<?php

class WPF_Klaviyo {

	/**
	 * The CRM slug.
	 *
	 * @var string
	 */
	public $slug = 'klaviyo';

	/**
	 * The CRM name.
	 *
	 * @var string
	 */
	public $name = 'Klaviyo';

	/**
	 * Contains API key (needed for some requests)
	 */

	public $key;

	/**
	 * Client ID for OAuth.
	 *
	 * @var string
	 * @since  3.46.0
	 */
	public $client_id = '052edb27-d8a1-45c9-874a-8644b7739336';

	/**
	 * Client secret for OAuth.
	 *
	 * @var string
	 * @since  3.46.0
	 */
	public $client_secret = 'UVBHL5jnTf5bVxj19Emvaxaqxc8wQ7LwMpiXBUNnzzm0UUlKS83QxBBhU9EroXcNmbsjSyd6yRiZii6E_1v7lg';


	/**
	 * Contains API params
	 */

	public $params;

	/**
	 * Lets pluggable functions know which features are supported by the CRM
	 */

	public $supports = array( 'events', 'add_fields', 'events_multi_key', 'auto_oauth', 'disconnect' );

	/**
	 * Allows text to be overridden for CRMs that use different segmentation labels (groups, lists, etc)
	 *
	 * @var string
	 */
	public $tag_type = 'List';


	/**
	 * Lets us link directly to editing a contact record.
	 *
	 * @var string
	 */

	public $edit_url = 'https://www.klaviyo.com/profile/%s';

	/**
	 * The last $source used to create/update a contact.
	 *
	 * @since 3.43.19
	 *
	 * @var string The source name.
	 */
	public $last_source = '';

	/**
	 * Get things started
	 *
	 * @access  public
	 * @since   2.0
	 */
	public function __construct() {

		// Set up admin options
		if ( is_admin() ) {
			require_once __DIR__ . '/admin/class-admin.php';
			new WPF_Klaviyo_Admin( $this->slug, $this->name, $this );
		}

		add_filter( 'http_response', array( $this, 'handle_http_response' ), 50, 3 );
	}

	/**
	 * Sets up hooks specific to this CRM
	 *
	 * @access public
	 * @return void
	 */
	public function init() {

		// Slow down the batch processses to get around API limits.
		add_filter( 'wpf_batch_sleep_time', array( $this, 'set_sleep_time' ) );
		add_filter( 'wpf_crm_post_data', array( $this, 'format_post_data' ) );
		add_filter( 'wpf_format_field_value', array( $this, 'format_field_value' ), 10, 3 );

		add_filter( 'wpf_woocommerce_customer_data', array( $this, 'format_phone_numbers' ) );
		add_filter( 'wpf_user_register', array( $this, 'format_phone_numbers' ) );
		add_filter( 'wpf_user_update', array( $this, 'format_phone_numbers' ), 5 ); // 5 so it's before WPF_WooCommerce::user_update().

		add_filter( 'wpf_user_tags', array( $this, 'format_tags' ) );
		add_filter( 'wpf_remove_tags', array( $this, 'format_tags' ) );
	}

	/**
	 * Slow down batch processses to get around API throttling.
	 *
	 * Burst: 3/second
	 * Steady: 60/minute
	 *
	 * @since 3.44.2
	 *
	 * @param int $seconds The seconds.
	 * @return int Sleep time.
	 */
	public function set_sleep_time( $seconds ) {
		return 2;
	}

	/**
	 * Formats POST data received from HTTP Posts into standard format
	 *
	 * @since 3.44.14
	 *
	 * @param array $post_data The post data.
	 * @return array The post data.
	 */
	public function format_post_data( $post_data ) {

		if ( isset( $post_data['email'] ) ) {
			$post_data['contact_id'] = $this->get_contact_id( sanitize_email( $post_data['email'] ) );
		}

		return $post_data;
	}

	/**
	 * Formats field values for the Klaviyo API.
	 *
	 * @since 3.44.24
	 *
	 * @param mixed  $value      The field value.
	 * @param string $field_type The field type.
	 * @param array  $field      The field ID in the CRM.
	 * @return mixed The formatted field value.
	 */
	public function format_field_value( $value, $field_type, $field ) {

		if ( 'date' === $field_type ) {
			$value = wpf_get_iso8601_date( $value );
		}

		return $value;
	}

	/**
	 * Check HTTP Response for errors and return WP_Error if found
	 *
	 * @access public
	 * @return array|WP_Error
	 */
	public function handle_http_response( $response, $args, $url ) {

		if ( false !== strpos( $url, 'klaviyo' ) && 'WP Fusion; ' . home_url() === $args['user-agent'] ) {

			$response_code = wp_remote_retrieve_response_code( $response );
			$body_json     = json_decode( wp_remote_retrieve_body( $response ) );

