<?php
/**
 * Inviting people to a company by email, from the storefront or WP Admin.
 */

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

class CrewCommerce_Invitations {

    private static $instance = null;

    public static function get_instance() {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    private function __construct() {
        add_action('wp_ajax_crewcommerce_invite_member', array($this, 'ajax_invite_member'));
        add_action('wp_ajax_crewcommerce_admin_invite_member', array($this, 'ajax_admin_invite_member'));
        add_action('template_redirect', array($this, 'handle_invite_link'));
    }

    const INVITE_TTL = 14 * DAY_IN_SECONDS;

    private static function invite_meta_key() {
        return crewcommerce_site_meta_key('_crewcommerce_invite');
    }

    /**
     * AJAX: invite someone by email. Creates their account if needed and adds them to the company.
     */
    public function ajax_invite_member() {
        check_ajax_referer('crewcommerce_nonce', 'nonce');
        $this->do_invite_member();
    }

    /**
     * Invite logic shared by the storefront and admin AJAX handlers.
     * Callers check their own nonce first; it can't be checked again here.
     */
    private function do_invite_member() {
        $current_user_id = get_current_user_id();
        $team_accounts   = CrewCommerce_Team_Accounts::get_instance();

        // A site administrator can pass a company; everyone else invites to
        // their own company.
        $posted_company = isset($_POST['company_id']) ? absint(wp_unslash($_POST['company_id'])) : 0; // phpcs:ignore WordPress.Security.NonceVerification.Missing -- verified by the caller.
        $by_store_owner = false;
        if ($posted_company && current_user_can('manage_options')) {
            $company_id     = $posted_company;
            $inviter_role   = 'admin';
            $by_store_owner = true;
        } else {
            $company_id  = $team_accounts->get_user_company($current_user_id);
            $inviter_role = $team_accounts->get_user_role($current_user_id);
        }

        if (!$company_id || !in_array($inviter_role, array('admin', 'manager'), true)) {
            wp_send_json_error(__('Insufficient permissions.', 'crewcommerce'));
        }

        // phpcs:disable WordPress.Security.NonceVerification.Missing -- verified by the caller.
        $email = isset($_POST['email']) ? sanitize_email(wp_unslash($_POST['email'])) : '';
        $role  = isset($_POST['role']) ? sanitize_key(wp_unslash($_POST['role'])) : 'requester';
        // phpcs:enable

        $valid_roles = array('admin', 'manager', 'requester');
        if (!in_array($role, $valid_roles, true)) {
            $role = 'requester';
        }

        // Only a company Admin (or the store owner) can make someone an Admin.
        if ('admin' === $role && 'admin' !== $inviter_role) {
            wp_send_json_error(__('Only the company Admin can invite another Admin.', 'crewcommerce'));
        }

        if (!is_email($email)) {
            wp_send_json_error(__('Please enter a valid email address.', 'crewcommerce'));
        }

        $company    = get_post($company_id);
        $inviter    = get_user_by('ID', $current_user_id);
        $existing   = get_user_by('email', $email);

        if (!$company) {
            wp_send_json_error(__('Your company could not be found. Please contact the site administrator.', 'crewcommerce'));
        }

        if ($existing) {
            $existing_company = (int) $team_accounts->get_user_company($existing->ID);
            if ($existing_company === (int) $company_id) {
                wp_send_json_error(__('That person is already on your team. Change their role in the team list.', 'crewcommerce'));
            }
            if ($existing_company) {
                wp_send_json_error(__('That user is already a member of another company.', 'crewcommerce'));
            }

            // The store owner adds people directly.
            if ($by_store_owner) {
                $team_accounts->add_team_member($existing->ID, $company_id, $role);
                $this->send_team_invite_email($existing->user_email, $existing->display_name, $inviter->display_name, $company->post_title, false, wc_get_account_endpoint_url('crewcommerce-dashboard'), $role, $existing->user_login);
                wp_send_json_success(__('Team member added and notified by email.', 'crewcommerce'));
            }

            // Anyone else's invitation has to be accepted: joining a company
            // lets its Managers approve, and see, that person's orders.
            $token = wp_generate_password(32, false);
            update_user_meta($existing->ID, self::invite_meta_key(), array(
                'company_id' => (int) $company_id,
                'role'       => $role,
                'token'      => hash('sha256', $token),
                'expires'    => time() + self::INVITE_TTL,
                'inviter_id' => (int) $current_user_id,
            ));
            $accept_link = add_query_arg('crewcommerce_invite', rawurlencode($token), wc_get_page_permalink('myaccount'));
            $this->send_team_invite_email($existing->user_email, $existing->display_name, $inviter->display_name, $company->post_title, false, $accept_link, $role, $existing->user_login);
            wp_send_json_success(__('Invitation sent. They join your team once they accept it from the email.', 'crewcommerce'));
        }

        // Create new WP user with a random password they'll reset
        $username = sanitize_user(strstr($email, '@', true), true);
        if (empty($username) || username_exists($username)) {
            $username = 'user_' . substr(md5($email . time()), 0, 8);
        }

        $random_password = wp_generate_password(16, false);
        $user_id = wp_insert_user(array(
            'user_login' => $username,
            'user_email' => $email,
            'user_pass'  => $random_password,
            'role'       => 'customer',
        ));

        if (is_wp_error($user_id)) {
            wp_send_json_error($user_id->get_error_message());
        }

        $team_accounts->add_team_member($user_id, $company_id, $role);

