<?php
/**
 * HSSM Notifications Class
 * 
 * Handles all email notifications for the slide manager
 * 
 * @package Hi_School_Slide_Manager
 * @since 1.0.0
 */

// Prevent direct access
if ( ! defined( 'ABSPATH' ) ) {
    exit( 'Direct access forbidden.' );
}

/**
 * HSSM Notifications Class
 */
class HSSM_Notifications {
    
    /**
     * Constructor
     * 
     * @since 1.0.0
     */
    public function __construct() {
        // We'll hook into actions that trigger notifications
    }

    /**
     * Get notification settings
     * 
     * @return array Array of email addresses for different roles
     */
    public static function get_settings() {
        $defaults = array(
            'editor_emails' => '',
            'itc_emails'    => '',
        );

        $settings = get_option( 'hssm_notification_settings', false );
        if ( ! is_array( $settings ) ) {
            $settings = $defaults;
        } else {
            $settings = wp_parse_args( $settings, $defaults );
        }

        $has_current = '' !== trim( (string) $settings['editor_emails'] ) || '' !== trim( (string) $settings['itc_emails'] );
        if ( $has_current ) {
            return $settings;
        }

        $legacy = get_option( 'hssm_notification_emails', array() );
        if ( empty( $legacy ) ) {
            return $settings;
        }

        if ( is_array( $legacy ) ) {
            $legacy_emails = array_filter( array_map( 'sanitize_email', $legacy ) );
            $legacy_string = implode( ',', $legacy_emails );
        } else {
            $legacy_string = sanitize_text_field( (string) $legacy );
        }

        if ( '' === $legacy_string ) {
            return $settings;
        }

        $settings['editor_emails'] = $legacy_string;
        update_option( 'hssm_notification_settings', $settings );
        delete_option( 'hssm_notification_emails' );

        return $settings;
    }

    /**
     * Save notification settings
     * 
     * @param array $settings Array of settings
     * @return bool True if saved successfully
     */
    public static function save_settings( $settings ) {
        $clean_settings = array(
            'editor_emails' => sanitize_textarea_field( $settings['editor_emails'] ),
            'itc_emails' => sanitize_textarea_field( $settings['itc_emails'] )
        );
        
        return update_option( 'hssm_notification_settings', $clean_settings );
    }

    /**
     * Helper to get emails as array from string
     * 
     * @param string $emails_string Comma or newline separated emails
     * @return array Array of valid email addresses
     */
    private function get_emails_array( $emails_string ) {
        if ( empty( $emails_string ) ) {
            return array();
        }

        // Replace newlines with commas
        $emails_string = str_replace( array( "\r", "\n" ), ',', $emails_string );
        $emails = explode( ',', $emails_string );
        
        $clean_emails = array();
        foreach ( $emails as $email ) {
            $email = sanitize_email( trim( $email ) );
            if ( is_email( $email ) ) {
                $clean_emails[] = $email;
            }
        }
        
        return array_unique( $clean_emails );
    }

    /**
     * Confirmation token for ITC live emails (does not depend on a logged-in session).
     *
     * @since 1.1.3
     * @param int $slide_id Slide ID.
     * @return string
     */
    public static function get_confirm_token( $slide_id ) {
        return hash( 'sha256', absint( $slide_id ) . '|' . wp_salt( 'auth' ) );
    }

    /**
     * Whether a confirmation token is valid.
     *
     * @since 1.1.3
     * @param int    $slide_id Slide ID.
     * @param string $token    Token from the email link.
     * @return bool
     */
    public static function is_valid_confirm_token( $slide_id, $token ) {
        return is_string( $token ) && hash_equals( self::get_confirm_token( $slide_id ), $token );
    }

    /**
     * Preview page URL for a slide.
     *
     * @since 1.1.3
     * @param int $slide_id Slide ID.
     * @return string
     */
    private function get_preview_link( $slide_id ) {
        $start_date = get_post_meta( $slide_id, '_hssm_start_date', true );
        if ( $start_date && preg_match( '/^(\d{4}-\d{2}-\d{2})/', $start_date, $matches ) ) {
            $date = $matches[1];
        } else {
            $date = current_time( 'Y-m-d' );
        }

