#!/usr/bin/perl -w

# Copyright (C) 2007, 2008, 2009, 2011, 2012, 2013 Apple Inc.  All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# 1.  Redistributions of source code must retain the above copyright
#     notice, this list of conditions and the following disclaimer. 
# 2.  Redistributions in binary form must reproduce the above copyright
#     notice, this list of conditions and the following disclaimer in the
#     documentation and/or other materials provided with the distribution. 
# 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
#     its contributors may be used to endorse or promote products derived
#     from this software without specific prior written permission. 
#
# THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

# This script attempts to find the point at which a regression (or progression)
# of behavior occurred by searching WebKit nightly builds.

# To override the location where the nightly builds are downloaded or the path
# to the Safari web browser, create a ~/.bisect-buildsrc file with one or more of
# the following lines (use "~/" to specify a path from your home directory):
#
# $branch = "branch-name";
# $nightlyDownloadDirectory = "~/path/to/nightly/downloads";
# $safariPath = "/path/to/Safari.app";

use strict;

use File::Basename;
use File::Path;
use File::Spec;
use File::Temp qw(tempfile);
use FindBin;
use Getopt::Long;
use Time::HiRes qw(usleep);

use lib $FindBin::Bin;
use webkitdirs qw(safariPathFromSafariBundle);

sub createTempFile($);
sub downloadNightly($$$);
sub findMacOSXVersion();
sub findNearestNightlyIndex(\@$$);
sub findSafariVersion($);
sub loadSettings();
sub makeNightlyList($$$$);
sub max($$) { return $_[0] > $_[1] ? $_[0] : $_[1]; }
sub mountAndRunNightly($$$$);
sub parseRevisions($$;$);
sub printStatus($$$);
sub printTracLink($$);
sub promptForTest($);

loadSettings();

my %validBranches = map { $_ => 1 } qw(feature-branch trunk);
my $branch = $Settings::branch;
my $nightlyDownloadDirectory = $Settings::nightlyDownloadDirectory;
my $safariPath = $Settings::safariPath;

my @nightlies;

my $isProgression;
my $localOnly;
my @revisions;
my $sanityCheck;
my $showHelp;
my $testURL;

# Fix up -r switches in @ARGV
@ARGV = map { /^(-r)(.+)$/ ? ($1, $2) : $_ } @ARGV;

my $result = GetOptions(
    "b|branch=s"             => \$branch,
    "d|download-directory=s" => \$nightlyDownloadDirectory,
    "h|help"                 => \$showHelp,
    "l|local!"               => \$localOnly,
    "p|progression!"         => \$isProgression,
    "r|revisions=s"          => \&parseRevisions,
    "safari-path=s"          => \$safariPath,
    "s|sanity-check!"        => \$sanityCheck,
);
$testURL = shift @ARGV;

$branch = "feature-branch" if $branch eq "feature";
if (!exists $validBranches{$branch}) {
    print STDERR "ERROR: Invalid branch '$branch'\n";
    $showHelp = 1;
}

if (!$result || $showHelp || scalar(@ARGV) > 0) {
    print STDERR "Search WebKit nightly builds for changes in behavior.\n";
    print STDERR "Usage: " . basename($0) . " [options] [url]\n";
    print STDERR <<END;
  [-b|--branch name]             name of the nightly build branch (default: trunk)
  [-d|--download-directory dir]  nightly build download directory (default: ~/Library/Caches/WebKit-Nightlies)
  [-h|--help]                    show this help message
  [-l|--local]                   only use local (already downloaded) nightlies
  [-p|--progression]             searching for a progression, not a regression
  [-r|--revision M[:N]]          specify starting (and optional ending) revisions to search
  [--safari-path path]           path to Safari application bundle (default: /Applications/Safari.app)
  [-s|--sanity-check]            verify both starting and ending revisions before bisecting
END
    exit 1;
}

my $nightlyWebSite = "http://nightly.webkit.org";
my $nightlyBuildsURLBase = $nightlyWebSite . File::Spec->catdir("/builds", $branch, "mac");
my $nightlyFilesURLBase = $nightlyWebSite . File::Spec->catdir("/files", $branch, "mac");

$nightlyDownloadDirectory = glob($nightlyDownloadDirectory) if $nightlyDownloadDirectory =~ /^~/;
$safariPath = glob($safariPath) if $safariPath =~ /^~/;
$safariPath = safariPathFromSafariBundle($safariPath) if $safariPath =~ m#\.app/*#;

