#!/usr/bin/env perl
# -*- mode: Perl; -*-
# Version 4.20.8
# See the file COPYING in the main distribution directory for copyright notice.

# Important Assumptions: This script runs under the run-as-class-master 
# wrapper, which gives it the effective UID of the class master account,
# sets PATH to /usr/bin, MASTERDIR and GRADINGDIR to the correct values, 
# copies HOME and PWD from the user, and clears the rest of the environment, 
# including environment variables affecting Perl.

# Usage: 
#   team-members [ -u LOGIN ] [ TEAM ]
#     Prints logins of members of TEAM (if I am one of them or otherwise 
#     authorized), and otherwise finds and prints all teams of which I am
#     a member.  The -u switch (privileged) uses LOGIN as the requesting user.
#   team-members -r TEAM LOGIN ...
#     Remove the given LOGINs from TEAM, if currently members.
#     Must be privileged to specify a LOGIN other than your own, or to use this
#     command at all if parameters file does not allow unprivileged team 
#     modification.
#   team-members -a TEAM LOGIN ...
#     Add LOGINs to TEAM.  If the user is not privileged, then the parameters
#     file must allow unprivileged team modification and the user must be 
#     in TEAM previously.
#   team-members -c TEAM LOGIN ...
#     Create TEAM, with initial members given by the listed LOGINs.  If the 
#     user is not privileged, then LOGIN must include the current user and 
#     the parameters file must allow unprivileged team modification.  
#   team-members -d TEAM
#     Delete TEAM, which must be empty.  The user must be privileged.

use POSIX qw(strftime);
use Net::Domain qw(hostname hostfqdn);
unshift (@INC, '/home/ff/cs61b/grading-software/share/lib');

@ARGV0 = @ARGV;

require "GradingBase.pl";
CmndLine ("u:acrd", 0, 20);
require "GradingCommon.pl";

GetPermissions ($0, @ARGV0);

$ENV{"PATH"}='/usr/bin';

sub GetTeam {
    my ($team) = @_;
    my %team;
    open (TEAM, "$TEAM_DIR/$team") or return undef;
    while (<TEAM>) {
	chomp;
        if (/^\s*#/) {
            next;
        }
	$team{$_} = 1;
    }
    close TEAM;
    return %team;
}

sub Report {
    my ($team, %members) = @_;
    return if (not %members);
    my $line = join (" ", sort (keys %members));
    print "$team: $line\n";
}

$me = MyLogin ();
$authorized = $AUTHORIZED{$me};
if ($opt_u and $authorized) {
    $me = $opt_u;
} else {
    if ($opt_u and $me ne $opt_u) {
	Fatal ("You are not authorized to inquire for $opt_u.");
    }
}

if ( ($opt_u ? 1 : 0) + ($opt_a ? 1 : 0) + ($opt_c ? 1 : 0) + ($opt_d ? 1 : 0)
     + ($opt_r ? 1 : 0) > 1) {
    Usage ();
}

if ($opt_d and not $authorized) {
    Fatal ("You are not authorized to delete a team.");
}

if (($opt_a or $opt_c or $opt_r) and not $authorized) {
    Fatal ("You are not authorized to modify teams.");
}

if (@ARGV) {
    $team = shift @ARGV;
} else {
    $team = undef;
}

if (($opt_a or $opt_c or $opt_d or $opt_r) and not $team) {
    Usage ();
}

if ($opt_c) {
    if (TeamExists ($team)) {
	Fatal ("Team $team already exists.");
    }
    if ($team !~ /^[A-Z][a-zA-Z0-9_-]*$/) {
	Fatal ("Team name does not have the right form.");
    }
}
elsif (not TeamExists ($team)) {
    Fatal ("No such team as $team.");
}

@logins = @ARGV;
foreach (@logins) {
    $logins{$_} = 1;
}

if ($opt_a or $opt_r or $opt_c) {
    if (not @logins) {
	Usage ();
    }
} elsif (@logins) {
    Usage ();
}

if ($team) {
    %members = GetTeam ($team);
} else {
    foreach (<$TEAM_DIR/*>) {
	($team) = m{.*/(.*)};
	%members = GetTeam ($team);
	if ($members{$me}) {
	    Report ($team, %members);
	}
    }
    exit 0;
}

foreach $login (@logins) {
    if (not StudentExists ($login)) {
	Fatal ("Login $login is not registered.");
    }
}

$changed = 0;
if ($opt_c) {
    if (not $authorized and not grep (/^$me$/, @logins)) {
	Fatal ("You must be a member of any team you create.");
    }
    %members = %logins;
    $changed = 1;
} elsif ($opt_r) {
    foreach (@logins) {
	if ($authorized or $_ eq $me) {
	    delete $members{$_};
	    $changed = 1;
	}
    }
} elsif ($opt_a) {
    if (not $authorized and not $members{$me}) {
	Fatal ("You may not add members to team you're not on.");
    }
    %members = (%members, %logins);
    $changed = 1;
} elsif ($opt_d) {
    unlink ("$TEAM_DIR/$team");
} else {
    if ($authorized or $members{$me}) {
	Report ($team, %members);
    }
}

if ($changed) {
    umask (0177);
    open(TEAM, ">", "$TEAM_DIR/$team") 
	|| Fatal ("Could not write $TEAM_DIR/$team.");
    @members = sort (keys %members);
    foreach $member (@members) {
	print TEAM "$member\n";
    }
    close TEAM
	|| Fatal ("Problem writing $TEAM_DIR/$team.");
}

exit 0;