			// Handle successful responses
			if ( 200 === $response_code || 201 === $response_code || 202 === $response_code ) {
				return $response;
			}

			// Handle authorization errors and try to refresh token
			if ( ( 401 === $response_code || 403 === $response_code ) && false === strpos( $url, 'oauth/token' ) ) {

				if ( isset( $body_json->errors[0]->detail ) && false !== strpos( $body_json->errors[0]->detail, 'authentication' ) ) {
					// Try to refresh the access token.
					$access_token = $this->refresh_token();

					if ( is_wp_error( $access_token ) ) {
						return new WP_Error( 'error', sprintf( __( 'Error refreshing access token: %s', 'wp-fusion-lite' ), $access_token->get_error_message() ) );
					}

					// Update the authorization header and retry the request.
					$args['headers']['Authorization'] = 'Bearer ' . $access_token;
					$response                         = wp_remote_request( $url, $args );

					return $response;
				}
			}

			if ( isset( $body_json->message ) ) {

				$response = new WP_Error( 'error', $body_json->message );

			} elseif ( isset( $body_json->detail ) ) {

				$response = new WP_Error( 'error', $body_json->detail );

			} elseif ( isset( $body_json->errors ) ) {

				foreach ( $body_json->errors as $error ) {

					if ( 'duplicate_profile' === $error->code && ! empty( $error->meta ) ) {

						// Duplicate handling. Take the duplicate ID out of the
						// response and update them instead.

						$body           = json_decode( $args['body'] );
						$url            = str_replace( $body->data->id, $error->meta->duplicate_profile_id, $url );
						$body->data->id = $error->meta->duplicate_profile_id;
						$args['body']   = wp_json_encode( $body );
						$args['method'] = 'PATCH';

						$response = wp_remote_post( $url, $args );

						if ( is_wp_error( $response ) ) {
							return $response;
						} else {

							$user_id = wpf_get_user_id( $body->data->id );

							if ( ! empty( $user_id ) ) {
								// If it's an update to an existing user, update their ID.
								update_user_meta( $user_id, WPF_CONTACT_ID_META_KEY, sanitize_text_field( $body->data->id ) );
							}

							return $args; // return the body so add_contact() can get the ID.
						}
					} elseif ( 'invalid' === $error->code && isset( $error->source->pointer ) && '/data' !== $error->source->pointer ) {

						// Convert pointer path to array keys.
						$path = explode( '/', trim( $error->source->pointer, '/' ) );

						// Get the body data.
						$body = json_decode( $args['body'], true );

						// Remove the invalid field by traversing the path.
						$current  = &$body;
						$last_key = array_pop( $path );

						// Navigate through the path.
						foreach ( $path as $key ) {
							if ( isset( $current[ $key ] ) ) {
								$current = &$current[ $key ];
							}
						}

						// Remove the invalid field and try again.
						if ( isset( $current[ $last_key ] ) ) {
							unset( $current[ $last_key ] );

							// Update the request body.
							$args['body'] = wp_json_encode( $body );

							// Try the request again.
							$response = wp_remote_post( $url, $args );

						}

						return $response;

					} elseif ( 'not_found' === $error->code ) {

						// If the contact ID is not found, return a not_found error to attempt to look it up again.
						return new WP_Error( 'not_found', $error->detail );
					}
				}

				$response = new WP_Error( 'error', implode( ' ', wp_list_pluck( $body_json->errors, 'detail' ) ) );
			}
		}

		return $response;
	}


	/**
	 * Gets params for API calls
	 *
	 * @access  public
	 * @return  array Params
	 */
	public function get_params( $access_key = null ) {

		// Get saved data from DB
		if ( empty( $access_key ) ) {
			$access_key = wpf_get_option( 'klaviyo_token' );
			if ( empty( $access_key ) ) {
				$access_key = wpf_get_option( 'klaviyo_key' );
			}
		}

		$this->params = array(
			'timeout'    => 30,
			'user-agent' => 'WP Fusion; ' . home_url(),
			'headers'    => array(
				'Accept'       => 'application/json',
				'Content-Type' => 'application/json',
				'Revision'     => '2025-07-15',
			),
		);

		if ( wpf_get_option( 'klaviyo_token' ) ) {
			$this->params['headers']['Authorization'] = 'Bearer ' . $access_key;
		} else {
			$this->params['headers']['Authorization'] = 'Klaviyo-API-Key ' . $access_key;
		}

		$this->key = $access_key;

		return $this->params;
	}

	/**
	 * Authorize the application and generate access and refresh tokens.
	 *
	 * @since 3.46.0
	 *
	 * @param string $code The authorization code.
	 * @param string $code_verifier The PKCE code verifier.
	 * @return bool|string The access token or false if error.
	 */
	public function authorize( $code, $code_verifier ) {

