#!/usr/bin/perl

# Update gitea based on version provided
# Author: Tracey Clark
# Created: 2019-03-04
# You must have a mail transport agent installed to run this script

# Note: Daily backups are also being run from cron
# /home/gitea/gitea_backup.sh

# Re-write to use this dir according to gitea docs
# https://docs.gitea.io/en-us/install-from-binary/

use strict;
use warnings;
use LWP::UserAgent;
use IO::Compress::Bzip2 qw(bzip2 $Bzip2Error) ;
use Data::Dumper;
use JSON;
use Sort::Versions;
use Getopt::Long qw(GetOptions);
use Term::ANSIColor qw(:constants);

my ($verbose, $info);

GetOptions(
    'info!'     => \$info,
    'verbose!'  => \$verbose,
);

##########################################
### The user must set these variables ###
# SET email address
my $email='tclark77@tlcnet.info';
my $filetype='-linux-amd64';

# https://api.github.com/repos/go-gitea/gitea/releases/latest
# This URL will only have one version listed
my $gitea_bin_dir = '/home/gitea/bin/';
my $gitea_bin = $gitea_bin_dir . '/gitea';
my $gitea_current_version_string = `$gitea_bin --version`;
my $alphanum_ver = 0;

chomp $gitea_current_version_string;
print("System is running \"$gitea_current_version_string\"\n");

unless ( defined $gitea_current_version_string ) {
     die "[DIE]: Unable to get the version of the gitea binary on the system: $!";
}

my %binary_file = get_current_version($gitea_current_version_string);
my $gitea_current_version = $binary_file{'version'};
my $baseURL = q{https://github.com/go-gitea/gitea/};
my $latestURL = q{https://api.github.com/repos/go-gitea/gitea/releases/latest};

# https://hubpages.com/technology/Use-Perl-to-access-REST-API
# Spin up the browser object
my $ua = LWP::UserAgent->new(
    cookie_jar => {}, # keep cookies in RAM but not persistent between sessions
    );

my $resp = $ua->get($latestURL);
my $latest_release_hash = decode_json($resp->content)
    or die "[DIE]: Unable to parse the version data! Output is:\n $resp";

my $orig_tag = $latest_release_hash->{tag_name};
my $tag = $orig_tag;
substr($tag, 0, 1, '');
print("Latest upstream version is $tag\n");
my $release_id = $latest_release_hash->{id}; # Works
printf("Release id: $release_id\n");

my $unz_filename = 'gitea-' . $tag . $filetype;
printf("Uncompressed filename: $unz_filename\n");
  #ex: gitea-1.7.6-linux-amd64

my $download_filename = $unz_filename . '.xz';
printf("Download file target: $download_filename\n");
  #ex: gitea-1.7.6-linux-amd64.xz

if ( versioncmp($gitea_current_version, $tag) == -1 ) {
    printf("Version tag is greater than the system version, proceeding with update\n");
    backup_bin( \%binary_file );

    my $download_url = get_download_url( $download_filename, $release_id );
    print("Downloading the compressed binary\n");
    print("Download URL we got from the sub is $download_url\n");
    `wget -P $gitea_bin_dir $download_url`;
    my $xz_file = $gitea_bin_dir . $download_filename;

    if (defined $info) {
        print YELLOW "[INFO] xz file is $xz_file\n", RESET;
    }

    install_bin($download_filename);

=devel
    # TODO
    # If can start then
        # Rename new binary to gitea
        # Remove .xz file
        # Notify success notify(1)
    # If no start notify and end & notify fail notify(0)
=cut
}

my $status = check_gitea_status();
if( $status =~ /active/) {
    print(GREEN "[INFO] Gitea service is active\n", RESET);
}
unless( $status =~ /active/) {
    die RED "[DIE] Status of gitea service is no good! OMGURD\n", RESET;
}
$gitea_current_version_string = `$gitea_bin --version`;
chomp $gitea_current_version_string;
%binary_file = get_current_version($gitea_current_version_string);
$gitea_current_version = $binary_file{'version'};

if ( versioncmp($gitea_current_version, $tag) == -1 ) {
    printf("Upstream version tag is STILL greater than the current system version, something went wrong\n");
}
else {
    print("Write something here to call cleanup and remove the old xz file and uncompressed file\n");
}
#TODO Add check if running binary is the same version as what we downloaded