$nightlyDownloadDirectory = File::Spec->catdir($nightlyDownloadDirectory, $branch);
if (! -d $nightlyDownloadDirectory) {
    mkpath($nightlyDownloadDirectory, 0, 0755) || die "Could not create $nightlyDownloadDirectory: $!";
}

@nightlies = makeNightlyList($localOnly, $nightlyDownloadDirectory, findMacOSXVersion(), findSafariVersion($safariPath));

my $startIndex = $revisions[0] ? findNearestNightlyIndex(@nightlies, $revisions[0], 'ceil') : 0;
my $endIndex = $revisions[1] ? findNearestNightlyIndex(@nightlies, $revisions[1], 'floor') : $#nightlies;

my $tempFile = createTempFile($testURL);

if ($sanityCheck) {
    my $didReproduceBug;

    do {
        printf "\nChecking starting revision r%s...\n",
            $nightlies[$startIndex]->{rev};
        downloadNightly($nightlies[$startIndex]->{file}, $nightlyFilesURLBase, $nightlyDownloadDirectory);
        mountAndRunNightly($nightlies[$startIndex]->{file}, $nightlyDownloadDirectory, $safariPath, $tempFile);
        $didReproduceBug = promptForTest($nightlies[$startIndex]->{rev});
        $startIndex-- if $didReproduceBug < 0;
    } while ($didReproduceBug < 0);
    die "ERROR: Bug reproduced in starting revision!  Do you need to test an earlier revision or for a progression?"
        if $didReproduceBug && !$isProgression;
    die "ERROR: Bug not reproduced in starting revision!  Do you need to test an earlier revision or for a regression?"
        if !$didReproduceBug && $isProgression;

    do {
        printf "\nChecking ending revision r%s...\n",
            $nightlies[$endIndex]->{rev};
        downloadNightly($nightlies[$endIndex]->{file}, $nightlyFilesURLBase, $nightlyDownloadDirectory);
        mountAndRunNightly($nightlies[$endIndex]->{file}, $nightlyDownloadDirectory, $safariPath, $tempFile);
        $didReproduceBug = promptForTest($nightlies[$endIndex]->{rev});
        $endIndex++ if $didReproduceBug < 0;
    } while ($didReproduceBug < 0);
    die "ERROR: Bug NOT reproduced in ending revision!  Do you need to test a later revision or for a progression?"
        if !$didReproduceBug && !$isProgression;
    die "ERROR: Bug reproduced in ending revision!  Do you need to test a later revision or for a regression?"
        if $didReproduceBug && $isProgression;
}

printStatus($nightlies[$startIndex]->{rev}, $nightlies[$endIndex]->{rev}, $isProgression);

my %brokenRevisions = ();
while (abs($endIndex - $startIndex) > 1) {
    my $index = $startIndex + int(($endIndex - $startIndex) / 2);

    my $didReproduceBug;
    do {
        if (exists $nightlies[$index]) {
            my $buildsLeft = max(max(0, $endIndex - $index - 1), max(0, $index - $startIndex - 1));
            my $plural = $buildsLeft == 1 ? "" : "s";
            printf "\nChecking revision r%s (%d build%s left to test after this)...\n", $nightlies[$index]->{rev}, $buildsLeft, $plural;
            downloadNightly($nightlies[$index]->{file}, $nightlyFilesURLBase, $nightlyDownloadDirectory);
            mountAndRunNightly($nightlies[$index]->{file}, $nightlyDownloadDirectory, $safariPath, $tempFile);
            $didReproduceBug = promptForTest($nightlies[$index]->{rev});
        }
        if ($didReproduceBug < 0) {
            $brokenRevisions{$nightlies[$index]->{rev}} = $nightlies[$index]->{file};
            delete $nightlies[$index];
            $endIndex--;
            if (scalar(keys %brokenRevisions) % 2 == 0) {
                # Even tries to bisect to the left
                $index = int(($startIndex + $index) / 2);
            } else {
                # Odd tries to bisect to the right
                $index = int(($index + $endIndex) / 2);
            }
        }
    } while ($didReproduceBug < 0);

    if ($didReproduceBug && !$isProgression || !$didReproduceBug && $isProgression) {
        $endIndex = $index;
    } else {
        $startIndex = $index;
    }

    print "\nBroken revisions skipped: r" . join(", r", keys %brokenRevisions) . "\n"
        if scalar keys %brokenRevisions > 0;
    printStatus($nightlies[$startIndex]->{rev}, $nightlies[$endIndex]->{rev}, $isProgression);
}