		// Format the request as form data (not JSON) as required by Klaviyo.
		$form_data = array(
			'grant_type'    => 'authorization_code',
			'code'          => $code,
			'redirect_uri'  => "https://wpfusion.com/oauth/?action=wpf_get_{$this->slug}_token",
			'code_verifier' => $code_verifier,
		);

		$body = http_build_query( $form_data );

		$params = array(
			'timeout'    => 30,
			'user-agent' => 'WP Fusion; ' . home_url(),
			'body'       => $body,
			'headers'    => array(
				'Authorization' => 'Basic ' . base64_encode( $this->client_id . ':' . $this->client_secret ),
				'Content-Type'  => 'application/x-www-form-urlencoded',
			),
		);

		$response = wp_remote_post( 'https://a.klaviyo.com/oauth/token', $params );

		if ( is_wp_error( $response ) ) {
			wp_fusion()->admin_notices->add_notice( 'Error requesting authorization code: ' . $response->get_error_message() );
			wpf_log( 'error', 0, 'Error requesting authorization code: ' . $response->get_error_message() );
			return false;
		}

		$response_code = wp_remote_retrieve_response_code( $response );
		$body_json     = json_decode( wp_remote_retrieve_body( $response ) );

		if ( 200 !== $response_code ) {
			$error_message = 'Unknown error';
			if ( $body_json && isset( $body_json->error_description ) ) {
				$error_message = $body_json->error_description;
			} elseif ( $body_json && isset( $body_json->error ) ) {
				$error_message = $body_json->error;
			}

			wp_fusion()->admin_notices->add_notice( 'Error requesting authorization: ' . $error_message );
			wpf_log( 'error', 0, 'Error requesting authorization: ' . $error_message );
			return false;
		}

		if ( ! $body_json || ! isset( $body_json->access_token ) ) {
			wp_fusion()->admin_notices->add_notice( 'Invalid response from Klaviyo during authorization.' );
			wpf_log( 'error', 0, 'Invalid response from Klaviyo during authorization.' );
			return false;
		}

		wp_fusion()->settings->set( 'klaviyo_refresh_token', $body_json->refresh_token );
		wp_fusion()->settings->set( 'klaviyo_token', $body_json->access_token );
		wp_fusion()->settings->set( 'crm', $this->slug );

		return $body_json->access_token;
	}

	/**
	 * Refresh an access token from a refresh token.
	 *
	 * @since 3.46.0
	 *
	 * @return string|WP_Error The access token, or error.
	 */
	public function refresh_token() {

		$refresh_token = wpf_get_option( 'klaviyo_refresh_token' );

		if ( empty( $refresh_token ) ) {
			return new WP_Error( 'error', 'Authorization failed and no refresh token found.' );
		}

		// Format the request as form data (not JSON) as required by Klaviyo.
		$form_data = array(
			'grant_type'    => 'refresh_token',
			'refresh_token' => $refresh_token,
		);

		$body = http_build_query( $form_data );

		$params = array(
			'timeout'    => 30,
			'user-agent' => 'WP Fusion; ' . home_url(),
			'body'       => $body,
			'headers'    => array(
				'Authorization' => 'Basic ' . base64_encode( $this->client_id . ':' . $this->client_secret ),
				'Content-Type'  => 'application/x-www-form-urlencoded',
			),
		);

		$response = wp_remote_post( 'https://a.klaviyo.com/oauth/token', $params );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$response_code = wp_remote_retrieve_response_code( $response );
		$body_json     = json_decode( wp_remote_retrieve_body( $response ) );

		if ( 200 !== $response_code ) {
			$error_message = 'Unknown error';
			if ( $body_json && isset( $body_json->error_description ) ) {
				$error_message = $body_json->error_description;
			} elseif ( $body_json && isset( $body_json->error ) ) {
				$error_message = $body_json->error;
			}

			return new WP_Error( 'error', 'Error refreshing access token: ' . $error_message );
		}

		if ( ! $body_json || ! isset( $body_json->access_token ) ) {
			return new WP_Error( 'error', 'Invalid response from Klaviyo while refreshing access token.' );
		}

		wp_fusion()->settings->set( 'klaviyo_token', $body_json->access_token );
		wp_fusion()->settings->set( 'klaviyo_refresh_token', $body_json->refresh_token );

		$this->get_params( $body_json->access_token );

		return $body_json->access_token;
	}

	/**
	 * Disconnect from Klaviyo: revoke the OAuth refresh token and clear local tokens.
	 *
	 * Called by WPF_CRM_Disconnect from both the wpfusion.com revoke URL and the
	 * settings-reset hook.
	 *
	 * @since 3.47.10
	 *
	 * @return bool|WP_Error True on success (or if already disconnected),
	 *                      WP_Error when the revoke API call failed.
	 */
	public function disconnect() {

