<?php
/*
 * CRON - Email Parser (DirectoryTree ImapEngine)
 * Process emails and create/update tickets using DirectoryTree\ImapEngine (no PHP IMAP extension required)
 */

// Start the timer
$script_start_time = microtime(true);

// Set working directory to the directory this cron script lives at.
chdir(dirname(__FILE__));

// Ensure we're running from command line
if (php_sapi_name() !== 'cli') {
    die("This script must be run from the command line.\n");
}

// Prevent overlapping runs of this script
$cron_lock_script = __FILE__;
require_once "includes/cron_lock.php";

// Autoload (Webklex & any composer deps)
require_once "../libs/vendor/autoload.php";

// Get ITFlow config & helper functions
require_once "../config.php";

// Set Timezone
require_once "../includes/inc_set_timezone.php";
require_once "../functions.php";

// Get settings for the "default" company
require_once "../includes/load_global_settings.php";

$config_ticket_prefix = escapeSql($config_ticket_prefix);
$config_ticket_from_name = escapeSql($config_ticket_from_name);
$config_ticket_email_parse_unknown_senders = intval($row['config_ticket_email_parse_unknown_senders']);

// Get company name & phone & timezone
$sql = mysqli_query($mysqli, "SELECT company_name, company_phone, company_phone_country_code FROM companies, settings WHERE companies.company_id = settings.company_id AND companies.company_id = 1");
$row = mysqli_fetch_assoc($sql);
$company_name = escapeSql($row['company_name']);
$company_phone = escapeSql(formatPhoneNumber($row['company_phone'], $row['company_phone_country_code']));

// Check cron is enabled
if ($config_enable_cron == 0) {
    logApp("Cron-Email-Parser", "error", "Cron Email Parser unable to run - cron not enabled in admin settings.");
    cronJobStop("Cron: is not enabled -- Quitting..");
}

// Check setting enabled
if ($config_ticket_email_parse == 0) {
    logApp("Cron-Email-Parser", "error", "Cron Email Parser unable to run - not enabled in admin settings.");
    cronJobStop("Email Parser: Feature is not enabled - check Settings > Ticketing > Email-to-ticket parsing. See https://docs.itflow.org/ticket_email_parse  -- Quitting..");
}

// Overlapping runs are prevented by cron/includes/cron_lock.php. This script used to keep a
// lock file of its own alongside that one, which needed a five minute age heuristic to
// recover from a killed run and could only end itself with exit() - fatal to a dispatched
// job. flock covers the same ground and the kernel drops it however the process ends.

// Allowed attachment extensions
$allowed_extensions = array('jpg', 'jpeg', 'gif', 'png', 'webp', 'pdf', 'txt', 'md', 'doc', 'docx', 'csv', 'xls', 'xlsx', 'xlsm', 'zip', 'tar', 'gz');

// Processing limits
$max_emails_per_run = 50;          // Cap per cron run to bound memory usage (cron catches up on the next run)
$max_attachment_bytes = 15728640;  // 15 MB - larger attachments are skipped & logged
$max_inline_embed_bytes = 2097152; // 2 MB - larger inline images are saved as regular attachments instead of base64-embedded in the ticket body

/** ------------------------------------------------------------------
 * Ticket / Reply helpers (unchanged)
 * ------------------------------------------------------------------ */
function addTicket($contact_id, $contact_name, $contact_email, $client_id, $date, $subject, $message, $attachments, $original_message_file, $ccs) {
    global $mysqli, $config_app_name, $company_name, $company_phone, $config_ticket_prefix, $config_ticket_client_general_notifications, $config_ticket_new_ticket_notification_email, $config_base_url, $config_ticket_from_name, $config_ticket_from_email, $config_ticket_default_billable, $allowed_extensions;
    $bad_pattern = "/do[\W_]*not[\W_]*reply|no[\W_]*reply/i"; // Email addresses to ignore

    // Atomically increment and get the new ticket number
    mysqli_query($mysqli, "
        UPDATE settings
        SET
            config_ticket_next_number = LAST_INSERT_ID(config_ticket_next_number),
            config_ticket_next_number = config_ticket_next_number + 1
        WHERE company_id = 1
    ");

    $ticket_number = mysqli_insert_id($mysqli);

    // Clean up the message
    $message = trim($message);
    // Remove DOCTYPE and meta tags
    $message = preg_replace('/<!DOCTYPE[^>]*>/i', '', $message);
    $message = preg_replace('/<meta[^>]*>/i', '', $message);
    // Remove <html>, <head>, <body> and their closing tags
    $message = preg_replace('/<\/?(html|head|body)[^>]*>/i', '', $message);
    // Collapse excess whitespace
    $message = preg_replace('/\s+/', ' ', $message);
    // Convert newlines to <br>
    $message = nl2br($message);
    // Wrap final formatted message
    $message = "<i>Email from: <b>$contact_name</b> &lt;$contact_email&gt; at $date:-</i> <br><br><div style='line-height:1.5;'>$message</div>";

    $ticket_prefix_esc = mysqli_real_escape_string($mysqli, $config_ticket_prefix);
    $message_esc = mysqli_real_escape_string($mysqli, $message);
    $contact_email_esc = mysqli_real_escape_string($mysqli, $contact_email);
    $client_id = intval($client_id);

    $url_key = randomString(32);

    mysqli_query($mysqli, "INSERT INTO tickets SET ticket_prefix = '$ticket_prefix_esc', ticket_number = $ticket_number, ticket_source = 'Email', ticket_subject = '$subject', ticket_details = '$message_esc', ticket_priority = 'Low', ticket_status = 1, ticket_billable = $config_ticket_default_billable, ticket_created_by = 0, ticket_contact_id = $contact_id, ticket_url_key = '$url_key', ticket_client_id = $client_id");
    $id = mysqli_insert_id($mysqli);
    applyTicketSla($id);