        $sites = wp_get_post_terms( $slide_id, 'hssm_site', array( 'fields' => 'slugs' ) );
        $first_site = ( ! is_wp_error( $sites ) && ! empty( $sites ) ) ? $sites[0] : '';

        return add_query_arg(
            array(
                'hssm_date'    => $date,
                'hssm_site'    => $first_site,
                'hssm_preview' => $slide_id,
            ),
            hssm_get_page_url_by_template( 'page-slide-preview.php', '/slide-preview/' )
        );
    }

    /**
     * ITC confirmation page URL.
     *
     * @since 1.1.3
     * @param int $slide_id Slide ID.
     * @return string
     */
    private function get_confirmation_link( $slide_id ) {
        return add_query_arg(
            array(
                'slide_id'    => $slide_id,
                'hssm_token'  => self::get_confirm_token( $slide_id ),
            ),
            hssm_get_page_url_by_template( 'page-slide-confirmation.php', '/slide-confirmation/' )
        );
    }

    /**
     * Front dashboard URL.
     *
     * @since 1.1.3
     * @return string
     */
    private function get_dashboard_link( $slide_id = 0 ) {
        $url = hssm_get_page_url_by_template( 'page-slide-dashboard.php', '/slide-dashboard/' );
        if ( $slide_id ) {
            $url = add_query_arg( 'hssm_focus', absint( $slide_id ), $url );
        }
        return $url;
    }

    /**
     * Whether the slide is currently visible on companion sites.
     *
     * @since 1.1.3
     * @param int $slide_id Slide ID.
     * @return bool
     */
    private function is_slide_currently_live( $slide_id ) {
        $post = get_post( $slide_id );
        if ( ! $post || 'publish' !== $post->post_status ) {
            return false;
        }

        $now   = current_time( 'timestamp' );
        $start = get_post_meta( $slide_id, '_hssm_start_date', true );
        if ( $start ) {
            $start_ts = strtotime( $start );
            if ( false !== $start_ts && $start_ts > $now ) {
                return false;
            }
        }

        $end = get_post_meta( $slide_id, '_hssm_end_date', true );
        if ( $end ) {
            $end_ts = strtotime( $end );
            if ( false !== $end_ts && $end_ts < $now ) {
                return false;
            }
        }

        return true;
    }

    /**
     * Human-readable site list, with URLs when configured.
     *
     * @since 1.1.3
     * @param int $slide_id Slide ID.
     * @return string
     */
    private function format_site_lines( $slide_id ) {
        $terms = wp_get_post_terms( $slide_id, 'hssm_site' );
        if ( is_wp_error( $terms ) || empty( $terms ) ) {
            return 'None';
        }

        $catalog = array();
        if ( class_exists( 'HSSM_Main' ) ) {
            foreach ( HSSM_Main::get_companion_sites() as $site ) {
                $catalog[ $site['slug'] ] = $site;
            }
        }

        $lines = array();
        foreach ( $terms as $term ) {
            $line = $term->name . ' (' . $term->slug . ')';
            if ( ! empty( $catalog[ $term->slug ]['url'] ) ) {
                $line .= ' - ' . $catalog[ $term->slug ]['url'];
            }
            $lines[] = $line;
        }

        return implode( "\n", $lines );
    }

    /**
     * Mark a one-time notification as sent.
     *
     * @since 1.1.3
     * @param int    $slide_id Slide ID.
     * @param string $key      Meta key.
     * @return bool True if this is the first send.
     */
    private function mark_sent_once( $slide_id, $key ) {
        if ( get_post_meta( $slide_id, $key, true ) ) {
            return false;
        }

        update_post_meta( $slide_id, $key, current_time( 'mysql' ) );
        return true;
    }

    /**
     * Send ITC the go-live email when a slide first reaches publish.
     *
     * @since 1.1.3
     * @param string  $new_status New status.
     * @param string  $old_status Previous status.
     * @param WP_Post $post       Post object.
     */
    public function on_slide_status_change( $new_status, $old_status, $post ) {
        if ( ! $post instanceof WP_Post || 'hssm_slide' !== $post->post_type ) {
            return;
        }

        if ( 'publish' !== $new_status || 'publish' === $old_status ) {
            return;
        }