printTracLink($nightlies[$startIndex]->{rev}, $nightlies[$endIndex]->{rev});

unlink $tempFile if $tempFile;

exit 0;

sub createTempFile($)
{
    my ($url) = @_;

    return undef if !$url;

    my ($fh, $tempFile) = tempfile(
        basename($0) . "-XXXXXXXX",
        DIR => File::Spec->tmpdir(),
        SUFFIX => ".html",
        UNLINK => 0,
    );
    print $fh "<meta http-equiv=\"refresh\" content=\"0; $url\">\n";
    close($fh);

    return $tempFile;
}

sub downloadNightly($$$)
{
    my ($filename, $urlBase, $directory) = @_;
    my $path = File::Spec->catfile($directory, $filename);
    if (! -f $path) {
        print "Downloading $filename to $directory...\n";
        `curl -# -o '$path' '$urlBase/$filename'`;
    }
}

sub findMacOSXVersion()
{
    my $version;
    open(SW_VERS, "-|", "/usr/bin/sw_vers") || die;
    while (<SW_VERS>) {
        $version = $1 if /^ProductVersion:\s+([^\s]+)/;
    }
    close(SW_VERS);
    return $version;
}

sub findNearestNightlyIndex(\@$$)
{
    my ($nightlies, $revision, $round) = @_;

    my $lowIndex = 0;
    my $highIndex = $#{$nightlies};

    return $highIndex if uc($revision) eq 'HEAD' || $revision >= $nightlies->[$highIndex]->{rev};
    return $lowIndex if $revision <= $nightlies->[$lowIndex]->{rev};

    while (abs($highIndex - $lowIndex) > 1) {
        my $index = $lowIndex + int(($highIndex - $lowIndex) / 2);
        if ($revision < $nightlies->[$index]->{rev}) {
            $highIndex = $index;
        } elsif ($revision > $nightlies->[$index]->{rev}) {
            $lowIndex = $index;
        } else {
            return $index;
        }
    }

    return ($round eq "floor") ? $lowIndex : $highIndex;
}

sub findSafariVersion($)
{
    my ($path) = @_;
    my $versionPlist = File::Spec->catdir(dirname(dirname($path)), "version.plist");
    my $version;
    open(PLIST, "< $versionPlist") || die;
    while (<PLIST>) {
        if (m#^\s*<key>CFBundleShortVersionString</key>#) {
            $version = <PLIST>;
            $version =~ s#^\s*<string>([0-9.]+)[^<]*</string>\s*[\r\n]*#$1#;
        }
    }
    close(PLIST);
    return $version;
}

sub loadSettings()
{
    package Settings;

    our $branch = "trunk";
    our $nightlyDownloadDirectory = File::Spec->catdir($ENV{HOME}, "Library/Caches/WebKit-Nightlies");
    our $safariPath = "/Applications/Safari.app";

    my $rcfile = File::Spec->catdir($ENV{HOME}, ".bisect-buildsrc");
    return if !-f $rcfile;

    my $result = do $rcfile;
    die "Could not parse $rcfile: $@" if $@;
}

sub makeNightlyList($$$$)
{
    my ($useLocalFiles, $localDirectory, $macOSXVersion, $safariVersion) = @_;
    my @files;

    if ($useLocalFiles) {
        opendir(DIR, $localDirectory) || die "$!";
        foreach my $file (readdir(DIR)) {
            if ($file =~ /^WebKit-SVN-r([0-9]+)\.dmg$/) {
                push(@files, +{ rev => $1, file => $file });
            }
        }
        closedir(DIR);
    } else {
        open(NIGHTLIES, "curl -s $nightlyBuildsURLBase/all |") || die;

        while (my $line = <NIGHTLIES>) {
            chomp $line;
            my ($revision, $timestamp, $url) = split(/,/, $line);
            my $nightly = basename($url);
            push(@files, +{ rev => $revision, file => $nightly });
        }
        close(NIGHTLIES);
    }

