mbid-poller/poller.pl

#!/usr/bin/env perl
# -*- Perl -*-

use strict;
use warnings;

use open qw(:std :encoding(UTF-8));

use Data::Dumper qw(Dumper);
use Getopt::Std;
use IO::Handle;
use JSON::Tiny qw(decode_json);
use LWP::UserAgent;
use Time::Duration;
use URI::Escape;

# --- Environment Variables ---
use constant LIDARR_BASE => $ENV{LIDARR_BASE} || 'http://localhost:8686';

getopts('bfhv');

my $fresh_result  = defined $::opt_f ? $::opt_f : 0; # vs STALE

# Define the list of IDs to process
my @ids_to_process;
my $ua    = new LWP::UserAgent; # Initialize LWP::UserAgent
my $json_content;

# --- Input Logic: Prioritized Checks ---

# 1. Check for API URL (Highest Priority)
if (my $api_url = $ENV{MBID_API_URL}) {
    print STDERR "Fetching IDs from API URL: $api_url\n";
    my $res = $ua->get($api_url);
    unless ($res->is_success) {
        die "FATAL: Failed to fetch data from API: " . $res->status_line . "\n";
    }
    $json_content = $res->content;
}
# 2. Check for JSON File (Second Priority)
elsif (my $json_file = $ENV{MBID_JSON_FILE}) {
    print STDERR "Loading IDs from JSON file: $json_file\n";
    open my $fh, '<:encoding(UTF-8)', $json_file or die "Could not open $json_file: $!";
    $json_content = do { local $/; <$fh> };
    close $fh;
}
# 3. Check for a single URL/ID (Lowest Priority)
elsif (my $single_url = $ENV{MBID_URL}) {
    push @ids_to_process, $single_url;
} 
else {
    die "FATAL: Must set MBID_API_URL, MBID_JSON_FILE, OR MBID_URL.\n";
}


# --- JSON Parsing Logic (Applies to API URL and JSON File) ---
if ($json_content) {
    my $data;
    eval {
        $data = decode_json($json_content);
    };
    if ($@) {
        die "Error decoding JSON from source: $@\n";
    }

    # Extract the 'foreignId' from each object in the array
    if (ref $data eq 'ARRAY') {
        foreach my $item (@$data) {
            if (ref $item eq 'HASH' && exists $item->{foreignId}) {
                push @ids_to_process, $item->{foreignId};
            } else {
                warn "Skipping malformed item in input (missing 'foreignId').\n";
            }
        }
    } else {
        die "Input content was not a JSON array.\n";
    }
}


# --- Main Processing Loop ---
foreach my $id (@ids_to_process) {
    chomp $id;
    print "\n--- Processing: $id ---\n";

    my $type = 'artist'; # Assuming 'foreignId' provides an artist MBID

    my $json = ping_api($type, $id);

    print "- add-to-lidarr: " .
        LIDARR_BASE . "/add/search?term=" . uri_escape("lidarr:$id") . "\n";
}

## subroutines

sub ping_api {
  my ($type, $id) = @_;
  my $ua    = new LWP::UserAgent;
  my $start = time();
  my $loops = 0;
  my $api   = "https://api.lidarr.audio/api/v0.4/$type/$id";
  my $json;

  print STDERR "Pinging $api\n";
  
  while (1) {
    $loops++;
    print STDERR "- attempt $loops...\n";
    my $res = $ua->get($api);
    my $status = $res->code;
    
    if ($res->is_success) {
      eval {
	$json = decode_json($res->content);
      };
      if ($@) {
	chomp $@;
	warn "Retrying: JSON decode failed: $@\n";
      } elsif ($fresh_result and $res->header('cf-cache-status') eq 'STALE') {
	$status .= ' STALE';
    warn "Retrying: Response is STALE ($status)\n";
      } else {
        # *** VALIDATION CHECK ***
        my @validation_warnings = validate($type, $json);
        if (@validation_warnings) {
            warn "Retrying: Validation failed: " . join(', ', @validation_warnings) . "\n";
        } else {
            # Success: HTTP 2xx, JSON parsed, and content passed validation
            last;
        }
      }
    } else {
        # Log failure if not success and retry
        warn "Retrying: HTTP failed with status $status\n";
    }
    sleep 5;
  }

  my $elapsed = time() - $start;
  print "- ready ($loops attempts, " . duration($elapsed) . ")\n"
    if $loops > 1;
  if ($type eq 'artist') {
    print "- artist: " . $json->{artistname} . "\n";
  } else {
    print "- album: " . $json->{title} . "\n";
  }

  return $json;
}

sub validate {
  my ($type, $json) = @_;
  my @warnings;
  if ($type eq 'artist') {
    # make sure there are albums
    unless (exists $json->{Albums} and scalar @{$json->{Albums}}) {
      push(@warnings, 'no albums');
    }
  }
  else {
    # detect Unknown Artist problem
    unless (exists $json->{artists} and scalar @{$json->{artists}} and
	    exists $json->{artists}[0]{artistname} and
	    $json->{artists}[0]{artistname} !~ m%^Unknown Artist \(%) {
      push(@warnings, 'no artist');
    }
    unless (exists $json->{Releases} and scalar @{$json->{Releases}}) {
      push(@warnings, 'no releases');
    }
    else {
      unless (exists $json->{Releases}[0]{Tracks} and
	      scalar @{$json->{Releases}[0]{Tracks}}) {
	push(@warnings, 'no tracks');
      }
    }
  }
  if (@warnings) {
    warn 'WARNING: ' . join(', ', @warnings) . "\n";
    return 0;
  }
  return 1;
}