#!/usr/bin/perl
# License: AGPLv3-or-later
# see files COPYRIGHT, LICENSE, and AGPL-3.0.txt included in canonical repository for details.
#  https://k.sfconservancy.org/NPO-Accounting/beancount-tools-in-Perl

use strict;
use warnings;
use autodie qw(:all);

use Getopt::Long;
use File::Spec::Functions;
use File::Temp qw/:mktemp/;

use POSIX qw(mkfifo);
use IPC::Shareable;
use IPC::Run qw(start pump finish timeout);


my $BEANCOUNT_QUERY_CMD = "/usr/bin/bean-query";

my($VERBOSE, $BEANCOUNT_DIR, $LOAD_FILE, $REPOSITORY_URL, $FIFO_DIR) = (0, undef, undef, undef, undef);

GetOptions("verbose=i" => \$VERBOSE, "beancountDir=s" => \$BEANCOUNT_DIR,
           "loadFile=s" => \$LOAD_FILE, "repositoryURL=s" => \$REPOSITORY_URL, 'fifoDir=s' => \$FIFO_DIR);

sub UsageAndExit($) {
  print STDERR "usage: $0 --loadFile=/path/to/file.beancount --beancountDir=/path/to/beancountdir --fifoDir=/path/to/directory/for/fifos [ --repositoryURL=URL_OF_REPOSITORY --verbose=N ]\n";
  print STDERR "\n  $_[0]\n";
  exit 2;
}
UsageAndExit("/path/to/direcotry/for/fifos must be provided and be an existing directory")
  unless (defined $FIFO_DIR and -d $FIFO_DIR);

UsageAndExit("/path/to/file.beancount/path/to/beancountdir must be provided and be an existing directory")
  unless (defined $BEANCOUNT_DIR and -d $BEANCOUNT_DIR);
chdir $BEANCOUNT_DIR;

UsageAndExit("/path/to/file.beancount must a relative path to a file that exists in $BEANCOUNT_DIR")
  unless (defined $LOAD_FILE and -r $LOAD_FILE);

if (defined $REPOSITORY_URL) {
  UsageAndExit("if --repositoryURL is provided, $BEANCOUNT_DIR must be a checkout of a Git repository, but there is no $BEANCOUNT_DIR/.git/config.")
  unless (-r '.git/config');

  open(my $gitFH, "<", ".git/config");
  my $repoString;
  while (my $line = <$gitFH>) {
    chomp $line;
    $repoString = $1
      if $line =~ /^\s*url\s*=\s*(\S+)\s*$/;
  }
  close $gitFH;
  UsageAndExit("if --repositoryURL is provided, the checkout found in $BEANCOUNT_DIR must be of that repository, but .git/config does not list a URL.") unless defined $REPOSITORY_URL;
  UsageAndExit("if --repositoryURL is provided, the checkout found in $BEANCOUNT_DIR must be of that repository, but it instead appears to be a checkout of $repoString.")
    unless ($repoString eq $REPOSITORY_URL);
}
my $glue = 'BeAn';
my %options = (
               create    => 'yes',
               exclusive => 0,
               mode      => 0600,
               destroy   => 'yes',
      );
my %query;
tie %query, 'IPC::Shareable', $glue, { %options } or
  die "server: tie failed for $glue\n";

%query = ();

my %beancountData;
tie %beancountData, 'IPC::Shareable', $glue, { %options } or
  die "server: tie failed\n";

my ($currentFormat, $runningBeanQuery, $rbcIn, $rbcOut, $rbcErr);

sub StartRunningBeanQuery {
  my($format) = @_;
  $format = $currentFormat unless defined $format;
  $currentFormat = $format;

  my @cmd = ($BEANCOUNT_QUERY_CMD);
  push(@cmd, '-f', $query{format}) if defined $query{format};
  push(@cmd, $LOAD_FILE);
  $runningBeanQuery = start \@cmd, '<pty<', \$rbcIn,  '>pty>', \$rbcOut, '2>', \$rbcErr;
  pump $runningBeanQuery until $rbcOut =~ /^\s*beancount\s*\>\s*/m;
}
StartRunningBeanQuery('text');

