<?php
/**
 * Normalized event model and controlled vocabularies.
 *
 * @package Enrollment_Verifier_Logger
 */

defined( 'ABSPATH' ) || exit;

/**
 * Event model helpers.
 */
class EVLFL_Event {

	const ACTION_ENROLLED   = 'enrolled';
	const ACTION_UNENROLLED = 'unenrolled';

	/**
	 * Actions.
	 *
	 * @return array<string,string> value => label.
	 */
	public static function get_actions() {
		return array(
			self::ACTION_ENROLLED   => __( 'Enrolled', 'accesstrace-for-learndash' ),
			self::ACTION_UNENROLLED => __( 'Unenrolled', 'accesstrace-for-learndash' ),
		);
	}

	/**
	 * Sources (extensible via filter).
	 *
	 * @return array<string,string>
	 */
	public static function get_sources() {
		$sources = array(
			'admin'       => __( 'Admin', 'accesstrace-for-learndash' ),
			'learndash'   => __( 'LearnDash', 'accesstrace-for-learndash' ),
			'membership'  => __( 'Membership', 'accesstrace-for-learndash' ),
			'woocommerce' => __( 'WooCommerce', 'accesstrace-for-learndash' ),
			'edd'         => __( 'Easy Digital Downloads', 'accesstrace-for-learndash' ),
			'rest_api'    => __( 'REST API', 'accesstrace-for-learndash' ),
			'cron'        => __( 'Cron', 'accesstrace-for-learndash' ),
			'wp_cli'      => __( 'WP-CLI', 'accesstrace-for-learndash' ),
			'custom_code' => __( 'Custom code', 'accesstrace-for-learndash' ),
			'import'      => __( 'Import', 'accesstrace-for-learndash' ),
			'unknown'     => __( 'Unknown', 'accesstrace-for-learndash' ),
		);
		return self::clean_vocab( apply_filters( 'evlfl_sources', $sources ), $sources );
	}

	/**
	 * Triggers (extensible via filter).
	 *
	 * @return array<string,string>
	 */
	public static function get_triggers() {
		$triggers = array(
			'manual'                => __( 'Manual', 'accesstrace-for-learndash' ),
			'membership_activated'  => __( 'Membership activated', 'accesstrace-for-learndash' ),
			'purchase'              => __( 'Purchase', 'accesstrace-for-learndash' ),
			'access_reset'          => __( 'Access reset (repeat purchase)', 'accesstrace-for-learndash' ),
			'api'                   => __( 'API', 'accesstrace-for-learndash' ),
			'import'                => __( 'Import', 'accesstrace-for-learndash' ),
			'bulk_operation'        => __( 'Bulk operation', 'accesstrace-for-learndash' ),
			'custom_code'           => __( 'Custom code', 'accesstrace-for-learndash' ),
			'course_access_expired' => __( 'Course access expired', 'accesstrace-for-learndash' ),
			'membership_expired'    => __( 'Membership expired', 'accesstrace-for-learndash' ),
			'membership_cancelled'  => __( 'Membership cancelled', 'accesstrace-for-learndash' ),
			'refund'                => __( 'Refund', 'accesstrace-for-learndash' ),
			'unknown'               => __( 'Unknown', 'accesstrace-for-learndash' ),
		);
		return self::clean_vocab( apply_filters( 'evlfl_triggers', $triggers ), $triggers );
	}

	/**
	 * Verification statuses.
	 *
	 * @return array<string,string>
	 */
	public static function get_statuses() {
		return array(
			'valid'   => __( 'Valid', 'accesstrace-for-learndash' ),
			'invalid' => __( 'Invalid', 'accesstrace-for-learndash' ),
			'unknown' => __( 'Unknown', 'accesstrace-for-learndash' ),
		);
	}

	/**
	 * Confidence levels.
	 *
	 * @return array<string,string>
	 */
	public static function get_confidences() {
		return array(
			'confirmed' => __( 'Confirmed', 'accesstrace-for-learndash' ),
			'detected'  => __( 'Detected', 'accesstrace-for-learndash' ),
			'inferred'  => __( 'Inferred', 'accesstrace-for-learndash' ),
			'unknown'   => __( 'Unknown', 'accesstrace-for-learndash' ),
		);
	}

	/**
	 * Actor types.
	 *
	 * @return array<string,string>
	 */
	public static function get_actor_types() {
		return array(
			'admin'   => __( 'Admin', 'accesstrace-for-learndash' ),
			'user'    => __( 'User', 'accesstrace-for-learndash' ),
			'system'  => __( 'System', 'accesstrace-for-learndash' ),
			'cron'    => __( 'Cron', 'accesstrace-for-learndash' ),
			'api'     => __( 'API', 'accesstrace-for-learndash' ),
			'unknown' => __( 'Unknown', 'accesstrace-for-learndash' ),
		);
	}

