use LWP::UserAgent;
use EPrints;

use JSON;

use strict;
use warnings;

my $eprints = EPrints->new;
my $repo = $eprints->current_repository;
exit( 0 ) unless( defined $repo );

my $alt_type = $repo->param( 'id_type' ) or exit;
my $alt_id = $repo->param( 'id' ) or exit;


# Full list if types: citations id doi pmid arxiv ads uri isbn

my $allowed_id_types = $repo->config( "altmetric", "allowed_types" );
# fall back to default if needed.
$allowed_id_types = [qw/doi isbn/] if !defined $allowed_id_types;

# Details to be displayed if they have any score.
my $sources = $repo->config( "altmetric", "sources" );
$sources = [qw / fbwalls feeds gplus msm rdts qna tweeters bluesky wikipedia policies guidelines patents videos / ] if ! defined $sources;

my $errmsg;
my $out = {};

binmode( STDOUT, ":utf8" );

# note we always reply to the Ajax request with 200 OK
EPrints::Apache::AnApache::send_status_line( $repo->get_request, 200 );
$repo->send_http_header( "content_type"=> "application/json; charset=utf-8" );

# API key now mandatory.
my $api_key = $repo->config( 'altmetric', 'api_key' );
if( !defined $api_key )
{
	return_error( $repo->phrase( 'lib/altmetric:auth_reqd' ) );
	exit;
}

unless ( grep {$_ eq $alt_type} @{$allowed_id_types} ) {
	return_error( $repo->phrase( 'lib/altmetric:not_found' ) );
	exit;
}

my $ua = LWP::UserAgent->new();
$ua->agent( 'eprints/' . EPrints->human_version );

if( EPrints::Utils::is_set( $ENV{HTTP_proxy} ) )
{
	$ua->proxy( 'http', $ENV{HTTP_proxy} )
}

my $alt_url = URI->new( $repo->config( 'altmetric', 'base_url' )."/$alt_type/$alt_id" );


if( EPrints::Utils::is_set( $api_key ) )
{
	$alt_url->query_form( key => $api_key );
}

my $req = HTTP::Request->new( GET => $alt_url );
my $res = $ua->request($req);
my $c;

if( $res->is_success )
{
	$c = $res->content;
}
else
{
	# other error codes (from: https://details-page-api-docs.altmetric.com/shared/status-codes.html):
	# 401: Auth reqd.
	# 403: Forbidden
	# 404: Not found
	# 429: rate limited
	# 502: API down for maintenance
	if( $res->code == 401 )
	{
		# This could either be a 'need to provide a key' or 'API key was wrong'
		return_error( $repo->phrase( 'lib/altmetric:auth_reqd' ) . "\n" . $res->content );
		exit;
	}
	elsif( $res->code == 403 )
	{
		return_error( $repo->phrase( 'lib/altmetric:forbidden' ) );
		exit;
	}
	elsif( $res->code == 404 )
	{
		return_error( $repo->phrase( 'lib/altmetric:not_found' ) );
		exit;
	}
	elsif( $res->code == 429 )
	{
		return_error( $repo->phrase( 'lib/altmetric:rate_limited' ) );
		exit;
	}
	elsif( $res->code == 502 )
	{
		return_error( $repo->phrase( 'lib/altmetric:down_for_maintenance' ) );
		exit;
	}
	else
	{
		# We may be here because of an old version of LWP that is causing a security exception from the altmetric api
		# In case that is the case, we will (re) sanitize the params and use curl

		if( $alt_type eq 'doi' ){
			unless ( $alt_id =~ /10\.(\d+\.*)+[\/](([^\s\.])+\.*)+/  ) {
				return_error( $repo->phrase( 'lib/altmetric:bad_id' ) );
				exit;
			}
		}
		elsif( $alt_type eq 'isbn' )
		{
			unless ( $alt_id =~ /(?=(?:\D*\d){10}(?:(?:\D*\d){3})?$)/ ) {
				return_error( $repo->phrase( 'lib/altmetric:bad_id' ) );
				exit;
			}
		}
	}
	# Opts: s = silent; S = but still report errors; k = insecure
	$c = `curl -sSk "$alt_url"`;
}

my $json = eval { decode_json( $c ) };
if( $@ )
{
	# Don't send the error message to the browser - but log it
	print STDERR "Altmetric: broken JSON from API ($alt_type --> $alt_id)\n", $@;

	return_error( $repo->phrase( 'lib/altmetric:json_decode_error' ) );
	exit;
}

# This will be converted to a json string
my $f = $repo->make_doc_fragment();

if( defined $json->{images}->{medium} )
{
	# the altmetric score shown on the badge is rounded up. Ceil here matches that score.
	my $score = defined $json->{score} ? "Altmetric score: ".POSIX::ceil($json->{score}) : '';
	my $img = $repo->make_element( "img", src => $json->{images}->{medium}, class => 'altmetric_donut', alt => $score );
	$f->appendChild( $img );
}

my $d = $repo->make_element( "div", class => "altmetric_details_panel" );
$f->appendChild( $d );
foreach my $s ( @$sources )
{
	if( defined $json->{"cited_by_${s}_count"} && $repo->get_lang->has_phrase( "lib/altmetric:cited_by_${s}", $repo ) )
	{
		my $phr_id = "lib/altmetric:cited_by_${s}";
		$phr_id .= "_plural" if ( $json->{"cited_by_${s}_count"} > 1 && $repo->get_lang->has_phrase( "lib/altmetric:cited_by_${s}_plural", $repo ) );

		my $r = $repo->make_element( "div", class => "altmetric_row altmetric_${s}" );
		$r->appendChild( $repo->html_phrase( $phr_id, count => $repo->make_text( $json->{"cited_by_${s}_count"} ) ) );
		$d->appendChild( $r );
	}
}

if( defined $json->{"readers"} )
{
	my $had_reader = 0;

	foreach my $reader ( qw / mendeley citeulike / )
	{
		if( defined $json->{"readers"}->{$reader} && $json->{"readers"}->{$reader} > 0 && $repo->get_lang->has_phrase( "lib/altmetric:readers_${reader}", $repo ) )
		{
			my $phr_id = "lib/altmetric:readers_${reader}";
			$phr_id .= "_plural" if ( $json->{"readers"}->{$reader} > 1 && $repo->get_lang->has_phrase( "lib/altmetric:readers_${reader}_plural", $repo ) );

			my $r = $repo->make_element( "div", class => "altmetric_row altmetric_${reader}" );
			$r->appendChild( $repo->html_phrase( $phr_id, count => $repo->make_text( $json->{"readers"}->{$reader} ) ) );
			if( !$had_reader )
			{
				$d->appendChild( $repo->make_element( "br" ) );
				$had_reader = 1;
			}
			$d->appendChild( $r );
		}
	}
}

# to_string used because it removes unnecessary namespaces
$out->{html} = EPrints::XML::to_string( $f, "utf-8", 1 );
EPrints::XML::dispose( $f );

# This is used to provide a link to more details
$out->{details_url} = $json->{'details_url'};

print STDOUT encode_json( $out );
exit;

sub return_error
{
	my( $err_msg ) = @_;

	my $out = {};
	$out->{error} = 1;
	$out->{message} = $err_msg;

	print STDOUT encode_json( $out );
	
}