<?php
if ( ! defined( 'ABSPATH' ) ) exit;

/**
 * Lead Funnels: the templates and what a wizard answer may contain.
 *
 * A template says which kind of form a funnel needs, whether it delivers a file, and what the wizard starts with. Each
 * template is data. Pro (or an add-on) can register more through the 'acquis_funnel_templates' filter, and a template
 * that needs Pro is simply not registered in Lite, so Lite never lists something it cannot do.
 *
 * Every answer is sanitized here against a fixed schema before anything is created: nothing from the browser is trusted.
 */
class ACQUIS_Funnel_Templates {

    /** The fields a funnel form may be built from, in display order. key => array( label, type, required ). */
    public static function standard_fields() {
        return array(
            'first_name' => array( 'label' => __( 'First name', 'acquisitionsuite' ),    'type' => 'text',  'required' => 1 ),
            'last_name'  => array( 'label' => __( 'Last name', 'acquisitionsuite' ),     'type' => 'text',  'required' => 0 ),
            'email'      => array( 'label' => __( 'Email address', 'acquisitionsuite' ), 'type' => 'email', 'required' => 1 ),
            'phone'      => array( 'label' => __( 'Phone number', 'acquisitionsuite' ),  'type' => 'phone', 'required' => 0 ),
            'company'    => array( 'label' => __( 'Company', 'acquisitionsuite' ),       'type' => 'text',  'required' => 0 ),
            'website'    => array( 'label' => __( 'Website', 'acquisitionsuite' ),       'type' => 'url',   'required' => 0 ),
        );
    }