		$refresh_token = wpf_get_option( 'klaviyo_refresh_token' );

		if ( empty( $refresh_token ) ) {
			return true;
		}

		// Format the request as form data (not JSON) as required by Klaviyo.
		$form_data = array(
			'token_type_hint' => 'refresh_token',
			'token'           => $refresh_token,
		);

		$body = http_build_query( $form_data );

		$params = array(
			'timeout'    => 30,
			'user-agent' => 'WP Fusion; ' . home_url(),
			'body'       => $body,
			'headers'    => array(
				'Authorization' => 'Basic ' . base64_encode( $this->client_id . ':' . $this->client_secret ),
				'Content-Type'  => 'application/x-www-form-urlencoded',
			),
		);

		$response = wp_remote_post( 'https://a.klaviyo.com/oauth/revoke', $params );

		if ( is_wp_error( $response ) ) {
			wpf_log( 'error', 0, 'Error revoking Klaviyo token: ' . $response->get_error_message() );
			return $response;
		}

		$response_code = wp_remote_retrieve_response_code( $response );

		// Klaviyo returns 200 for successful revocation.
		if ( 200 !== $response_code ) {
			$body_json     = json_decode( wp_remote_retrieve_body( $response ) );
			$error_message = 'Unknown error';

			if ( $body_json && isset( $body_json->error_description ) ) {
				$error_message = $body_json->error_description;
			} elseif ( $body_json && isset( $body_json->error ) ) {
				$error_message = $body_json->error;
			}

			wpf_log( 'error', 0, 'Error revoking Klaviyo token: ' . $error_message );
			return new WP_Error( 'error', 'Error revoking token: ' . $error_message );
		}

		// Clear stored tokens from database.
		wp_fusion()->settings->set( 'klaviyo_token', '' );
		wp_fusion()->settings->set( 'klaviyo_refresh_token', '' );
		wp_fusion()->settings->set( 'connection_configured', false );

		wpf_log( 'notice', 0, 'Klaviyo OAuth tokens successfully revoked.' );

		return true;
	}

	/**
	 * Backwards-compatible alias for {@see self::disconnect()}.
	 *
	 * @since      3.46.2
	 * @deprecated 3.47.10 Use disconnect() instead.
	 *
	 * @return bool|WP_Error True on success, error on failure.
	 */
	public function revoke_token() {
		return $this->disconnect();
	}

	/**
	 * Initialize connection
	 *
	 * @access  public
	 * @return  bool
	 */
	public function connect( $access_key = null, $test = false ) {

		if ( $test == false ) {
			return true;
		}

		if ( ! $this->params ) {
			$this->get_params( $access_key );
		}

		$request  = 'https://a.klaviyo.com/api/lists';
		$response = wp_remote_get( $request, $this->params );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		return true;
	}


	/**
	 * Performs initial sync once connection is configured
	 *
	 * @access public
	 * @return bool
	 */
	public function sync() {

		if ( is_wp_error( $this->connect() ) ) {
			return false;
		}

		$this->sync_tags();
		$this->sync_crm_fields();

		do_action( 'wpf_sync' );

		return true;
	}

	/**
	 * Formats phone numbers from WooCommerce for the Klaviyo API.
	 *
	 * @since 3.42.12
	 *
	 * @param array $customer_data The customer data.
	 * @return array The customer data.
	 */
	public function format_phone_numbers( $customer_data ) {

		if ( ! empty( $customer_data['billing_phone'] ) ) {
			$customer_data['billing_phone'] = wpf_phone_number_to_e164( $customer_data['billing_phone'], $customer_data['billing_country'] );

			// E.164 format: + followed by country code and number, 7-15 digits total after +
			if ( ! preg_match( '/^\+\d{7,15}$/', $customer_data['billing_phone'] ) ) {
				wpf_log( 'notice', wpf_get_current_user_id(), 'Klaviyo phone number is potentially invalid (not E.164 format): ' . $customer_data['billing_phone'] );
				unset( $customer_data['billing_phone'] );
			}
		}

		if ( ! empty( $customer_data['shipping_phone'] ) ) {
			$customer_data['shipping_phone'] = wpf_phone_number_to_e164( $customer_data['shipping_phone'], $customer_data['shipping_country'] );