    // Logging
    logAudit("Ticket", "Create", "Email parser: Client contact $contact_email_esc created ticket $ticket_prefix_esc$ticket_number ($subject) ($id)", $client_id, $id);

    mkdirMissing('../uploads/tickets/');
    $att_dir = "../uploads/tickets/" . $id . "/";
    mkdirMissing($att_dir);

    // Move original .eml into the ticket folder
    rename("../uploads/tmp/{$original_message_file}", "{$att_dir}/{$original_message_file}");
    $original_message_file_esc = mysqli_real_escape_string($mysqli, $original_message_file);
    mysqli_query($mysqli, "INSERT INTO ticket_attachments SET ticket_attachment_name = 'Original-parsed-email.eml', ticket_attachment_reference_name = '$original_message_file_esc', ticket_attachment_ticket_id = $id");

    // Save non-inline attachments
    foreach ($attachments as $attachment) {
        $att_name = $attachment['name'];
        $att_extension = strtolower(pathinfo($att_name, PATHINFO_EXTENSION));

        if (in_array($att_extension, $allowed_extensions)) {
            $att_saved_filename = md5(uniqid(rand(), true)) . '.' . $att_extension;
            $att_saved_path = $att_dir . $att_saved_filename;
            file_put_contents($att_saved_path, $attachment['content']);

            $ticket_attachment_name = escapeSql($att_name);
            $ticket_attachment_reference_name = escapeSql($att_saved_filename);

            $ticket_attachment_name_esc = mysqli_real_escape_string($mysqli, $ticket_attachment_name);
            $ticket_attachment_reference_name_esc = mysqli_real_escape_string($mysqli, $ticket_attachment_reference_name);
            mysqli_query($mysqli, "INSERT INTO ticket_attachments SET ticket_attachment_name = '$ticket_attachment_name_esc', ticket_attachment_reference_name = '$ticket_attachment_reference_name_esc', ticket_attachment_ticket_id = $id");
        } else {
            $ticket_attachment_name_esc = mysqli_real_escape_string($mysqli, $att_name);
            logAudit("Ticket", "Edit", "Email parser: Blocked attachment $ticket_attachment_name_esc from Client contact $contact_email_esc for ticket $ticket_prefix_esc$ticket_number", $client_id, $id);
        }
    }

    // Add unknown guests as ticket watcher
    if ($client_id == 0 && !preg_match($bad_pattern, $contact_email_esc)) {
        mysqli_query($mysqli, "INSERT INTO ticket_watchers SET watcher_email = '$contact_email_esc', watcher_ticket_id = $id");
    }

    // Add CCs as ticket watchers
    foreach ($ccs as $cc) {
        if (filter_var($cc, FILTER_VALIDATE_EMAIL) && !preg_match($bad_pattern, $cc)) {
            $cc_esc = mysqli_real_escape_string($mysqli, $cc);
            mysqli_query($mysqli, "INSERT INTO ticket_watchers SET watcher_email = '$cc_esc', watcher_ticket_id = $id");
        }
    }

    // External email
    $data = [];
    if ($config_ticket_client_general_notifications == 1 && !preg_match($bad_pattern, $contact_email)) {
        $subject_email = "Ticket created - [$config_ticket_prefix$ticket_number] - $subject";
        $body = "<i style='color: #808080'>##- Please type your reply above this line -##</i><br><br>Hello $contact_name,<br><br>Thank you for your email. A ticket regarding \"$subject\" has been automatically created for you.<br><br>Ticket: $config_ticket_prefix$ticket_number<br>Subject: $subject<br>Status: New<br>Portal: <a href='https://$config_base_url/guest/guest_view_ticket.php?ticket_id=$id&url_key=$url_key'>View ticket</a><br><br>--<br>$company_name - Support<br>$config_ticket_from_email<br>$company_phone";
        $data[] = [
            'from' => $config_ticket_from_email,
            'from_name' => $config_ticket_from_name,
            'recipient' => $contact_email,
            'recipient_name' => $contact_name,
            'subject' => $subject_email,
            'body' => mysqli_real_escape_string($mysqli, $body)
        ];
    }

    // Internal email
    if ($config_ticket_new_ticket_notification_email) {
        if ($client_id == 0) {
            $client_name = "Guest";
            $client_uri = '';
        } else {
            $client_sql = mysqli_query($mysqli, "SELECT client_name FROM clients WHERE client_id = $client_id");
            $client_row = mysqli_fetch_assoc($client_sql);
            $client_name = escapeSql($client_row['client_name']);
            $client_uri = "&client_id=$client_id";
        }
        $email_subject = "$config_app_name - New Ticket - $client_name: $subject";
        $email_body = "Hello, <br><br>This is a notification that a new ticket has been raised in ITFlow. <br>Client: $client_name<br>Priority: Low (email parsed)<br>Link: https://$config_base_url/agent/ticket.php?ticket_id=$id$client_uri <br><br>--------------------------------<br><br><b>$subject</b><br>$message";

        $data[] = [
            'from' => $config_ticket_from_email,
            'from_name' => $config_ticket_from_name,
            'recipient' => $config_ticket_new_ticket_notification_email,
            'recipient_name' => $config_ticket_from_name,
            'subject' => $email_subject,
            'body' => mysqli_real_escape_string($mysqli, $email_body)
        ];
    }

    addToMailQueue($data);
    triggerCustomAction('ticket_create', $id);

    return true;
}

function addReply($from_email, $date, $subject, $ticket_number, $message, $attachments) {
    global $mysqli, $config_app_name, $company_name, $company_phone, $config_ticket_prefix, $config_base_url, $config_ticket_from_name, $config_ticket_from_email, $allowed_extensions;

    $ticket_reply_type = 'Client';
    // $message contains the raw HTML body from IMAP