    /** @return array id => template */
    public static function all() {
        $std = array( 'first_name', 'last_name', 'email' );
        $all = array(
            'free_resource' => array(
                'id'          => 'free_resource',
                'label'       => __( 'Offer a free resource', 'acquisitionsuite' ),
                'description' => __( 'Turn visitors into qualified leads.', 'acquisitionsuite' ),
                'icon'        => 'dashicons-download',
                'purpose'     => 'file_gate',
                'needs_file'  => true,
                'defaults'    => array(
                    'name'         => __( 'Free guide', 'acquisitionsuite' ),
                    'headline'     => __( 'Download our free guide', 'acquisitionsuite' ),
                    'description'  => __( 'Enter your details and we will send it to you.', 'acquisitionsuite' ),
                    'fields'       => $std,
                    'button_label' => __( 'Download now', 'acquisitionsuite' ),
                    'submit_label' => __( 'Get my download', 'acquisitionsuite' ),
                    'after_message' => __( 'Thanks! Your download is on its way.', 'acquisitionsuite' ),
                    'email_subject' => __( 'Your download is ready, {full_name}', 'acquisitionsuite' ),
                    'email_body'   => __( "Hi {full_name},\n\nThanks for your interest. Your file {file_name} is ready.", 'acquisitionsuite' ),
                ),
            ),
            'email_list'    => array(
                'id'          => 'email_list',
                'label'       => __( 'Grow your email list', 'acquisitionsuite' ),
                'description' => __( 'Build and nurture your subscribers.', 'acquisitionsuite' ),
                'icon'        => 'dashicons-email-alt',
                'purpose'     => 'registration',
                'needs_file'  => false,
                'defaults'    => array(
                    'name'         => __( 'Newsletter signup', 'acquisitionsuite' ),
                    'headline'     => __( 'Join our newsletter', 'acquisitionsuite' ),
                    'description'  => __( 'Tips and updates, straight to your inbox.', 'acquisitionsuite' ),
                    'fields'       => array( 'first_name', 'email' ),
                    'button_label' => __( 'Subscribe', 'acquisitionsuite' ),
                    'submit_label' => __( 'Subscribe', 'acquisitionsuite' ),
                    'after_message' => __( 'You are on the list. Thanks for subscribing!', 'acquisitionsuite' ),
                    'email_subject' => __( 'Welcome, {full_name}', 'acquisitionsuite' ),
                    'email_body'   => __( "Hi {full_name},\n\nThanks for subscribing. We will be in touch soon.", 'acquisitionsuite' ),
                ),
            ),
            'enquiry'       => array(
                'id'          => 'enquiry',
                'label'       => __( 'Capture service enquiries', 'acquisitionsuite' ),
                'description' => __( 'Collect qualified enquiries.', 'acquisitionsuite' ),
                'icon'        => 'dashicons-businessman',
                'purpose'     => 'custom',
                'needs_file'  => false,
                'defaults'    => array(
                    'name'         => __( 'Service enquiries', 'acquisitionsuite' ),
                    'headline'     => __( 'Tell us what you need', 'acquisitionsuite' ),
                    'description'  => __( 'We usually reply within one working day.', 'acquisitionsuite' ),
                    'fields'       => array( 'first_name', 'last_name', 'email', 'phone', 'company' ),
                    'button_label' => __( 'Make an enquiry', 'acquisitionsuite' ),
                    'submit_label' => __( 'Send enquiry', 'acquisitionsuite' ),
                    'after_message' => __( 'Thanks! We have received your enquiry and will reply shortly.', 'acquisitionsuite' ),
                    'email_subject' => __( 'We received your enquiry, {full_name}', 'acquisitionsuite' ),
                    'email_body'   => __( "Hi {full_name},\n\nThanks for getting in touch. We will reply as soon as we can.", 'acquisitionsuite' ),
                ),
            ),
            'waitlist'      => array(
                'id'          => 'waitlist',
                'label'       => __( 'Join a waitlist', 'acquisitionsuite' ),
                'description' => __( 'Build anticipation before launch.', 'acquisitionsuite' ),
                'icon'        => 'dashicons-megaphone',
                'purpose'     => 'registration',
                'needs_file'  => false,
                'tags'        => array( __CLASS__, 'tags_waitlist' ),
                'pro_defaults' => array( 'tags' => array( 'waitlist' ) ),
                'extra'       => array(
                    array( 'key' => 'waitlist_for', 'label' => __( 'What are people waiting for?', 'acquisitionsuite' ), 'type' => 'text', 'required' => false,
                           'help' => __( 'Used in the confirmation, for example "the spring cohort". Leave empty to use your site name.', 'acquisitionsuite' ) ),
                ),
                'defaults'    => array(
                    'name'         => __( 'Launch waitlist', 'acquisitionsuite' ),
                    'headline'     => __( 'Join the waitlist', 'acquisitionsuite' ),
                    'description'  => __( 'Be the first to know when we open.', 'acquisitionsuite' ),
                    'fields'       => array( 'first_name', 'email' ),
                    'button_label' => __( 'Join the waitlist', 'acquisitionsuite' ),
                    'submit_label' => __( 'Join the waitlist', 'acquisitionsuite' ),
                    'after_message' => __( 'You are on the list. We will email you as soon as {waitlist_for} is ready.', 'acquisitionsuite' ),
                    'email_subject' => __( 'You are on the waitlist, {full_name}', 'acquisitionsuite' ),
                    'email_body'   => __( "Hi {full_name},\n\nYou are on the waitlist for {waitlist_for}. We will email you as soon as it is ready.", 'acquisitionsuite' ),
