#!/usr/bin/perl -w

use 5.010;
use strict;
use warnings;

use lib qw(
    lib
);

# NAME: Restore Redis::CappedCollection collection dump.

use bytes;
use Getopt::Long qw(
    GetOptions
);
use JSON::XS ();
use Try::Tiny;

use Redis::CappedCollection qw(
    $DEFAULT_SERVER
    $DEFAULT_PORT
);

my ( $collection, $dump_fh, $json ) = setup();

my @data_fields = qw(
    list_id
    data_id
    data
    data_time
);
my $number_data_fields = scalar @data_fields;

while ( my $encoded = <$dump_fh> ) {
    chomp $encoded;

    my $error;

    my $decoded = try {
        $json->decode( $encoded );
    } catch {
        $error = $_;
        warn "failed to decode JSON ($error): $encoded";
    };
    next if $error;

    my @data_info;
    foreach my $key ( @data_fields ) {
        my $value = delete $decoded->{ $key };
        push( @data_info, $value ) if defined $value;
    }

    my $no_complete_information = scalar( @data_info ) != $number_data_fields;
    if ( $no_complete_information || %$decoded ) {
        warn "Invalid record: $encoded";
        next if $no_complete_information;
    }

    $collection->insert( @data_info );
}

close $dump_fh;

exit 0;

sub setup {
    my ( $help, $host, $port, $collection_name, $dump_file );

    $host = $DEFAULT_SERVER;
    $port = $DEFAULT_PORT;

    my $ret = GetOptions(
        'host=s'        => \$host,
        'port=i'        => \$port,
        'collection=s'  => \$collection_name,
        'dump-file=s'   => \$dump_file,
        "help|?"        => \$help,
    );

    if ( !$ret || $help )
    {
        say <<"HELP";
Usage: $0 [--host="..."] [--port=...] --collection="..." [--dump-file="..."] [--help]

Connect to redis server, creates the specified Redis::CappedCollection collection from specified file or STDIN instead.
Use default settings and 'older_allowed => 1'.

Options:
    --help
        Display this help and exit.

    --host="..."
        The server should contain an IP address of Redis server.
        If the server is not provided, '${DEFAULT_SERVER}' is used as the default for the Redis server.
    --port=N
        The server port.
        Default ${DEFAULT_PORT} (the default for the Redis server).
    --collection="..."
        The collection name.
    --dump-file="..."
        Path to previously created dump file.
        If not specified, the STDIN used.
HELP
        exit 1;
    }

    die "Error: Redis::CappedCollection collection name required, use --collection to specify\n"
        unless $collection_name;

    my $redis_server = "$host:$port";

    my $collection = try {
        Redis::CappedCollection->create(
            redis           => $redis_server,
            name            => $collection_name,
            older_allowed   => 1,
        );
    } catch {
        my $error = $_;
        die "Error: Redis::CappedCollection collection '$collection_name' not created on '$redis_server'.\n$error\n";
    };

    my $dump_fh;
    if ( $dump_file ) {
        open( $dump_fh, '<', $dump_file ) or die "cannot open < $dump_file: $!";
    } else {
        $dump_fh = *STDIN;
    }

    my $json = JSON::XS->new;

    return( $collection, $dump_fh, $json );
}