#!/usr/bin/perl -w

# Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc.  All rights reserved.
# Copyright (C) 2009 Torch Mobile 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.

# Script to put change log comments in as default check-in comment.

use strict;
use Getopt::Long;
use File::Basename;
use File::Spec;
use FindBin;
use lib $FindBin::Bin;
use VCSUtils;
use webkitdirs;

sub createCommitMessage(@);
sub fixEnvironment();
sub loadTermReadKey();
sub normalizeLineEndings($$);
sub patchAuthorshipString($$$);
sub removeLongestCommonPrefixEndingInDoubleNewline(\%);
sub isCommitLogEditor($);

my $endl = "\n";

sub printUsageAndExit
{
    my $programName = basename($0);
    print STDERR <<EOF;
Usage: $programName [--regenerate-log] <log file>
       $programName --print-log <ChangeLog file> [<ChangeLog file>...]
       $programName --help
EOF
    exit 1;
}

my $help = 0;
my $printLog = 0;
my $regenerateLog = 0;

my $getOptionsResult = GetOptions(
    'help' => \$help,
    'print-log' => \$printLog,
    'regenerate-log' => \$regenerateLog,
);

if (!$getOptionsResult || $help) {
    printUsageAndExit();
}

die "Can't specify both --print-log and --regenerate-log\n" if $printLog && $regenerateLog;

if ($printLog) {
    printUsageAndExit() unless @ARGV;
    print createCommitMessage(@ARGV);
    exit 0;
}

my $log = $ARGV[0];
if (!$log) {
    printUsageAndExit();
}

fixEnvironment();

my $baseDir = baseProductDir();

my $editor = $ENV{SVN_LOG_EDITOR};
$editor = $ENV{CVS_LOG_EDITOR} if !$editor;
$editor = "" if $editor && isCommitLogEditor($editor);

my $splitEditor = 1;
if (!$editor) {
    my $builtEditorApplication = "$baseDir/Release/Commit Log Editor.app/Contents/MacOS/Commit Log Editor";
    if (-x $builtEditorApplication) {
        $editor = $builtEditorApplication;
        $splitEditor = 0;
    }
}
if (!$editor) {
    my $builtEditorApplication = "$baseDir/Debug/Commit Log Editor.app/Contents/MacOS/Commit Log Editor";
    if (-x $builtEditorApplication) {
        $editor = $builtEditorApplication;
        $splitEditor = 0;
    }
}
if (!$editor) {
    my $builtEditorApplication = "$ENV{HOME}/Applications/Commit Log Editor.app/Contents/MacOS/Commit Log Editor";
    if (-x $builtEditorApplication) {
        $editor = $builtEditorApplication;
        $splitEditor = 0;
    }
}

$editor = $ENV{EDITOR} if !$editor;
$editor = "/usr/bin/vi" if !$editor;

my @editor;
if ($splitEditor) {
    @editor = split ' ', $editor;
} else {
    @editor = ($editor);
}

my $inChangesToBeCommitted = !isGit();
my @changeLogs = ();
my $logContents = "";
my $existingLog = 0;
open LOG, $log or die "Could not open the log file.";
while (<LOG>) {
    if (isGit()) {
        if (/^# Changes to be committed:$/) {
            $inChangesToBeCommitted = 1;
        } elsif ($inChangesToBeCommitted && /^# \S/) {
            $inChangesToBeCommitted = 0;
        }
    }

    if (!isGit() || /^#/) { #
        $logContents .= $_;
    } else {
        # $_ contains the current git log message
        # (without the log comment info). We don't need it.
    }
    $existingLog = isGit() && !(/^#/ || /^\s*$/) unless $existingLog;

    push @changeLogs, makeFilePathRelative($1) if $inChangesToBeCommitted && (/^(?:M|A)....(.*ChangeLog)\r?\n?$/ || /^#\t(?:modified|new file):   (.*ChangeLog)$/) && !/-ChangeLog$/;
}
close LOG;

