#!/usr/bin/perl
# update channel metadata, etc
use local::lib;
use v5.10;
use strict;
use warnings;

use FindBin qw( $RealBin );
use lib "$RealBin/lib";

BEGIN {
    $ENV{TZ}   = 'UTC';
    $ENV{CRON} = !$ENV{DEBUG};
}

use Cpanel::JSON::XS qw( encode_json );
use DateTime ();
use List::Util qw( any );
use LogBot::Config qw( find_config load_all_configs load_config reload_config save_config );
use LogBot::Database qw( dbh replace_sql_placeholders );
use LogBot::Util qw( file_for logbot_init nick_is_bot round spurt );
use LogBot::Web::Colour qw( nick_hash );
use Mojo::Log ();
use Readonly;

# channels with activity are archived after 6 months.
Readonly::Scalar my $ARCHIVE_TIME => 60 * 60 * 24 * (365 / 2);

# newly logged channels have 5 days for activity before they are deleted.
# a channel is considered empty if there's fewer than EMPTY_THRESHOLD messages.
Readonly::Scalar my $EMPTY_THRESHOLD => 5;
Readonly::Scalar my $DELETE_TIME     => 60 * 60 * 24 * 5;

my @configs;
if (@ARGV && $ARGV[0] eq '--all') {
    shift;
    @configs = values %{ load_all_configs() };
} else {
    push @configs, load_config(find_config(shift));
}
@configs || die "syntax: syntax: logbot-nightly <config file|--all>\n";

my $log = Mojo::Log->new(path => "$RealBin/log/nightly.log");

foreach my $config (sort { $a->{name} cmp $b->{name} } @configs) {
    logbot_init($config, name => 'logbot-nightly', quiet => 1);

    # generate meta data
    generate_meta($config) unless $ENV{NO_META};

    # stop logging and leave stale channels
    say $config->{name}, ': archiving stale channels' if $ENV{DEBUG};
    archive_stale_channels($config);

    # remove orphaned data
    say $config->{name}, ': removing orphaned entries' if $ENV{DEBUG};
    remove_orphaned_entries($config);
}

sub generate_meta {
    my ($config) = @_;

    # generate network meta (all channels)
    generate_channel_meta($config, undef);
    generate_hours_meta($config, undef);

    foreach my $channel ('_empty', sort keys %{ $config->{channels} }) {
        next if $config->{channels}->{$channel}->{no_logs};

        say $config->{name}, ': ', $channel if $ENV{DEBUG};

        # generate data for about #channel
        generate_channel_meta($config, $channel);
        generate_hours_meta($config, $channel);
        generate_nicks_meta($config, $channel);
    }
    delete $config->{channels}->{_empty};
}

sub generate_channel_meta {
    my ($config, $channel) = @_;
    my $dbh         = dbh($config);
    my $now         = DateTime->now();
    my $output_file = file_for($config, 'meta', $channel, 'meta');

    my $six_months = $now->clone()->subtract(months => 6);
    my $one_month  = $now->clone()->subtract(months => 1);

    my $meta = {};

    if ($channel) {
        #<<<
        $meta->{first_time} = $dbh->selectrow_array(
            'SELECT time FROM logs WHERE channel = ? ORDER BY time ASC LIMIT 1',
            undef, $channel
        );
        $meta->{active_events} = $dbh->selectrow_array(
            'SELECT COUNT(*) FROM logs WHERE channel = ? AND time >= ' . $six_months->epoch,
            undef, $channel
        );
        $meta->{active_nicks} = $dbh->selectrow_array(
            'SELECT COUNT(*) FROM ('
                . 'SELECT DISTINCT nick FROM logs WHERE channel = ? AND time >= ' . $six_months->epoch . ')',
            undef, $channel
        );
        $meta->{event_count} = $dbh->selectrow_array(
            'SELECT COUNT(*) FROM logs WHERE channel = ?',
            undef, $channel
        );
        #>>>
    } else {
        #<<<
        $meta->{first_time} = $dbh->selectrow_array(
            'SELECT time FROM logs ORDER BY time ASC LIMIT 1'
        );
        $meta->{active_events} = $dbh->selectrow_array(
            'SELECT COUNT(*) FROM logs WHERE time >= ' . $six_months->epoch
        );
        $meta->{active_nicks} = $dbh->selectrow_array(
            'SELECT COUNT(*) FROM ('
                . 'SELECT DISTINCT nick FROM logs WHERE time >= ' . $six_months->epoch . ')'
        );
        $meta->{event_count} = $dbh->selectrow_array(
            'SELECT COUNT(*) FROM logs'
        );
        #>>>
    }

    $meta->{active_events_days} = $six_months->delta_days($now)->in_units('days');

