#!/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 Mail::Sendmail qw(sendmail %mailcfg);
use Getopt::Long;
use Data::Dumper;
use Email::Valid;

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,$initial_reply_to,$initial_subject,@files,$from,$compose);

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

# 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,
                    "chain-reply-to!" => \$chain_reply_to,
                    "smtp-server=s" => \$smtp_server,
                    "compose" => \$compose,
         );

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

open(GITVAR,"-|","git-var","-l")
        or die "Failed to open pipe from git-var: $!";

my ($author,$committer);
while(<GITVAR>) {
        chomp;
        my ($var,$data) = split /=/,$_,2;
        my @fields = split /\s+/, $data;

        my $ident = join(" ", @fields[0...(@fields-3)]);

        if ($var eq 'GIT_AUTHOR_IDENT') {
                $author = $ident;
        } elsif ($var eq 'GIT_COMMITTER_IDENT') {
                $committer = $ident;
        }
}
close(GITVAR);

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 \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) {
        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.

   --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.

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

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);


# 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 $message_id_from = Email::Valid->address($from);
my $message_id_template = "<%s-git-send-email-$message_id_from>";

sub make_message_id
{
        my $date = `date "+\%s"`;
        chomp($date);
        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 = "";

sub send_message
{
        my $to = join (", ", unique_email_list(@to));

        %mail = (       To      =>      $to,
                        From    =>      $from,
                        CC      =>      $cc,
                        Subject =>      $subject,
                        Message =>      $message,
                        'Reply-to'      =>      $from,
                        'In-Reply-To'   =>      $reply_to,
                        'Message-ID'    =>      $message_id,
                        'X-Mailer'      =>      "git-send-email",
                );

        $mail{smtp} = $smtp_server;
        $mailcfg{mime} = 0;

        #print Data::Dumper->Dump([\%mail],[qw(*mail)]);

        sendmail(%mail) or die $Mail::Sendmail::error;

        print "OK. Log says:\n", $Mail::Sendmail::log;
        print "\n\n"
}


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

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

        @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+(.*)$/) {
                                        printf("(mbox) Adding cc: %s from line '%s'\n",
                                                $2, $_);
                                        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",
                                                $_, $_);

                                        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) {
                                my $c = $1;
                                chomp $c;
                                push @cc, $c;
                                printf("(sob) Adding cc: %s from line '%s'\n",
                                        $c, $_);
                        }
                }
        }
        close F;

        $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");

}



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

        foreach my $entry (@_) {
                my $clean = Email::Valid->address($entry);
                next if $seen{$clean}++;
                push @emails, $entry;
        }
        return @emails;
}