtoupper( preg_replace( '/[^a-z0-9]/i', '_', $provider ) ?? '' ) . '_' . strtoupper( $which );
	}

	/**
	 * Sanitizes the option. Blank secret fields keep the stored secret, so
	 * the secret never has to be printed back into the settings page.
	 *
	 * @param mixed $value Submitted value.
	 * @return array<string,mixed>
	 */
	public static function sanitize( mixed $value ): array {
		$value    = is_array( $value ) ? $value : array();
		$current  = self::all();
		$provider = sanitize_key( (string) ( $value['captcha_provider'] ?? '' ) );

		$clean = array(
			'captcha_provider'         => array_key_exists( $provider, Captcha::providers() ) ? $provider : '',
			'keys'                     => array(),
			'recaptcha_threshold'      => min( 0.9, max( 0.1, round( (float) ( $value['recaptcha_threshold'] ?? 0.5 ), 1 ) ) ),
			'use_disallowed_list'      => ! empty( $value['use_disallowed_list'] ),
			'store_ip'                 => ! empty( $value['store_ip'] ),
			'retention_days'           => max( 0, min( 3650, (int) ( $value['retention_days'] ?? 0 ) ) ),
			'delete_data_on_uninstall' => ! empty( $value['delete_data_on_uninstall'] ),
		);

		foreach ( array_keys( Captcha::providers() ) as $id ) {
			$submitted = isset( $value['keys'][ $id ] ) && is_array( $value['keys'][ $id ] ) ? $value['keys'][ $id ] : array();
			$site_key  = self::clean_key( (string) ( $submitted['site_key'] ?? '' ) );
			$secret    = self::clean_key( (string) ( $submitted['secret_key'] ?? '' ) );
			$old       = is_array( $current['keys'][ $id ] ?? null ) ? $current['keys'][ $id ] : array();

			$clean['keys'][ $id ] = array(
				'site_key'   => $site_key,
				'secret_key' => ! empty( $submitted['clear_secret'] ) ? '' : ( '' !== $secret ? $secret : (string) ( $old['secret_key'] ?? '' ) ),
			);
		}

		return $clean;
	}

	/**
	 * Keys are opaque tokens: keep only safe characters.
	 *
	 * @param string $key Raw key.
	 */
	private static function clean_key( string $key ): string {
		return substr( preg_replace( '/[^A-Za-z0-9_\-.]/', '', trim( $key ) ) ?? '', 0, 200 );
	}
}