    if (eval "v$macOSXVersion" ge v10.5) {
        if ($safariVersion eq "4 Public Beta") {
            @files = grep { $_->{rev} >= 39682 } @files;
        } elsif (eval "v$safariVersion" ge v3.2) {
            @files = grep { $_->{rev} >= 37348 } @files;
        } elsif (eval "v$safariVersion" ge v3.1) {
            @files = grep { $_->{rev} >= 29711 } @files;
        } elsif (eval "v$safariVersion" ge v3.0) {
            @files = grep { $_->{rev} >= 25124 } @files;
        } elsif (eval "v$safariVersion" ge v2.0) {
            @files = grep { $_->{rev} >= 19594 } @files;
        } else {
            die "Requires Safari 2.0 or newer";
        }
    } elsif (eval "v$macOSXVersion" ge v10.4) {
        if ($safariVersion eq "4 Public Beta") {
            @files = grep { $_->{rev} >= 39682 } @files;
        } elsif (eval "v$safariVersion" ge v3.2) {
            @files = grep { $_->{rev} >= 37348 } @files;
        } elsif (eval "v$safariVersion" ge v3.1) {
            @files = grep { $_->{rev} >= 29711 } @files;
        } elsif (eval "v$safariVersion" ge v3.0) {
            @files = grep { $_->{rev} >= 19992 } @files;
        } elsif (eval "v$safariVersion" ge v2.0) {
            @files = grep { $_->{rev} >= 11976 } @files;
        } else {
            die "Requires Safari 2.0 or newer";
        }
    } else {
        die "Requires Mac OS X 10.4 (Tiger) or 10.5 (Leopard)";
    }

    my $nightlycmp = sub { return $a->{rev} <=> $b->{rev}; };

    return sort $nightlycmp @files;
}

sub mountAndRunNightly($$$$)
{
    my ($filename, $directory, $safari, $tempFile) = @_;
    my $mountPath = "/Volumes/WebKit";
    my $webkitApp = File::Spec->catfile($mountPath, "WebKit.app");
    my $diskImage = File::Spec->catfile($directory, $filename);
    my $devNull = File::Spec->devnull();

    my $i = 0;
    while (-e $mountPath) {
        $i++;
        usleep 100 if $i > 1;
        `hdiutil detach '$mountPath' 2> $devNull`;
        die "Could not unmount $diskImage at $mountPath" if $i > 100;
    }
    die "Can't mount $diskImage: $mountPath already exists!" if -e $mountPath;

    print "Mounting disk image and running WebKit...\n";
    `hdiutil attach '$diskImage'`;
    $i = 0;
    while (! -e $webkitApp) {
        usleep 100;
        $i++;
        die "Could not mount $diskImage at $mountPath" if $i > 100;
    }

    my $frameworkPath;
    if (-d "/Volumes/WebKit/WebKit.app/Contents/Frameworks") {
        my $osXVersion = join('.', (split(/\./, findMacOSXVersion()))[0..1]);
        $frameworkPath = "/Volumes/WebKit/WebKit.app/Contents/Frameworks/$osXVersion";
    } else {
        $frameworkPath = "/Volumes/WebKit/WebKit.app/Contents/Resources";
    }

    $tempFile ||= "";
    `DYLD_FRAMEWORK_PATH=$frameworkPath WEBKIT_UNSET_DYLD_FRAMEWORK_PATH=YES $safari $tempFile`;

    `hdiutil detach '$mountPath' 2> $devNull`;
}

sub parseRevisions($$;$)
{
    my ($optionName, $value, $ignored) = @_;

    if ($value =~ /^r?([0-9]+|HEAD):?$/i) {
        push(@revisions, $1);
        die "Too many revision arguments specified" if scalar @revisions > 2;
    } elsif ($value =~ /^r?([0-9]+):?r?([0-9]+|HEAD)$/i) {
        $revisions[0] = $1;
        $revisions[1] = $2;
    } else {
        die "Unknown revision '$value':  expected 'M' or 'M:N'";
    }
}

sub printStatus($$$)
{
    my ($startRevision, $endRevision, $isProgression) = @_;
    printf "\n%s: r%s  %s: r%s\n",
        $isProgression ? "Fails" : "Works", $startRevision,
        $isProgression ? "Works" : "Fails", $endRevision;
}

sub printTracLink($$)
{
    my ($startRevision, $endRevision) = @_;
    printf("http://trac.webkit.org/log/trunk/?rev=%s&stop_rev=%s\n", $endRevision, $startRevision + 1);
}

sub promptForTest($)
{
    my ($revision) = @_;
    print "Did the bug reproduce in r$revision (yes/no/broken)? ";
    my $answer = <STDIN>;
    return 1 if $answer =~ /^(1|y.*)$/i;
    return -1 if $answer =~ /^(-1|b.*)$/i; # Broken
    return 0;
}