<?php
/**
 * Settings and state option access.
 *
 * @package studiou-wc-mail-queue
 * @copyright 2026 QUADARAX
 * @author    Dalibor Votruba <dvotruba@quadarax.com>
 * @license   GPL-2.0-or-later
 */

defined( 'ABSPATH' ) || exit;

/**
 * Class Studiou_WCMQ_Settings
 */
class Studiou_WCMQ_Settings {

	const OPTION       = 'studiou_wcmq_settings';
	const STATE_OPTION = 'studiou_wcmq_state';

	const STATE_ENABLED  = 'enabled';
	const STATE_DRAINING = 'draining';
	const STATE_DISABLED = 'disabled';

	/**
	 * Email ids that WooCommerce produces at runtime but does not always
	 * register in WC()->mailer()->get_emails().
	 *
	 * `WC_Email_Customer_Refunded_Order::trigger()` reassigns its own $this->id
	 * to 'customer_partially_refunded_order' on a partial refund, but the class
	 * that reports that id from get_emails() is only registered when the alpha
	 * `block_email_editor` feature is on. Without this table the settings screen
	 * can never offer the id, so partial-refund mail silently bypasses the queue.
	 *
	 * Re-audit on every WooCommerce major upgrade.
	 *
	 * id => id of the parent email whose checkbox it sits next to.
	 */
	const RUNTIME_ALIAS_IDS = array(
		'customer_partially_refunded_order' => 'customer_refunded_order',
	);

	/**
	 * Cached, sanitized settings for this request.
	 *
	 * @var array|null
	 */
	private static $cache = null;

	/**
	 * Default settings.
	 *
	 * @return array
	 */
	public static function defaults() {
		return array(
			'rate_per_minute'       => 5,
			'handled_contexts'      => array( 'customer_completed_order' ),
			'retention_sent_days'   => 7,
			'retention_failed_days' => 30,
			'retention_log_days'    => 14,
			'max_attempts'          => 3,
			'max_reclaims'          => 5,
			'claim_timeout'         => 900,
			'debug'                 => false,
		);
	}

	/**
	 * All settings, sanitized on read.
	 *
	 * An option array is a mutable surface; never trust what comes back.
	 *
	 * @return array
	 */
	public static function all() {
		if ( null === self::$cache ) {
			$raw         = get_option( self::OPTION, array() );
			self::$cache = self::sanitize( is_array( $raw ) ? $raw : array() );
		}
		return self::$cache;
	}

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

	/**
	 * Persist settings.
	 *
	 * @param array $raw Raw input.
	 */
	public static function update( array $raw ) {
		$clean = self::sanitize( $raw );
		update_option( self::OPTION, $clean, true );
		self::$cache = $clean;
	}

	/**
	 * Coerce anything into a valid settings array.
	 *
	 * @param array $raw Raw input.
	 * @return array
	 */
	public static function sanitize( array $raw ) {
		$d = self::defaults();

		$contexts = array();
		if ( isset( $raw['handled_contexts'] ) && is_array( $raw['handled_contexts'] ) ) {
			foreach ( $raw['handled_contexts'] as $id ) {
				$id = sanitize_key( (string) $id );
				if ( '' !== $id ) {
					$contexts[] = $id;
				}
			}
			$contexts = array_values( array_unique( $contexts ) );
		} else {
			$contexts = $d['handled_contexts'];
		}

		return array(
			'rate_per_minute'       => self::clamp_int( $raw, 'rate_per_minute', 1, 60, $d['rate_per_minute'] ),
			'handled_contexts'      => $contexts,
			'retention_sent_days'   => self::clamp_int( $raw, 'retention_sent_days', 0, 3650, $d['retention_sent_days'] ),
			'retention_failed_days' => self::clamp_int( $raw, 'retention_failed_days', 0, 3650, $d['retention_failed_days'] ),
			'retention_log_days'    => self::clamp_int( $raw, 'retention_log_days', 0, 3650, $d['retention_log_days'] ),
			'max_attempts'          => self::clamp_int( $raw, 'max_attempts', 1, 10, $d['max_attempts'] ),
			'max_reclaims'          => self::clamp_int( $raw, 'max_reclaims', 1, 20, $d['max_reclaims'] ),
			'claim_timeout'         => self::clamp_int( $raw, 'claim_timeout', 60, 86400, $d['claim_timeout'] ),
			'debug'                 => ! empty( $raw['debug'] ),
		);
	}