    // 1) Remove the reply separator and everything below it (HTML-aware)
    // This matches: <i ...>##- Please type your reply above this line -##</i> and EVERYTHING after it
    $message = preg_replace(
        '/<i[^>]*>##-\s*Please\s+type\s+your\s+reply\s+above\s+this\s+line\s*-##<\/i>.*$/is',
        '',
        $message
    );

    // 2) Clean up the remaining message

    // Remove DOCTYPE and meta tags
    $message = preg_replace('/<!DOCTYPE[^>]*>/i', '', $message);
    $message = preg_replace('/<meta[^>]*>/i', '', $message);

    // Remove <html>, <head>, <body> and their closing tags
    $message = preg_replace('/<\/?(html|head|body)[^>]*>/i', '', $message);

    // Trim leading/trailing whitespace
    $message = trim($message);

    // Normalize line breaks to spaces
    $message = preg_replace('/\r\n|\r|\n/', ' ', $message);

    // Convert to <br> for HTML display
    $message = nl2br($message);

    // 3) Final wrapper
    $message = "<i>Email from: $from_email at $date:-</i><br><br><div style='line-height:1.5;'>$message</div>";

    $ticket_number_esc = intval($ticket_number);
    $message_esc = mysqli_real_escape_string($mysqli, $message);
    $from_email_esc = mysqli_real_escape_string($mysqli, $from_email);

    $row = mysqli_fetch_assoc(mysqli_query($mysqli, "SELECT ticket_id, ticket_subject, ticket_status, ticket_contact_id, ticket_client_id, contact_email, client_name
        FROM tickets
        LEFT JOIN contacts on tickets.ticket_contact_id = contacts.contact_id
        LEFT JOIN clients on tickets.ticket_client_id = clients.client_id
        WHERE ticket_number = $ticket_number_esc LIMIT 1"));

    if ($row) {
        $ticket_id = intval($row['ticket_id']);
        $ticket_subject = escapeSql($row['ticket_subject']);
        $ticket_status = escapeSql($row['ticket_status']);
        $ticket_reply_contact = intval($row['ticket_contact_id']);
        $ticket_contact_email = escapeSql($row['contact_email']);
        $client_id = intval($row['ticket_client_id']);
        if ($client_id) {
            $client_uri = "&client_id=$client_id";
        } else {
            $client_uri = '';
        }
        $client_name = escapeSql($row['client_name']);

        if ($ticket_status == 5) {
            $config_ticket_prefix_esc = mysqli_real_escape_string($mysqli, $config_ticket_prefix);
            $ticket_number_esc2 = mysqli_real_escape_string($mysqli, $ticket_number);

            appNotify("Ticket", "Email parser: $from_email attempted to re-open ticket $config_ticket_prefix_esc$ticket_number_esc2 (ID $ticket_id) - check inbox manually to see email", "/agent/ticket.php?ticket_id=$ticket_id$client_uri", $client_id);

            $email_subject = "Action required: This ticket is already closed";
            $email_body = "Hi there, <br><br>You've tried to reply to a ticket that is closed - we won't see your response. <br><br>Please raise a new ticket by sending a new e-mail to our support address below. <br><br>--<br>$company_name - Support<br>$config_ticket_from_email<br>$company_phone";

            $data = [
                [
                    'from' => $config_ticket_from_email,
                    'from_name' => $config_ticket_from_name,
                    'recipient' => $from_email,
                    'recipient_name' => $from_email,
                    'subject' => $email_subject,
                    'body' => mysqli_real_escape_string($mysqli, $email_body)
                ]
            ];

            addToMailQueue($data);
            return true;
        }

        if (empty($ticket_contact_email) || $ticket_contact_email !== $from_email) {
            $from_email_esc2 = mysqli_real_escape_string($mysqli, $from_email);
            $row2 = mysqli_fetch_assoc(mysqli_query($mysqli, "SELECT contact_id FROM contacts WHERE contact_email = '$from_email_esc2' AND contact_client_id = $client_id LIMIT 1"));
            if ($row2) {
                $ticket_reply_contact = intval($row2['contact_id']);
            } else {
                $ticket_reply_type = 'Internal';
                $ticket_reply_contact = '0';
                $message = "<b>WARNING: Contact email mismatch</b><br>$message";
                $message_esc = mysqli_real_escape_string($mysqli, $message);
            }
        }

        mysqli_query($mysqli, "INSERT INTO ticket_replies SET ticket_reply = '$message_esc', ticket_reply_type = '$ticket_reply_type', ticket_reply_time_worked = '00:00:00', ticket_reply_by = $ticket_reply_contact, ticket_reply_ticket_id = $ticket_id");
        $reply_id = mysqli_insert_id($mysqli);

        $ticket_dir = "../uploads/tickets/" . $ticket_id . "/";
        mkdirMissing($ticket_dir);

        foreach ($attachments as $attachment) {
            $att_name = $attachment['name'];
            $att_extension = strtolower(pathinfo($att_name, PATHINFO_EXTENSION));

            if (in_array($att_extension, $allowed_extensions)) {
                $att_saved_filename = md5(uniqid(rand(), true)) . '.' . $att_extension;
                $att_saved_path = $ticket_dir . $att_saved_filename;
                file_put_contents($att_saved_path, $attachment['content']);

                $ticket_attachment_name = escapeSql($att_name);
                $ticket_attachment_reference_name = escapeSql($att_saved_filename);

                $ticket_attachment_name_esc = mysqli_real_escape_string($mysqli, $ticket_attachment_name);
                $ticket_attachment_reference_name_esc = mysqli_real_escape_string($mysqli, $ticket_attachment_reference_name);
                mysqli_query($mysqli, "INSERT INTO ticket_attachments SET ticket_attachment_name = '$ticket_attachment_name_esc', ticket_attachment_reference_name = '$ticket_attachment_reference_name_esc', ticket_attachment_reply_id = $reply_id, ticket_attachment_ticket_id = $ticket_id");
            } else {
                $ticket_attachment_name_esc = mysqli_real_escape_string($mysqli, $att_name);
                logAudit("Ticket", "Edit", "Email parser: Blocked attachment $ticket_attachment_name_esc from Client contact $from_email_esc for ticket $config_ticket_prefix$ticket_number_esc", $client_id, $ticket_id);
            }
        }