                    'email_enabled' => 0,
                ),
            ),
            'webinar'       => array(
                'id'          => 'webinar',
                'label'       => __( 'Register webinar attendees', 'acquisitionsuite' ),
                'description' => __( 'Grow your webinar audience.', 'acquisitionsuite' ),
                'icon'        => 'dashicons-video-alt3',
                'purpose'     => 'registration',
                'needs_file'  => false,
                'tags'        => array( __CLASS__, 'tags_webinar' ),
                'pro_defaults' => array( 'tags' => array( 'webinar' ) ),
                'extra'       => array(
                    array( 'key' => 'event_title', 'label' => __( 'Webinar title', 'acquisitionsuite' ), 'type' => 'text', 'required' => true ),
                    array( 'key' => 'event_start', 'label' => __( 'Starts', 'acquisitionsuite' ), 'type' => 'datetime', 'required' => true,
                           'help' => __( 'In your site\'s timezone. Registrants get a link to add it to their calendar.', 'acquisitionsuite' ) ),
                    array( 'key' => 'event_length', 'label' => __( 'Length', 'acquisitionsuite' ), 'type' => 'select', 'required' => false, 'default' => '60',
                           'options' => array( '30' => __( '30 minutes', 'acquisitionsuite' ), '45' => __( '45 minutes', 'acquisitionsuite' ), '60' => __( '1 hour', 'acquisitionsuite' ), '90' => __( '90 minutes', 'acquisitionsuite' ), '120' => __( '2 hours', 'acquisitionsuite' ) ) ),
                    array( 'key' => 'event_link', 'label' => __( 'Join link', 'acquisitionsuite' ), 'type' => 'url', 'required' => false,
                           'help' => __( 'Zoom, Google Meet or similar. You can add it later by editing the funnel.', 'acquisitionsuite' ) ),
                ),
                'defaults'    => array(
                    'name'         => __( 'Webinar registration', 'acquisitionsuite' ),
                    'headline'     => __( 'Save your seat', 'acquisitionsuite' ),
                    'description'  => __( 'Register and we will send you the details.', 'acquisitionsuite' ),
                    'fields'       => array( 'first_name', 'email' ),
                    'button_label' => __( 'Register now', 'acquisitionsuite' ),
                    'submit_label' => __( 'Register', 'acquisitionsuite' ),
                    'after_message' => __( 'You are registered for {webinar_title} on {webinar_date}.', 'acquisitionsuite' ),
                    'email_subject' => __( 'You are registered: {webinar_title}', 'acquisitionsuite' ),
                    'email_body'   => __( "Hi {full_name},\n\nYou are registered for {webinar_title}.\n\nWhen: {webinar_date} at {webinar_time}\nJoin here: {webinar_link}\n\nAdd it to your calendar: {webinar_calendar_link}", 'acquisitionsuite' ),
                    'email_enabled' => 1, // the details are the point of the email
                ),
            ),
            'book_call'     => array(
                'id'          => 'book_call',
                'label'       => __( 'Book discovery calls', 'acquisitionsuite' ),
                'description' => __( 'Capture appointment requests.', 'acquisitionsuite' ),
                'icon'        => 'dashicons-calendar-alt',
                'purpose'     => 'appointment',
                'needs_file'  => false,
                'tags'        => array( __CLASS__, 'tags_book_call' ),
                'prefill_redirect' => 'booking_url',
                'notify_default'   => 1,
                'pro_defaults' => array( 'tags' => array( 'call-request' ) ),
                'extra'       => array(
                    array( 'key' => 'booking_url', 'label' => __( 'Scheduling link', 'acquisitionsuite' ), 'type' => 'url', 'required' => false,
                           'help' => __( 'Calendly, Cal.com or similar. If you add one, people are sent there after the form.', 'acquisitionsuite' ) ),
                ),
                'defaults'    => array(
                    'name'         => __( 'Discovery call requests', 'acquisitionsuite' ),
                    'headline'     => __( 'Book a discovery call', 'acquisitionsuite' ),
                    'description'  => __( 'Tell us a little about you and when suits.', 'acquisitionsuite' ),
                    'fields'       => array( 'first_name', 'last_name', 'email', 'phone' ),
                    'custom'       => array(
                        array( 'label' => __( 'Preferred date', 'acquisitionsuite' ), 'type' => 'date', 'required' => 0 ),
                        array( 'label' => __( 'What would you like to discuss?', 'acquisitionsuite' ), 'type' => 'textarea', 'required' => 0 ),
                    ),
                    'button_label' => __( 'Book a call', 'acquisitionsuite' ),
                    'submit_label' => __( 'Request a call', 'acquisitionsuite' ),
                    'after_message' => __( 'Thanks! We have your request and will confirm a time shortly.', 'acquisitionsuite' ),
                    'email_subject' => __( 'We received your request, {full_name}', 'acquisitionsuite' ),
                    'email_body'   => __( "Hi {full_name},\n\nThanks for asking for a call. We will confirm a time shortly.\n\nPrefer to pick a time yourself? {booking_link}", 'acquisitionsuite' ),
                    'email_enabled' => 0,
                ),
            ),
        );
        /**
         * The funnel templates. Pro and add-ons add theirs here. A template needs: id, label, description, icon (a
         * dashicon class), purpose (file_gate, registration, appointment or custom), needs_file and defaults.
         *
         * @param array $all id => template
         */
        $filtered = apply_filters( 'acquis_funnel_templates', $all );
        $out      = array();
        foreach ( (array) $filtered as $id => $t ) {
            if ( is_array( $t ) && ! empty( $t['id'] ) && ! empty( $t['label'] ) && isset( $t['defaults'] ) ) {
                $out[ sanitize_key( $id ) ] = $t;
            }
        }
        return $out;
    }