	/**
	 * Read an int from raw input and clamp it.
	 *
	 * Non-numeric input falls back to the default rather than to 0 — a 0 here
	 * would reach the `60 / $rate` division.
	 *
	 * @param array  $raw     Raw input.
	 * @param string $key     Key.
	 * @param int    $min     Minimum.
	 * @param int    $max     Maximum.
	 * @param int    $default Fallback.
	 * @return int
	 */
	private static function clamp_int( array $raw, $key, $min, $max, $default ) {
		if ( ! isset( $raw[ $key ] ) || ! is_numeric( $raw[ $key ] ) ) {
			return (int) $default;
		}
		$value = (int) $raw[ $key ];
		if ( $value < $min ) {
			return (int) $min;
		}
		if ( $value > $max ) {
			return (int) $max;
		}
		return $value;
	}

	/**
	 * Mails per minute, clamped to a sane range.
	 *
	 * @return int
	 */
	public static function rate() {
		$rate = (int) self::get( 'rate_per_minute' );
		if ( $rate < 1 ) {
			$rate = 1;
		}
		if ( $rate > 60 ) {
			$rate = 60;
		}
		return $rate;
	}

	/**
	 * Seconds between sends.
	 *
	 * ceil(), never floor(). floor() rounds the spacing down, which rounds the
	 * rate UP above the configured cap for every rate that does not divide 60.
	 * The clamp in rate() also guarantees no division by zero.
	 *
	 * @return int
	 */
	public static function interval() {
		return max( 1, (int) ceil( 60 / self::rate() ) );
	}

	/**
	 * Whether the debug toggle is on.
	 *
	 * Read straight from the option to avoid recursing through all()/log().
	 *
	 * @return bool
	 */
	public static function debug() {
		$raw = get_option( self::OPTION, array() );
		return is_array( $raw ) && ! empty( $raw['debug'] );
	}

	/**
	 * Handled email ids.
	 *
	 * @return array
	 */
	public static function handled_contexts() {
		$contexts = self::get( 'handled_contexts' );
		return is_array( $contexts ) ? $contexts : array();
	}

	/**
	 * Whether this email id should be queued.
	 *
	 * @param string $context_id WC_Email id.
	 * @return bool
	 */
	public static function handles( $context_id ) {
		if ( ! is_string( $context_id ) || '' === $context_id ) {
			return false;
		}
		return in_array( $context_id, self::handled_contexts(), true );
	}

	/* ---------------------------------------------------------------------
	 * State
	 * ------------------------------------------------------------------ */

	/**
	 * Current state, defaulting to disabled.
	 *
	 * An mu-plugin activates the moment its file lands — there is no activation
	 * step at which an admin confirms anything. Dropping the file must not start
	 * intercepting live mail at an unconfigured rate. Fail closed.
	 *
	 * @return string
	 */
	public static function state() {
		$state = get_option( self::STATE_OPTION, self::STATE_DISABLED );
		if ( ! in_array( $state, array( self::STATE_ENABLED, self::STATE_DRAINING, self::STATE_DISABLED ), true ) ) {
			return self::STATE_DISABLED;
		}
		return $state;
	}

	/**
	 * Persist state.
	 *
	 * @param string $state New state.
	 */
	public static function set_state( $state ) {
		if ( ! in_array( $state, array( self::STATE_ENABLED, self::STATE_DRAINING, self::STATE_DISABLED ), true ) ) {
			return;
		}
		update_option( self::STATE_OPTION, $state, true );
	}
}