package VCP::Utils::p4 ;

=head1 NAME

VCP::Utils::p4 - utilities for dealing with the p4 command

=head1 SYNOPSIS

   use base qw( ... VCP::Utils::p4 ) ;

=head1 DESCRIPTION

A mix-in class providing methods shared by VCP::Source::p4 and VCP::Dest::p4,
mostly wrappers for calling the p4 command.

=cut

use strict ;

use VCP::Debug qw( debug debugging ) ;

=head1 METHODS

=over

=item repo_client

The p4 client name. This is an accessor for a data member in each class.
The data member should be part of VCP::Utils::p4, but the fields pragma
does not support multiple inheritance, so the accessor is here but all
derived classes supporting this accessor must provide for a key named
"P4_REPO_CLIENT".

=cut

sub repo_client {
   my $self = shift ;

   $self->{P4_REPO_CLIENT} = shift if @_ ;
   return $self->{P4_REPO_CLIENT} ;
}


=item p4

Calls the p4 command with the appropriate user, client, port, and password.

=cut

sub p4 {
   my $self = shift ;

   local $ENV{P4PASSWD} = $self->repo_password if defined $self->repo_password ;
   unshift @{$_[0]}, '-p', $self->repo_server  if defined $self->repo_server ;
   unshift @{$_[0]}, '-c', $self->repo_client  if defined $self->repo_client ;
   unshift @{$_[0]}, '-u', $self->repo_user    if defined $self->repo_user ;

   ## TODO: Specify an empty 

   ## localizing this was giving me some grief.  Can't recall what.
   ## PWD must be cleared because, unlike all other Unix utilities I
   ## know of, p4 looks at it and bases it's path calculations on it.
   my $tmp = $ENV{PWD} ;
   delete $ENV{PWD} ;

   my $args = shift ;
#if ( $ENV{UHOH} && grep( /^client$/, @$args ) && grep( /^-o$/, @$args ) ) {
#  warn( ">>>>>>>>>>>>>p4.exe @$args > bah1" );
#  system( "p4.exe @$args > bah1" );
#  system( "p4.exe @$args > bah2" );
#}

   $self->run_safely( [ "p4", @$args ], @_ ) ;
   $ENV{PWD} = $tmp if defined $tmp ;
}


=item parse_p4_form

   my %form = $self->parse_p4_form( $form );
   my %form = $self->parse_p4_form( \@command_to_emit_form );

Parses a p4 form and returns a list containing the form's data elements
in the order that they were accumulated.  This is suitable for initializing
a hash if order's not important, or an array if it is.

You can pass the form in verbatim, or a reference to a command to run
to get the form.  If the first parameter is an ARRAY reference, all
parameters will be passed to C<$self->p4> with stdout redirected to
a temporary variable.

Multiline fields will have trailing C<\n>s in the data, single-line fields
won't.  All fields have leading spaces on each line removed.

Comments are tagged with a field name of "#", blank (containing only spaces
if that) are tagged with a " ".  This is to allow accurate reproduction
of the file if reemitted.

NOTE: This does not implement 100% compatible p4 forms parsing; it should
be upwards compatible and one day we should implement full forms parsing.

=cut

## this simulates the real C++ tokenizer built in to p4.  That tokenizes
## p4 forms with a state machine that knows about quoting, text blocks,
## etc.  Some layer above the parser informs the parser about whether or
## not the current field is a text block.  This parser tries to emulate that
## tokenizer's behavior without implementing a low level state machine.

sub parse_p4_form {
   my $self = shift;

   my $form;
   
   if ( ref $_[0] eq "ARRAY" ) {
      $self->p4( $_[0], ">", \$form, @_[1..$#_] )
   }
   else {
      $form = shift;
   }

   my @lines = split /\r?\n/, $form;

   my @entries;
   my $cat;  ## Set when catenating lines together in a comment or value
   my $blanks = 0;

   for ( @lines ) {
      ++$blanks, next if /^$/;
      next if /^#/;
      if ( s/^\s*#\s*(.*)/$1/ ) {
         $blanks = 0;
         unless ( @entries && $entries[-2] eq "#" ) {
            chomp $entries[-1] if $cat;
            push @entries, ( "#", "" );
            $cat = 1;
         }
      }
      elsif ( /^([A-Za-z]+):[ \t]*(?:(\S.*))?\z/ ) {
         chomp $entries[-1] if $cat;
         $cat = undef;
         $blanks = 0;

         push @entries, $1;
         if ( defined $2 ) {
            push @entries, "$2\n";
         }
         else {
            push @entries, "";
         }
         $cat = 1;
         next;
      }

