<?php
/**
 * Settings store.
 *
 * Defaults follow the EU consumer rules (14-day withdrawal period, no reason
 * required for a withdrawal, the statutory button labels) and a common
 * 30-day returns policy, so a new store is compliant out of the box.
 *
 * @package ReturnKit
 */

namespace ReturnKit\Core;

use ReturnKit\Freemius\Gate;

defined( 'ABSPATH' ) || exit;

/**
 * Option-backed settings with type-safe sanitizing.
 */
class Settings {

	const OPTION = 'rtkt_settings';

	/**
	 * Effective settings cache for the current request.
	 *
	 * @var array|null
	 */
	private static $cache = null;

	/**
	 * Default settings.
	 *
	 * Strings are kept untranslated here (this runs before init); the views
	 * and the front end translate the defaults when they are still unchanged
	 * (see text()).
	 *
	 * @return array
	 */
	public static function defaults() {
		return array(
			// Returns.
			'returns_enabled'          => true,
			'return_days'              => 30,
			'window_start'             => 'completed',
			'return_statuses'          => 'completed',
			'guest_returns'            => true,
			'reasons'                  => "Wrong size or fit\nDamaged or defective\nNot as described\nWrong item sent\nChanged my mind\nArrived too late\nOther",
			'require_reason'           => true,
			'exclude_virtual'          => true,
			'exclude_sale'             => false,
			'exclude_categories'       => '',
			'return_instructions'      => '',
			'return_address'           => '',
			'restock_default'          => true,
			'refund_gateway_default'   => true,
			'account_endpoint'         => 'returns',
			'portal_page'              => 0,

			// EU withdrawal (Directive (EU) 2023/2673, Art. 11a CRD).
			'withdrawal_enabled'       => true,
			'withdrawal_days'          => 14,
			'withdrawal_grace_days'    => 0,
			'withdrawal_start'         => 'completed',
			'withdrawal_outside'       => 'warn',
			'withdrawal_statuses'      => "processing\non-hold\ncompleted",
			'withdrawal_items'         => true,
			'withdrawal_exclude_cats'  => '',
			'withdrawal_page'          => 0,
			'withdrawal_label'         => '',
			'withdrawal_confirm_label' => '',
			'withdrawal_in_account'    => true,
			'withdrawal_in_emails'     => true,
			'withdrawal_in_footer'     => false,

			// Spam protection for the public forms.
			'honeypot'                 => true,
			'ip_source'                => 'remote_addr',
			'min_seconds'              => 3,
			'rate_limit'               => 5,
			'turnstile_enabled'        => false,
			'turnstile_site_key'       => '',
			'turnstile_secret'         => '',

			// Notifications.
			'notify_admin'             => true,
			'admin_recipients'         => '',

			// Privacy.
			'anonymize_ip'             => true,

			// Pro: exchanges.
			'exchanges_enabled'        => false,
			'exchange_scope'           => 'variation',
			'exchange_upcharge'        => 'charge',
			'exchange_downcharge'      => 'credit',

			// Pro: store credit.
			'credit_enabled'           => false,
			'credit_bonus'             => 0,
			'credit_auto_apply'        => true,

			// Pro: labels.
			'labels_attach'            => true,

			// Pro: frequent-returner flags.
			'flags_enabled'            => false,
			'flag_count'               => 3,
			'flag_days'                => 90,
			'flag_rate'                => 50,
			'flag_hold'                => true,
			'flag_checkout_shield'     => true,

			// Pro: automatic approval.
			'auto_approve'             => false,
			'auto_approve_max'         => 100,
			'auto_approve_reasons'     => '',
		);
	}

	/**
	 * Keys holding the merchant's own content: never touched by "Reset to
	 * recommended".
	 *
	 * @return string[]
	 */
	public static function personal_keys() {
		return array( 'reasons', 'exclude_categories', 'return_instructions', 'return_address', 'portal_page', 'withdrawal_page', 'withdrawal_exclude_cats', 'withdrawal_label', 'withdrawal_confirm_label', 'turnstile_site_key', 'turnstile_secret', 'admin_recipients', 'account_endpoint', 'auto_approve_reasons' );
	}

	/**
	 * Allowed values for enumerated settings.
	 *
	 * @return array<string,string[]>
	 */
	public static function choices() {
		return array(
			'window_start'        => array( 'completed', 'created' ),
			'withdrawal_start'    => array( 'completed', 'created' ),
			'withdrawal_outside'  => array( 'warn', 'block' ),
			'ip_source'           => array( 'remote_addr', 'cloudflare', 'forwarded', 'real_ip' ),
			'exchange_scope'      => array( 'variation', 'any' ),
			'exchange_upcharge'   => array( 'charge', 'absorb' ),
			'exchange_downcharge' => array( 'credit', 'refund', 'keep' ),
		);
	}

