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package App::JsonLogUtils;
# ABSTRACT: Command line utilities for dealing with JSON-formatted log files
$App::JsonLogUtils::VERSION = '0.03';


use strict;
use warnings;

use Fcntl             qw(:seek);
use Iterator::Simple  qw(iterator iter igrep imap ichain);
use JSON::XS          qw(decode_json encode_json);
use Time::HiRes       qw(sleep);
use Term::SimpleColor;

use parent 'Exporter';

our @EXPORT_OK = qw(
  lines
  tail
  json_log
  json_cols
  json_cut
  json_grep
);


#-------------------------------------------------------------------------------
# Internal utilities
#-------------------------------------------------------------------------------
sub log_warn { warn red,    @_, default, "\n" }
sub log_info { warn yellow, @_, default, "\n" }

sub _open {
  my $path = shift || return;
  return $path if ref $path;

  open(my $fh, '<', $path) || return do{
    log_warn $!;
    return;
  };

  return $fh;
}



sub lines ($) {
  my $path = shift;
  my $fh   = _open($path) || return iter([]);
  imap{ chomp $_; $_ } iter $fh;
}



sub tail ($) {
  my $path = shift;
  my $fh   = _open($path) || return iter([]);
  my $pos  = 0;
  my $stop = 0;

  seek $fh, 0, SEEK_END;
  $pos = tell $fh;

  $SIG{INT} = sub{
    log_info 'Stopped';
    $stop = 1;
  };

  iterator{
    LINE:do{
      # Check for control-c