<?php
/**
 * Cron-only delivery of strict connected-platform lifecycle envelopes.
 *
 * No visitor, tracking, checkout or experiment-mutation path calls the service.
 *
 * @package abtestkit
 */

if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

define( 'ABTESTKIT_CONNECTED_TRANSPORT_HOOK', 'abtestkit_connected_transport' );
define( 'ABTESTKIT_CONNECTED_TRANSPORT_STATE_OPTION', 'abtestkit_connected_transport_state' );
define( 'ABTESTKIT_CONNECTED_HEARTBEAT_OPTION', 'abtestkit_connected_heartbeat_state' );

/** Schedule local cron registration only after a current agreement is cached. */
function abtestkit_connected_transport_schedule() : void {
    if ( ! abtestkit_connected_platform_can_create_or_launch() ) {
        return;
    }
    if ( ! wp_next_scheduled( ABTESTKIT_CONNECTED_TRANSPORT_HOOK ) ) {
        wp_schedule_event( time() + 5 * MINUTE_IN_SECONDS, ABTESTKIT_HOSTED_SYNC_INTERVAL, ABTESTKIT_CONNECTED_TRANSPORT_HOOK );
    }
}

function abtestkit_connected_transport_unschedule() : void {
    wp_clear_scheduled_hook( ABTESTKIT_CONNECTED_TRANSPORT_HOOK );
}

/** A revoked or intentionally disconnected connection has no queued work. */
function abtestkit_connected_transport_remove_local_state() : void {
    abtestkit_connected_transport_unschedule();
    delete_option( ABTESTKIT_CONNECTED_TRANSPORT_STATE_OPTION );
    delete_option( ABTESTKIT_CONNECTED_HEARTBEAT_OPTION );
    if ( defined( 'ABTESTKIT_CONNECTED_ENVIRONMENT_OPTION' ) ) {
        delete_option( ABTESTKIT_CONNECTED_ENVIRONMENT_OPTION );
    }
}

function abtestkit_connected_transport_maybe_schedule() : void {
    if ( ! abtestkit_connected_platform_can_create_or_launch() ) {
        abtestkit_connected_transport_unschedule();
        return;
    }
    abtestkit_connected_transport_schedule();
}
add_action( 'init', 'abtestkit_connected_transport_maybe_schedule', 21 );

/** Store only stable operational codes and times, never credentials or payloads. */
function abtestkit_connected_transport_state( string $error_code = '', bool $paused = false, bool $success = false ) : void {
    $state = get_option( ABTESTKIT_CONNECTED_TRANSPORT_STATE_OPTION, array() );
    $state = is_array( $state ) ? $state : array();
    $state['last_attempt_at'] = time();
    $state['last_error_code'] = $error_code;
    $state['paused'] = $paused;
    if ( $success ) {
        $state['last_success_at'] = time();
    }
    update_option( ABTESTKIT_CONNECTED_TRANSPORT_STATE_OPTION, $state, false );
}

/** Retry an entire claimed batch without changing its event IDs or payloads. */
function abtestkit_connected_transport_retry( array $claimed, string $code, int $now ) : void {
    foreach ( $claimed as $row ) {
        ABTestKit_Connected_Outbox::retry( (string) $row['event_id'], (string) $row['claim_token'], $code, $now );
    }
    abtestkit_connected_transport_state( $code );
}

/**
 * One bounded cron tick. A bad permanent response pauses this sender rather
 * than discarding accepted local events or repeatedly sending a poison batch.
 */
function abtestkit_connected_transport_run() : void {
    if ( ! abtestkit_connected_platform_can_create_or_launch() ) {
        abtestkit_connected_transport_unschedule();
        return;
    }
    $state = get_option( ABTESTKIT_CONNECTED_TRANSPORT_STATE_OPTION, array() );
    if ( is_array( $state ) && ! empty( $state['paused'] ) ) {
        return;
    }

    if ( 1 !== (int) get_option( ABTestKit_Connected_Outbox::SCHEMA_OPTION, 0 ) ) {
        $installed = ABTestKit_Connected_Outbox::install();
        if ( is_wp_error( $installed ) ) {
            abtestkit_connected_transport_state( 'storage_unavailable' );
            return;
        }
    }
    $installation = ABTestKit_Connected_Installation::get_or_create();
    if ( is_wp_error( $installation ) ) {
        abtestkit_connected_transport_state( $installation->get_error_code(), true );
        return;
    }
    $connection = abtestkit_hosted_get_connection();
    if ( ! is_array( $connection ) ) {
        return;
    }
    abtestkit_connected_reconcile_baselines();
    abtestkit_connected_collect_persisted_milestones();
    abtestkit_connected_onboarding_reconcile();
    if ( ! empty( $connection['pending_credential'] ) ) {
        if ( ! abtestkit_hosted_rotate_connection_credential( $connection ) ) {
            abtestkit_connected_transport_state( 'credential_recovery_failed' );
            return;
        }
        $connection = abtestkit_hosted_get_connection();
        if ( ! is_array( $connection ) ) {
            return;
        }
    }

    $now = time();
    $claimed = ABTestKit_Connected_Outbox::claim( $now );
    if ( is_wp_error( $claimed ) ) {
        abtestkit_connected_transport_state( 'storage_unavailable' );
        return;
    }
    if ( ! $claimed ) {
        return;
    }

    $events = array();
    foreach ( $claimed as $row ) {
        $event = json_decode( (string) $row['payload'], true );
        if ( ! is_array( $event ) || is_wp_error( ABTestKit_Connected_Event::validate( $event, $now ) ) || ! hash_equals( (string) $installation['installation_id'], (string) ( $event['installation_id'] ?? '' ) ) ) {
            abtestkit_connected_transport_state( 'invalid_local_event', true );
            return;
        }
        $events[] = $event;
    }
    $response = abtestkit_hosted_service_request(
        'POST',
        '/sites/' . (string) $connection['site_ref'] . '/events',
        array(
            'schema_version' => 1,
            'installation' => array(
                'installation_id' => (string) $installation['installation_id'],
                'home_url' => (string) $installation['home_url'],
                'environment' => (string) $installation['environment'],
                'created_at' => (int) $installation['created_at'],
            ),
            'events' => $events,
        ),
        (string) $connection['credential']
    );
    $finished_at = time();
    if ( is_wp_error( $response ) ) {
        abtestkit_connected_transport_retry( $claimed, 'transport', $finished_at );
        return;
    }
    $status = (int) $response['status'];
    if ( 401 === $status || 404 === $status ) {
        if ( ! abtestkit_hosted_remove_local_connection( $connection ) ) {
            abtestkit_connected_transport_retry( $claimed, 'transport', $finished_at );
        }
        return;
    }
    if ( 429 === $status || $status >= 500 ) {
        abtestkit_connected_transport_retry( $claimed, 429 === $status ? 'rate_limited' : 'service_unavailable', $finished_at );
        return;
    }
    if ( ! in_array( $status, array( 200, 202 ), true ) ) {
        abtestkit_connected_transport_state( 'service_rejected_batch', true );
        return;
    }
    $data = $response['data'];
    $keys = array_keys( $data );
    sort( $keys );
    if (
        array( 'accepted', 'duplicates' ) !== $keys ||
        ! is_int( $data['accepted'] ) || ! is_int( $data['duplicates'] ) ||
        $data['accepted'] < 0 || $data['duplicates'] < 0 ||
        $data['accepted'] + $data['duplicates'] !== count( $claimed )
    ) {
        abtestkit_connected_transport_retry( $claimed, 'transport', $finished_at );
        return;
    }
    foreach ( $claimed as $index => $row ) {
        if ( ! ABTestKit_Connected_Outbox::acknowledge( (string) $row['event_id'], (string) $row['claim_token'], $finished_at ) ) {
            abtestkit_connected_transport_state( 'acknowledgement_failed' );
            return;
        }
        abtestkit_connected_milestone_mark_acknowledged( $events[ $index ], (string) $connection['site_ref'] );
        abtestkit_connected_onboarding_mark_acknowledged( $events[ $index ], (string) $connection['site_ref'] );
    }
    abtestkit_connected_transport_state( '', false, true );
}
add_action( ABTESTKIT_CONNECTED_TRANSPORT_HOOK, 'abtestkit_connected_transport_run' );

/** A quiet site still reports contact, without sending experiment or visitor data. */
function abtestkit_connected_heartbeat_run() : void {
    if ( ! abtestkit_connected_platform_can_create_or_launch() ) {
        return;
    }
    $connection = abtestkit_hosted_get_connection();
    if ( ! is_array( $connection ) || ! empty( $connection['pending_credential'] ) ) {
        return;
    }
    $state = get_option( ABTESTKIT_CONNECTED_HEARTBEAT_OPTION, array() );
    $state = is_array( $state ) ? $state : array();
    $now = time();
    if (
        (int) ( $state['last_success_at'] ?? 0 ) > $now - DAY_IN_SECONDS ||
        (int) ( $state['last_attempt_at'] ?? 0 ) > $now - HOUR_IN_SECONDS
    ) {
        return;
    }
    $state['last_attempt_at'] = $now;
    $state['last_error_code'] = 'transport';
    update_option( ABTESTKIT_CONNECTED_HEARTBEAT_OPTION, $state, false );
    $response = abtestkit_hosted_service_request(
        'POST',
        '/sites/' . (string) $connection['site_ref'] . '/heartbeat',
        array( 'schema_version' => 1 ),
        (string) $connection['credential']
    );
    if ( is_wp_error( $response ) ) {
        return;
    }
    if ( 404 === (int) $response['status'] ) {
        $state['last_error_code'] = 'service_route_unavailable';
    } elseif ( 401 === (int) $response['status'] || 403 === (int) $response['status'] ) {
        $state['last_error_code'] = 'service_denied';
    } elseif ( 200 === (int) $response['status'] && array( 'acknowledged' => true ) === $response['data'] ) {
        $state['last_success_at'] = time();
        $state['last_error_code'] = '';
    } else {
        $state['last_error_code'] = 'service_unavailable';
    }
    update_option( ABTESTKIT_CONNECTED_HEARTBEAT_OPTION, $state, false );
}
add_action( ABTESTKIT_CONNECTED_TRANSPORT_HOOK, 'abtestkit_connected_heartbeat_run', 20 );