# # If install_bin good then cleanup()

# #notification( $email );



# ##### Subroutines #####

# sub check_deps {
#     # Check to make sure dependencies installed on system - unit test??
#     # bzip2 perl mods
# }

sub get_current_version {
    my $current_version_string=shift;
    my $current_version;
    if ( $current_version_string =~ m/ion\ (\d+\.\d+\.\d*)\s+b/ ) {
        $current_version = $1;
        printf("Version number of the installed gitea binary: $1\n");
    }
    elsif ( $current_version_string =~ m/ion\ (\d+\d+\w*)\s/ ) {
        $current_version = $1;
        printf("Current version number the installed gitea binary: $1\n");
        $alphanum_ver = 1;
    }
    my %binary_file = (
        input  => $gitea_bin,
        version => $current_version,
    );
    unless ( defined $current_version ) {
        die RED "[DIE]: Unable to get the current gitea version! Value is $current_version", RESET
    }
    return %binary_file;
}

sub backup_bin {
    # Ghetto to get it working for now

    my ( %opts ) = %{shift()};
    my $input = $opts{input};
    my $version = $opts{version};
    print GREEN "Backing up the current binary\n", RESET;
    if (defined $info) {
        print YELLOW "[INFO] Input in backup_bin sub is:\n  Directory $input\n  Version $version\n", RESET;
    }
    my $gitea_bin_backup = '/home/gitea/bin/gitea.' . $gitea_current_version . '.bz2';
    print GREEN "Gitea bin backup will be $gitea_bin_backup\n", RESET;
    system("cp $input $input.bak");

    # TODO
    # # Do this with a system call to make a compressed copy of the current binary
    # # bzip2 -k file.txt
    # # my $status = system("vi", "fred.txt");
    # # if (($status >>=8) != 0) {
    # #     die "[DIE] Failed to run vi";
    # # }
    # my $bzip_status = system("bzip2 -k", "$input");
    # if (($status >>=8) != 0) {
    #     die "[DIE] Failed to run bzip2";
    # }

  return;
}

sub get_download_url {
  my ($dl_filename, $rel_id) = @_;
  my $dl_url;
    # Get the download_url from the array
    my $assetsURL = 'https://api.github.com/repos/go-gitea/gitea/releases/' . $release_id . '/assets';
    if (defined $info) {
        print YELLOW "[INFO] Assets URL\n";
        print "$assetsURL\n", RESET;
    }

    my $asset_resp = $ua->get($assetsURL);
    my $asset_resp_array_ref = decode_json($asset_resp->content);

    if (defined $verbose) {
        printf(RED "[DEBUG] Array of hashes of the json response for the assets:\n");
        printf Dumper $asset_resp_array_ref, RESET;
    }

    foreach my $asset_ref (@{$asset_resp_array_ref}) {
        if (defined $verbose) {
            print(RED "[DEBUG] The asset ref in get_download_url is $asset_ref\n");
            print("The asset ref name in get_download_url is $asset_ref->{name}\n", RESET);
        }
        if ( $asset_ref->{name} eq $dl_filename ) {
            print ("Yay we have a match for our desired file :D and it is \n");
            print $asset_ref->{name} . "\n";
            $dl_url = $asset_ref->{browser_download_url};
            if (defined $info) {
                print YELLOW "[INFO] The download url from the response array is $dl_url\n", RESET;
            }
            return $dl_url;
        }
    }
     unless ( defined $dl_url ) {
        print( RED "ONOES we have no download URL from the github API! Trying to build one manually\n", RESET);
        # die RED "[DIE] Can't continue without a download URL", RESET;
        print BLUE "Tag we are passing *into* the build_download_url from get_download_url is $orig_tag\n", RESET;
        my $dl_url = build_download_url($orig_tag, $download_filename);
        return $dl_url;
    }
  return 0;
}

sub build_download_url {
    my ($url_tag, $url_file) = @_;
    print BLUE "Tag passed into build_download_url is $url_tag\n", RESET;
    # If getting the download URL fails through the API, use this to build it manually
    # URL is in the form of
    # https://github.com/go-gitea/gitea/releases/download/v1.15.2/gitea-1.15.2-linux-amd64.xz
    my $built_url = 'https://github.com/go-gitea/gitea/releases/download/' . $url_tag . '/' . $url_file;
    if (defined $info) {
        print YELLOW "The URL built for the download is $built_url\n", RESET;
    }
    return $built_url;

}

sub install_bin {
    my $filename=shift;
    #my $unz_binary =

    print("Unpacking the downloaded file, setting owner and permissions\n");
    # Copy the downloaded binary to gitea and chmod it 750
    # Doing this with a filthy system call because the perl library
    # for xz manipulation is a memory hog and buggy besides
    system("xz -d --keep /home/gitea/bin/$filename");
    system("systemctl stop gitea");
    system("cp $gitea_bin_dir/$unz_filename $gitea_bin");
    system("chown gitea.gitea $gitea_bin");
    system("chmod 750 $gitea_bin");

    # Restart service
    print("Restarting the gitea service\n");
    system("systemctl restart gitea");
    return;
}

sub check_gitea_status {
    my $gitea_status=`systemctl is-active gitea`;
    return $gitea_status;
}

sub cleanup {
# remove downloaded binary and old backup set install_status=success ELSE remove "gitea" and restore from backup and set install_status=fail
    return;
}

sub notification {
    my $to = shift;

    return;
}