#!/usr/bin/perl -w
#
# Copyright 2002,2005 Greg Kroah-Hartman <greg@kroah.com>
# Copyright 2005 Ryan Anderson <ryan@michonline.com>
#
# GPL v2 (See COPYING)
#
# Ported to support git "mbox" format files by Ryan Anderson <ryan@michonline.com>
#
# Sends a collection of emails to the given email addresses, disturbingly fast.
#
# Supports two formats:
# 1. mbox format files (ignoring most headers and MIME formatting - this is designed for sending patches)
# 2. The original format support by Greg's script:
#    first line of the message is who to CC,
#    and second line is the subject of the message.
#

use strict;
use warnings;
use Term::ReadLine;
use Getopt::Long;
use Data::Dumper;
use Net::SMTP;

# most mail servers generate the Date: header, but not all...
$ENV{LC_ALL} = 'C';
use POSIX qw/strftime/;

my $have_email_valid = eval { require Email::Valid; 1 };
my $smtp;

sub unique_email_list(@);
sub cleanup_compose_files();

# Constants (essentially)
my $compose_filename = ".msg.$$";

# Variables we fill in automatically, or via prompting:
my (@to,@cc,@initial_cc,$initial_reply_to,$initial_subject,@files,$from,$compose,$time);

# Behavior modification variables
my ($chain_reply_to, $smtp_server, $quiet, $suppress_from, $no_signed_off_cc) = (1, "localhost", 0, 0, 0);

# Example reply to:
#$initial_reply_to = ''; #<20050203173208.GA23964@foobar.com>';

my $term = new Term::ReadLine 'git-send-email';

# Begin by accumulating all the variables (defined above), that we will end up
# needing, first, from the command line:

my $rc = GetOptions("from=s" => \$from,
                    "in-reply-to=s" => \$initial_reply_to,
                    "subject=s" => \$initial_subject,
                    "to=s" => \@to,
                    "cc=s" => \@initial_cc,
                    "chain-reply-to!" => \$chain_reply_to,
                    "smtp-server=s" => \$smtp_server,
                    "compose" => \$compose,
                    "quiet" => \$quiet,
                    "suppress-from" => \$suppress_from,
                    "no-signed-off-cc|no-signed-off-by-cc" => \$no_signed_off_cc,
         );

# Now, let's fill any that aren't set in with defaults:

sub gitvar {
    my ($var) = @_;
    my $fh;
    my $pid = open($fh, '-|');
    die "$!" unless defined $pid;
    if (!$pid) {
        exec('git-var', $var) or die "$!";
    }
    my ($val) = <$fh>;
    close $fh or die "$!";
    chomp($val);
    return $val;
}

sub gitvar_ident {
    my ($name) = @_;
    my $val = gitvar($name);
    my @field = split(/\s+/, $val);
    return join(' ', @field[0...(@field-3)]);
}

my ($author) = gitvar_ident('GIT_AUTHOR_IDENT');
my ($committer) = gitvar_ident('GIT_COMMITTER_IDENT');

my $prompting = 0;
if (!defined $from) {
        $from = $author || $committer;
        do {
                $_ = $term->readline("Who should the emails appear to be from? ",
                        $from);
        } while (!defined $_);

        $from = $_;
        print "Emails will be sent from: ", $from, "\n";
        $prompting++;
}

if (!@to) {
        do {
                $_ = $term->readline("Who should the emails be sent to? ",
                                "");
        } while (!defined $_);
        my $to = $_;
        push @to, split /,/, $to;
        $prompting++;
}

if (!defined $initial_subject && $compose) {
        do {
                $_ = $term->readline("What subject should the emails start with? ",
                        $initial_subject);
        } while (!defined $_);
        $initial_subject = $_;
        $prompting++;
}

if (!defined $initial_reply_to && $prompting) {
        do {
                $_= $term->readline("Message-ID to be used as In-Reply-To for the first email? ",
                        $initial_reply_to);
        } while (!defined $_);

        $initial_reply_to = $_;
        $initial_reply_to =~ s/(^\s+|\s+$)//g;
}

if (!defined $smtp_server) {
        $smtp_server = "localhost";
}

if ($compose) {
        # Note that this does not need to be secure, but we will make a small
        # effort to have it be unique
        open(C,">",$compose_filename)
                or die "Failed to open for writing $compose_filename: $!";
        print C "From $from # This line is ignored.\n";
        printf C "Subject: %s\n\n", $initial_subject;
        printf C <<EOT;
GIT: Please enter your email below.
GIT: Lines beginning in "GIT: " will be removed.
GIT: Consider including an overall diffstat or table of contents
GIT: for the patch you are writing.