    public static function get( $id ) {
        $all = self::all();
        return isset( $all[ $id ] ) ? $all[ $id ] : null;
    }

    /**
     * The answers a funnel is built from, cleaned.
     *
     * @param string $template_id
     * @param array  $raw         What the browser sent (already JSON-decoded).
     * @param bool   $editing     True when changing an existing funnel: the form source cannot change then.
     * @param int    $funnel_id   The funnel being changed (0 when creating), so an extension can tell "this funnel" from others.
     * @return array|WP_Error { name, headline, description, file_id, form_mode, form_id, fields[], custom[], display,
     *                          button_label, submit_label, after{type,message,url}, email{enabled,subject,body},
     *                          notify{enabled,email}, pro{} }
     */
    public static function sanitize( $template_id, array $raw, $editing = false, $funnel_id = 0 ) {
        $tpl = self::get( sanitize_key( $template_id ) );
        if ( ! $tpl ) {
            return new WP_Error( 'template', __( 'That template is not available.', 'acquisitionsuite' ) );
        }
        $d = $tpl['defaults'];
        $t = function ( $key, $max ) use ( $raw ) {
            $v = isset( $raw[ $key ] ) && is_scalar( $raw[ $key ] ) ? sanitize_text_field( (string) $raw[ $key ] ) : '';
            return function_exists( 'mb_substr' ) ? mb_substr( $v, 0, $max ) : substr( $v, 0, $max );
        };
        $a = array(
            'template'     => $tpl['id'],
            'name'         => $t( 'name', 120 ),
            'headline'     => $t( 'headline', 150 ),
            'description'  => $t( 'description', 300 ),
            'button_label' => $t( 'button_label', 60 ),
            'submit_label' => $t( 'submit_label', 60 ),
        );
        if ( '' === $a['name'] ) {
            return new WP_Error( 'name', __( 'Enter a name for this funnel.', 'acquisitionsuite' ), array( 'field' => 'name' ) );
        }
        foreach ( array( 'headline', 'button_label', 'submit_label' ) as $k ) {
            if ( '' === $a[ $k ] ) {
                $a[ $k ] = (string) ( $d[ $k ] ?? '' );
            }
        }

        // ── Resource ──────────────────────────────────────────────────────
        $a['file_id'] = 0;
        if ( ! empty( $tpl['needs_file'] ) ) {
            $a['file_id'] = absint( $raw['file_id'] ?? 0 );
            if ( ! $a['file_id'] || ! ACQUIS_File_Manager::get_file_data( $a['file_id'] ) ) {
                return new WP_Error( 'file', __( 'Choose the file people should receive.', 'acquisitionsuite' ), array( 'field' => 'file_id' ) );
            }
        }

        // ── Form ──────────────────────────────────────────────────────────
        $a['form_mode'] = ( isset( $raw['form_mode'] ) && 'existing' === $raw['form_mode'] ) ? 'existing' : 'new';
        $a['form_id']   = 0;
        $a['fields']    = array();
        $a['custom']    = array();
        if ( 'existing' === $a['form_mode'] ) {
            $a['form_id'] = absint( $raw['form_id'] ?? 0 );
            if ( ! $a['form_id'] || ! ACQUIS_P3_DB::get_form( $a['form_id'] ) ) {
                return new WP_Error( 'form', __( 'Choose one of your existing forms.', 'acquisitionsuite' ), array( 'field' => 'form_id' ) );
            }
        } else {
            $std = self::standard_fields();
            foreach ( (array) ( $raw['fields'] ?? array() ) as $k ) {
                $k = sanitize_key( (string) $k );
                if ( isset( $std[ $k ] ) && ! in_array( $k, $a['fields'], true ) ) {
                    $a['fields'][] = $k;
                }
            }
            if ( ! in_array( 'email', $a['fields'], true ) ) {
                $a['fields'][] = 'email'; // A lead needs an email address.
            }
            // Keep the order of the standard list, not the order they were ticked in.
            $a['fields'] = array_values( array_intersect( array_keys( $std ), $a['fields'] ) );