        $ticket_assigned_to_sql = mysqli_query($mysqli, "SELECT ticket_assigned_to FROM tickets WHERE ticket_id = $ticket_id LIMIT 1");
        if ($ticket_assigned_to_sql) {
            $row3 = mysqli_fetch_assoc($ticket_assigned_to_sql);
            $ticket_assigned_to = intval($row3['ticket_assigned_to']);

            if ($ticket_assigned_to) {
                $tech_sql = mysqli_query($mysqli, "SELECT user_email, user_name FROM users WHERE user_id = $ticket_assigned_to LIMIT 1");
                $tech_row = mysqli_fetch_assoc($tech_sql);
                $tech_email = escapeSql($tech_row['user_email']);
                $tech_name = escapeSql($tech_row['user_name']);

                $email_subject = "$config_app_name - Ticket updated - [$config_ticket_prefix$ticket_number] $ticket_subject";
                $email_body    = "Hello $tech_name,<br><br>A new reply has been added to the below ticket.<br><br>Client: $client_name<br>Ticket: $config_ticket_prefix$ticket_number<br>Subject: $ticket_subject<br>Link: https://$config_base_url/agent/ticket.php?ticket_id=$ticket_id$client_uri<br><br>--------------------------------<br>$message_esc";

                $data = [
                    [
                        'from' => $config_ticket_from_email,
                        'from_name' => $config_ticket_from_name,
                        'recipient' => $tech_email,
                        'recipient_name' => $tech_name,
                        'subject' => mysqli_real_escape_string($mysqli, $email_subject),
                        'body' => mysqli_real_escape_string($mysqli, $email_body)
                    ]
                ];
                addToMailQueue($data);
            }
        }

        mysqli_query($mysqli, "UPDATE tickets SET ticket_status = 2, ticket_resolved_at = NULL WHERE ticket_id = $ticket_id AND ticket_client_id = $client_id LIMIT 1");
        resetTicketResolutionSla($ticket_id);

        // Only record the reopen when the ticket was not already open
        if (intval($ticket_status) !== 2) {
            logTicketHistory($ticket_id, "$from_email_esc replied by email, reopening the ticket");
        }

        logAudit("Ticket", "Edit", "Email parser: Client contact $from_email_esc updated ticket $config_ticket_prefix$ticket_number_esc ($subject)", $client_id, $ticket_id);
        triggerCustomAction('ticket_reply_client', $ticket_id);
        return true;
    } else {
        return false;
    }
}

/** ------------------------------------------------------------------
 * OAuth helpers + provider guard
 * ------------------------------------------------------------------ */

// returns true if expires_at ('Y-m-d H:i:s') is in the past (or missing)
function tokenExpired(?string $expires_at): bool {
    if (empty($expires_at)) return true;
    $ts = strtotime($expires_at);
    if ($ts === false) return true;
    // refresh a little early (60s) to avoid race
    return ($ts - 60) <= time();
}

// very small form-encoded POST helper using curl
/**
 * Get a valid access token for Google Workspace IMAP via refresh token if needed.
 * Uses settings: config_mail_oauth_client_id / _client_secret / _refresh_token / _access_token / _access_token_expires_at
 * Updates globals if refreshed (so later logging can reflect it if you want to persist).
 */
function getGoogleAccessToken(string $username): ?string {
    // pull from global settings variables you already load
    global $mysqli,
           $config_mail_oauth_client_id,
           $config_mail_oauth_client_secret,
           $config_mail_oauth_refresh_token,
           $config_mail_oauth_access_token,
           $config_mail_oauth_access_token_expires_at;

    // If we have a not-expired token, use it
    if (!empty($config_mail_oauth_access_token) && !tokenExpired($config_mail_oauth_access_token_expires_at)) {
        return $config_mail_oauth_access_token;
    }

    // Need to refresh?
    if (empty($config_mail_oauth_client_id) || empty($config_mail_oauth_client_secret) || empty($config_mail_oauth_refresh_token)) {
        // Nothing we can do
        return null;
    }

    $resp = httpFormPost(
        'https://oauth2.googleapis.com/token',
        [
            'client_id'     => $config_mail_oauth_client_id,
            'client_secret' => $config_mail_oauth_client_secret,
            'refresh_token' => $config_mail_oauth_refresh_token,
            'grant_type'    => 'refresh_token',
        ]
    );

    if (!$resp['ok']) return null;

    $json = json_decode($resp['body'], true);
    if (!is_array($json) || empty($json['access_token'])) return null;

    // Calculate new expiry
    $expires_at = date('Y-m-d H:i:s', time() + (int)($json['expires_in'] ?? 3600));

    // Update in-memory globals (and persist to DB)
    $config_mail_oauth_access_token = $json['access_token'];
    $config_mail_oauth_access_token_expires_at = $expires_at;