EOT
        close(C);

        my $editor = $ENV{EDITOR};
        $editor = 'vi' unless defined $editor;
        system($editor, $compose_filename);

        open(C2,">",$compose_filename . ".final")
                or die "Failed to open $compose_filename.final : " . $!;

        open(C,"<",$compose_filename)
                or die "Failed to open $compose_filename : " . $!;

        while(<C>) {
                next if m/^GIT: /;
                print C2 $_;
        }
        close(C);
        close(C2);

        do {
                $_ = $term->readline("Send this email? (y|n) ");
        } while (!defined $_);

        if (uc substr($_,0,1) ne 'Y') {
                cleanup_compose_files();
                exit(0);
        }

        @files = ($compose_filename . ".final");
}


# Now that all the defaults are set, process the rest of the command line
# arguments and collect up the files that need to be processed.
for my $f (@ARGV) {
        if (-d $f) {
                opendir(DH,$f)
                        or die "Failed to opendir $f: $!";

                push @files, grep { -f $_ } map { +$f . "/" . $_ }
                                sort readdir(DH);

        } elsif (-f $f) {
                push @files, $f;

        } else {
                print STDERR "Skipping $f - not found.\n";
        }
}

if (@files) {
        unless ($quiet) {
                print $_,"\n" for (@files);
        }
} else {
        print <<EOT;
git-send-email [options] <file | directory> [... file | directory ]
Options:
   --from         Specify the "From:" line of the email to be sent.

   --to           Specify the primary "To:" line of the email.

   --cc           Specify an initial "Cc:" list for the entire series
                  of emails.

   --compose      Use \$EDITOR to edit an introductory message for the
                  patch series.

   --subject      Specify the initial "Subject:" line.
                  Only necessary if --compose is also set.  If --compose
                  is not set, this will be prompted for.

   --in-reply-to  Specify the first "In-Reply-To:" header line.
                  Only used if --compose is also set.  If --compose is not
                  set, this will be prompted for.

   --chain-reply-to If set, the replies will all be to the previous
                  email sent, rather than to the first email sent.
                  Defaults to on.

   --no-signed-off-cc Suppress the automatic addition of email addresses
                 that appear in a Signed-off-by: line, to the cc: list.
                 Note: Using this option is not recommended.

   --smtp-server  If set, specifies the outgoing SMTP server to use.
                  Defaults to localhost.

  --suppress-from Supress sending emails to yourself if your address
                  appears in a From: line.

   --quiet      Make git-send-email less verbose.  One line per email should be
                all that is output.

Error: Please specify a file or a directory on the command line.
EOT
        exit(1);
}

# Variables we set as part of the loop over files
our ($message_id, $cc, %mail, $subject, $reply_to, $message);

sub extract_valid_address {
        my $address = shift;
        if ($have_email_valid) {
                return Email::Valid->address($address);
        } else {
                # less robust/correct than the monster regexp in Email::Valid,
                # but still does a 99% job, and one less dependency
                return ($address =~ /([^\"<>\s]+@[^<>\s]+)/);
        }
}

# Usually don't need to change anything below here.

# we make a "fake" message id by taking the current number
# of seconds since the beginning of Unix time and tacking on
# a random number to the end, in case we are called quicker than
# 1 second since the last time we were called.

