#! /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 Date::Parse qw(str2time);
use Mail::Sendmail;
use Encode;

my $_execmode = $ARGV[0] || 0;
sub VERBOSE () { $_execmode eq 'verbose' };
sub DEBUG   () { VERBOSE or $_execmode eq 'debug' };
use Data::Dumper;

DEBUG and warn "$0: debug mode";

my $conf = loadconf("$Bin/config.yml");
if (! defined $conf) {
    die "$0: cannot parse config file.\n";
}
my $stat = loadconf("$Bin/status.yml");
if (! defined $stat) {
    $stat = {};
}

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

my $tweets = {};
%$tweets = (
    %$tweets,
    %{ or_search($bot, $conf->{hashtag}, $stat->{search}) }
);
%$tweets = (
    %$tweets,
    %{ mentions_ids($bot, $stat->{mention}) }
);

foreach my $id (sort keys %$tweets) {
    # $tweets->{$id}{type} eq 'search'  => found by search API
    #                      eq 'mention' => found by mention API
    my $skip;
    if ($tweets->{$id}{type} eq 'retweet') {
        DEBUG and warn "skipping $id that was already retweeted\n";
        $skip = 'retweet';
    }
    if (defined $conf->{allow}) {
        $skip = 'allow';
        foreach my $screen_name ( @{ $conf->{allow}{screen_name} } ) {
            if ($tweets->{$id}{screen_name} eq $screen_name) {
                DEBUG and warn "$id was allowed by screen_name\n";
                undef $skip;
                last;
            }
        }
        foreach my $user_id ( @{ $conf->{allow}{user_id} } ) {
            if ($tweets->{$id}{user_id} eq $user_id) {
                DEBUG and warn "$id was allowed by user_id\n";
                undef $skip;
                last;
            }
        }
    }
    
    if (defined $conf->{mail}) {
        my $send;
        foreach my $pickup ( @{ $conf->{mail}{pickup} } ) {
            if ($tweets->{$id}{type} eq $pickup) {
                $send = 1;
                last;
            }
        }
        if ($conf->{mail}{ignore_allowed}) {
            if (defined $conf->{allow} and ! defined $skip) {
                # this tweet was allowed to retweet, so that be ignored on mail
                undef $send;
            }
        }
        
        if ($send) {
            if (! exists($conf->{mail}{body}) ) {
                $conf->{mail}{body} =
                    "[localtime(date)] http://twitter.com/<screen_name>/status/<status_id> text\n" .
                    "----------------------------------------\n"
                ;
            }
            $conf->{mail}{body} .=
                "[" . localtime($tweets->{$id}{date}) . "] " .
                "http://twitter.com/" .
                $tweets->{$id}{screen_name} . "/status/" .
                $tweets->{$id}{status_id} . " " .
                $tweets->{$id}{text} . "\n"
            ;
        }
    }
    
    if ($skip) {
        $stat->{$tweets->{$id}{type}} = $id;
        next;
    }
    
    DEBUG or sleep($conf->{sleep});
    
    # do retweet found tweets
    my $res;
    eval {
        DEBUG  or $res = $bot->retweet($id);
        DEBUG and warn "retweet($id) => ", Dumper($tweets->{$id});
    };
    if ($@) {
        evalrescue($@);
        warn "status_id => $id\n";
        next;
    }
    
    $stat->{$tweets->{$id}{type}} = $id;
}

if ($conf->{mail}{body}) {
    my $body = encode("iso-2022-jp", $conf->{mail}{body});
    
    my %mail = (
        Smtp            => $conf->{mail}{server},
        From            => $conf->{mail}{from},
        To              => join(", ", @{ $conf->{mail}{to} }),
        Subject         => $conf->{mail}{subject},
        "Content-Type"  => $conf->{mail}{contenttype},
        Body            => $body,
    );
    DEBUG and warn "sending mail => ", Dumper(\%mail);
    
    DEBUG or sendmail(%mail) or warn "Error sending mail: $Mail::Sendmail::error\n";
}

if (ref $tweets and keys %{$tweets}) {
    # save last status to yaml file
    DEBUG  or YAML::Tiny::DumpFile("$Bin/status.yml", $stat);
    DEBUG and warn "status.yml => ", Dumper($stat);
}


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' $!\n";
    }
    
    DEBUG and warn "'$file' => ", Dumper($yaml);
    
    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 or_search {
    # search tweets containing keywords
    #   param   => Net::Twitter::Lite::WithAPIv1_1 object, ArrayRef of keywords, since_id
    #   ret     => HashRef of status_id (timeline order is destroyed)
    #               or undef (none is found)
    
    my $bot      = shift @_;
    my $keywords = shift @_;
    my $since_id = shift @_ || 1;
    
    my $key = "";
    foreach my $word (@$keywords) {
        if ($key) {
            $key .= " OR $word";
        }
        else {
            $key = $word;
        }
    }
    DEBUG and warn "searching '$key'";
    
    my $res;
    my $ids = {};
    eval {
        if ($key) {
            $res = $bot->search(
                {
                    q           => $key,
                    since_id    => $since_id,
                }
            );
        }
        VERBOSE and warn Dumper($res);
        if ($res->{statuses}) {
            foreach my $tweet (@{$res->{statuses}}) {
                my $res = $bot->show_status($tweet->{id});
                VERBOSE and warn Dumper($res);
                
                my $id = {
                    date        => str2time($res->{created_at}),
                    screen_name => $res->{user}{screen_name},
                    status_id   => $res->{id},
                    text        => $res->{text},
                    user_id     => $res->{user}{id},
                };
                if ($res->{retweeted_status}) {
                    $id->{retweet_of}   = $res->{retweeted_status}{id};
                    $id->{type}         = 'retweet';
                }
                else {
                    $id->{type} = 'search';
                }
                $ids->{$tweet->{id}} = $id;
            }
        }
    };
    if ($@) {
        evalrescue($@);
    }
    
    DEBUG and warn "search result => ", Dumper($ids);
    return $ids;
}

sub mentions_ids {
    # return status_ids mentioned to me
    #   param   => Net::Twitter::Lite::WithAPIv1_1 object, since_id
    #   ret     => HashRef of status_id (timeline order is destroyed)
    #               or undef (none is found)
    
    my $bot      = shift @_;
    my $since_id = shift @_ || 1;
    
    my $res;
    eval {
        $res = $bot->mentions(
            {
                since_id    => $since_id,
            }
        );
        VERBOSE and warn Dumper($res);
    };
    if ($@) {
        evalrescue($@);
    }
    
    my $ids = {};
    if ($res && @{$res}) {
        $ids = {
            map {
                $_->{id} => {
                    date        => str2time($_->{created_at}),
                    screen_name => $_->{user}{screen_name},
                    status_id   => $_->{id},
                    text        => $_->{text},
                    type        => 'mention',
                    user_id     => $_->{user}{id},
                }
            } @{$res}
        };
    }
    
    DEBUG and warn "mentions result => ", Dumper($ids);
    return $ids;
}

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 $twitter_error->{errors} && ref($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 $@;
    }
}