            $types = array( 'text', 'textarea', 'number', 'phone', 'url', 'date' );
            $new_fields = 0;
            $seen_keys  = array();
            foreach ( (array) ( $raw['custom'] ?? array() ) as $c ) {
                $label = is_array( $c ) && isset( $c['label'] ) && is_scalar( $c['label'] ) ? sanitize_text_field( (string) $c['label'] ) : '';
                if ( '' === $label ) {
                    continue;
                }
                // A field the form already has (shown when editing) keeps its key, so renaming it never makes a new one,
                // and keeps its type, so a dropdown stays a dropdown. It can be of any type and have any name.
                $key = '';
                if ( $editing && isset( $c['key'] ) && is_string( $c['key'] ) && preg_match( '/^[a-z0-9_]{1,64}$/', $c['key'] ) && ! isset( $std[ $c['key'] ] ) && ! in_array( $c['key'], $seen_keys, true ) ) {
                    $key = $c['key'];
                }
                if ( '' === $key && $new_fields >= 5 ) {
                    continue; // at most five NEW custom fields at a time
                }
                if ( '' !== $key ) {
                    $type = isset( $c['type'] ) && is_string( $c['type'] ) && preg_match( '/^[a-z0-9_-]{1,30}$/', $c['type'] ) ? $c['type'] : 'text';
                } else {
                    $type = isset( $c['type'] ) && in_array( $c['type'], $types, true ) ? $c['type'] : 'text';
                    $new_fields++;
                }
                $item = array( 'label' => substr( $label, 0, 80 ), 'type' => $type, 'required' => empty( $c['required'] ) ? 0 : 1 );
                if ( '' !== $key ) {
                    $item['key'] = $key;
                    $seen_keys[] = $key;
                }
                $a['custom'][] = $item;
            }
        }
        if ( $editing ) {
            // The form a funnel was built on does not change afterwards: make a new funnel for a different form.
            unset( $a['form_mode'], $a['form_id'] );
        }

        // Embedded and popup are always there. Floating and slide-in are added to the allowed list by Pro.
        $display          = isset( $raw['display'] ) ? sanitize_key( (string) $raw['display'] ) : 'embedded';
        $allowed          = (array) apply_filters( 'acquis_form_display_styles', array( 'embedded', 'popup' ) );
        $a['display']     = in_array( $display, array( 'embedded', 'popup', 'floating', 'slidein' ), true ) && in_array( $display, $allowed, true ) ? $display : 'embedded';
        $a['slidein_delay'] = isset( $raw['slidein_delay'] ) && is_numeric( $raw['slidein_delay'] ) ? max( 0, min( 300, (int) $raw['slidein_delay'] ) ) : 8;

        // ── The template's own questions ──────────────────────────────────
        $a['extra'] = array();
        foreach ( (array) ( $tpl['extra'] ?? array() ) as $def ) {
            $res = self::clean_extra( $def, isset( $raw['extra'][ $def['key'] ] ) ? $raw['extra'][ $def['key'] ] : '', $editing );
            if ( is_wp_error( $res ) ) {
                return $res;
            }
            $a['extra'][ $def['key'] ] = $res;
        }

        $sec = wp_parse_args( (array) ( $tpl['sections'] ?? array() ), array( 'after' => 1, 'email' => 1, 'notify' => 1 ) );

        // ── After submission ──────────────────────────────────────────────
        $after = $sec['after'] ? (array) ( $raw['after'] ?? array() ) : array();
        $type  = ( isset( $after['type'] ) && 'redirect' === $after['type'] ) ? 'redirect' : 'message';
        $url   = '';
        if ( 'redirect' === $type ) {
            $url = esc_url_raw( trim( (string) ( $after['url'] ?? '' ) ), array( 'http', 'https' ) );
            if ( '' === $url ) {
                return new WP_Error( 'after_url', __( 'Enter the address people should be sent to, starting with https://.', 'acquisitionsuite' ), array( 'field' => 'after_url' ) );
            }
        }
        $msg = sanitize_text_field( (string) ( $after['message'] ?? '' ) );
        $a['after'] = array(
            'type'    => $type,
            'message' => '' !== $msg ? substr( $msg, 0, 300 ) : (string) ( $d['after_message'] ?? '' ),
            'url'     => $url,
        );