/** Let an administrator retry a permanently paused batch after investigation. */
function abtestkit_connected_transport_retry_now() : void {
    if ( ! current_user_can( 'manage_options' ) ) {
        wp_die( esc_html__( 'You are not allowed to manage this connection.', 'abtestkit' ) );
    }
    check_admin_referer( 'abtestkit_connected_transport_retry_now' );
    if ( ! abtestkit_connected_platform_can_create_or_launch() ) {
        abtestkit_hosted_redirect( 'connection-failed' );
    }
    $state = get_option( ABTESTKIT_CONNECTED_TRANSPORT_STATE_OPTION, array() );
    $state = is_array( $state ) ? $state : array();
    $state['paused'] = false;
    $state['last_error_code'] = '';
    update_option( ABTESTKIT_CONNECTED_TRANSPORT_STATE_OPTION, $state, false );
    if ( ! wp_next_scheduled( ABTESTKIT_CONNECTED_TRANSPORT_HOOK, array( 'manual' ) ) ) {
        // A paused batch may still hold its five-minute claim lease.
        wp_schedule_single_event( time() + ABTestKit_Connected_Outbox::LEASE_SECONDS + 1, ABTESTKIT_CONNECTED_TRANSPORT_HOOK, array( 'manual' ) );
    }
    abtestkit_hosted_redirect( 'sync-queued' );
}
add_action( 'admin_post_abtestkit_connected_transport_retry_now', 'abtestkit_connected_transport_retry_now' );

/** Show coverage gaps and paused delivery without exposing an event payload. */
function abtestkit_connected_transport_render_status() : void {
    $state = get_option( ABTESTKIT_CONNECTED_TRANSPORT_STATE_OPTION, array() );
    $collection = get_option( ABTESTKIT_CONNECTED_COLLECTION_STATE_OPTION, array() );
    $state = is_array( $state ) ? $state : array();
    $collection = is_array( $collection ) ? $collection : array();
    if ( ! empty( $state['paused'] ) ) {
        echo '<p>' . esc_html__( 'Connected data sync is paused. Your local tests and reports are unaffected.', 'abtestkit' ) . '</p>';
        echo '<form method="post" action="' . esc_url( admin_url( 'admin-post.php' ) ) . '">';
        echo '<input type="hidden" name="action" value="abtestkit_connected_transport_retry_now">';
        wp_nonce_field( 'abtestkit_connected_transport_retry_now' );
        echo '<button type="submit" class="button">' . esc_html__( 'Retry connected data sync', 'abtestkit' ) . '</button></form>';
    }
    if ( ! empty( $collection['last_gap_at'] ) ) {
        echo '<p>' . esc_html__( 'Some connected activity could not be queued. Local test results remain available; connected activity may be incomplete.', 'abtestkit' ) . '</p>';
    }
    $registration = abtestkit_connected_registration_state();
    $pending = 0;
    $site = abtestkit_hosted_get_connection();
    foreach ( $registration['records'] as $record ) {
        if ( is_array( $record ) && (
            (int) ( $record['confirmed_revision'] ?? 0 ) !== (int) ( $record['revision'] ?? 0 ) ||
            (string) ( $record['confirmed_site_ref'] ?? '' ) !== (string) ( $site['site_ref'] ?? '' )
        ) ) {
            ++$pending;
        }
    }
    if ( $pending > 0 ) {
        /* translators: %d: number of experiments awaiting hosted registration. */
        echo '<p>' . esc_html( sprintf( _n( '%d experiment is awaiting connected registration; local test behavior is unaffected.', '%d experiments are awaiting connected registration; local test behavior is unaffected.', $pending, 'abtestkit' ), $pending ) ) . '</p>';
    }
    if ( ! empty( $registration['last_error_code'] ) ) {
        echo '<p>' . esc_html__( 'Connected registration could not be confirmed. The plugin will retry; existing local tests are unaffected.', 'abtestkit' ) . '</p>';
    }
}