    $at_esc  = mysqli_real_escape_string($mysqli, $config_mail_oauth_access_token);
    $exp_esc = mysqli_real_escape_string($mysqli, $config_mail_oauth_access_token_expires_at);
    mysqli_query($mysqli, "UPDATE settings SET
        config_mail_oauth_access_token = '{$at_esc}',
        config_mail_oauth_access_token_expires_at = '{$exp_esc}'
        WHERE company_id = 1
    ");

    return $config_mail_oauth_access_token;
}

/**
 * Get a valid access token for Microsoft 365 IMAP via refresh token if needed.
 * Uses settings: config_mail_oauth_client_id / _client_secret / _tenant_id / _refresh_token / _access_token / _access_token_expires_at
 */
function getMicrosoftAccessToken(string $username): ?string {
    global $mysqli,
           $config_mail_oauth_client_id,
           $config_mail_oauth_client_secret,
           $config_mail_oauth_tenant_id,
           $config_mail_oauth_refresh_token,
           $config_mail_oauth_access_token,
           $config_mail_oauth_access_token_expires_at;

    if (!empty($config_mail_oauth_access_token) && !tokenExpired($config_mail_oauth_access_token_expires_at)) {
        return $config_mail_oauth_access_token;
    }

    if (empty($config_mail_oauth_client_id) || empty($config_mail_oauth_client_secret) || empty($config_mail_oauth_refresh_token) || empty($config_mail_oauth_tenant_id)) {
        return null;
    }

    $url = "https://login.microsoftonline.com/".rawurlencode($config_mail_oauth_tenant_id)."/oauth2/v2.0/token";

    $resp = httpFormPost($url, [
        'client_id'     => $config_mail_oauth_client_id,
        'client_secret' => $config_mail_oauth_client_secret,
        'refresh_token' => $config_mail_oauth_refresh_token,
        'grant_type'    => 'refresh_token',
        // IMAP/SMTP scopes typically included at initial consent; not needed for refresh
    ]);

    if (!$resp['ok']) return null;

    $json = json_decode($resp['body'], true);
    if (!is_array($json) || empty($json['access_token'])) return null;

    $expires_at = date('Y-m-d H:i:s', time() + (int)($json['expires_in'] ?? 3600));

    $config_mail_oauth_access_token = $json['access_token'];
    $config_mail_oauth_access_token_expires_at = $expires_at;

    $at_esc  = mysqli_real_escape_string($mysqli, $config_mail_oauth_access_token);
    $exp_esc = mysqli_real_escape_string($mysqli, $config_mail_oauth_access_token_expires_at);
    mysqli_query($mysqli, "UPDATE settings SET
        config_mail_oauth_access_token = '{$at_esc}',
        config_mail_oauth_access_token_expires_at = '{$exp_esc}'
        WHERE company_id = 1
    ");

    return $config_mail_oauth_access_token;
}

// Provider from settings (may be NULL/empty to disable IMAP polling)
$imap_provider = $config_imap_provider ?? '';
if ($imap_provider === null) $imap_provider = '';

if ($imap_provider === '') {
    // IMAP disabled by admin: exit cleanly
    logApp("Cron-Email-Parser", "info", "IMAP polling skipped: provider not configured.");
    cronJobStop();
}

/** ------------------------------------------------------------------
 * ImapEngine setup (supports Standard / Google OAuth / Microsoft OAuth)
 * ------------------------------------------------------------------ */
use DirectoryTree\ImapEngine\Mailbox;

$validate_cert = true;

// Defaults from settings (standard IMAP)
$host = $config_imap_host;
$port = (int)$config_imap_port;
$encr = !empty($config_imap_encryption) ? $config_imap_encryption : 'notls'; // 'ssl'|'tls'|'notls'
$user = $config_imap_username;
$pass = $config_imap_password;
$auth = 'plain'; // 'oauth' for OAuth providers

if ($imap_provider === 'google_oauth') {
    $host = 'imap.gmail.com';
    $port = 993;
    $encr = 'ssl';
    $auth = 'oauth';
    $pass = getGoogleAccessToken($user);
    if (empty($pass)) {
        logApp("Cron-Email-Parser", "error", "Google OAuth: no usable access token (check refresh token/client credentials).");
        cronJobStop('', 1);
    }
} elseif ($imap_provider === 'microsoft_oauth') {
    $host = 'outlook.office365.com';
    $port = 993;
    $encr = 'ssl';
    $auth = 'oauth';
    $pass = getMicrosoftAccessToken($user);
    if (empty($pass)) {
        logApp("Cron-Email-Parser", "error", "Microsoft OAuth: no usable access token (check refresh token/client credentials/tenant).");
        cronJobStop('', 1);
    }
} else {
    // standard_imap (username/password)
    if (empty($host) || empty($port) || empty($user)) {
        logApp("Cron-Email-Parser", "error", "Standard IMAP: missing host/port/username.");
        cronJobStop('', 1);
    }
}

// Map Webklex-style encryption values to ImapEngine transports
// Webklex 'tls' = STARTTLS (port 143), ImapEngine 'tls' = implicit TLS, so translate
$encryption = match (strtolower($encr)) {
    'ssl'      => 'ssl',      // implicit TLS (993)
    'tls'      => 'starttls', // STARTTLS upgrade (143) - Webklex semantics
    'starttls' => 'starttls',
    default    => '',         // 'notls' / plain tcp
};

$mailbox = new Mailbox([
    'host'           => $host,
    'port'           => $port,
    'encryption'     => $encryption,
    'validate_cert'  => (bool)$validate_cert,
    'username'       => $user,            // full mailbox address (OAuth uses user as principal)
    'password'       => $pass,            // access token when $auth === 'oauth'
    'authentication' => $auth,            // 'oauth' or 'plain'
]);

try {
    $mailbox->connect();
} catch (\Throwable $e) {
    echo "Error connecting to IMAP server: " . $e->getMessage();
    cronJobStop('', 1);
}

$inbox = $mailbox->inbox();

// Resolve the processed-mail folder in a namespace-aware way.
// Most servers (Gmail, M365, Dovecot with an empty namespace prefix) allow
// root-level folders, so "ITFlow" is preferred. cPanel-style Dovecot uses a
// Maildir++ layout where the personal namespace prefix is "INBOX." - root
// CREATE fails there with "Client tried to access nonexistent namespace",
// and the folder must be addressed as "INBOX.ITFlow" (clients still display
// it as a top-level folder alongside Inbox).
$targetFolderName = 'ITFlow';
try {
    // INBOX always exists (RFC 3501) - use it to learn the hierarchy delimiter
    // (ImapEngine returns the literal string "NIL" for servers with a flat namespace)
    $delimiter = $mailbox->folders()->findOrFail('INBOX')->delimiter();
    if ($delimiter === '' || strcasecmp($delimiter, 'NIL') === 0) {
        $delimiter = '.';
    }