      if ( $cat ) {
         s/^\s//;  ## This may be too general.  May need to trim the same
                    ## number of characters from each line.
         $entries[-1] .= "\n" x $blanks;
         $blanks = 0;
         $entries[-1] .= $_ . "\n";
      }
      elsif ( ! length ) {
         next;
      }
      else {
         ## We warn instead of dieing in case p4 can output things we don't
         ## expect.  TODO: This could be bad, change to die() with a
         ## syntax error.
         warn "Ignoring '$_' from p4 output\n";
      }
   }
   chomp $entries[-1] if $cat;

   return @entries;
}


=item build_p4_form

   my $form = $self->build_p4_form( @form_fields );
   my $form = $self->build_p4_form( %form_fields );
   $self->build_p4_form( ..., \@command_to_emit_form );

Builds a p4 form and either returns it or submits it to the indicated command.

=cut

sub build_p4_form {
   my $self = shift;

   my @form;
   
   while ( @_ ) {
      last if ref $_[0] eq "ARRAY";  ## rest is a command.
      my ( $name, $value ) = ( shift, shift );

      if ( $name eq "#" ) {
         $value =~ s/^/# /mg;
         chomp $value;
         push @form, $value, "\n\n";
         next;
      }

      push @form, ( $name, ":" );

      if ( $value =~ tr/\n// ) {
         push @form, "\n";
         $value =~ s/^(?!$)/\t/gm;
         chomp $value;
         push @form, $value, "\n\n";
      }
      else {
         push @form, ( " ", $value, "\n\n" );
      }
   }

   my $form = join "", @form;
   @form = ();

   $self->p4( $_[0], "<", \$form, @_[1..$#_] ) if @_;

   return $form;
}


=item parse_p4_repo_spec

Calls $self->parse_repo_spec, the post-processes the repo_user in to a user
name and a client view. If the user specified no client name, then a client
name of "vcp_tmp_$$" is used by default.

This also initializes the client to have a mapping to a working directory
under /tmp, and arranges for the current client definition to be restored
or deleted on exit.

=cut

sub parse_p4_repo_spec {
   my $self = shift ;
   my ( $spec ) = @_ ;

   my $parsed_spec = $self->parse_repo_spec( $spec ) ;

   my ( $user, $client ) ;
   ( $user, $client ) = $self->repo_user =~ m/([^()]*)(?:\((.*)\))?/
      if defined $self->repo_user ;
   $client = "vcp_tmp_$$" unless defined $client && length $client ;

   $self->repo_user( $user ) ;
   $self->repo_client( $client ) ;

   if ( $self->can( "min" ) ) {
      my $filespec = $self->repo_filespec ;

      ## If a change range was specified, we need to list the files in
      ## each change.  p4 doesn't allow an @ range in the filelog command,
      ## for wataver reason, so we must parse it ourselves and call lots
      ## of filelog commands.  Even if it did, we need to chunk the list
      ## so that we don't consume too much memory or need a temporary file
      ## to contain one line per revision per file for an entire large
      ## repo.
      my ( $name, $min, $comma, $max ) ;
      ( $name, $min, $comma, $max ) =
	 $filespec =~ m/^([^@]*)(?:@(-?\d+)(?:(\D|\.\.)((?:\d+|#head)))?)?$/i
	 or die "Unable to parse p4 filespec '$filespec'\n";

      die "'$comma' should be ',' in change_id range in '$filespec'\n"
	 if defined $comma && $comma ne ',' ;

      if ( ! defined $min ) {
	 $min = 1 ;
	 $max = '#head' ;
      }

      if ( ! defined $max ) {
	 $max = $min ;
      }
      elsif ( lc( $max ) eq '#head' ) {
	 $self->p4( [qw( counter change )], \$max ) ;
	 chomp $max ;
      }

      if ( $max == 0 ) {
         ## TODO: make this a "normal exit"
         die "Current change number is 0, no work to do\n";
      }

      if ( $min < 0 ) {
	 $min = $max + $min ;
      }

      $self->repo_filespec( $name ) ;
      $self->min( $min ) ;
      $self->max( $max ) ;
   }

   return $parsed_spec ;
}


=item init_p4_view

   $self->init_p4_view

Borrows or creates a client with the right view.  Only called from
VCP::Dest::p4, since VCP::Source::p4 uses non-view oriented commands.

