# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
#
# This Source Code Form is "Incompatible With Secondary Licenses", as
# defined by the Mozilla Public License, v. 2.0.

package Bugzilla::Mailer;

use 5.10.1;
use strict;
use warnings;

use base qw(Exporter);
@Bugzilla::Mailer::EXPORT = qw(MessageToMTA build_thread_marker);

use Bugzilla::Constants;
use Bugzilla::Error;
use Bugzilla::Hook;
use Bugzilla::Util;

use Date::Format qw(time2str);

use Encode qw(encode);
use Encode::MIME::Header;
use Email::Address;
use Email::MIME;
# Return::Value 1.666002 pollutes the error log with warnings about this
# deprecated module. We have to set NO_CLUCK = 1 before loading Email::Send
# to disable these warnings.
BEGIN {
    $Return::Value::NO_CLUCK = 1;
}
use Email::Send;
use Sys::Hostname;
use Bugzilla::Version qw(vers_cmp);

sub MessageToMTA {
    my ($msg, $send_now) = (@_);
    my $method = Bugzilla->get_param_with_override('mail_delivery_method');
    return if $method eq 'None';

    if (Bugzilla->get_param_with_override('use_mailer_queue') and !$send_now) {
        Bugzilla->job_queue->insert('send_mail', { msg => $msg });
        return;
    }

    my $dbh = Bugzilla->dbh;

    my $email;
    if (ref $msg) {
        $email = $msg;
    }
    else {
        # RFC 2822 requires us to have CRLF for our line endings and
        # Email::MIME doesn't do this for us until 1.911. We use \015 (CR) and \012 (LF)
        # directly because Perl translates "\n" depending on what platform
        # you're running on. See http://perldoc.perl.org/perlport.html#Newlines
        # We check for multiple CRs because of this Template-Toolkit bug:
        # https://rt.cpan.org/Ticket/Display.html?id=43345
        if (vers_cmp($Email::MIME::VERSION, 1.911) == -1) {
            $msg =~ s/(?:\015+)?\012/\015\012/msg;
        }

        $email = new Email::MIME($msg);
    }

    # Ensure that we are not sending emails too quickly to recipients.
    if (Bugzilla->get_param_with_override('use_mailer_queue')
        && (EMAIL_LIMIT_PER_MINUTE || EMAIL_LIMIT_PER_HOUR))
    {
        $dbh->do(
            "DELETE FROM email_rates WHERE message_ts < "
            . $dbh->sql_date_math('LOCALTIMESTAMP(0)', '-', '1', 'HOUR'));

        my $recipient = $email->header('To');

        if (EMAIL_LIMIT_PER_MINUTE) {
            my $minute_rate = $dbh->selectrow_array(
                "SELECT COUNT(*)
                   FROM email_rates
                  WHERE recipient = ?  AND message_ts >= "
                        . $dbh->sql_date_math('LOCALTIMESTAMP(0)', '-', '1', 'MINUTE'),
                undef,
                $recipient);
            if ($minute_rate >= EMAIL_LIMIT_PER_MINUTE) {
                die EMAIL_LIMIT_EXCEPTION;
            }
        }
        if (EMAIL_LIMIT_PER_HOUR) {
            my $hour_rate = $dbh->selectrow_array(
                "SELECT COUNT(*)
                   FROM email_rates
                  WHERE recipient = ?  AND message_ts >= "
                        . $dbh->sql_date_math('LOCALTIMESTAMP(0)', '-', '1', 'HOUR'),
                undef,
                $recipient);
            if ($hour_rate >= EMAIL_LIMIT_PER_HOUR) {
                die EMAIL_LIMIT_EXCEPTION;
            }
        }
    }

    # We add this header to uniquely identify all email that we
    # send as coming from this Bugzilla installation.
    #
    $email->header_set('X-Bugzilla-URL', Bugzilla->localconfig->{urlbase});

    # We add this header to mark the mail as "auto-generated" and
    # thus to hopefully avoid auto replies.
    $email->header_set('Auto-Submitted', 'auto-generated');

    # MIME-Version must be set otherwise some mailsystems ignore the charset
    $email->header_set('MIME-Version', '1.0') if !$email->header('MIME-Version');

    # Encode the headers correctly in quoted-printable
    foreach my $header ($email->header_names) {
        my @values = $email->header($header);
        # We don't recode headers that happen multiple times.
        next if scalar(@values) > 1;
        if (my $value = $values[0]) {
            if (Bugzilla->params->{'utf8'} && !utf8::is_utf8($value)) {
                utf8::decode($value);
            }