	/**
	 * Integer bounds as [min, max].
	 *
	 * @return array<string,int[]>
	 */
	private static function bounds() {
		return array(
			'return_days'           => array( 1, 3650 ),
			// The statutory period is at least 14 days.
			'withdrawal_days'       => array( 14, 3650 ),
			'withdrawal_grace_days' => array( 0, 90 ),
			'portal_page'           => array( 0, PHP_INT_MAX ),
			'withdrawal_page'       => array( 0, PHP_INT_MAX ),
			'min_seconds'           => array( 0, 60 ),
			'rate_limit'            => array( 1, 1000 ),
			'credit_bonus'          => array( 0, 100 ),
			'flag_count'            => array( 1, 1000 ),
			'flag_days'             => array( 7, 3650 ),
			'flag_rate'             => array( 1, 100 ),
			'auto_approve_max'      => array( 0, 1000000 ),
		);
	}

	/**
	 * Effective settings: stored values over defaults.
	 *
	 * @return array
	 */
	public static function all() {
		if ( null === self::$cache ) {
			$stored      = get_option( self::OPTION, array() );
			self::$cache = self::apply_gates( wp_parse_args( is_array( $stored ) ? $stored : array(), self::defaults() ) );
		}
		return self::$cache;
	}

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

	/**
	 * Merge, sanitize and persist a partial settings update.
	 *
	 * @param array $input Raw values.
	 * @return array Effective settings after saving.
	 */
	public static function update( array $input ) {
		$stored  = get_option( self::OPTION, array() );
		$current = wp_parse_args( is_array( $stored ) ? $stored : array(), self::defaults() );
		$clean   = self::sanitize( array_merge( $current, $input ) );
		$before  = $current['account_endpoint'];
		update_option( self::OPTION, $clean );
		self::$cache = null;
		if ( $before !== $clean['account_endpoint'] ) {
			// The My Account endpoint is a rewrite rule.
			update_option( 'woocommerce_queue_flush_rewrite_rules', 'yes' );
		}
		return self::all();
	}

	/**
	 * Forget the per-request cache (after saving, or in tests).
	 *
	 * @return void
	 */
	public static function flush() {
		self::$cache = null;
	}

	/**
	 * Type-safe sanitizing of every known key; unknown keys are dropped.
	 *
	 * @param array $input Raw values.
	 * @return array
	 */
	public static function sanitize( array $input ) {
		$defaults = self::defaults();
		$choices  = self::choices();
		$bounds   = self::bounds();
		$out      = array();

		foreach ( $defaults as $key => $default ) {
			$value = array_key_exists( $key, $input ) ? $input[ $key ] : $default;

			if ( is_bool( $default ) ) {
				$out[ $key ] = filter_var( $value, FILTER_VALIDATE_BOOLEAN );
			} elseif ( is_int( $default ) ) {
				$value       = is_numeric( $value ) ? (int) $value : $default;
				$out[ $key ] = isset( $bounds[ $key ] ) ? max( $bounds[ $key ][0], min( $bounds[ $key ][1], $value ) ) : $value;
			} elseif ( isset( $choices[ $key ] ) ) {
				$value       = sanitize_key( (string) $value );
				$out[ $key ] = in_array( $value, $choices[ $key ], true ) ? $value : $default;
			} elseif ( is_array( $value ) ) {
				// Multi-selects post arrays; they are stored as lines.
				$out[ $key ] = implode( "\n", array_map( 'strval', array_filter( $value, 'is_scalar' ) ) );
			} else {
				$out[ $key ] = is_scalar( $value ) ? (string) $value : '';
			}
		}

		$out['reasons']                  = implode( "\n", self::clean_lines( $out['reasons'], array( __CLASS__, 'clean_reason' ), "\n" ) );
		// The default list saved unchanged in the site language stays "the
		// defaults" (shown in each visitor's language), not a custom list.
		if ( implode( "\n", \ReturnKit\Domain\Reasons::default_labels() ) === $out['reasons'] ) {
			$out['reasons'] = self::defaults()['reasons'];
		}
		$out['auto_approve_reasons']     = implode( "\n", self::clean_lines( $out['auto_approve_reasons'], array( __CLASS__, 'clean_reason' ), "\n" ) );
		$out['return_statuses']          = implode( "\n", self::clean_lines( $out['return_statuses'], array( __CLASS__, 'clean_status' ) ) );
		$out['withdrawal_statuses']      = implode( "\n", self::clean_lines( $out['withdrawal_statuses'], array( __CLASS__, 'clean_status' ) ) );
		$out['exclude_categories']       = implode( "\n", self::clean_lines( $out['exclude_categories'], 'absint' ) );
		$out['withdrawal_exclude_cats']  = implode( "\n", self::clean_lines( $out['withdrawal_exclude_cats'], 'absint' ) );
		$out['admin_recipients']         = implode( "\n", self::clean_lines( $out['admin_recipients'], array( __CLASS__, 'clean_recipient' ) ) );
		$out['return_instructions']      = sanitize_textarea_field( $out['return_instructions'] );
		$out['return_address']           = sanitize_textarea_field( $out['return_address'] );
		$out['withdrawal_label']         = sanitize_text_field( $out['withdrawal_label'] );
		$out['withdrawal_confirm_label'] = sanitize_text_field( $out['withdrawal_confirm_label'] );
		$out['turnstile_site_key']       = self::clean_key( $out['turnstile_site_key'] );
		$out['turnstile_secret']         = self::clean_key( $out['turnstile_secret'] );