    # because we calculate the event count nightly for the network-wide stats,
    # round to nearest 1000 to make it clear it's an approximation
    if (!$channel) {
        $meta->{event_count} = round($meta->{event_count} / 1000) * 1000;
    }

    say '  ', encode_json($meta) if $ENV{DEBUG};
    spurt($output_file, encode_json($meta));
}

sub generate_hours_meta {
    my ($config, $channel) = @_;
    my $dbh = dbh($config);
    my $output_file = file_for($config, 'meta', $channel, 'hours');

    my $sql = 'SELECT CAST(time % (24 * 3600) AS INT), COUNT(*) FROM logs';
    $sql .= ' WHERE channel = ?' if $channel;
    $sql .= ' GROUP BY CAST(time % (24 * 3600) AS INT)';
    my @values;
    push @values, $channel if $channel;
    say '  ', replace_sql_placeholders($dbh, $sql, \@values) if $ENV{DEBUG};

    my %values;
    foreach my $row (@{ $dbh->selectall_arrayref($sql, undef, @values) }) {
        my ($ss, $value) = @{$row};
        my $hh = sprintf('%.1f', $ss / (60 * 60));
        $hh = '0.0' if $hh == 24;
        $values{$hh} += $value;
    }

    my @data;
    for (my $hh = 0; $hh < 24; $hh += 0.1) {
        $hh = sprintf('%.1f', $hh);
        push @data, [$hh * 1.0, ($values{$hh} || 0) * 1];
    }

    my $json = {
        data  => \@data,
        lines => {
            show => \1,
            fill => \1,
        },
    };
    spurt($output_file, encode_json($json));
}

sub generate_nicks_meta {
    my ($config, $channel) = @_;
    my $dbh = dbh($config);
    my $output_file = file_for($config, 'meta', $channel, 'nicks');

    my $sql = 'SELECT nick, COUNT(*) AS count FROM logs';
    $sql .= ' WHERE channel = ?' if $channel;
    $sql .= ' GROUP BY nick';
    $sql .= ' ORDER BY COUNT(*) DESC, nick ASC';
    $sql .= ' LIMIT 20';
    my @values;
    push @values, $channel if $channel;
    say '  ', replace_sql_placeholders($dbh, $sql, \@values) if $ENV{DEBUG};

    my $data = $dbh->selectall_arrayref($sql, { Slice => {} }, @values);

    my $json = [];
    foreach my $event (@{$data}) {
        $event->{hash} = nick_hash($event->{nick});
        $event->{bot} = nick_is_bot($config, $event->{nick});
        push @{$json}, $event;
    }

    spurt($output_file, encode_json($json));
}

sub archive_stale_channels {
    my ($config) = @_;

    my $now    = time();
    my $reload = 0;
    foreach my $channel (sort keys %{ $config->{channels} }) {
        next if $config->{channels}->{$channel}->{disabled};
        next if $config->{channels}->{$channel}->{archived};

        my $dbh = dbh($config);

        # some messages are always ignored when determining channel activity
        my @ignore;

        # notices from the irc network itself
        # just stripping ^irc. isn't ideal but works for most networks.
        (my $network = $config->{irc}->{host}) =~ s/^irc\.//;
        $network =~ s/:\d+$//;
        push @ignore, "type = 2 AND nick LIKE '%.$network'";

        # ignore our own messages
        push @ignore, 'nick = ' . $dbh->quote($config->{irc}->{nick});

        my $where = 'channel = ' . $dbh->quote($channel) . ' AND NOT ((' . join(') OR (', @ignore) . '))';

        # empty channels
        my $count = $dbh->selectrow_array('SELECT COUNT(*) FROM logs WHERE ' . $where);
        if ($count < $EMPTY_THRESHOLD) {
            my $first_time =
                $dbh->selectrow_array('SELECT time FROM logs WHERE channel = ? ORDER BY time LIMIT 1', undef, $channel);
            next if $first_time && $now - $first_time <= $DELETE_TIME;
            my $msg = $config->{name} . ": channel $channel is empty ($count) and stale, deleting";
            $log->info($msg);
            say $msg if $ENV{DEBUG};

            $config = reload_config($config);
            delete $config->{channels}->{$channel};
            save_config($config);
            next;
        }

        # stale channels
        my $last_time = $dbh->selectrow_array('SELECT time FROM logs WHERE ' . $where . ' ORDER BY time DESC LIMIT 1');
        next unless $last_time;
        if ($now - $last_time > $ARCHIVE_TIME) {
            my $msg = $config->{name} . ": $channel is stale, archiving";
            $log->info($msg);
            say $msg if $ENV{DEBUG};

            $config = reload_config($config);
            $config->{channels}->{$channel}->{archived} = 1;
            save_config($config);
            next;
        }
    }

    if ($reload) {
        system("$RealBin/logbot-irc", $config->{_derived}->{file}, '--reload');
    }
}

sub remove_orphaned_entries {
    my ($config) = @_;
    my $dbh = dbh($config, read_write => 1);

    my @channels = sort keys %{ $config->{channels} };

    my $db_channels = $dbh->selectcol_arrayref('SELECT DISTINCT channel FROM logs ORDER BY channel');
    my @orphans;
    foreach my $channel (@{$db_channels}) {
        next if any { $_ eq $channel } @channels;
        push @orphans, $channel;
    }
    if (@orphans) {
        say 'deleting orphaned channels: ', join(', ', @orphans) if $ENV{DEBUG};
        $dbh->do('DELETE FROM logs WHERE channel in (' . join(',', ('?') x scalar(@orphans)) . ')', undef, @orphans);
    }

    $dbh->do('DELETE FROM topics WHERE NOT (channel in (' . join(',', ('?') x scalar(@channels)) . '))',
        undef, @channels);
}