# We'll setup a template for the message id, using the "from" address:
my $message_id_from = extract_valid_address($from);
my $message_id_template = "<%s-git-send-email-$message_id_from>";

sub make_message_id
{
        my $date = time;
        my $pseudo_rand = int (rand(4200));
        $message_id = sprintf $message_id_template, "$date$pseudo_rand";
        #print "new message id = $message_id\n"; # Was useful for debugging
}



$cc = "";
$time = time - scalar $#files;

sub send_message
{
        my @recipients = unique_email_list(@to);
        my $to = join (",\n\t", @recipients);
        @recipients = unique_email_list(@recipients,@cc);
        my $date = strftime('%a, %d %b %Y %H:%M:%S %z', localtime($time++));
        my $gitversion = '@@GIT_VERSION@@';
        if ($gitversion =~ m/..GIT_VERSION../) {
            $gitversion = `git --version`;
            chomp $gitversion;
            # keep only what's after the last space
            $gitversion =~ s/^.* //;
        }

        my $header = "From: $from
To: $to
Cc: $cc
Subject: $subject
Reply-To: $from
Date: $date
Message-Id: $message_id
X-Mailer: git-send-email $gitversion
";
        $header .= "In-Reply-To: $reply_to\n" if $reply_to;

        $smtp ||= Net::SMTP->new( $smtp_server );
        $smtp->mail( $from ) or die $smtp->message;
        $smtp->to( @recipients ) or die $smtp->message;
        $smtp->data or die $smtp->message;
        $smtp->datasend("$header\n$message") or die $smtp->message;
        $smtp->dataend() or die $smtp->message;
        $smtp->ok or die "Failed to send $subject\n".$smtp->message;

        if ($quiet) {
                printf "Sent %s\n", $subject;
        } else {
                print "OK. Log says:
Date: $date
Server: $smtp_server Port: 25
From: $from
Subject: $subject
Cc: $cc
To: $to

Result: ", $smtp->code, ' ', ($smtp->message =~ /\n([^\n]+\n)$/s), "\n";
        }
}

$reply_to = $initial_reply_to;
make_message_id();
$subject = $initial_subject;

foreach my $t (@files) {
        open(F,"<",$t) or die "can't open file $t";

        my $author_not_sender = undef;
        @cc = @initial_cc;
        my $found_mbox = 0;
        my $header_done = 0;
        $message = "";
        while(<F>) {
                if (!$header_done) {
                        $found_mbox = 1, next if (/^From /);
                        chomp;

                        if ($found_mbox) {
                                if (/^Subject:\s+(.*)$/) {
                                        $subject = $1;

                                } elsif (/^(Cc|From):\s+(.*)$/) {
                                        if ($2 eq $from) {
                                                next if ($suppress_from);
                                        }
                                        else {
                                                $author_not_sender = $2;
                                        }
                                        printf("(mbox) Adding cc: %s from line '%s'\n",
                                                $2, $_) unless $quiet;
                                        push @cc, $2;
                                }

                        } else {
                                # In the traditional
                                # "send lots of email" format,
                                # line 1 = cc
                                # line 2 = subject
                                # So let's support that, too.
                                if (@cc == 0) {
                                        printf("(non-mbox) Adding cc: %s from line '%s'\n",
                                                $_, $_) unless $quiet;

                                        push @cc, $_;

                                } elsif (!defined $subject) {
                                        $subject = $_;
                                }
                        }

                        # A whitespace line will terminate the headers
                        if (m/^\s*$/) {
                                $header_done = 1;
                        }
                } else {
                        $message .=  $_;
                        if (/^Signed-off-by: (.*)$/i && !$no_signed_off_cc) {
                                my $c = $1;
                                chomp $c;
                                push @cc, $c;
                                printf("(sob) Adding cc: %s from line '%s'\n",
                                        $c, $_) unless $quiet;
                        }
                }
        }
        close F;
        if (defined $author_not_sender) {
                $message = "From: $author_not_sender\n\n$message";
        }

        $cc = join(", ", unique_email_list(@cc));

        send_message();

        # set up for the next message
        if ($chain_reply_to || length($reply_to) == 0) {
                $reply_to = $message_id;
        }
        make_message_id();
}

if ($compose) {
        cleanup_compose_files();
}

sub cleanup_compose_files() {
        unlink($compose_filename, $compose_filename . ".final");

}

$smtp->quit if $smtp;

sub unique_email_list(@) {
        my %seen;
        my @emails;

        foreach my $entry (@_) {
                my $clean = extract_valid_address($entry);
                next if $seen{$clean}++;
                push @emails, $entry;
        }
        return @emails;
}