# We want to match the line endings of the existing log file in case they're
# different from perl's line endings.
$endl = $1 if $logContents =~ /(\r?\n)/;

my $keepExistingLog = 1;
if ($regenerateLog && $existingLog && scalar(@changeLogs) > 0 && loadTermReadKey()) {
    print "Existing log message detected, Use 'r' to regenerate log message from ChangeLogs, or any other key to keep the existing message.\n";
    Term::ReadKey::ReadMode('cbreak');
    my $key = Term::ReadKey::ReadKey(0);
    Term::ReadKey::ReadMode('normal');
    $keepExistingLog = 0 if ($key eq "r");
}

# Don't change anything if there's already a log message (as can happen with git-commit --amend).
exec (@editor, @ARGV) if $existingLog && $keepExistingLog;

my $first = 1;
open NEWLOG, ">$log.edit" or die;
if (isGit() && @changeLogs == 0) {
    # populate git commit message with WebKit-format ChangeLog entries unless explicitly disabled
    my $branch = gitBranch();
    chomp(my $webkitGenerateCommitMessage = `git config --bool branch.$branch.webkitGenerateCommitMessage`);
    if ($webkitGenerateCommitMessage eq "") {
        chomp($webkitGenerateCommitMessage = `git config --bool core.webkitGenerateCommitMessage`);
    }
    if ($webkitGenerateCommitMessage ne "false") {
        open CHANGELOG_ENTRIES, "-|", "$FindBin::Bin/prepare-ChangeLog --git-index --no-write" or die "prepare-ChangeLog failed: $!.\n";
        while (<CHANGELOG_ENTRIES>) {
            print NEWLOG normalizeLineEndings($_, $endl);
        }
        close CHANGELOG_ENTRIES;
    }
} else {
    print NEWLOG createCommitMessage(@changeLogs);
}
print NEWLOG $logContents;
close NEWLOG;

system (@editor, "$log.edit");

open NEWLOG, "$log.edit" or exit;
my $foundComment = 0;
while (<NEWLOG>) {
    $foundComment = 1 if (/\S/ && !/^CVS:/);
}
close NEWLOG;

if ($foundComment) {
    open NEWLOG, "$log.edit" or die;
    open LOG, ">$log" or die;
    while (<NEWLOG>) {
        print LOG;
    }
    close LOG;
    close NEWLOG;
}

unlink "$log.edit";

sub createCommitMessage(@)
{
    my @changeLogs = @_;

    my $topLevel = determineVCSRoot();

    my %changeLogSort;
    my %changeLogContents;
    for my $changeLog (@changeLogs) {
        open CHANGELOG, $changeLog or die "Can't open $changeLog";
        my $contents = "";
        my $blankLines = "";
        my $lineCount = 0;
        my $date = "";
        my $author = "";
        my $email = "";
        my $hasAuthorInfoToWrite = 0;
        while (<CHANGELOG>) {
            if (/^\S/) {
                last if $contents;
            }
            if (/\S/) {
                $contents .= $blankLines if $contents;
                $blankLines = "";

                my $line = $_;

                # Remove indentation spaces
                $line =~ s/^ {8}//;

                # Grab the author and the date line
                if ($line =~ m/^([0-9]{4}-[0-9]{2}-[0-9]{2})\s+(.*[^\s])\s+<(.*)>/ && $lineCount == 0) {
                    $date = $1;
                    $author = $2;
                    $email = $3;
                    $hasAuthorInfoToWrite = 1;
                    next;
                }

                if ($hasAuthorInfoToWrite) {
                    my $isReviewedByLine = $line =~ m/^(?:Reviewed|Rubber[ \-]?stamped) by/;
                    my $isModifiedFileLine = $line =~ m/^\* .*:/;

                    # Insert the authorship line if needed just above the "Reviewed by" line or the
                    # first modified file (whichever comes first).
                    if ($isReviewedByLine || $isModifiedFileLine) {
                        $hasAuthorInfoToWrite = 0;
                        my $authorshipString = patchAuthorshipString($author, $email, $date);
                        if ($authorshipString) {
                            $contents .= "$authorshipString\n";
                            $contents .= "\n" if $isModifiedFileLine;
                        }
                    }
                }