	/**
	 * Human label for a vocabulary value; falls back to a readable form for
	 * identifiers registered by future integrations.
	 *
	 * @param string $type  One of action, source, trigger, status, confidence, actor_type.
	 * @param string $value Stored value.
	 * @return string
	 */
	public static function label( $type, $value ) {
		$map = array();
		switch ( $type ) {
			case 'action':
				$map = self::get_actions();
				break;
			case 'source':
				$map = self::get_sources();
				break;
			case 'trigger':
				$map = self::get_triggers();
				break;
			case 'status':
				$map = self::get_statuses();
				break;
			case 'confidence':
				$map = self::get_confidences();
				break;
			case 'actor_type':
				$map = self::get_actor_types();
				break;
		}
		$value = (string) $value;
		if ( isset( $map[ $value ] ) ) {
			return $map[ $value ];
		}
		return '' === $value ? '' : ucwords( str_replace( '_', ' ', $value ) );
	}

	/**
	 * Validate and sanitize an event array. Returns null when the event is unusable.
	 *
	 * @param array $event Raw event.
	 * @return array|null
	 */
	public static function normalize( $event ) {
		if ( ! is_array( $event ) ) {
			return null;
		}
		$user_id   = isset( $event['user_id'] ) ? absint( $event['user_id'] ) : 0;
		$course_id = isset( $event['course_id'] ) ? absint( $event['course_id'] ) : 0;
		$action    = isset( $event['action'] ) ? sanitize_key( $event['action'] ) : '';
		if ( $user_id < 1 || $course_id < 1 || ! isset( self::get_actions()[ $action ] ) ) {
			return null;
		}

		$actor_id = isset( $event['actor_id'] ) ? absint( $event['actor_id'] ) : 0;
		$time     = isset( $event['event_time'] ) ? (string) $event['event_time'] : '';
		if ( ! preg_match( '/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}$/', $time ) || false === strtotime( $time . ' UTC' ) ) {
			$time = gmdate( 'Y-m-d H:i:s' );
		}
		$reason = isset( $event['verification_reason'] ) ? wp_strip_all_tags( (string) $event['verification_reason'] ) : '';

		return array(
			'user_id'             => $user_id,
			'course_id'           => $course_id,
			'action'              => $action,
			'source'              => self::pick( $event, 'source', self::get_sources() ),
			'event_trigger'       => self::pick( $event, 'event_trigger', self::get_triggers() ),
			'actor_type'          => self::pick( $event, 'actor_type', self::get_actor_types() ),
			'actor_id'            => $actor_id > 0 ? $actor_id : null,
			'status'              => self::pick( $event, 'status', self::get_statuses() ),
			'verification_reason' => '' === $reason ? null : substr( $reason, 0, 1000 ),
			'confidence'          => self::pick( $event, 'confidence', self::get_confidences() ),
			'event_time'          => $time,
			'metadata'            => self::clean_metadata( isset( $event['metadata'] ) ? $event['metadata'] : array() ),
		);
	}

	/**
	 * Pick an allowlisted value or "unknown".
	 *
	 * @param array  $event Event.
	 * @param string $key   Key.
	 * @param array  $allow Allowlist (value => label).
	 * @return string
	 */
	private static function pick( $event, $key, $allow ) {
		$value = isset( $event[ $key ] ) && is_scalar( $event[ $key ] ) ? sanitize_key( (string) $event[ $key ] ) : '';
		return isset( $allow[ $value ] ) ? $value : 'unknown';
	}

	/**
	 * Clean a filtered vocabulary defensively (filter results are untrusted).
	 *
	 * @param mixed $filtered What the filter returned.
	 * @param array $defaults Built-in entries (always kept).
	 * @return array
	 */
	private static function clean_vocab( $filtered, $defaults ) {
		if ( ! is_array( $filtered ) ) {
			return $defaults;
		}
		$out = array();
		foreach ( $filtered as $key => $label ) {
			$key = sanitize_key( (string) $key );
			if ( '' !== $key && is_scalar( $label ) ) {
				$out[ substr( $key, 0, 50 ) ] = (string) $label;
			}
		}
		return $out + $defaults;
	}

	/**
	 * Sanitize metadata: scalars/arrays only, limited depth, no sensitive keys.
	 *
	 * @param mixed $data  Metadata.
	 * @param int   $depth Current depth.
	 * @return array
	 */
	public static function clean_metadata( $data, $depth = 0 ) {
		$out = array();
		if ( ! is_array( $data ) || $depth > 3 ) {
			return $out;
		}
		foreach ( $data as $key => $value ) {
			$key = is_int( $key ) ? $key : sanitize_key( (string) $key );
			if ( '' === $key || ( is_string( $key ) && preg_match( '/pass|token|secret|nonce|cookie|auth|api_?key/i', $key ) ) ) {
				continue;
			}
			if ( is_array( $value ) ) {
				$out[ $key ] = self::clean_metadata( $value, $depth + 1 );
			} elseif ( is_bool( $value ) || is_int( $value ) || is_float( $value ) || null === $value ) {
				$out[ $key ] = $value;
			} elseif ( is_string( $value ) ) {
				$out[ $key ] = substr( sanitize_text_field( $value ), 0, 255 );
			}
		}
		return $out;
	}
}