			// E.164 format: + followed by country code and number, 7-15 digits total after +
			if ( ! preg_match( '/^\+\d{7,15}$/', $customer_data['shipping_phone'] ) ) {
				wpf_log( 'notice', wpf_get_current_user_id(), 'Klaviyo phone number is potentially invalid (not E.164 format): ' . $customer_data['shipping_phone'] );
				unset( $customer_data['shipping_phone'] );
			}
		}

		return $customer_data;
	}

	/**
	 * Allows lists applied with optin consent to be used for access control, and removed
	 * by the remove_tags() function.
	 *
	 * @since 3.43.8
	 *
	 * @param array $tags The tags.
	 * @return array The tags.
	 */
	public function format_tags( $tags ) {

		foreach ( $tags as $tag ) {

			if ( false !== strpos( $tag, '_optin' ) ) {

				$tags[] = str_replace( '_optin', '', $tag );
			}
		}

		return $tags;
	}

	/**
	 * Sync Tags.
	 *
	 * Gets all available tags and saves them to options.
	 *
	 * @since 3.41.21 Added support for pagination.
	 * @since 3.46.4 Added support for segments (read-only).
	 *
	 * @return array Lists and segments.
	 */
	public function sync_tags() {

		$available_tags = array();
		$continue       = true;

		$request = 'https://a.klaviyo.com/api/lists';

		// Get all lists.
		while ( $continue ) {

			$response = wp_remote_get( $request, $this->get_params() );

			if ( is_wp_error( $response ) ) {
				return $response;
			}

			$response = json_decode( wp_remote_retrieve_body( $response ) );

			foreach ( $response->data as $list ) {
				$available_tags[ $list->id ]            = array(
					'label'    => $list->attributes->name,
					'category' => 'Lists',
				);
				$available_tags[ $list->id . '_optin' ] = array(
					'label'    => $list->attributes->name . ' ' . __( '(opt-in to marketing)', 'wp-fusion-lite' ),
					'category' => 'Lists',
				);
			}

			$response->links->next ? $request = $response->links->next : $continue = false;

		}

		// Get all segments (read-only for access control).
		$continue = true;
		$request  = 'https://a.klaviyo.com/api/segments';

		while ( $continue ) {

			$response = wp_remote_get( $request, $this->get_params() );

			if ( is_wp_error( $response ) ) {
				// If segments API fails, just continue with lists.
				wpf_log( 'error', 0, 'Error fetching Klaviyo segments: ' . $response->get_error_message() );
				break;
			}

			$response = json_decode( wp_remote_retrieve_body( $response ) );

			if ( ! empty( $response->data ) ) {
				foreach ( $response->data as $segment ) {
					$available_tags[ 'segment_' . $segment->id ] = array(
						'label'    => $segment->attributes->name,
						'category' => 'Segments (Read Only)',
					);
				}
			}

			$response->links->next ? $request = $response->links->next : $continue = false;

		}

		wp_fusion()->settings->set( 'available_tags', $available_tags );

		return $available_tags;
	}


	/**
	 * Loads all custom fields from CRM and merges with local list
	 *
	 * @access public
	 * @return array CRM Fields
	 */
	public function sync_crm_fields() {

		$crm_fields = array(
			'Standard Fields' => array(),
			'Custom Fields'   => array(),
		);

		$custom_fields = wpf_get_option( 'crm_fields' );

		if ( ! empty( $custom_fields ) && ! empty( $custom_fields['Custom Fields'] ) ) {
			// Make sure we don't lose any user-created custom fields.
			$crm_fields['Custom Fields'] = $custom_fields['Custom Fields'];
		}

		// Load built in fields first.
		require __DIR__ . '/admin/klaviyo-fields.php';

		foreach ( $klaviyo_fields as $field ) {
			$crm_fields['Standard Fields'][ $field['crm_field'] ] = $field['crm_label'];
		}

		// Custom fields.

		$request  = 'https://a.klaviyo.com/api/profiles/';
		$response = wp_remote_get( $request, $this->get_params() );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$response = json_decode( wp_remote_retrieve_body( $response ) );

		if ( ! empty( $response->data ) ) {

			foreach ( $response->data as $person ) {

				if ( ! empty( $person->attributes->properties ) ) {
					foreach ( $person->attributes->properties as $key => $value ) {
						if ( ! isset( $crm_fields['Standard Fields'][ $key ] ) ) {
							$crm_fields['Custom Fields'][ $key ] = $key;
						}
					}
				}
			}
		}

		asort( $crm_fields['Custom Fields'] );

		wp_fusion()->settings->set( 'crm_fields', $crm_fields );

		return $crm_fields;
	}


	/**
	 * Gets contact ID for a user based on email address
	 *
	 * @access public
	 * @return int Contact ID
	 */
	public function get_contact_id( $email_address ) {

		if ( ! $this->params ) {
			$this->get_params();
		}

		$request  = 'https://a.klaviyo.com/api/profiles/?filter=equals(email,"' . $email_address . '")';
		$response = wp_remote_get( $request, $this->params );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$response = json_decode( wp_remote_retrieve_body( $response ) );

		if ( isset( $response->data[0] ) ) {

			return $response->data[0]->id;

