#!/usr/bin/perl

package Ernad::Chungju;

use strict;
use warnings;

use File::Copy;
use Data::Dumper;
use File::Basename;
use XML::LibXML;

## fixme!!! This should come from the configuration
my $allport='nep-all';

my $ernad_ns='http://ernad.openlib.org';
my $xhtml_ns='http://www.w3.org/1999/xhtml';

my $dom=XML::LibXML->new();
my $home_dir=$ENV{'HOME'} // '' ;
if(not $home_dir) {
  $home_dir='/home/ernad';
}
my $orders_outstanding_dir="$home_dir/opt/chungju/orders";
my $orders_accepted_dir="$home_dir/var/chungju/orders/accepted";
my $orders_refused_dir="$home_dir/var/chungju/orders/refused";
my $orders_fullfilled_dir="$home_dir/var/chungju/orders/fullfilled";
my $adverts_dir="$home_dir/var/chungju/adverts";
my $adverts_fullfilled_dir="$home_dir/var/chungju/adverts/fullfilled";
my $previous_report_file="$home_dir/var/chungju/last_order_report.txt";
my $accepted_orders_file="$home_dir/var/chungju/accepted_orders.txt";

sub inject_advert_into_rif {
  my $advert_element=shift;
  my $rif_file=shift;
  if(not -f $rif_file) {
    warn "no such file $rif_file";
    exit;
  }
  my $rif_doc = $dom->parse_file($rif_file);
  my $xc = XML::LibXML::XPathContext->new($rif_doc);
  $xc->registerNs('h', 'http://www.w3.org/1999/xhtml');
  $xc->registerNs('a', 'http://amf.openlib.org');
  $xc->registerNs('e', 'http://ernad.openlib.org');
  ## clears existing ad_elemnet
  foreach my $existing_advert_element ($xc->findnodes('//e:advert')) {
    ## fixme. This will not remove adverts with a 
    if($existing_advert_element->hasAttribute('report')) {
      next;
    }
    $existing_advert_element->parentNode->removeChild($existing_advert_element);
  }
  ## let's place the advert next to the issuedate
  my $issuedate_element=$xc->findnodes('//e:issuedate')->[0];
  if(not defined($issuedate_element)) {
    die "no issuedate in rif $rif_file";
  }
  my $collection_element=$xc->findnodes('/a:amf/a:collection')->[0];
  $collection_element->insertAfter($advert_element,$issuedate_element);
  $rif_doc->toFile($rif_file,2);
  return $rif_doc;
}

sub transform_order_to_advert {
  my $order_file=shift;
  my $report=shift;
  ## find order file from that
  my $order_file_name=basename($order_file);
  my $order_date=&order_file_to_order_date($order_file); 
  my $order_doc = $dom->parse_file($order_file);
  my $order_element=$order_doc->documentElement();
  my $report_id_text_upper = XML::LibXML::Text->new(uc($report));
  my $report_id_text_lower = XML::LibXML::Text->new(lc($report));
  my $advert_element = $order_doc->createElement('advert');
  $advert_element->setNamespace($ernad_ns,'e');  
  my $xc = XML::LibXML::XPathContext->new($order_doc);
  $xc->registerNs('h', 'http://www.w3.org/1999/xhtml');
  $xc->registerNs('e', 'http://ernad.openlib.org');
  foreach my $report_id_element ($xc->findnodes('//e:report_id')) {
    my $case=$report_id_element->getAttribute('case') // '';
    ## use lower case by default
    my $replace_text=$report_id_text_lower->cloneNode;
    if($case eq 'upper') {
      $replace_text=$report_id_text_upper->cloneNode;
    }
    $report_id_element->parentNode->replaceChild($replace_text,$report_id_element);
  }
  my $text_element=$xc->findnodes('/e:order/e:text')->[0];
  my $html_element=$xc->findnodes('/e:order/e:html')->[0];
  $advert_element->appendChild($text_element);
  $advert_element->appendChild($html_element);
  return $advert_element;
}

### Find the advert file when the report is the allport.
### Copy into the curent file for the other report
#sub find_and_organize_order_file_allport {
#  my $orders_outstanding_dir="$home_dir/opt/chungju/orders";
#  my $orders_fullfilled_dir="$home_dir/var/chungju/orders";
#  my $to_do_dates=&get_dates_from_dir($orders_outstanding_dir);
#  my $done_dates=&get_dates_from_dir($orders_fullfilled_dir);
#  foreach my $done_date (keys %{$done_dates}) {
#    if(defined($to_do_dates->{$done_date})) {
#      delete $to_do_dates->{$done_date};
#    }    
#  }
#  my @orders_to_do=sort keys $to_do_dates;
#  my $date=$orders_to_do[0];
#  if(not defined($date)) {
#    return 0;
#  }
#  my $order_file="$orders_outstanding_dir/$date.xml";
#  my $current_file="$orders_fullfilled_dir/$date"."_current.xml";
#  my $fullfilled_file="$orders_fullfilled_dir/$date.xml";
#  ## copy to the current file
#  copy($order_file,$current_file);
#  copy($order_file,$fullfilled_file);
#  return $fullfilled_file;
#}
#
### Find the file if the report is not the allport simply use the file
### marked as current. If there are serveral report the last and warn.
#sub find_and_organize_order_file_non_allport {
#  my $orders_fullfilled_dir="$home_dir/var/chungju/orders";
#  my $count_current_files=0;
#  my $current_file='';
#  foreach $current_file (`ls $orders_fullfilled_dir`) {
#    if(not $current_file=~m|^(\d{4}-\d{2}-\d{2})_current\.xml$|) {
#      next;
#    }    
#    $count_current_files++;
#  }
#  if($count_current_files>1) {
#    warn "more than one current file";
#  }
#  if(not $count_current_files) {
#    warn "no current files found";
#    exit;
#  }      
#  return $current_file;
#}
#
sub get_dates_from_dir {
  my $dir=shift;
  my $o;
  if(not -d $dir) {
    warn "no such directory: $dir";
    exit;
  }
  foreach my $file (`ls $dir`) {
    chomp $file;
    if(not $file=~m|^(\d{4}-\d{2}-\d{2})\.xml$|) {
      next;
    }
    my $date=$1;
    my $size=`stat -c %s $dir/$file`;
    chomp $size;
    $o->{$date}=$size;
  }
  return $o;
}


sub report_on_state_of_order_file {
  my $order_file=shift;
  ## optional arguments, required for monitoring
  ## to avoid repeating reports
  ## these will not be defined in a more detailed report
  my $accepted_orders=shift;
  ## output structure
  my $out;
  ## default is that we need to take action
  my $action=1;
  ## the report
  my $report='';
  if(not $order_file=~m|^\d{4}-\d{2}-\d{2}\.xml$|) {
    return;
  }
  my $result='';
  my $accepted_file="$orders_accepted_dir/$order_file";
  my $refused_file="$orders_refused_dir/$order_file"; 
  my $fullfilled_file="$orders_fullfilled_dir/$order_file";
  my $fullfilled_file_exists=0;
  my $order_file_age=-M "$orders_outstanding_dir/$order_file";
  my $accepted_file_age=-M $accepted_file;
  my $refused_file_age=-M $refused_file;

  if(-f $fullfilled_file) {
    $fullfilled_file_exists=1;
  }
  ## status is 'new', 'changed' or 'old'.
  my $status_accepted=&find_status($order_file,$orders_accepted_dir);
  my $status_refused=&find_status($order_file,$orders_refused_dir);
  ## just to prettyprint the order
  my $order=substr($order_file,0,length($order_file)-4);
  ## new order
  if($status_accepted eq 'new' and $status_refused eq 'new') {
    $result="A new order $order is available.\n";
    if($fullfilled_file_exists) {
      $result.="But there is an advert file for it. Something is wrong.\n";
    }
  } 
  if($status_accepted eq 'new' and $status_refused eq 'changed') {
    $result="A new version of refused order $order is available.\n";
    if($fullfilled_file_exists) {
      $result.="But there is an advert file for it. Something is wrong.\n";
    }
  } 
  if($status_accepted eq 'new' and $status_refused eq 'old') {
    $result="The order $order is still refused, no new decision.\n";
    $action=0;
    if($fullfilled_file_exists) {
      $result.="But there is an advert file for it. Something is wrong.\n";
    }
  } 
  if($status_accepted eq 'old' and $status_refused eq 'new') {
    $result="The order $order is accepted.\n";    
    $action=0;
    ## this was not known, and we check for it
    if(defined($accepted_orders)
       and not defined($accepted_orders->{$order})) {
      $action=1;
      $accepted_orders->{$order}=1;
    } 
  }
  if($status_accepted eq 'changed' and $status_refused eq 'new') {
    $result="A new version of an accepted order $order is available.\n";
    if($fullfilled_file_exists) {
      $result.="But there is an advert file it. Something is wrong.\n";
    }
    if(defined($accepted_orders)) {
      delete $accepted_orders->{$order};
    }
  }
  if($status_accepted eq 'changed' and $status_refused eq 'old') {
    if($accepted_file_age > $refused_file_age) {
      $result="The order $order is refused but an earlier version was accepted.\n";
      $result.="I am deleting the earlier accepted version\n";
      unlink($accepted_file);
    }
    if($accepted_file_age < $refused_file_age) {
      $result="The current order is refused but a different, more recent version was accepted.\n";
      $result.="I am deleting the more recent accepted version\n";
      unlink($accepted_file);
    }
    if(defined($accepted_orders)) {
      delete $accepted_orders->{$order};
    }
  }
  if($status_accepted eq 'changed' and $status_refused eq 'changed') {
    $result="Yikes. The order $order_file has been changed that has been accepted and refused.\n";
    $result.="I treat it as as new order. I will remove the accepted and refused order.\n";
    unlink($accepted_file);
    unlink($refused_file);
    if(defined($accepted_orders)) {
      delete $accepted_orders->{$order};
    }
  }
  if($status_accepted eq 'old' and $status_refused eq 'old') {
    $result="Yikes. The same order $order is both accepted and refused\n.";
    if($accepted_file_age > $refused_file_age) {
      $result.="I am deleting the earlier accepted version\n";
      unlink($accepted_file);
      if(defined($accepted_orders)) {
        delete $accepted_orders->{$order};
      }
    }
    if($accepted_file_age < $refused_file_age) {
      $result="The current add is refused but a different, more recent version was accepted.\n";
      $result.="I am deleting the earlier refused version\n";
      unlink($refused_file);
    }
  }
  if($status_accepted eq 'old' and $status_refused eq 'changed') {    
    if($order_file_age < $refused_file_age) {
      $result="An earlier order that was refused has been accepted.\n";
      ## no more action on this required
      $action=0;
      ## if this was not known,
      if(defined($accepted_orders)
         and not defined($accepted_orders->{$order})) {
        $accepted_orders->{$order}=1;
      } 
    }
    if($order_file_age > $refused_file_age) {
      $result="A version of the order was recently refused by the order accepted.";
      $result.="Somehing is wrong\n";
    }
  }
  $out->{'result'}=$result;
  $out->{'action'}=$action;
  $out->{'accepted'}=$status_accepted;
  return $out;
}

