#!/usr/bin/perl

use lib '../../perl/blib/lib';
use strict;
use warnings;
use Git;

sub get_times {
        my $name = shift;
        open my $fh, "<", $name or return undef;
        my $line = <$fh>;
        return undef if not defined $line;
        close $fh or die "cannot close $name: $!";
        $line =~ /^(?:(\d+):)?(\d+):(\d+(?:\.\d+)?) (\d+(?:\.\d+)?) (\d+(?:\.\d+)?)$/
                or die "bad input line: $line";
        my $rt = ((defined $1 ? $1 : 0.0)*60+$2)*60+$3;
        return ($rt, $4, $5);
}

sub format_times {
        my ($r, $u, $s, $firstr) = @_;
        if (!defined $r) {
                return "<missing>";
        }
        my $out = sprintf "%.2f(%.2f+%.2f)", $r, $u, $s;
        if (defined $firstr) {
                if ($firstr > 0) {
                        $out .= sprintf " %+.1f%%", 100.0*($r-$firstr)/$firstr;
                } elsif ($r == 0) {
                        $out .= " =";
                } else {
                        $out .= " +inf";
                }
        }
        return $out;
}

my (@dirs, %dirnames, %dirabbrevs, %prefixes, @tests);
while (scalar @ARGV) {
        my $arg = $ARGV[0];
        my $dir;
        last if -f $arg or $arg eq "--";
        if (! -d $arg) {
                my $rev = Git::command_oneline(qw(rev-parse --verify), $arg);
                $dir = "build/".$rev;
        } else {
                $arg =~ s{/*$}{};
                $dir = $arg;
                $dirabbrevs{$dir} = $dir;
        }
        push @dirs, $dir;
        $dirnames{$dir} = $arg;
        my $prefix = $dir;
        $prefix =~ tr/^a-zA-Z0-9/_/c;
        $prefixes{$dir} = $prefix . '.';
        shift @ARGV;
}

if (not @dirs) {
        @dirs = ('.');
}
$dirnames{'.'} = $dirabbrevs{'.'} = "this tree";
$prefixes{'.'} = '';

shift @ARGV if scalar @ARGV and $ARGV[0] eq "--";

@tests = @ARGV;
if (not @tests) {
        @tests = glob "p????-*.sh";
}

my $resultsdir = "test-results";
if (exists $ENV{GIT_PERF_SUBSECTION} and $ENV{GIT_PERF_SUBSECTION} ne "") {
        $resultsdir .= "/" . $ENV{GIT_PERF_SUBSECTION};
}

my @subtests;
my %shorttests;
for my $t (@tests) {
        $t =~ s{(?:.*/)?(p(\d+)-[^/]+)\.sh$}{$1} or die "bad test name: $t";
        my $n = $2;
        my $fname = "$resultsdir/$t.subtests";
        open my $fp, "<", $fname or die "cannot open $fname: $!";
        for (<$fp>) {
                chomp;
                /^(\d+)$/ or die "malformed subtest line: $_";
                push @subtests, "$t.$1";
                $shorttests{"$t.$1"} = "$n.$1";
        }
        close $fp or die "cannot close $fname: $!";
}

sub read_descr {
        my $name = shift;
        open my $fh, "<", $name or return "<error reading description>";
        binmode $fh, ":utf8" or die "PANIC on binmode: $!";
        my $line = <$fh>;
        close $fh or die "cannot close $name";
        chomp $line;
        return $line;
}

sub have_duplicate {
        my %seen;
        for (@_) {
                return 1 if exists $seen{$_};
                $seen{$_} = 1;
        }
        return 0;
}
sub have_slash {
        for (@_) {
                return 1 if m{/};
        }
        return 0;
}

sub print_default_results {
        my %descrs;
        my $descrlen = 4; # "Test"
        for my $t (@subtests) {
                $descrs{$t} = $shorttests{$t}.": ".read_descr("$resultsdir/$t.descr");
                $descrlen = length $descrs{$t} if length $descrs{$t}>$descrlen;
        }

        my %newdirabbrevs = %dirabbrevs;
        while (!have_duplicate(values %newdirabbrevs)) {
                %dirabbrevs = %newdirabbrevs;
                last if !have_slash(values %dirabbrevs);
                %newdirabbrevs = %dirabbrevs;
                for (values %newdirabbrevs) {
                        s{^[^/]*/}{};
                }
        }

        my %times;
        my @colwidth = ((0)x@dirs);
        for my $i (0..$#dirs) {
                my $d = $dirs[$i];
                my $w = length (exists $dirabbrevs{$d} ? $dirabbrevs{$d} : $dirnames{$d});
                $colwidth[$i] = $w if $w > $colwidth[$i];
        }
        for my $t (@subtests) {
                my $firstr;
                for my $i (0..$#dirs) {
                        my $d = $dirs[$i];
                        $times{$prefixes{$d}.$t} = [get_times("$resultsdir/$prefixes{$d}$t.times")];
                        my ($r,$u,$s) = @{$times{$prefixes{$d}.$t}};
                        my $w = length format_times($r,$u,$s,$firstr);
                        $colwidth[$i] = $w if $w > $colwidth[$i];
                        $firstr = $r unless defined $firstr;
                }
        }
        my $totalwidth = 3*@dirs+$descrlen;
        $totalwidth += $_ for (@colwidth);

        printf "%-${descrlen}s", "Test";
        for my $i (0..$#dirs) {
                my $d = $dirs[$i];
                printf "   %-$colwidth[$i]s", (exists $dirabbrevs{$d} ? $dirabbrevs{$d} : $dirnames{$d});
        }
        print "\n";
        print "-"x$totalwidth, "\n";
        for my $t (@subtests) {
                printf "%-${descrlen}s", $descrs{$t};
                my $firstr;
                for my $i (0..$#dirs) {
                        my $d = $dirs[$i];
                        my ($r,$u,$s) = @{$times{$prefixes{$d}.$t}};
                        printf "   %-$colwidth[$i]s", format_times($r,$u,$s,$firstr);
                        $firstr = $r unless defined $firstr;
                }
                print "\n";
        }
}

binmode STDOUT, ":utf8" or die "PANIC on binmode: $!";

print_default_results();