        // Send password-reset style invite
        $reset_key  = get_password_reset_key(get_user_by('ID', $user_id));
        $reset_link = is_wp_error($reset_key) ? wc_get_page_permalink('myaccount') :
            add_query_arg(array('key' => $reset_key, 'login' => rawurlencode($username)), wc_get_page_permalink('myaccount') . 'lost-password/');

        $this->send_team_invite_email($email, $username, $inviter->display_name, $company->post_title, true, $reset_link, $role, $username);

        wp_send_json_success(__('Invitation sent. The user will receive an email to set their password and join the team.', 'crewcommerce'));
    }

    /**
     * Send team invite email
     */
    private function send_team_invite_email($to_email, $to_name, $inviter_name, $company_name, $is_new_user, $reset_link = '', $role = 'requester', $username = '') {
        $role_labels = array(
            'admin'     => __('Admin', 'crewcommerce'),
            'manager'   => __('Manager', 'crewcommerce'),
            'requester' => __('Requester', 'crewcommerce'),
        );
        $role_label = $role_labels[$role] ?? ucfirst($role);

        if ($is_new_user) {
            /* translators: 1: company name, 2: store name, 3: role */
            $subject = sprintf(__('You have been invited to join %1$s on %2$s as a %3$s', 'crewcommerce'), $company_name, get_bloginfo('name'), $role_label);
            $message = sprintf(
                __("Hello,\n\n%1\$s has invited you to join their team at %2\$s on %3\$s as a %4\$s.\n\nYour username is: %5\$s\n\nTo get started, click the link below to set your password:\n%6\$s\n\nOnce logged in, you will have access to the team purchasing dashboard.", 'crewcommerce'),
                $inviter_name, $company_name, get_bloginfo('name'), $role_label, $username, $reset_link
            );
        } else {
            /* translators: 1: company name, 2: store name, 3: role */
            $subject = sprintf(__('You have been invited to join %1$s on %2$s as a %3$s', 'crewcommerce'), $company_name, get_bloginfo('name'), $role_label);
            $message = sprintf(
                /* translators: 1: person's name, 2: inviter's name, 3: company name, 4: store name, 5: role, 6: link */
                __("Hello %1\$s,\n\n%2\$s has invited you to join the %3\$s team on %4\$s as a %5\$s. As a member, your orders may need approval from the company's managers, who can see them.\n\nTo accept, log in and open this link:\n%6\$s\n\nIf you weren't expecting this, ignore this email and nothing changes.", 'crewcommerce'),
                $to_name, $inviter_name, $company_name, get_bloginfo('name'), $role_label, $reset_link
            );
        }
        wp_mail($to_email, $subject, $message);
    }

    /**
     * AJAX: Invite member from admin dashboard (crewcommerce_admin_nonce)
     */
    public function ajax_admin_invite_member() {
        check_ajax_referer('crewcommerce_admin_nonce', 'nonce');

        if (!current_user_can('manage_options')) {
            wp_send_json_error(__('Insufficient permissions.', 'crewcommerce'));
        }

        $company_id = isset($_POST['company_id']) ? absint(wp_unslash($_POST['company_id'])) : 0;
        if (!$company_id || get_post_type($company_id) !== 'crewcommerce_company') {
            wp_send_json_error(__('Invalid company.', 'crewcommerce'));
        }

        $this->do_invite_member();
    }

    /**
     * Accept an invitation from the link in the email. The link's token is
     * the proof; it only works for the account it was sent to.
     */
    public function handle_invite_link() {
        if (!isset($_GET['crewcommerce_invite'])) { // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- the secret token is the proof.
            return;
        }
        $token = sanitize_text_field(wp_unslash($_GET['crewcommerce_invite'])); // phpcs:ignore WordPress.Security.NonceVerification.Recommended

        if (!is_user_logged_in()) {
            // WooCommerce sends people back to this link after they log in.
            wc_add_notice(__('Log in to accept your team invitation.', 'crewcommerce'), 'notice');
            return;
        }

        $user_id  = get_current_user_id();
        $team     = CrewCommerce_Team_Accounts::get_instance();
        $invite   = get_user_meta($user_id, self::invite_meta_key(), true);
        $redirect = wc_get_page_permalink('myaccount');

        $valid = is_array($invite) && !empty($invite['token']) && is_string($token) && '' !== $token
            && hash_equals((string) $invite['token'], hash('sha256', $token))
            && (int) $invite['expires'] >= time();

        if (!$valid) {
            wc_add_notice(__('This invitation link isn’t valid for this account or has expired. Ask for a new invitation.', 'crewcommerce'), 'error');
        } elseif ($team->get_user_company($user_id)) {
            delete_user_meta($user_id, self::invite_meta_key());
            wc_add_notice(__('You’re already part of a company, so this invitation can’t be accepted.', 'crewcommerce'), 'error');
        } elseif ('crewcommerce_company' !== get_post_type((int) $invite['company_id'])) {
            delete_user_meta($user_id, self::invite_meta_key());
            wc_add_notice(__('That company no longer exists.', 'crewcommerce'), 'error');
        } else {
            $team->add_team_member($user_id, (int) $invite['company_id'], $invite['role']);
            delete_user_meta($user_id, self::invite_meta_key());
            /* translators: %s: company name */
            wc_add_notice(sprintf(__('You’ve joined %s.', 'crewcommerce'), get_the_title((int) $invite['company_id'])), 'success');
            $redirect = wc_get_account_endpoint_url('crewcommerce-dashboard');
        }

        wp_safe_redirect($redirect);
        exit;
    }
}