        // ── Delivery email (for this funnel only) ─────────────────────────
        $email = $sec['email'] ? (array) ( $raw['email'] ?? array() ) : array();
        $a['email'] = array(
            'enabled' => ! empty( $email['enabled'] ) ? 1 : 0,
            'subject' => substr( sanitize_text_field( (string) ( $email['subject'] ?? '' ) ), 0, 190 ),
            'body'    => substr( sanitize_textarea_field( (string) ( $email['body'] ?? '' ) ), 0, 3000 ),
        );
        if ( $a['email']['enabled'] && ( '' === $a['email']['subject'] || '' === trim( $a['email']['body'] ) ) ) {
            return new WP_Error( 'email', __( 'Write a subject and a message for the delivery email, or switch the custom email off.', 'acquisitionsuite' ), array( 'field' => 'email' ) );
        }

        // ── Notify me ─────────────────────────────────────────────────────
        $notify = $sec['notify'] ? (array) ( $raw['notify'] ?? array() ) : array();
        $addr   = sanitize_email( (string) ( $notify['email'] ?? '' ) );
        $on     = ! empty( $notify['enabled'] );
        if ( $on && '' === $addr ) {
            $addr = (string) get_option( 'admin_email' );
        }
        if ( $on && ! is_email( $addr ) ) {
            return new WP_Error( 'notify', __( 'Enter a valid email address for the notification.', 'acquisitionsuite' ), array( 'field' => 'notify_email' ) );
        }
        $a['notify'] = array( 'enabled' => $on ? 1 : 0, 'email' => $on ? $addr : '' );

        /**
         * Pro (and add-ons) clean their own part of the answers here and return it under a key of their choosing, or
         * return a WP_Error to stop the build.
         *
         * @param array $answers The cleaned answers so far.
         * @param array $raw     What the browser sent.
         * @param array $tpl     The template.
         * @param int   $funnel_id The funnel being edited, 0 when creating.
         */
        $a = apply_filters( 'acquis_funnel_answers', $a, $raw, $tpl, (int) $funnel_id );
        return $a;
    }

    /** The shortcode to place a funnel's form on a page. */
    public static function shortcode( $template_id, $form_id, $file_id = 0, array $answers = array() ) {
        $tpl = self::get( $template_id );
        if ( $tpl && ! empty( $tpl['needs_file'] ) ) {
            $label = isset( $answers['button_label'] ) && '' !== $answers['button_label'] ? ' label="' . esc_attr( str_replace( '"', '', $answers['button_label'] ) ) . '"' : '';
            return '[acquis_download id="' . absint( $file_id ) . '" form="' . absint( $form_id ) . '"' . $label . ']';
        }
        $display = isset( $answers['display'] ) && in_array( $answers['display'], array( 'popup', 'floating', 'slidein' ), true ) ? $answers['display'] : 'embedded';
        $delay   = 'slidein' === $display && isset( $answers['slidein_delay'] ) ? ' delay="' . (int) $answers['slidein_delay'] . '"' : '';
        return '[acquis_form id="' . absint( $form_id ) . '" display="' . $display . '"' . $delay . ']';
    }

    // ── A template's own questions ─────────────────────────────────────────

    /**
     * One answer to one of a template's extra questions, cleaned by its type.
     *
     * @return string|WP_Error
     */
    private static function clean_extra( array $def, $value, $editing ) {
        $value = is_scalar( $value ) ? trim( (string) $value ) : '';
        $field = 'extra_' . $def['key'];
        $need  = ! empty( $def['required'] );
        $fail  = function ( $text ) use ( $field ) {
            return new WP_Error( $field, $text, array( 'field' => $field ) );
        };
        if ( '' === $value && isset( $def['default'] ) ) {
            $value = (string) $def['default'];
        }
        if ( '' === $value ) {
            /* translators: %s: the name of a question in the wizard */
            return $need ? $fail( sprintf( __( 'Fill in: %s', 'acquisitionsuite' ), $def['label'] ) ) : '';
        }
        switch ( $def['type'] ) {
            case 'url':
                $u = esc_url_raw( $value, array( 'http', 'https' ) );
                return '' === $u ? $fail( __( 'Enter an address starting with https://.', 'acquisitionsuite' ) ) : $u;
            case 'datetime':
                $d = DateTimeImmutable::createFromFormat( 'Y-m-d\TH:i', $value, wp_timezone() );
                if ( ! $d || $d->format( 'Y-m-d\TH:i' ) !== $value ) {
                    return $fail( __( 'Choose a date and time.', 'acquisitionsuite' ) );
                }
                if ( ! $editing && $d->getTimestamp() < time() ) {
                    return $fail( __( 'Choose a date and time in the future.', 'acquisitionsuite' ) );
                }
                return $value;
            case 'number':
                if ( ! is_numeric( $value ) || (float) $value < 0 ) {
                    return $fail( __( 'Enter a number.', 'acquisitionsuite' ) );
                }
                return (string) round( (float) $value, 2 );
            case 'select':
                return isset( $def['options'][ $value ] ) ? $value : $fail( __( 'Choose one of the options.', 'acquisitionsuite' ) );
            case 'textarea':
                return substr( sanitize_textarea_field( $value ), 0, 1000 );
            default:
                return substr( sanitize_text_field( $value ), 0, 200 );
        }
    }

    /**
     * The values a funnel offers as {tags} in its after-submission message and its delivery email, on top of {full_name},
     * {email}, {file_name} and {site_name}. They come from the funnel's own answers, so editing the funnel changes what
     * the next registrant is told.
     *
     * @return array tag (with braces) => value
     */
    public static function tags( $template_id, array $answers ) {
        $tpl = self::get( $template_id );
        if ( $tpl && ! empty( $tpl['tags'] ) && is_callable( $tpl['tags'] ) ) {
            return (array) call_user_func( $tpl['tags'], $answers );
        }
        return array();
    }

    public static function tags_waitlist( array $a ) {
        $for = trim( (string) ( $a['extra']['waitlist_for'] ?? '' ) );
        return array( '{waitlist_for}' => '' !== $for ? $for : (string) get_bloginfo( 'name' ) );
    }

    public static function tags_book_call( array $a ) {
        $url = (string) ( $a['extra']['booking_url'] ?? '' );
        return array( '{booking_link}' => '' !== $url ? $url : (string) home_url( '/' ) );
    }

    public static function tags_webinar( array $a ) {
        $e     = (array) ( $a['extra'] ?? array() );
        $title = (string) ( $e['event_title'] ?? $a['name'] ?? '' );
        $link  = (string) ( $e['event_link'] ?? '' );
        $start = ! empty( $e['event_start'] ) ? DateTimeImmutable::createFromFormat( 'Y-m-d\TH:i', (string) $e['event_start'], wp_timezone() ) : false;
        $date  = $time = $cal = '';
        if ( $start ) {
            $mins = max( 5, (int) ( $e['event_length'] ?? 60 ) );
            $end  = $start->modify( '+' . $mins . ' minutes' );
            $date = wp_date( get_option( 'date_format' ), $start->getTimestamp() );
            $time = wp_date( get_option( 'time_format' ) . ' T', $start->getTimestamp() );
            $utc  = new DateTimeZone( 'UTC' );
            // add_query_arg() does not encode its values, and a title has spaces: build the query properly.
            $cal  = 'https://calendar.google.com/calendar/render?' . http_build_query( array(
                'action'  => 'TEMPLATE',
                'text'    => $title,
                'dates'   => $start->setTimezone( $utc )->format( 'Ymd\THis\Z' ) . '/' . $end->setTimezone( $utc )->format( 'Ymd\THis\Z' ),
                'details' => '' !== $link ? $link : '',
            ), '', '&', PHP_QUERY_RFC3986 );
        }
        return array(
            '{webinar_title}'         => $title,
            '{webinar_date}'          => $date,
            '{webinar_time}'          => $time,
            '{webinar_link}'          => '' !== $link ? $link : __( '(the link will be sent before the start)', 'acquisitionsuite' ),
            '{webinar_calendar_link}' => $cal,
        );
    }
}