    // Candidate paths, in order of preference
    $candidates = [
        $targetFolderName,                              // Root-level (empty namespace prefix)
        'INBOX' . $delimiter . $targetFolderName,       // INBOX-prefixed namespace (e.g. cPanel Dovecot)
    ];

    // Re-use the folder if it already exists at either location
    $targetFolder = null;
    foreach ($candidates as $candidate) {
        if ($targetFolder = $mailbox->folders()->find($candidate)) {
            $targetFolderPath = $candidate;
            break;
        }
    }

    // Otherwise create it, falling back to the namespace-prefixed path if the
    // server rejects root-level creation
    if (!$targetFolder) {
        $creation_errors = [];
        foreach ($candidates as $candidate) {
            try {
                $targetFolder = $mailbox->folders()->create($candidate);
                $targetFolderPath = $candidate;
                break;
            } catch (\Throwable $e) {
                $creation_errors[] = "[$candidate]: " . $e->getMessage();
            }
        }
        if (!$targetFolder) {
            throw new \Exception("CREATE rejected for all candidate paths - " . implode(' / ', $creation_errors));
        }

        // Subscribe to the newly created folder so it's visible in mail clients
        // that only display subscribed folders (common with Dovecot/Roundcube).
        // Non-fatal - some servers ignore or reject SUBSCRIBE entirely.
        try {
            $mailbox->connection()->subscribe(
                \DirectoryTree\ImapEngine\Support\Str::toImapUtf7($targetFolderPath)
            );
        } catch (\Throwable $e) {
            logApp("Cron-Email-Parser", "warning", "Created folder [$targetFolderPath] but could not subscribe to it: " . $e->getMessage());
        }
    }
} catch (\Throwable $e) {
    logApp("Cron-Email-Parser", "error", "Unable to find/create target folder [$targetFolderName]: " . $e->getMessage());
    cronJobStop('', 1);
}

// Fetch unseen messages (headers, body & flags; BODY.PEEK so they stay unread)
// unflagged() skips messages a previous run flagged for manual attention,
// so they aren't pointlessly re-processed every run forever
$messages = $inbox->messages()
    ->withHeaders()
    ->withBody()
    ->withFlags()
    ->leaveUnread()
    ->unseen()
    ->unflagged()
    ->limit($max_emails_per_run)
    ->get();

// Counters
$processed_count = 0;
$unprocessed_count = 0;

// Process messages
foreach ($messages as $message) {
    try {
        $email_processed = false;

        // From
        $from_addr  = $message->from(); // ?Address
        $from_email = escapeSql($from_addr?->email() ?: 'itflow-guest@example.com');
        $from_name  = escapeSql($from_addr?->name() ?: 'Unknown');

        $from_domain = explode("@", $from_email);
        $from_domain = escapeSql(end($from_domain));

        // Subject
        $subject = escapeSql((string)$message->subject() ?: 'No Subject');

        // Skip vacation/out-of-office auto-responders to prevent mail loops (RFC 3834)
        // Some* NDRs use "auto-generated" and are still handled by the NDR logic below
        // Todo: Combine with the NDR logic so we can update the ticket too
        $auto_submitted = strtolower((string)($message->header('Auto-Submitted')?->getValue() ?? ''));
        $precedence     = strtolower((string)($message->header('Precedence')?->getValue() ?? ''));
        if (str_starts_with($auto_submitted, 'auto-replied') || $precedence === 'auto_reply') {
            logApp("Cron-Email-Parser", "info", "Email parser skipped auto-responder from $from_email ($subject)");
                appNotify(
                    "Mail",
                    "Email parser: Skipped auto-responder message from $from_email. Subject: $subject",
                    "",
                    0
                );
            $processed_count++;
            $message->markSeen();
            $message->move($targetFolderPath);
            continue;
        }

        // Save original message as .eml (ImapEngine: raw headers + raw body)
        mkdirMissing('../uploads/tmp/');
        $original_message_file = "processed-eml-" . randomString(200) . ".eml";
        $raw_message = (string)$message; // head + body, CRLF separated
        file_put_contents("../uploads/tmp/{$original_message_file}", $raw_message);

        // CC (deduplicated, excluding the sender)
        $ccs = array();
        foreach ($message->cc() as $cc_addr) {
            $cc_mail = strtolower($cc_addr->email());
            if ($cc_mail && $cc_mail !== strtolower($from_email) && !in_array($cc_mail, $ccs)) {
                $ccs[] = $cc_mail;
            }
        }

        // Date (string)
        $dateObj = $message->date(); // ?CarbonInterface
        $date    = escapeSql($dateObj ? $dateObj->setTimezone(date_default_timezone_get())->format('Y-m-d H:i:s') : date('Y-m-d H:i:s'));

        // Body (prefer HTML)
        $message_body_html = $message->html();
        $message_body_text = $message->text();

        if (!empty($message_body_html)) {
            $message_body = $message_body_html;
        } elseif (!empty($message_body_text)) {
            $message_body = nl2br(htmlspecialchars($message_body_text));
        } else {
            // Final fallback - raw body
            $message_body = nl2br(htmlspecialchars($message->body()));
        }

        // Handle attachments (inline vs regular)
        $attachments = [];
        foreach ($message->attachments() as $att) {
            $dispo   = strtolower((string)$att->contentDisposition());
            $cid     = $att->contentId();               // Content-ID (without <>)
            $content = $att->contents();                // binary
            $mime    = $att->contentType();
            $name    = $att->filename() ?: 'attachment';
            $size    = strlen($content);