        $this->notify_itc_slide_live( $post->ID );
    }

    /**
     * Notify ITC of already-published slides whose start date just arrived.
     *
     * @since 1.1.3
     */
    public function notify_due_live_slides() {
        $slides = get_posts(
            array(
                'post_type'      => 'hssm_slide',
                'post_status'    => 'publish',
                'posts_per_page' => 50,
                'meta_query'     => array(
                    array(
                        'key'     => '_hssm_itc_live_sent',
                        'compare' => 'NOT EXISTS',
                    ),
                ),
            )
        );

        foreach ( $slides as $slide ) {
            $this->notify_itc_slide_live( $slide->ID );
        }
    }

    /**
     * Send notification to Editor when slide is Scheduled or Published Immediately
     * 
     * @param int $slide_id Slide ID
     * @param string $status 'scheduled' or 'published'
     */
    public function notify_editor_slide_created( $slide_id, $status ) {
        $settings = self::get_settings();
        $emails = $this->get_emails_array( $settings['editor_emails'] );
        
        if ( empty( $emails ) ) {
            hssm_debug_log( 'No Editor emails configured for notification.' );
            return;
        }

        $slide = get_post( $slide_id );
        if ( ! $slide ) {
            return;
        }

        $start_date = get_post_meta( $slide_id, '_hssm_start_date', true );
        $publish_date = $start_date ? $start_date : current_time( 'Y-m-d' );
        $status_label = ( 'scheduled' === $status ) ? 'Scheduled' : 'Published Immediately';

        $subject = sprintf( 'New Slide %s: "%s"', $status_label, $slide->post_title );

        $message  = "A new slide has been {$status_label}.\n\n";
        $message .= 'Title: ' . $slide->post_title . "\n";
        $message .= 'Target Date: ' . $publish_date . "\n";
        $message .= "Target Sites:\n" . $this->format_site_lines( $slide_id ) . "\n\n";
        $message .= 'Preview: ' . $this->get_preview_link( $slide_id ) . "\n";
        $message .= 'Dashboard: ' . $this->get_dashboard_link( $slide_id ) . "\n\n";
        $message .= 'Please review the slide.';

        foreach ( $emails as $email ) {
            wp_mail( $email, $subject, $message );
        }
    }

    /**
     * Send notification to Creator (Author) when slide is Approved
     * 
     * @param int $slide_id Slide ID
     */
    public function notify_creator_slide_approved( $slide_id ) {
        $slide = get_post( $slide_id );
        if ( ! $slide ) {
            return;
        }

        $author_email = get_the_author_meta( 'user_email', $slide->post_author );
        if ( ! is_email( $author_email ) ) {
            return;
        }

        $subject = 'Your Slide Has Been Approved: "' . $slide->post_title . '"';

        $message  = "Good news! Your slide has been approved.\n\n";
        $message .= 'Title: ' . $slide->post_title . "\n";
        $message .= "Target Sites:\n" . $this->format_site_lines( $slide_id ) . "\n\n";
        $message .= 'Preview: ' . $this->get_preview_link( $slide_id ) . "\n";
        $message .= 'Dashboard: ' . $this->get_dashboard_link( $slide_id ) . "\n\n";
        $message .= 'It is now scheduled or published according to your settings.';

        wp_mail( $author_email, $subject, $message );
    }

    /**
     * Notify ITC to review date range after approval.
     *
     * @since 1.1.3
     * @param int $slide_id Slide ID.
     */
    public function notify_itc_slide_approved( $slide_id ) {
        if ( ! $this->mark_sent_once( $slide_id, '_hssm_itc_approved_sent' ) ) {
            return;
        }

        $settings = self::get_settings();
        $emails   = $this->get_emails_array( $settings['itc_emails'] );
        if ( empty( $emails ) ) {
            hssm_debug_log( 'No ITC emails configured for approval notification.' );
            return;
        }