=cut

sub init_p4_view {
   my $self = shift ;

   my $client = $self->repo_client ;

   $self->repo_client( undef ) ;
   my $client_exists = grep $_ eq $client, $self->p4_clients ;
   debug "p4: client '$client' exists" if $client_exists && debugging $self ;
   $self->repo_client( $client ) ;
   my $client_spec = $self->p4_get_client_spec ;
## work around a wierd intermittant failure on Win32.  The
## Options: line *should* end in nomodtime normdir
## instead it looks like:
##
## Options:	noallwrite noclobber nocompress unlocked nomÔ+
##
## but only occasionally!
$client_spec = $self->p4_get_client_spec
    if $^O =~ /Win32/ && $client_spec =~ /[\x80-\xFF]/;

   $self->queue_p4_restore_client_spec( $client_exists ? $client_spec : undef );

   my $p4_spec = $self->repo_filespec ;
   $p4_spec =~ s{(/(\.\.\.)?)?$}{/...} ;
   my $work_dir = $self->work_root ;

   $client_spec =~ s{^Root.*}{Root:\t$work_dir}m ;
   $client_spec =~ s{^View.*}{View:\n\t$p4_spec\t//$client/...\n}ms ;
   debug "p4: using client spec", $client_spec if debugging $self ;
   $client_spec =~ s{^(Options:.*)}{$1 nocrlf}m 
      if $^O =~ /Win32/ ;
   $client_spec =~ s{^LineEnd.*}{LineEnd:\tunix}mi ;

   debug "p4: using client spec", $client_spec if debugging $self ;

   $self->p4_set_client_spec( $client_spec ) ;

}

=item p4_clients

Returns a list of known clients.

=cut

sub p4_clients {
   my $self = shift ;

   my $clients ;
   $self->p4( [ "clients", ], ">", \$clients ) ;
   return map { /^Client (\S*)/ ; $1 } split /\n/m, $clients ;
}

=item p4_get_client_spec

Returns the current client spec for the named client. The client may or may not
exist first, grep the results from L</p4_clients> to see if it already exists.

=cut

sub p4_get_client_spec {
   my $self = shift ;
   my $client_spec ;
   $self->p4( [ "client", "-o" ], ">", \$client_spec ) ;
   return $client_spec ;
}


=item queue_p4_restore_client_spec

   $self->queue_p4_restore_client_spec( $client_spec ) ;

Saves a copy of the named p4 client and arranges for it's restoral on exit
(assuming END blocks run). Used when altering a user-specified client that
already exists.

If $client_spec is undefined, then the named client will be deleted on
exit.

Note that END blocks may be skipped in certain cases, like coredumps,
kill -9, or a call to POSIX::exit().  None of these should happen except
in debugging, but...

=cut

my @client_backups ;

END {
   my $child_exit;
   {
      local $?;  ## Protect this; we're about to run a child process and
                 ## we want to exit with the appropriate value.
      for ( @client_backups ) {
         my ( $object, $name, $spec ) = @$_ ;
         my $tmp_name = $object->repo_client ;
         $object->repo_client( $name ) ;
         if ( defined $spec ) {
            $object->p4_set_client_spec( $spec ) ;
         }
         else {
            my $out ;
            $object->p4( [ "client", "-df", $object->repo_client ], ">", \$out);
            warn "vcp: unexpected stdout from p4:\np4: ", $out
               unless $out =~ /^Client\s.*\sdeleted./ ;
            $child_exit = $?;
         }
         $object->repo_client( $tmp_name ) ;
         $_ = undef ;
      }
      @client_backups = () ;
   }
   $? = $child_exit if $child_exit && ! $?;
}


sub queue_p4_restore_client_spec {
   my $self = shift ;
   my ( $client_spec ) = @_ ;
   push @client_backups, [ $self, $self->repo_client, $client_spec ] ;
}

=item p4_set_client_spec

   $self->p4_set_client_spec( $client_spec ) ;

Writes a client spec to the repository.

=cut


sub p4_set_client_spec {
   my $self = shift ;
   my ( $client_spec ) = @_ ;

   ## Capture stdout so it doesn't leak.
   my $out ;
   $self->p4( [ "client", "-i" ], "<", \$client_spec, ">", \$out ) ;

   die "vcp: unexpected stdout from p4:\np4: ", $out
      unless $out =~ /^Client\s.*\ssaved.$/ ;
}

=back

=head1 COPYRIGHT

Copyright 2000, Perforce Software, Inc.  All Rights Reserved.

This module and the VCP package are licensed according to the terms given in
the file LICENSE accompanying this distribution, a copy of which is included in
L<vcp>.

=cut

1 ;