#!/usr/bin/perl

use strict;
use utf8;

use TAP::Parser;
use Data::Dumper;
use Cwd;

binmode(STDOUT, ':utf8');
binmode(STDERR, ':utf8');

my %overrides = ();

if (-r 'overrides.txt') {
    read_overrides();
}

my @reports = sort @ARGV;

my $total;
my %section_points = ('A' => 0, 'B' => 0, 'C' => 0);

my $student_id = get_student_id();

if (defined $student_id) {
    print "STUDENT ID is $student_id\n";
} else {
    print "UNKNOWN STUDENT ID\n";
}

intro();

for my $report (@reports) {
    update_total($report, process_report($report));
}

outro($total);

sub get_student_id {
    my $pwd = cwd();

    if (my ($student_id) = ($pwd =~ m{-s(\d{5,7})(/arena)?})) {
        return $student_id;
    }

    return undef;
}

sub update_total {
    my ($report_file_path, $points) = @_;

    my $section = get_section($report_file_path);

    if (defined $section && $section ne 'A') {
        if ($section_points{$section} > 0) {
            print "UWAGA: TYLKO ZADANIE Z NAJWIĘKSZĄ LICZBĄ PUNKTÓW BĘDZIE LICZONE DLA DZIAŁU $section\n";
        }

        if ($points > $section_points{$section}) {
            $total = $total - $section_points{$section} + $points;
            $section_points{$section} = $points;
        }
    } else {
        $total += $points;
    }
}

sub get_section {
    my ($report_file_path) = @_;

    if (my ($section) = ($report_file_path =~ m{Task([ABC])})) {
        return $section;
    }

    return undef;
}

sub get_failures_and_successes {
    my ($file_path) = @_;

    open my $tap_fh, $file_path or die $!;

    my $tap_parser = TAP::Parser->new( { source => $tap_fh } );

    while ( my $result = $tap_parser->next ) {
    }

    return (scalar($tap_parser->actual_failed), scalar($tap_parser->passed))
}

sub process_report {
    my ($report_file) = @_;

    my ($task_id) = ($report_file =~ m{^(.*)/report\.txt$});

    my $override_key = get_override_key($student_id, $task_id);

    if (exists $overrides{$override_key}) {
        my $override_points = $overrides{$override_key};

        print $task_id, " ", "FROM overrides.txt: ", $override_points, "\n";

        return $override_points;
    }

    my ($nb_of_failures, $nb_of_successes) = get_failures_and_successes($report_file);

    my $success = ($nb_of_failures == 0 && $nb_of_successes > 0);

    my ($points, $deadline, $total, $remainder) = parse_description($task_id);

    print $task_id, " ", ($success ? "PASSED" : "FAILED");

    if (!check_deadline($task_id, $deadline)) {
        $success = 0;
    }

    if (!check_if_the_right_task($student_id, $task_id, $total, $remainder)) {
        print " WRONG TASK!";
        $success = 0;
    }

    if (!$success) {
        $points = 0;
    }

    if ($success) {
        print "   POINTS: $points";
    }

    print "\n";

    return $points;
}

sub check_deadline {
    my ($task_id, $deadline) = @_;

    for my $file (glob "$task_id/*") {
        if ($file !~ m{\.(in|arg|out|exp|\~)$|/(description\.txt|run)$}) {
            my $last_timestamp = `(cd ../djfz-2019-s$student_id ; git log -1 --format=\%cd --date=iso $file 2> /dev/null)`;

            if ($last_timestamp =~ m{\S}) {
                chomp $last_timestamp;
                if ($last_timestamp gt $deadline) {
                    print " TOO LATE [$file: $last_timestamp later than $deadline]";
                    return 0;
                }
            }
        }
    }

    return 1;
}

sub check_if_the_right_task {
    my ($student_id, $task_id, $total, $remainder) = @_;

    if (defined($total)) {
        if ($student_id % $total != $remainder) {
            return 0;
        }
    }

    return 0 if $task_id =~ m{^TaskE} and not is_estudent($student_id);

    return 0 if $task_id =~ m{^TaskA} and is_estudent($student_id);

    return 1;
}

sub intro {
    print_header();
    print "SUMMARY\n\n";
}

sub outro {
    my ($points) = @_;

    print "\nTOTAL POINTS: $points\n";

    open my $fh, '>', 'result.csv';
    print $fh "POINTS\n";
    print $fh $points, "\n";
    close($fh);

    print_header();
}


sub print_header {
    print "=" x 20,"\n";
}

sub parse_description {
    my ($task_id) = @_;

    open my $fh, '<', "$task_id/description.txt" or die "???";

    my $points = 0;
    my $deadline = undef;
    my $total = undef;
    my $remainder = undef;

    while (my $line=<$fh>) {
        if ($line =~ m{^POINTS\s*:\s*(\d+)\s*$}) {
            $points = $1;
        } elsif ($line =~ m{^DEADLINE\s*:\s*(.*?)\s*$}) {
            $deadline = $1;
        } elsif ($line =~ m{^REMAINDER\s*:\s*(\d+)/(\d+)\s*$}) {
            $remainder = $1;
            $total = $2;
        }
    }

    return ($points, $deadline, $total, $remainder);
}

sub read_overrides {
    open my $fh, '<', 'overrides.txt';

    while (my $line=<$fh>) {
        chomp $line;
        my ($id, $task, $points, $info) = split/\s+/,$line;

        $overrides{get_override_key($id, "Task".$task)} = $points;
    }
}

sub get_override_key {
    my ($id, $task) = @_;

    return $id.'+'.$task;
}

sub is_estudent {
    my ($id) = @_;

    my $suffix = substr($id, 1);

    my %estudents = map { $_ => 1 } split/\n/,<<'END_OF_NUMBERS';
16136
21804
30291
30686
32746
32753
32754
32757
32759
32778
32813
32837
34595
34596
34598
34599
34603
34604
34608
34650
34654
39546
40549
42335
42611
42612
42613
42614
50169
50711
52484
84146
END_OF_NUMBERS

    if ($estudents{$suffix}) {
        return 1;
    }

    return 0;
}