while (1) {
  if (not defined $query{question}) {
    print STDERR "No question posed..." if $VERBOSE > 2;
    if (defined $query{fifoName}) {
      print STDERR "fifo still active; locking to clear it..." if $VERBOSE > 2;
      (tied %query)->shlock;
      print STDERR "clearing fifo, $query{fifoName}..." if $VERBOSE > 2;
      no autodie 'unlink'; unlink($query{fifoName});
      %query = ();
      (tied %query)->shunlock;
      print STDERR "fifo cleared & lock released." if $VERBOSE > 2;
    }
    print STDERR "sleep for 2 seconds\n" if $VERBOSE > 2;
    sleep 2;
    next;
  } elsif ($query{question} !~  /^[\,\=\~\-\@\w.\s\"\'\_\(\)\<\>\*\.\!]+$/) {
    print STDERR "Query string $query{question} looks suspicious, not running beancount query!\n";
    (tied %query)->shlock;
    $query{fifoName} = mktemp("REJECTED_beancount-query-fifo-this-file-does-not-exist_${$}_XXXXXXXXX");
    (tied %query)->shunlock;
    sleep 2;
  } elsif (defined $query{format} and $query{format} !~ /^(?:csv|text)$/) {
    print STDERR "format string $query{format} is not text or csv, not running beancount query!\n";
    (tied %query)->shlock;
    $query{question} = $query{format} = undef;
    $query{fifoName} = mktemp("REJECTED_beancount-query-fifo-this-file-does-not-exist_${$}_XXXXXXXXX");
    (tied %query)->shunlock;
  } elsif (not defined $query{fifoName}) {
    if (defined $query{format} and $query{format} ne 'text') {
      print STDERR "format string $query{format} is not supported yet!\n";
      (tied %query)->shlock;
      $query{question} = $query{format} = undef;
      $query{fifoName} = mktemp("REJECTED_beancount-$query{format}_not_supported_${$}_XXXXXXXXX");
      (tied %query)->shunlock;
      next;
    }
    print STDERR "Runing query:  $query{question}\n" if $VERBOSE > 0;
    $rbcOut = "";
    $rbcErr = "";
    my $ques = $query{question};
    $ques =~ s/\n/ /gm;
    $rbcIn = "$ques\n";
    pump $runningBeanQuery until $rbcOut =~ /^\s*beancount\s*\>\s*/m;
    (tied %query)->shlock;
    print STDERR "Acquired shlock on tied variable.\n" if $VERBOSE > 1;
    $query{fifoName} = undef;
    my $cnt = 0;
    my $fifoFileName = mktemp(catfile($FIFO_DIR, "beancount-query-fifo_${$}_XXXXXXXXX"));
    mkfifo($fifoFileName, 0700);
    die "unable to create fifo in $fifoFileName: $!" unless -p $fifoFileName;
    print STDERR "Created $fifoFileName..." if $VERBOSE > 1;
    $query{fifoName} = $fifoFileName;
    (tied %query)->shunlock;
    open(my $fifoFH, ">", $fifoFileName);
    print STDERR "and beginning write to it." if $VERBOSE > 1;
    my($seenSeperator, $prevLine) =  (0, "");
    foreach my $line (split /\n/, $rbcOut) {
      # Occasionally, some of the SELECT statement is printed back to
      #  $rbcOut.  Avoid reproducing this in output by waiting for the line
      #  of ----'s.  Thus, this only works in text mode right now.
      unless ($seenSeperator) {
        if ($line =~ /^\s*$/) {
          $seenSeperator = 1;
        } elsif ($currentFormat eq 'text' and $line =~ /^\s*\-+\s*$/) {
          $seenSeperator = 1;
          print "$prevLine\n";
        }
        $prevLine = $line;
        next;
      }
      last if $line =~ /^\s*beancount\s*\>\s*/;
      print STDERR "." unless ($cnt++ % 500) or ($VERBOSE <= 1);
      print $fifoFH "$line\n";
      $prevLine = $line;
    }
    close $fifoFH;
    $rbcOut = "";
    $rbcIn = "";
    (tied %query)->shlock; $query{question} = undef; (tied %query)->shunlock;
    print STDERR "...done!  Data now in $fifoFileName\n" if $VERBOSE > 0;
  }
}
finish $runningBeanQuery;

###############################################################################
#
# Local variables:
# compile-command: "perl -c bean-query-goofy-daemon.plx"
# perl-indent-level: 2
# End: