#! /usr/bin/perl -w

use strict;
use warnings;
use utf8;

## IMPORTANT ##
# When Net::Twitter::Lite encounters a Twitter API error or a network error, 
# it throws a Net::Twitter::Lite::Error object. 
# You can catch and process these exceptions by using eval blocks and testing $@
## from http://search.cpan.org/perldoc?Net::Twitter::Lite#ERROR_HANDLING
use Net::Twitter::Lite::WithAPIv1_1;
use FindBin qw($Bin);
use YAML::Tiny;
use Data::Dumper;
use Encode;

my $help = sub {
    die <<EOM;
usage: $0 [text_file_to_tweet]
EOM
};
if ($ARGV[0] && ($ARGV[0] eq '--help' || $ARGV[0] eq '-h') ) {
    &{$help};
}

my $file = $ARGV[0] || 'update.log';
my $conf = loadconf("$Bin/config.yml");
if (! defined $conf) {
    die "$0: cannot parse config file.";
}

my $bot = login($conf);
if (! $bot->authorized) {
    die "$0: this client is not yet authorized.";
}

open TWEET, $file or die "$0: cannot open file: $file";
eval {
    my $update = "";
    my $res;
    foreach my $line (<TWEET>) {
        chomp $line;
        $update .= $line;
    }
    if (length $update) {
        $update = decode('utf8', $update);
        $res = $bot->update($update);
    }
    
    foreach my $line (split /\n/, Dumper $res) {
        if ($line =~ /undef/) { next; }
        print STDERR $line, "\n";
    }
    if (ref $res) {
        my $status = $res;
        my $text = "";
        $text .= "(". $status->{id} . ") ";
        $text .= ($status->{user}{name}) ? $status->{user}{name} : $status->{from_user};
        $text .= " [" . $status->{created_at} . "]";
        $text .= " ".  $status->{text};
        $text =~ s/\n//;
        print encode('sjis', $text), "\n";
    }
};
if ($@) {
    evalrescue($@);
}


sub loadconf {
    # load configration data from yaml formatted file
    #   param   => scalar string of filename
    #   ret     => hash object of yaml data
    
    my $file = shift @_;
    
    my $yaml = YAML::Tiny->read($file);
    
    if ($!) {
        warn "$0: '$file' $!";
    }
    
    return $yaml->[0];
}

sub login {
    # make Net::Twitter::Lite::WithAPIv1_1 object and login
    #   param   => hash object of configration
    #   ret     => Net::Twitter::Lite::WithAPIv1_1 object
    
    my $conf = shift @_;
    
    my $bot = Net::Twitter::Lite::WithAPIv1_1->new(
        consumer_key    => $conf->{consumer_key},
        consumer_secret => $conf->{consumer_secret},
        legacy_lists_api => 0,
    );
    
    $bot->access_token($conf->{access_token});
    $bot->access_token_secret($conf->{access_token_secret});
    
    return $bot;
}

sub evalrescue {
    # output error message at eval error
    
    use Scalar::Util qw(blessed);
    
    if (blessed $@ && $@->isa('Net::Twitter::Lite::Error')) {
        warn $@->error;
        if ($@->twitter_error) {
            my $twitter_error = $@->twitter_error;
            if (defined $twitter_error->{errors}) {
                foreach my $error (@{$twitter_error->{errors}}) {
                    warn "code => "   , $error->{code}, "\n";
                    warn "message => ", $error->{message}, "\n";
                }
            }
            else {
                # unknown HASH structure
                use Data::Dumper;
                warn Dumper $twitter_error;
            }
        }
    }
    else {
        warn $@;
    }
}