#!/usr/bin/perl
##
## This script will help update manifest.yaml and Changelog.md before a release
## Any merge to master that changes the version line in manifest.yaml 
## is considered as a new release.
##
## When ready to make a release, please run ./scripts/prepare-release
## and commit push the final result!
use File::Basename;
use Cwd 'abs_path';

# find its way to the root of git's repository
my $scriptsdirname = dirname(abs_path(__FILE__));
chdir "$scriptsdirname/..";
print "✓ Entering directory:".`pwd`;

# ensures that the current branch is ahead of origin/main
my $diff= `git diff`;
chop $diff;
if ($diff =~ /./) {
	die("ERROR: Please commit all the changes before calling the prepare-release script.");
} else {
	print("✓ All changes are comitted.\n");
}
system("git fetch origin");
my $vcount = `git rev-list --left-right --count origin/main...HEAD`;
$vcount =~ /^([0-9]+)[ \t]*([0-9]+)$/;
if ($2>0) {
	die("ERROR: the current HEAD is not ahead of origin/main\n. Please use git merge origin/main.");
} else {
	print("✓ Current HEAD is up to date with origin/main.\n");
}

mkdir ".changes";
my $currentbranch = `git rev-parse --abbrev-ref HEAD`;
chop $currentbranch;
$currentbranch =~ s/[^a-zA-Z._-]+/-/g;
my $changefile=".changes/$currentbranch.md";
my $origmanifestfile=".changes/$currentbranch--manifest.yaml";
my $origchangelogfile=".changes/$currentbranch--Changelog.md";

my $exit_code=system("wget -O $origmanifestfile https://raw.githubusercontent.com/tfhe/spqlios-fft/main/manifest.yaml");
if ($exit_code!=0 or ! -f $origmanifestfile) {
	die("ERROR: failed to download manifest.yaml");
}
$exit_code=system("wget -O $origchangelogfile https://raw.githubusercontent.com/tfhe/spqlios-fft/main/Changelog.md");
if ($exit_code!=0 or ! -f $origchangelogfile) {
	die("ERROR: failed to download Changelog.md");
}

# read the current version (from origin/main manifest)
my $vmajor = 0;
my $vminor = 0;
my $vpatch = 0;
my $versionline = `grep '^version: ' $origmanifestfile | cut -d" " -f2`;
chop $versionline;
if (not $versionline =~ /^([0-9]+)\.([0-9]+)\.([0-9]+)$/) {
	die("ERROR: invalid version in manifest file: $versionline\n");
} else {
	$vmajor = int($1);
	$vminor = int($2);
	$vpatch = int($3);
}
print "Version in manifest file: $vmajor.$vminor.$vpatch\n";

if (not -f $changefile) {
	## create a changes file
	open F,">$changefile";
	print F "# Changefile for branch $currentbranch\n\n";
	print F "## Type of release (major,minor,patch)?\n\n";
	print F "releasetype: patch\n\n";
	print F "## What has changed (please edit)?\n\n";
	print F "- This has changed.\n";
	close F;
}

system("editor $changefile");

# compute the new version
my $nvmajor;
my $nvminor;
my $nvpatch;
my $changelog;
my $recordchangelog=0;
open F,"$changefile";
while ($line=<F>) {
	chop $line;
	if ($recordchangelog) {
		($line =~ /^$/) and next;
		$changelog .= "$line\n";
		next;
	}
	if ($line =~ /^releasetype *: *patch *$/) {
		$nvmajor=$vmajor;
		$nvminor=$vminor;
		$nvpatch=$vpatch+1;
	}
	if ($line =~ /^releasetype *: *minor *$/) {
		$nvmajor=$vmajor;
		$nvminor=$vminor+1;
		$nvpatch=0;
	}
	if ($line =~ /^releasetype *: *major *$/) {
		$nvmajor=$vmajor+1;
		$nvminor=0;
		$nvpatch=0;
	}
	if ($line =~ /^## What has changed/) {
		$recordchangelog=1;
	}
}
close F;
print "New version: $nvmajor.$nvminor.$nvpatch\n";
print "Changes:\n$changelog";

# updating manifest.yaml
open F,"manifest.yaml";
open G,">.changes/manifest.yaml";
while ($line=<F>) {
	if ($line =~ /^version *: */) {
		print G "version: $nvmajor.$nvminor.$nvpatch\n";
		next;
	}
	print G $line;
}
close F;
close G;
# updating Changelog.md
open F,"$origchangelogfile";
open G,">.changes/Changelog.md";
print G <<EOF
# Changelog

All notable changes to this project will be documented in this file.
this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

EOF
;
print G "## [$nvmajor.$nvminor.$nvpatch] - ".`date '+%Y-%m-%d'`."\n";
print G "$changelog\n";
my $skip_section=1;
while ($line=<F>) {
	if ($line =~ /^## +\[([0-9]+)\.([0-9]+)\.([0-9]+)\] +/) {
		if ($1>$nvmajor) {
			die("ERROR: found larger version $1.$2.$3 in the Changelog.md\n");
		} elsif ($1<$nvmajor) {
			$skip_section=0;
		} elsif ($2>$nvminor) {
			die("ERROR: found larger version $1.$2.$3 in the Changelog.md\n");
		} elsif ($2<$nvminor) {
			$skip_section=0;
		} elsif ($3>$nvpatch) {
			die("ERROR: found larger version $1.$2.$3 in the Changelog.md\n");
		} elsif ($2<$nvpatch) {
			$skip_section=0;
		} else {
			$skip_section=1;
		}
	}
	($skip_section) and next;
	print G $line;
}
close F;
close G;

print "-------------------------------------\n";
print "THIS WILL BE UPDATED:\n";
print "-------------------------------------\n";
system("diff -u manifest.yaml .changes/manifest.yaml");
system("diff -u Changelog.md .changes/Changelog.md");
print "-------------------------------------\n";
print "To proceed: press <enter> otherwise <CTRL+C>\n";
my $bla;
$bla=<STDIN>;
system("cp -vf .changes/manifest.yaml manifest.yaml");
system("cp -vf .changes/Changelog.md Changelog.md");
system("git commit -a -m \"Update version and changelog.\"");
system("git push");
print("✓ Changes have been committed and pushed!\n");
print("✓ A new release will be created when this branch is merged to main.\n");