            // Skip oversized attachments entirely
            if ($size > $max_attachment_bytes) {
                logApp("Cron-Email-Parser", "warning", "Email parser skipped oversized attachment " . escapeSql($name) . " (" . round($size / 1048576, 1) . " MB) from $from_email ($subject)");
                continue;
            }

            // Embed small inline images as data URIs; oversized inline images fall through and are saved as regular attachments
            $is_inline = false;
            if ($dispo === 'inline' && $cid && $content !== '' && $size <= $max_inline_embed_bytes) {
                $cid_trim  = trim($cid, '<>');
                $dataUri   = "data:$mime;base64,".base64_encode($content);
                $message_body = str_replace(["cid:$cid_trim", "cid:<$cid_trim>"], $dataUri, $message_body);
                $is_inline = true;
            }

            if (!$is_inline && $content !== '') {
                $attachments[] = ['name' => $name, 'content' => $content];
            }
        }

        // 1. Reply to existing ticket with the number in subject
        if (preg_match("/\[" . preg_quote($config_ticket_prefix, '/') . "(\d+)\]/", $subject, $ticket_number_matches)) {
            $ticket_number = intval($ticket_number_matches[1]);
            $email_processed = addReply($from_email, $date, $subject, $ticket_number, $message_body, $attachments);
        }

        // 2. Fuzzy duplicate check using a known contact/domain and similar_text subject
        if (!$email_processed && strlen(trim($subject)) > 10) {
            $contact_id = 0;
            $client_id  = 0;

            // First: check if sender is a registered contact
            $from_email_esc = mysqli_real_escape_string($mysqli, $from_email);
            $contact_sql = mysqli_query($mysqli, "SELECT * FROM contacts WHERE contact_email = '$from_email_esc' AND contact_archived_at IS NULL LIMIT 1");
            $contact_row = mysqli_fetch_assoc($contact_sql);

            if ($contact_row) {
                $contact_id = intval($contact_row['contact_id']);
                $client_id  = intval($contact_row['contact_client_id']);
            } else {
                // Else: check if sender domain is registered
                $from_domain_esc = mysqli_real_escape_string($mysqli, $from_domain);
                $domain_sql = mysqli_query($mysqli, "SELECT domain_client_id, domain_name FROM domains WHERE domain_name = '$from_domain_esc' AND domain_archived_at IS NULL LIMIT 1");
                $domain_row = mysqli_fetch_assoc($domain_sql);

                if ($domain_row && $from_domain == $domain_row['domain_name']) {
                    $client_id = intval($domain_row['domain_client_id']);
                }
            }

            // If we found either a contact or a domain, check recent tickets for a matching subject
            if ($client_id) {
                $recent_tickets_sql = mysqli_query($mysqli,
                    "SELECT ticket_id, ticket_number, ticket_subject
                    FROM tickets
                    WHERE ticket_client_id = $client_id AND ticket_resolved_at IS NULL
                    AND ticket_created_at >= DATE_SUB(NOW(), INTERVAL 7 DAY)"
                );

                while ($rowt = mysqli_fetch_assoc($recent_tickets_sql)) {
                    $ticket_number = intval($rowt['ticket_number']);
                    $existing_subject = $rowt['ticket_subject'];

                    // Calculate similarity percentage
                    similar_text(strtolower($subject), strtolower($existing_subject), $percent);

                    if ($percent >= 95) {
                        // Treat as a reply/duplicate
                        $email_processed = addReply($from_email, $date, $subject, $ticket_number, $message_body, $attachments);
                        break;
                    }
                }
            }
        }

        // 3. A known, registered contact?
        if (!$email_processed) {
            $from_email_esc = mysqli_real_escape_string($mysqli, $from_email);
            $any_contact_sql = mysqli_query($mysqli, "SELECT * FROM contacts WHERE contact_email = '$from_email_esc' AND contact_archived_at IS NULL LIMIT 1");
            $rowc = mysqli_fetch_assoc($any_contact_sql);

            if ($rowc) {
                $contact_name  = escapeSql($rowc['contact_name']);
                $contact_id    = intval($rowc['contact_id']);
                $contact_email = escapeSql($rowc['contact_email']);
                $client_id     = intval($rowc['contact_client_id']);

                $email_processed = addTicket($contact_id, $contact_name, $contact_email, $client_id, $date, $subject, $message_body, $attachments, $original_message_file, $ccs);
            }
        }

        // 4. A known domain?
        if (!$email_processed) {
            $from_domain_esc = mysqli_real_escape_string($mysqli, $from_domain);
            $domain_sql = mysqli_query($mysqli, "SELECT domain_client_id, domain_name FROM domains WHERE domain_name = '$from_domain_esc' AND domain_archived_at IS NULL LIMIT 1");
            $rowd = mysqli_fetch_assoc($domain_sql);

            if ($rowd && $from_domain == $rowd['domain_name']) {
                $client_id = intval($rowd['domain_client_id']);

                // Create a new contact
                $contact_name  = $from_name;
                $contact_email = $from_email;
                mysqli_query($mysqli, "INSERT INTO contacts SET contact_name = '".mysqli_real_escape_string($mysqli, $contact_name)."', contact_email = '".mysqli_real_escape_string($mysqli, $contact_email)."', contact_notes = 'Added automatically via email parsing.', contact_client_id = $client_id");
                $contact_id = mysqli_insert_id($mysqli);

                logAudit("Contact", "Create", "Email parser: created contact " . mysqli_real_escape_string($mysqli, $contact_name), $client_id, $contact_id);
                triggerCustomAction('contact_create', $contact_id);

                $email_processed = addTicket($contact_id, $contact_name, $contact_email, $client_id, $date, $subject, $message_body, $attachments, $original_message_file, $ccs);
            }
        }

        // 5. Unknown sender allowed?
        if (!$email_processed && $config_ticket_email_parse_unknown_senders) {