		} else {

			return false;

		}
	}


	/**
	 * Gets all tags currently applied to the user
	 *
	 * @access public
	 * @return array Tags
	 */
	public function get_tags( $contact_id ) {

		if ( ! $this->params ) {
			$this->get_params();
		}
		$user_tags = array();

		// Get list memberships.
		$request  = 'https://a.klaviyo.com/api/profiles/' . $contact_id . '/lists';
		$response = wp_remote_get( $request, $this->params );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$response = json_decode( wp_remote_retrieve_body( $response ) );

		// Klaviyo sometimes returns unknown lists (maybe deleted ones?). We'll exclude them.
		$available_tags = wpf_get_option( 'available_tags', array() );

		if ( ! empty( $response->data ) ) {

			foreach ( $response->data as $list ) {

				if ( ! isset( $available_tags[ $list->id ] ) ) {
					continue;
				}

				$user_tags[] = $list->id;
			}
		}

		// Get segment memberships.
		$request  = 'https://a.klaviyo.com/api/profiles/' . $contact_id . '/segments';
		$response = wp_remote_get( $request, $this->params );

		if ( ! is_wp_error( $response ) ) {
			$response = json_decode( wp_remote_retrieve_body( $response ) );

			if ( ! empty( $response->data ) ) {
				foreach ( $response->data as $segment ) {
					$segment_tag = 'segment_' . $segment->id;

					if ( isset( $available_tags[ $segment_tag ] ) ) {
						$user_tags[] = $segment_tag;
					}
				}
			}
		}

		return $user_tags;
	}

	/**
	 * Applies tags to a contact
	 *
	 * @return bool|WP_Error True on success, error on failure.
	 */
	public function apply_tags( $tags, $contact_id ) {

		// Filter out segment tags - segments are read-only.
		$filtered_tags = array();
		foreach ( $tags as $tag_id ) {
			if ( 0 === strpos( $tag_id, 'segment_' ) ) {
				wpf_log( 'notice', wpf_get_current_user_id(), 'Cannot apply segment tag <strong>' . $tag_id . '</strong> - segments are read-only.' );
				continue;
			}
			$filtered_tags[] = $tag_id;
		}

		if ( empty( $filtered_tags ) ) {
			return true; // No applicable tags.
		}

		$params = $this->get_params();

		$optin_data = array(
			'data' => array(
				'type'          => 'profile-subscription-bulk-create-job',
				'attributes'    => array(
					'custom_source' => $this->last_source ?: __( 'WP Fusion', 'wp-fusion-lite' ),
					'profiles'      => array(
						'data' => array(
							array(
								'type'       => 'profile',
								'id'         => $contact_id,
								'attributes' => array(
									'email'         => wp_fusion()->crm->get_email_from_cid( $contact_id ),
									'subscriptions' => array(
										'email' => array(
											'marketing' => array(
												'consent' => 'SUBSCRIBED',
											),
										),
									),
								),
							),
						),
					),
				),
				'relationships' => array(
					'list' => array(
						'data' => array(
							'type' => 'list',
						),
					),
				),
			),
		);

		foreach ( $filtered_tags as $tag_id ) {

			if ( false === strpos( $tag_id, '_optin' ) ) {

				if ( in_array( $tag_id . '_optin', $filtered_tags ) ) {
					continue; // if we're set to opt them in as well, don't do a normal add.
				}

				// Non explicit consent, adds them to the list NEVER SUBSCRIBED.

				$data = array(
					'data' => array(
						array(
							'type' => 'profile',
							'id'   => $contact_id,
						),
					),
				);

				$request        = 'https://a.klaviyo.com/api/lists/' . $tag_id . '/relationships/profiles/';
				$params['body'] = wp_json_encode( $data );

			} else {

				// Explicit consent. Adds them to the list SUBSCRIBED.
				$optin_data['data']['relationships']['list']['data']['id'] = str_replace( '_optin', '', $tag_id );
				$request = 'https://a.klaviyo.com/api/profile-subscription-bulk-create-jobs/';

				$params['body'] = wp_json_encode( $optin_data );

			}

			$response = wp_remote_post( $request, $params );

			if ( is_wp_error( $response ) ) {
				return $response;
			}
		}

		return true;
	}

	/**
	 * Removes tags from a contact
	 *
	 * @access public
	 * @return bool|WP_Error
	 */
	public function remove_tags( $tags, $contact_id ) {

		// Filter out segment tags - segments are read-only.
		$filtered_tags = array();
		foreach ( $tags as $tag_id ) {
			if ( 0 === strpos( $tag_id, 'segment_' ) ) {
				wpf_log( 'notice', wpf_get_current_user_id(), 'Cannot remove segment tag <strong>' . $tag_id . '</strong> - segments are read-only.' );
				continue;
			}
			$filtered_tags[] = $tag_id;
		}

		if ( empty( $filtered_tags ) ) {
			return true; // No applicable tags.
		}

		$params = $this->get_params();

		$data = array(
			'data' => array(
				array(
					'type' => 'profile',
					'id'   => $contact_id,
				),
			),
		);

		$params['body']   = wp_json_encode( $data );
		$params['method'] = 'DELETE';

		// Remove any optin flags.