            # avoid excessive line wrapping done by Encode.
            local $Encode::Encoding{'MIME-Q'}->{'bpl'} = 998;

            my $encoded = encode('MIME-Q', $value);
            $email->header_set($header, $encoded);
        }
    }

    my $from = $email->header('From');

    my ($hostname, @args);
    my $mailer_class = $method;
    if ($method eq "Sendmail") {
        $mailer_class = 'Bugzilla::Send::Sendmail';
        if (ON_WINDOWS) {
            $Email::Send::Sendmail::SENDMAIL = SENDMAIL_EXE;
        }
        push @args, "-i";
        # We want to make sure that we pass *only* an email address.
        if ($from) {
            my ($email_obj) = Email::Address->parse($from);
            if ($email_obj) {
                my $from_email = $email_obj->address;
                push(@args, "-f$from_email") if $from_email;
            }
        }
    }
    else {
        # Sendmail will automatically append our hostname to the From
        # address, but other mailers won't.
        my $urlbase = Bugzilla->localconfig->{urlbase};
        $urlbase =~ m|//([^:/]+)[:/]?|;
        $hostname = $1;
        $from .= "\@$hostname" if $from !~ /@/;
        $email->header_set('From', $from);

        # Sendmail adds a Date: header also, but others may not.
        if (!defined $email->header('Date')) {
            $email->header_set('Date', time2str("%a, %d %b %Y %T %z", time()));
        }
    }

    # For tracking/diagnostic purposes, add our hostname
    my $generated_by = $email->header('X-Generated-By') || '';
    if ($generated_by =~ tr/\/// < 3) {
        $email->header_set('X-Generated-By' => $generated_by . '/' . hostname() . "($$)");
    }

    if ($method eq "SMTP") {
        push @args, Host  => Bugzilla->params->{"smtpserver"},
                    username => Bugzilla->params->{"smtp_username"},
                    password => Bugzilla->params->{"smtp_password"},
                    Hello => $hostname,
                    Debug => Bugzilla->params->{'smtp_debug'};
    }

    Bugzilla::Hook::process('mailer_before_send',
                            { email => $email, mailer_args => \@args });

    # Allow for extensions to to drop the bugmail by clearing the 'to' header
    return if $email->header('to') eq '';

    $email->walk_parts(sub {
        my ($part) = @_;
        return if $part->parts > 1; # Top-level
        my $content_type = $part->content_type || '';
        $content_type =~ /charset=['"](.+)['"]/;
        # If no charset is defined or is the default us-ascii,
        # then we encode the email to UTF-8 if Bugzilla has utf8 enabled.
        # XXX - This is a hack to workaround bug 723944.
        if (!$1 || $1 eq 'us-ascii') {
            my $body = $part->body;
            if (Bugzilla->params->{'utf8'}) {
                $part->charset_set('UTF-8');
                # encoding_set works only with bytes, not with utf8 strings.
                my $raw = $part->body_raw;
                if (utf8::is_utf8($raw)) {
                    utf8::encode($raw);
                    $part->body_set($raw);
                }
            }
            $part->encoding_set('quoted-printable') if !is_7bit_clean($body);
        }
    });

    if ($method eq "Test") {
        my $filename = bz_locations()->{'datadir'} . '/mailer.testfile';
        open TESTFILE, '>>', $filename;
        # From - <date> is required to be a valid mbox file.
        print TESTFILE "\n\nFrom - " . $email->header('Date') . "\n" . $email->as_string;
        close TESTFILE;
    }
    else {
        # This is useful for both Sendmail and Qmail, so we put it out here.
        local $ENV{PATH} = SENDMAIL_PATH;
        my $mailer = Email::Send->new({ mailer => $mailer_class,
                                        mailer_args => \@args });
        my $retval = $mailer->send($email);
        ThrowCodeError('mail_send_error', { msg => $retval, mail => $email })
            if !$retval;
    }

    # insert into email_rates
    if (Bugzilla->get_param_with_override('use_mailer_queue')
        && (EMAIL_LIMIT_PER_MINUTE || EMAIL_LIMIT_PER_HOUR))
    {
        $dbh->do(
            "INSERT INTO email_rates(recipient, message_ts) VALUES (?, LOCALTIMESTAMP(0))",
            undef,
            $email->header('To')
        );
    }
}

# Builds header suitable for use as a threading marker in email notifications
sub build_thread_marker {
    my ($bug_id, $user_id, $is_new) = @_;

    if (!defined $user_id) {
        $user_id = Bugzilla->user->id;
    }

    my $sitespec = '@' . Bugzilla->localconfig->{urlbase};
    $sitespec =~ s/:\/\//\./; # Make the protocol look like part of the domain
    $sitespec =~ s/^([^:\/]+):(\d+)/$1/; # Remove a port number, to relocate
    if ($2) {
        $sitespec = "-$2$sitespec"; # Put the port number back in, before the '@'
    }

    my $threadingmarker = "References: <bug-$bug_id-$user_id$sitespec>";
    if ($is_new) {
        $threadingmarker .= "\nMessage-ID: <bug-$bug_id-$user_id$sitespec>";
    }
    else {
        my $rand_bits = generate_random_password(10);
        $threadingmarker .= "\nMessage-ID: <bug-$bug_id-$user_id-$rand_bits$sitespec>" .
                            "\nIn-Reply-To: <bug-$bug_id-$user_id$sitespec>";
    }

    return $threadingmarker;
}

1;