            $bad_from_pattern = "/daemon|postmaster|bounce|mta/i"; //  Stop NDRs with bad subjects raising new tickets
            if (!preg_match($bad_from_pattern, $from_email)) {
                $email_processed = addTicket(0, $from_name, $from_email, 0, $date, $subject, $message_body, $attachments, $original_message_file, $ccs);

            } else {

                // Probably an NDR message without a ticket ref in the subject

                $failed_recipient  = null;
                $diagnostic_code   = null;
                $status_code       = null;
                $original_subject  = null;
                $original_to       = null;

                // ImapEngine: walk the parsed MIME parts to find DSN info
                foreach ($message->parse()->getAllParts() as $part) {

                    $ctype = strtolower((string)$part->getContentType());
                    $body  = $part->getContent() ?? '';

                    // 1. Delivery status block
                    if (strpos($ctype, 'delivery-status') !== false) {

                        if (preg_match('/Final-Recipient:\s*rfc822;\s*(.+)/i', $body, $m)) {
                            $failed_recipient = escapeSql(trim($m[1]));
                        }

                        if (preg_match('/Diagnostic-Code:\s*(.+)/i', $body, $m)) {
                            $diagnostic_code = escapeSql(trim($m[1]));
                        }

                        if (preg_match('/Status:\s*([0-9\.]+)/i', $body, $m)) {
                            $status_code = escapeSql(trim($m[1]));
                        }
                    }

                    // 2. Original message headers
                    if (strpos($ctype, 'message/rfc822') !== false) {

                        if (preg_match('/^To:\s*(.+)$/mi', $body, $m)) {
                            $original_to = escapeSql(trim($m[1]));
                        }

                        if (preg_match('/^Subject:\s*(.+)$/mi', $body, $m)) {
                            $original_subject = escapeSql(trim($m[1]));
                        }
                    }
                }

                // 3. Fallback: extract diagnostic from human-readable text/plain
                if (!$diagnostic_code) {
                    $text = $message->text() ?? '';

                    // Exim puts diagnostics on an indented line
                    if (preg_match('/\n\s{2,}(.+)/', $text, $m)) {
                        $diagnostic_code = escapeSql(trim($m[1]));
                    }
                }

                // Fallbacks
                $failed_recipient = $failed_recipient ?: 'unknown recipient';
                $diagnostic_code  = $diagnostic_code ?: 'unknown diagnostic code';
                $status_code      = $status_code ?: 'unknown status code';
                $original_subject = $original_subject ?: $subject;

                appNotify(
                    "Ticket",
                    "Email parser: NDR - Message to $failed_recipient bounced. Subject: $original_subject Diagnostics: $status_code / $diagnostic_code - check ITFlow folder manually to see email",
                    "",
                    0
                );

                // If the original subject has a ticket, add the NDR there too
                if (preg_match("/\[" . preg_quote($config_ticket_prefix, '/') . "(\d+)\]/", $original_subject, $ticket_number_matches)) {

                    $ticket_number = intval($ticket_number_matches[1]);

                    // Craft a clean bounce message
                    $reply_body = "Email delivery failed.\n".
                        "Recipient: $failed_recipient\n".
                        "Status: $status_code\n".
                        "Diagnostic: $diagnostic_code\n";

                    // No attachments
                    addReply(
                        $from_email,
                        $date,
                        $original_subject,
                        $ticket_number,
                        $reply_body,
                        []
                    );

                }

                $email_processed = true;
            }
        }


        // Flag/move based on processing result
        if ($email_processed) {
            $processed_count++; // increment first so a move failure doesn't hide the success
            try {
                $message->markSeen();
                // Move to the top-level "ITFlow" folder
                $message->move($targetFolderPath);
                // optional: logApp("Cron-Email-Parser", "info", "Moved message to ITFlow");
            } catch (\Throwable $e) {
                $subj = (string)$message->subject();
                $uid  = $message->uid();
                $path = $targetFolder->path();
                logApp(
                    "Cron-Email-Parser",
                    "warning",
                    "Move failed (subject=\"$subj\", uid=$uid) to [$path]: ".$e->getMessage()
                );
            }
        } else {
            $unprocessed_count++;
            try {
                $message->markFlagged();
                $message->unmarkSeen();
            } catch (\Throwable $e) {
                logApp("Cron-Email-Parser", "warning", "Flag update failed: ".$e->getMessage());
            }
        }

    } catch (\Throwable $e) {
        // One bad message must not kill the whole run - flag it for manual attention and continue
        $unprocessed_count++;
        logApp("Cron-Email-Parser", "warning", "Email parser failed to process message UID " . $message->uid() . ": " . $e->getMessage());
        try {
            $message->markFlagged();
            $message->unmarkSeen();
        } catch (\Throwable $e2) {
            // ignore
        }
    }

    // Cleanup temp .eml if still present (e.g., reply path)
    if (isset($original_message_file)) {
        $tmp_path = "../uploads/tmp/{$original_message_file}";
        if (file_exists($tmp_path)) { @unlink($tmp_path); }
        unset($original_message_file);
    }
}

// Expunge & disconnect
try {
    $inbox->expunge();
} catch (\Throwable $e) {
    // ignore
}
$mailbox->disconnect();

// Execution timing (optional)
$script_end_time = microtime(true);
$execution_time = $script_end_time - $script_start_time;
$execution_time_formatted = number_format($execution_time, 2);

$processed_info = "Processed: $processed_count email(s), Unprocessed: $unprocessed_count email(s)";
if ($processed_count || $unprocessed_count) {
    logApp("Cron-Email-Parser", "info", "Cron Email Parser executed in $execution_time_formatted seconds. $processed_info");
}

// DEBUG
echo "Processed Emails: $processed_count\n";
echo "Unprocessed Emails: $unprocessed_count\n";