        $slide = get_post( $slide_id );
        if ( ! $slide ) {
            return;
        }

        $start_date = get_post_meta( $slide_id, '_hssm_start_date', true );
        $end_date   = get_post_meta( $slide_id, '_hssm_end_date', true );

        $subject = 'Slide Approved for Review: "' . $slide->post_title . '"';

        $message  = "A slide has been approved. Please review the date range and preview before it goes live.\n\n";
        $message .= 'Title: ' . $slide->post_title . "\n";
        $message .= 'Start Date: ' . ( $start_date ? $start_date : 'Immediate' ) . "\n";
        $message .= 'End Date: ' . ( $end_date ? $end_date : 'None' ) . "\n";
        $message .= "Target Sites:\n" . $this->format_site_lines( $slide_id ) . "\n\n";
        $message .= 'Preview: ' . $this->get_preview_link( $slide_id ) . "\n";
        $message .= 'Dashboard: ' . $this->get_dashboard_link( $slide_id );

        foreach ( $emails as $email ) {
            wp_mail( $email, $subject, $message );
        }
    }

    /**
     * Send notification to ITCGuys when slide goes LIVE
     * 
     * @param int $slide_id Slide ID
     */
    public function notify_itc_slide_live( $slide_id ) {
        if ( ! $this->is_slide_currently_live( $slide_id ) ) {
            return;
        }

        if ( ! $this->mark_sent_once( $slide_id, '_hssm_itc_live_sent' ) ) {
            return;
        }

        $settings = self::get_settings();
        $emails   = $this->get_emails_array( $settings['itc_emails'] );
        if ( empty( $emails ) ) {
            hssm_debug_log( 'No ITC emails configured for live notification.' );
            return;
        }

        $slide = get_post( $slide_id );
        if ( ! $slide ) {
            return;
        }

        $subject = 'ACTION REQUIRED: Slide is LIVE - "' . $slide->post_title . '"';

        $message  = "A slide has just gone LIVE.\n\n";
        $message .= 'Title: ' . $slide->post_title . "\n";
        $message .= "Sites:\n" . $this->format_site_lines( $slide_id ) . "\n\n";
        $message .= "Please check the sites to ensure it is displaying correctly.\n";
        $message .= "Once verified, click the confirmation link to notify the Editor and Author:\n\n";
        $message .= $this->get_confirmation_link( $slide_id );

        foreach ( $emails as $email ) {
            wp_mail( $email, $subject, $message );
        }
    }

    /**
     * Send FINAL notification to Editor and Author (triggered by ITC confirmation)
     * 
     * @param int $slide_id Slide ID
     * @return bool True if the confirmation email was sent.
     */
    public function notify_all_confirmed_live( $slide_id ) {
        $slide = get_post( $slide_id );
        if ( ! $slide ) {
            return false;
        }

        if ( ! $this->mark_sent_once( $slide_id, '_hssm_live_confirmed' ) ) {
            return false;
        }

        $settings      = self::get_settings();
        $editor_emails = $this->get_emails_array( $settings['editor_emails'] );
        $author_email  = get_the_author_meta( 'user_email', $slide->post_author );
        $recipients    = array_unique( array_filter( array_merge( $editor_emails, array( $author_email ) ) ) );

        if ( empty( $recipients ) ) {
            hssm_debug_log( 'No recipients for live confirmation email.' );
            return true;
        }

        $subject = 'CONFIRMED: Slide is Live and Verified - "' . $slide->post_title . '"';

        $message  = "The slide has been verified as LIVE by the ITC team.\n\n";
        $message .= 'Title: ' . $slide->post_title . "\n";
        $message .= "Status: Live & Verified\n";
        $message .= "Sites:\n" . $this->format_site_lines( $slide_id ) . "\n\n";
        $message .= 'Dashboard: ' . $this->get_dashboard_link( $slide_id ) . "\n";
        $message .= 'Preview: ' . $this->get_preview_link( $slide_id );

        foreach ( $recipients as $email ) {
            if ( is_email( $email ) ) {
                wp_mail( $email, $subject, $message );
            }
        }

        return true;
    }
}