		$filtered_tags = array_unique( $this->format_tags( $filtered_tags ) );

		foreach ( $filtered_tags as $tag_id ) {

			$request  = 'https://a.klaviyo.com/api/lists/' . $tag_id . '/relationships/profiles/';
			$response = wp_remote_post( $request, $params );

			if ( is_wp_error( $response ) ) {
				return $response;
			}
		}

		return true;
	}

	/**
	 * Formats the contact data for the Klaviyo API.
	 *
	 * @since 3.40.41
	 *
	 * @param array $data The contact data.
	 * @return array The complete API payload.
	 */
	public function format_contact_payload( $data ) {

		$body = array(
			'data' => array(
				'type'       => 'profile',
				'attributes' => array(),
			),
		);

		$crm_fields = wpf_get_option( 'crm_fields' );
		$attributes = array();
		$properties = array();

		foreach ( $data as $key => $value ) {

			if ( ! is_scalar( $value ) ) {
				wpf_log( 'notice', wpf_get_current_user_id(), 'Skipping non-scalar value for field <strong>' . $key . '</strong> (type: ' . gettype( $value ) . ')' );
				continue;
			}

			// Save the last source used to create/update a contact.
			if ( '$source' === $key ) {
				$this->last_source = $value;
				continue; // Don't include this in the payload.
			}

			// Handle compound fields first (fields with + like location+address1).
			if ( false !== strpos( $key, '+' ) ) {
				$parts = explode( '+', $key, 2 ); // Limit to 2 parts in case there are multiple + signs.

				if ( 2 === count( $parts ) ) {
					$parent_field = $parts[0];
					$child_field  = $parts[1];

					// Initialize the parent object if it doesn't exist.
					if ( ! isset( $attributes[ $parent_field ] ) ) {
						$attributes[ $parent_field ] = array();
					}

					$attributes[ $parent_field ][ $child_field ] = $value;
				}
				continue;
			}

			// Handle fields with $ prefix (standard Klaviyo fields).
			if ( 0 === strpos( $key, '$' ) || isset( $crm_fields['Standard Fields'][ $key ] ) ) {

				$field_name                = ltrim( $key, '$' );
				$attributes[ $field_name ] = $value;
			} else {
				// If it's not a known standard field, treat as custom property.
				$properties[ $key ] = $value;
			}
		}

        // Set the attributes in the body.
        $body['data']['attributes'] = $attributes;

        // Custom properties must be nested under attributes.properties per Klaviyo JSON:API.
        if ( ! empty( $properties ) ) {
            if ( ! isset( $body['data']['attributes']['properties'] ) || ! is_array( $body['data']['attributes']['properties'] ) ) {
                $body['data']['attributes']['properties'] = array();
            }
            $body['data']['attributes']['properties'] = array_merge( $body['data']['attributes']['properties'], $properties );
        }

		return $body;
	}

	/**
	 * Adds a new contact
	 *
	 * @since 3.40.41
	 *
	 * @param array $data The contact data.
	 * @return int|WP_Error Contact ID or WP_Error
	 */
	public function add_contact( $data ) {

		$body = $this->format_contact_payload( $data );

		$request        = 'https://a.klaviyo.com/api/profiles';
		$params         = $this->get_params();
		$params['body'] = wp_json_encode( $body );

		// Check payload size limit (100KB as per Klaviyo API docs).
		if ( strlen( $params['body'] ) > 102400 ) {
			return new WP_Error( 'payload_too_large', __( 'Profile payload exceeds 100KB limit', 'wp-fusion-lite' ) );
		}

		$response = wp_remote_post( $request, $params );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$response_body = json_decode( wp_remote_retrieve_body( $response ) );

		return $response_body->data->id;
	}

	/**
	 * Update contact
	 *
	 * @since 3.40.41
	 *
	 * @param string $contact_id The contact ID.
	 * @param array  $data       The contact data.
	 * @return bool|WP_Error True on success, WP_Error on failure.
	 */
	public function update_contact( $contact_id, $data ) {

		$body = $this->format_contact_payload( $data );

		// Add the contact ID for updates.
		$body['data']['id'] = $contact_id;

		$request          = 'https://a.klaviyo.com/api/profiles/' . $contact_id;
		$params           = $this->get_params();
		$params['body']   = wp_json_encode( $body );
		$params['method'] = 'PATCH';