                $lineCount++;
                $contents .= $line;
            } else {
                $blankLines .= $_;
            }
        }
        if ($hasAuthorInfoToWrite) {
            # We didn't find anywhere to put the authorship info, so just put it at the end.
            my $authorshipString = patchAuthorshipString($author, $email, $date);
            $contents .= "\n$authorshipString\n" if $authorshipString;
            $hasAuthorInfoToWrite = 0;
        }

        close CHANGELOG;

        $changeLog = File::Spec->abs2rel(File::Spec->rel2abs($changeLog), $topLevel);

        my $label = dirname($changeLog);
        $label = "top level" unless length $label;

        my $sortKey = lc $label;
        if ($label eq "top level") {
            $sortKey = "";
        } elsif ($label eq "LayoutTests") {
            $sortKey = lc "~, LayoutTests last";
        }

        $changeLogSort{$sortKey} = $label;
        $changeLogContents{$label} = $contents;
    }

    my $commonPrefix = removeLongestCommonPrefixEndingInDoubleNewline(%changeLogContents);

    my $first = 1;
    my @result;
    push @result, normalizeLineEndings($commonPrefix, $endl);
    for my $sortKey (sort keys %changeLogSort) {
        my $label = $changeLogSort{$sortKey};
        if (keys %changeLogSort > 1) {
            push @result, normalizeLineEndings("\n", $endl) if !$first;
            $first = 0;
            push @result, normalizeLineEndings("$label: ", $endl);
        }
        push @result, normalizeLineEndings($changeLogContents{$label}, $endl);
    }

    return join '', @result;
}

sub fixEnvironment()
{
    return unless isMsys() && isGit();

    # When this script gets run from inside git commit, msys-style paths in the
    # environment will have been turned into Windows-style paths with forward
    # slashes. This screws up functions like File::Spec->rel2abs, which seem to
    # rely on $PWD having an msys-style path. We convert the paths back to
    # msys-style here by transforming "c:/foo" to "/c/foo" (e.g.). See
    # <http://webkit.org/b/48527>.
    foreach my $key (keys %ENV) {
        $ENV{$key} =~ s#^([[:alpha:]]):/#/$1/#;
    }
}

sub loadTermReadKey()
{
    eval { require Term::ReadKey; };
    return !$@;
}

sub normalizeLineEndings($$)
{
    my ($string, $endl) = @_;
    $string =~ s/\r?\n/$endl/g;
    return $string;
}

sub patchAuthorshipString($$$)
{
    my ($authorName, $authorEmail, $authorDate) = @_;

    return if $authorEmail eq changeLogEmailAddress();
    return "Patch by $authorName <$authorEmail> on $authorDate";
}

sub removeLongestCommonPrefixEndingInDoubleNewline(\%)
{
    my ($hashOfStrings) = @_;

    my @strings = values %{$hashOfStrings};
    return "" unless @strings > 1;

    my $prefix = shift @strings;
    my $prefixLength = length $prefix;
    foreach my $string (@strings) {
        while ($prefixLength) {
            last if substr($string, 0, $prefixLength) eq $prefix;
            --$prefixLength;
            $prefix = substr($prefix, 0, -1);
        }
        last unless $prefixLength;
    }

    return "" unless $prefixLength;

    my $lastDoubleNewline = rindex($prefix, "\n\n");
    return "" unless $lastDoubleNewline > 0;

    foreach my $key (keys %{$hashOfStrings}) {
        $hashOfStrings->{$key} = substr($hashOfStrings->{$key}, $lastDoubleNewline);
    }
    return substr($prefix, 0, $lastDoubleNewline + 2);
}

sub isCommitLogEditor($)
{
    my $editor = shift;
    return $editor =~ m/commit-log-editor/;
}