sub order_file_to_order_date {
  my $order_file_name=shift;
  my $order_date=substr($order_file_name,0,length($order_file_name)-4);
  return $order_date;
}

## 
sub find_status {
  my $file=shift;
  my $dir=shift;
  my $order_file="$orders_outstanding_dir/$file";
  my $dir_file="$dir/$file";
  if(not -f $dir_file) {
    return 'new';
  }
  if(`diff -w $dir_file $order_file`) {
    return 'changed';
  }
  return 'old';
}

sub fullfill_order {
  my $order_file=shift;
  my $fullfill_date=shift;
  if(not $order_file=~m|^(\d{4}-\d{2}-\d{2})\.xml$|) {
    die;
  } 
  if(not $fullfill_date=~m|^\d{4}-\d{2}-\d{2}$|) {
    die;
  } 
  my $order_date=&order_file_to_order_date($order_file); 
  my $fullfilled_file="$orders_fullfilled_dir/$order_file";
  if(-f $fullfilled_file) {
   return "order $order_date already fullfilled\n";
  }
  my $advert_file="$adverts_fullfilled_dir/$order_date.xml";
  if(-f $advert_file) {
    return "There is already an avert file for $fullfill_date\n";
  }
  my $parser = XML::LibXML->new;
  my $order_doc=$parser->parse_file("$orders_accepted_dir/$order_file");
  $order_doc->setEncoding('utf-8');
  my $root_element=$order_doc->documentElement;
  $root_element->setAttribute('fullfill_date',$fullfill_date);
  $order_doc->toFile("$fullfilled_file",2);
  print "writing $advert_file\n";
  $order_doc->toFile("$advert_file",2);
  ## return 0 on success
  return 0;
}

## finds an order to fullfill
sub find_order_to_fullfill {
  foreach my $order_file (`ls $orders_outstanding_dir`) {
    chomp $order_file;
    if(not $order_file=~m|^\d{4}-\d{2}-\d{2}\.xml$|) {
      next;
    }
    #print "order_file is $order_file\n";
    my $order_fullfilled_file="$orders_fullfilled_dir/$order_file";
    my $order_date=&Ernad::Chungju::order_file_to_order_date($order_file); 
    my $out=&Ernad::Chungju::report_on_state_of_order_file($order_file);  
    my $action=$out->{'action'};
    if($action) {
      print "order of $order_date needs work\n";
      next;
    }
    if(-f $order_fullfilled_file) {
      print "order $order_date is fullfilled\n";
      next;
    }
    return $order_file;
  }
  return '';
}


sub find_advert_to_put_in_subject_report {
  my $current_date=shift;
  foreach my $file (`ls -t $adverts_fullfilled_dir`) {
    chomp $file;
    my $fufi="$adverts_fullfilled_dir/$file";
    print "found advert fullfilled file $fufi\n";
    open my $fh, '<', "$fufi";
    binmode $fh; # drop all PerlIO layers possibly created by a use open pragma
    my $doc = XML::LibXML->load_xml(IO => $fh) or die;
    my $date=$doc->documentElement->getAttribute('fullfill_date') // '';
    if(not $date) {
      print "no fullfill date in $fufi\n";
      next;
    }
    if($date eq $current_date) {
      print "found advert $fufi\n";
      return $fufi;
    }
    print "fullfill_date on advert in file $file is $date, not $current_date\n";
  }
  return '';
}


1;