		$endpoint                = sanitize_title( $out['account_endpoint'] );
		$out['account_endpoint'] = '' !== $endpoint ? $endpoint : $defaults['account_endpoint'];

		if ( '' === $out['return_statuses'] ) {
			$out['return_statuses'] = $defaults['return_statuses'];
		}
		if ( '' === $out['withdrawal_statuses'] ) {
			$out['withdrawal_statuses'] = $defaults['withdrawal_statuses'];
		}

		// Gates are applied when settings are read (all()), not here, so Pro
		// configuration survives a lapsed license.
		return $out;
	}

	/**
	 * Force Pro-only options off on the free plan. Stored values are kept.
	 *
	 * @param array $settings Settings.
	 * @return array
	 */
	private static function apply_gates( array $settings ) {
		$map = array(
			'exchanges' => array( 'exchanges_enabled' ),
			'credit'    => array( 'credit_enabled' ),
			'labels'    => array( 'labels_attach' ),
			'flags'     => array( 'flags_enabled' ),
			'rules'     => array( 'auto_approve' ),
		);
		foreach ( $map as $feature => $keys ) {
			if ( ! Gate::can( $feature ) ) {
				foreach ( $keys as $key ) {
					$settings[ $key ] = false;
				}
			}
		}
		return $settings;
	}

	/**
	 * A setting text, translated while it still has its default (empty) value.
	 *
	 * @param string $key Setting key.
	 * @return string
	 */
	public static function text( $key ) {
		$value = trim( (string) self::get( $key ) );
		if ( '' !== $value ) {
			return $value;
		}
		$fallbacks = array(
			'withdrawal_label'         => __( 'Withdraw from contract here', 'returnkit' ),
			'withdrawal_confirm_label' => __( 'Confirm withdrawal', 'returnkit' ),
			'return_instructions'      => __( 'Pack the items securely and include your return number. We will refund you as soon as the items arrive.', 'returnkit' ),
		);
		return isset( $fallbacks[ $key ] ) ? $fallbacks[ $key ] : '';
	}

	/**
	 * A list setting (one entry per line) as an array.
	 *
	 * @param string $key Setting key.
	 * @return string[]
	 */
	public static function lines( $key ) {
		$value = (string) self::get( $key );
		if ( '' === $value ) {
			return array();
		}
		return array_values( array_filter( array_map( 'trim', explode( "\n", $value ) ), 'strlen' ) );
	}

	/**
	 * A list of IDs setting as integers.
	 *
	 * @param string $key Setting key.
	 * @return int[]
	 */
	public static function ids( $key ) {
		return array_values( array_filter( array_map( 'absint', self::lines( $key ) ) ) );
	}

	/**
	 * A reason label (single line, max 100 chars), or ''.
	 *
	 * @param string $value Raw entry.
	 * @return string
	 */
	public static function clean_reason( $value ) {
		$value = trim( sanitize_text_field( (string) $value ) );
		return function_exists( 'mb_substr' ) ? mb_substr( $value, 0, 100 ) : substr( $value, 0, 100 );
	}

	/**
	 * An order status slug without the wc- prefix, or ''.
	 *
	 * @param string $value Raw status.
	 * @return string
	 */
	public static function clean_status( $value ) {
		$value = sanitize_key( preg_replace( '/^wc-/', '', trim( (string) $value ) ) );
		if ( '' === $value ) {
			return '';
		}
		if ( function_exists( 'wc_get_order_statuses' ) ) {
			return array_key_exists( 'wc-' . $value, wc_get_order_statuses() ) ? $value : '';
		}
		return $value;
	}

	/**
	 * A notification recipient email, or '' when invalid.
	 *
	 * @param string $value Raw entry.
	 * @return string
	 */
	public static function clean_recipient( $value ) {
		$value = strtolower( trim( (string) $value ) );
		return is_email( $value ) ? $value : '';
	}

	/**
	 * Clean every line of a list through a normalizer; invalid lines are dropped.
	 *
	 * @param string   $text       Raw text.
	 * @param callable $normalizer Returns the clean entry or ''/0 to drop it.
	 * @param string   $separators Characters that separate entries.
	 * @return string[]
	 */
	private static function clean_lines( $text, $normalizer, $separators = "\n," ) {
		$out = array();
		foreach ( preg_split( '/[' . preg_quote( $separators, '/' ) . '\r]+/', (string) $text ) as $line ) {
			$line = trim( $line );
			if ( '' === $line ) {
				continue;
			}
			$clean = (string) call_user_func( $normalizer, $line );
			if ( '' !== $clean && '0' !== $clean ) {
				$out[ strtolower( $clean ) ] = $clean;
			}
		}
		return array_values( $out );
	}

	/**
	 * API key characters only.
	 *
	 * @param string $value Raw key.
	 * @return string
	 */
	private static function clean_key( $value ) {
		return (string) preg_replace( '/[^0-9A-Za-z_\-.]/', '', trim( (string) $value ) );
	}
}