		// Check payload size limit (100KB as per Klaviyo API docs).
		if ( strlen( $params['body'] ) > 102400 ) {
			return new WP_Error( 'payload_too_large', __( 'Profile payload exceeds 100KB limit', 'wp-fusion-lite' ) );
		}

		$response = wp_remote_post( $request, $params );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		return true;
	}

	/**
	 * Loads a contact and updates local user meta
	 *
	 * @access public
	 * @param string $contact_id The contact ID.
	 * @return array|WP_Error User meta data that was returned or WP_Error.
	 */
	public function load_contact( $contact_id ) {

		$request  = 'https://a.klaviyo.com/api/profiles/' . $contact_id;
		$response = wp_remote_get( $request, $this->get_params() );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$user_meta      = array();
		$contact_fields = wpf_get_option( 'contact_fields' );
		$crm_fields     = wpf_get_option( 'crm_fields' );
		$body_json      = json_decode( $response['body'], true );

		foreach ( $contact_fields as $field_id => $field_data ) {

			if ( ! $field_data['active'] ) {
				continue;
			}

			$crm_field = $field_data['crm_field'];

			// Handle compound fields (like location+address1).
			if ( false !== strpos( $crm_field, '+' ) ) {
				$parts = explode( '+', $crm_field, 2 );

				if ( 2 === count( $parts ) ) {
					$parent_field = $parts[0];
					$child_field  = $parts[1];

					if ( isset( $body_json['data']['attributes'][ $parent_field ][ $child_field ] ) ) {
						$user_meta[ $field_id ] = $body_json['data']['attributes'][ $parent_field ][ $child_field ];
					}
				}
				continue;
			}

			// Handle fields with $ prefix or standard fields.
			if ( 0 === strpos( $crm_field, '$' ) || ( ! empty( $crm_fields['Standard Fields'] ) && isset( $crm_fields['Standard Fields'][ $crm_field ] ) ) ) {

				$field_name = ltrim( $crm_field, '$' );

				if ( isset( $body_json['data']['attributes'][ $field_name ] ) ) {
					$user_meta[ $field_id ] = $body_json['data']['attributes'][ $field_name ];
				}
			} elseif ( isset( $body_json['data']['attributes']['properties'][ $crm_field ] ) ) {
				// Custom fields are stored in the properties field.
				$user_meta[ $field_id ] = $body_json['data']['attributes']['properties'][ $crm_field ];
			}
		}

		return $user_meta;
	}


	/**
	 * Gets a list of contact IDs based on tag
	 *
	 * @access public
	 * @return array Contact IDs returned
	 */
	public function load_contacts( $tag ) {

		$contact_ids = array();

		$request  = 'https://a.klaviyo.com/api/lists/' . $tag . '/profiles';
		$response = wp_remote_get( $request, $this->get_params() );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$response = json_decode( wp_remote_retrieve_body( $response ) );

		if ( ! empty( $response->data ) ) {

			foreach ( $response->data as $record ) {
				$contact_ids[] = $record->id;
			}
		}

		return $contact_ids;
	}



	/**
	 * Track event.
	 *
	 * Track an event with the Bento site tracking API.
	 *
	 * @since  3.40.40
	 *
	 * @param  string       $event      The event title.
	 * @param  string|array $event_data The event description.
	 * @param  bool|string  $email_address The user email address.
	 * @return bool|WP_Error True if success, WP_Error if failed.
	 */
	public function track_event( $event, $event_data = '', $email_address = false ) {

		if ( empty( $email_address ) && ! wpf_is_user_logged_in() ) {
			// Tracking only works if WP Fusion knows who the contact is.
			return false;
		}

		// Get the email address to track.
		if ( empty( $email_address ) ) {
			$user          = wpf_get_current_user();
			$email_address = $user->user_email;
		}

		$body = array(
			'data' => array(
				'type'       => 'event',
				'attributes' => array(
					'profile'    => array(
						'data' => array(
							'type'       => 'profile',
							'attributes' => array(
								'email' => $email_address,
							),
						),
					),
					'metric'     => array(
						'data' => array(
							'type'       => 'metric',
							'attributes' => array(
								'name' => $event,
							),
						),
					),
					'properties' => array(
						'event_title' => $event,
						'event_desc'  => $event_data,
					),
				),
			),
		);

		if ( is_array( $event_data ) ) {
			$body['data']['attributes']['properties'] = $event_data; // multi-key support.
		}

		$request        = 'https://a.klaviyo.com/api/events';
		$params         = $this->get_params();
		$params['body'] = wp_json_encode( $body );

		$response = wp_remote_post( $request, $params );

		if ( is_wp_error( $response ) ) {
			return $response;
		}

		return true;
	}
}
