# Copyright 2011-2016, Paul Johnson (paul@pjcj.net)

# This software is free.  It is licensed under the same terms as Perl itself.

# The latest version of this software should be available from my homepage:
# http://www.pjcj.net

package Devel::Cover::DB::IO::JSON;

use strict;
use warnings;

use Fcntl ":flock";

our $VERSION = '1.24'; # VERSION

my $Format;

BEGIN {
    $Format = "JSON"     if              eval "use JSON; 1";
    $Format = "JSON::PP" if !$Format and eval "use JSON::PP; 1";
    die "Can't load either JSON or JSON::PP" unless $Format;
}

sub new {
    my $class = shift;
    my $self  = { options => "", @_ };
    bless $self, $class
}

sub read {
    my $self   = shift;
    my ($file) = @_;

    open my $fh, "<", $file or die "Can't open $file: $!\n";
    flock $fh, LOCK_SH      or die "Can't lock $file: $!\n";
    local $/;
    my $data;
    eval {
        $data = $Format eq "JSON"
            ? JSON::decode_json(<$fh>)
            : JSON::PP::decode_json(<$fh>);
    };
    die "Can't read $file with $Format: $@" if $@;
    close $fh or die "Can't close $file: $!\n";
    $data
}

sub write {
    my $self = shift;
    my ($data, $file) = @_;

    my $json = $Format eq "JSON" ? JSON->new : JSON::PP->new;
    $json->utf8->allow_blessed;
    $json->ascii->pretty->canonical if $self->{options} =~ /\bpretty\b/i;
    open my $fh, ">", $file or die "Can't open $file: $!\n";
    flock $fh, LOCK_EX      or die "Can't lock $file: $!\n";
    print $fh $json->encode($data);
    close $fh or die "Can't close $file: $!\n";
    $self
}

1

__END__

=head1 NAME

Devel::Cover::DB::IO::JSON - JSON based IO routines for Devel::Cover::DB

=head1 VERSION

version 1.24

=head1 SYNOPSIS

 use Devel::Cover::DB::IO::JSON;

 my $io = Devel::Cover::DB::IO::JSON->new;
 my $data = $io->read($file);
 $io->write($data, $file);

=head1 DESCRIPTION

This module provides JSON based IO routines for Devel::Cover::DB.

=head1 SEE ALSO

 Devel::Cover

=head1 METHODS

=head2 new

 my $io = Devel::Cover::DB::IO::JSON->new;

Contructs the IO object.

=head2 read

 my $data = $io->read($file);

Returns a perl data structure representing the data read from $file.

=head2 write

 $io->write($data, $file);

Writes $data to $file in the format specified when creating $io.

=head1 BUGS

Huh?

=head1 LICENCE

Copyright 2011-2016, Paul Johnson (paul@pjcj.net)

This software is free.  It is licensed under the same terms as Perl itself.

The latest version of this software should be available from my homepage:
http://www.pjcj.net

=cut