#!/usr/bin/env perl
#
# Copyright (c) 2018-2024 OARC, 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 the copyright holder 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 THE COPYRIGHT HOLDERS AND 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 THE
# COPYRIGHT HOLDER OR 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.

use strict;
use warnings;
use YAML;

unless (scalar @ARGV > 1) {
    print "usage: dnscap-rssm-rssac002 [--no-recompile|--keep-dnscap-rssm|--sort|--skip-unsupported] <YAML files to merge...>\n";
    exit(1);
}

my %service = ();
my $earliest_start_period;
my $recompile = 1;
my $keep_dnscap_rssm = 0;
my $sort = 0;
my $skip_unsupported = 0;

foreach my $file (@ARGV) {
    if ($file eq '--no-recompile') {
        $recompile = 0;
        next;
    } elsif ($file eq '--keep-dnscap-rssm') {
        $keep_dnscap_rssm = 1;
        next;
    } elsif ($file eq '--sort') {
        $sort = 1;
        next;
    } elsif ($file eq '--skip-unsupported') {
        $skip_unsupported = 1;
        next;
    }
    foreach my $doc (YAML::LoadFile($file)) {
        my $version = delete $doc->{version};
        my $service = delete $doc->{service};
        my $start_period = delete $doc->{'start-period'};
        my $metric = delete $doc->{metric};
        unless ($version) {
            die "$file: not valid RSSAC002 YAML, missing version";
        }
        unless ($service) {
            die "$file: not valid RSSAC002 YAML, missing service";
        }
        unless ($start_period) {
            die "$file: not valid RSSAC002 YAML, missing start-period";
        }
        unless ($metric) {
            die "$file: not valid RSSAC002 YAML, missing metric";
        }
        unless ($version eq 'rssac002v3') {
            if ($skip_unsupported) {
                next;
            }
            die "$file: unsupported RSSAC002 version $version";
        }

        push(@{$service{$service}->{$metric}}, $doc);

        if (!$earliest_start_period or $start_period lt $earliest_start_period) {
            $earliest_start_period = $start_period;
        }
    }
}

foreach my $service (keys %service) {
    foreach my $metric (keys %{$service{$service}}) {
        my %doc = ();
        foreach (@{$service{$service}->{$metric}}) {
            eval {
                merge(\%doc, $_);
            };
            if ($@) {
                die "service $service metric $metric: $@";
            }
        }
        $service{$service}->{$metric} = \%doc;
    }
}

if ($recompile) {
    foreach my $service (keys %service) {
        my ($ipv4, $ipv6, $aggregated) = (0, 0, 0);
        my $metric;

        if ($keep_dnscap_rssm) {
            $metric = $service{$service}->{'dnscap-rssm-sources'};
        } else {
            $metric = delete $service{$service}->{'dnscap-rssm-sources'};
        }
        if ($metric) {
            if (ref($metric->{sources}) eq 'HASH') {
                foreach my $ip (keys %{$metric->{sources}}) {
                    if ($ip =~ /:/o) {
                        $ipv6++;
                    } else {
                        $ipv4++;
                    }
                }
            }
        }

        if ($keep_dnscap_rssm) {
            $metric = $service{$service}->{'dnscap-rssm-aggregated-sources'};
        } else {
            $metric = delete $service{$service}->{'dnscap-rssm-aggregated-sources'};
        }
        if ($metric) {
            if (ref($metric->{'aggregated-sources'}) eq 'HASH') {
                my @keys = keys %{$metric->{'aggregated-sources'}};
                $aggregated += scalar @keys;
            }
        }

        $service{$service}->{'unique-sources'} = {
            'num-sources-ipv4' => $ipv4,
            'num-sources-ipv6' => $ipv6,
            'num-sources-ipv6-aggregate' => $aggregated,
        };
    }
}

if ($sort) {
    my $first = 1;
    $YAML::SortKeys = 1;
    foreach my $service (sort keys %service) {
        foreach my $metric (sort keys %{$service{$service}}) {
            if ($first) {
                $first = 0;
            } else {
                print "\n";
            }
            print YAML::Dump({
                version => "rssac002v3",
                service => $service,
                'start-period' => $earliest_start_period,
                metric => $metric,
                %{ $service{$service}->{$metric} },
            });
        }
    }
} else {
    my $first = 1;
    $YAML::SortKeys = 0;
    foreach my $service (keys %service) {
        foreach my $metric (keys %{$service{$service}}) {
            if ($first) {
                $first = 0;
            } else {
                print "\n";
            }
            print YAML::Dump({
                version => "rssac002v3",
                service => $service,
                'start-period' => $earliest_start_period,
                metric => $metric,
                %{ $service{$service}->{$metric} },
            });
        }
    }
}

sub merge {
    my ( $doc, $measurements ) = @_;

    foreach my $key (keys %$measurements) {
        if (ref($doc->{$key}) eq 'HASH') {
            unless (ref($measurements->{$key}) eq 'HASH') {
                die "invalid measurement types for key $key: not a hash";
            }
            eval {
                merge($doc->{$key}, $measurements->{$key});
            };
            die $@ if ($@);
            next;
        }
        if (defined($doc->{$key})) {
            if (defined($measurements->{$key}) and $measurements->{$key} ne '') {
                $doc->{$key} += $measurements->{$key};
            }
        } else {
            $doc->{$key} = $measurements->{$key};
        }
    }
}