#
# Maintainers.pm - show information about maintainers
#

package Maintainers;

use strict;

use lib "Porting";

require "Maintainers.pl";
use vars qw(%Modules %Maintainers);

use vars qw(@ISA @EXPORT_OK);
@ISA = qw(Exporter);
@EXPORT_OK = qw(%Modules %Maintainers
		get_module_files get_module_pat
		show_results process_options);
require Exporter;

use File::Find;
use Getopt::Long;

my %MANIFEST;
if (open(MANIFEST, "MANIFEST")) {
    while (<MANIFEST>) {
	if (/^(\S+)\t+(.+)$/) {
	    $MANIFEST{$1}++;
	}
    }
    close MANIFEST;
} else {
    die "$0: Failed to open MANIFEST for reading: $!\n";
}

sub get_module_pat {
    my $m = shift;
    split ' ', $Modules{$m}{FILES};
}

sub get_module_files {
    my $m = shift;
    sort { lc $a cmp lc $b }
    map {
	-f $_ ? # Files as-is.
	    $_ :
	    -d _ ? # Recurse into directories.
	    do {
		my @files;
		find(
		     sub {
			 push @files, $File::Find::name
			     if -f $_ && exists $MANIFEST{$File::Find::name};
		     }, $_);
		@files;
	    }
	: glob($_) # The rest are globbable patterns.
	} get_module_pat($m);
}

sub get_maintainer_modules {
    my $m = shift;
    sort { lc $a cmp lc $b }
    grep { $Modules{$_}{MAINTAINER} eq $m }
    keys %Modules;
}

sub usage {
    print <<__EOF__;
$0: Usage: $0 [[--maintainer M --module M --files --check]|file ...]
--maintainer M	list all maintainers matching M
--module M	list all modules matching M
--files		list all files
--check		check consistency of Maintainers.pl
--opened	list all modules of files opened by perforce
Matching is case-ignoring regexp, author matching is both by
the short id and by the full name and email.  A "module" may
not be just a module, it may be a file or files or a subdirectory.
The options may be abbreviated to their unique prefixes
__EOF__
    exit(0);
}

my $Maintainer;
my $Module;
my $Files;
my $Check;
my $Opened;

sub process_options {
    usage()
	unless
	    GetOptions(
		       'maintainer=s'	=> \$Maintainer,
		       'module=s'	=> \$Module,
		       'files'		=> \$Files,
		       'check'		=> \$Check,
		       'opened'		=> \$Opened,
		      );

    my @Files;
   
    if ($Opened) {
	my @raw = `p4 opened`;
	die if $?;
	@Files =  map {s!#.*!!s; s!^//depot/.*?/perl/!!; $_} @raw;
    } else {
	@Files = @ARGV;
    }

    usage() if @Files && ($Maintainer || $Module || $Files);

    for my $mean ($Maintainer, $Module) {
	warn "$0: Did you mean '$0 $mean'?\n"
	    if $mean && -e $mean && $mean ne '.' && !$Files;
    }

    warn "$0: Did you mean '$0 -mo $Maintainer'?\n"
	if defined $Maintainer && exists $Modules{$Maintainer};

    warn "$0: Did you mean '$0 -ma $Module'?\n"
	if defined $Module     && exists $Maintainers{$Module};

    return ($Maintainer, $Module, $Files, @Files);
}

sub show_results {
    my ($Maintainer, $Module, $Files, @Files) = @_;

    if ($Maintainer) {
	for my $m (sort keys %Maintainers) {
	    if ($m =~ /$Maintainer/io || $Maintainers{$m} =~ /$Maintainer/io) {
		my @modules = get_maintainer_modules($m);
		if ($Module) {
		    @modules = grep { /$Module/io } @modules;
		}
		if ($Files) {
		    my @files;
		    for my $module (@modules) {
			push @files, get_module_files($module);
		    }
		    printf "%-15s @files\n", $m;
		} else {
		    if ($Module) {
			printf "%-15s @modules\n", $m;
		    } else {
			printf "%-15s $Maintainers{$m}\n", $m;
		    }
		}
	    }
	}
    } elsif ($Module) {
	for my $m (sort { lc $a cmp lc $b } keys %Modules) {
	    if ($m =~ /$Module/io) {
		if ($Files) {
		    my @files = get_module_files($m);
		    printf "%-15s @files\n", $m;
		} else {
		    printf "%-15s $Modules{$m}{MAINTAINER}\n", $m;
		}
	    }
	}
    } elsif (@Files) {
	my %ModuleByFile;

	for (@Files) { s:^\./:: }

	@ModuleByFile{@Files} = ();

	# First try fast match.

	my %ModuleByPat;
	for my $module (keys %Modules) {
	    for my $pat (get_module_pat($module)) {
		$ModuleByPat{$pat} = $module;
	    }
	}
	# Expand any globs.
	my %ExpModuleByPat;
	for my $pat (keys %ModuleByPat) {
	    if (-e $pat) {
		$ExpModuleByPat{$pat} = $ModuleByPat{$pat};
	    } else {
		for my $exp (glob($pat)) {
		    $ExpModuleByPat{$exp} = $ModuleByPat{$pat};
		}
	    }
	}
	%ModuleByPat = %ExpModuleByPat;
	for my $file (@Files) {
	    $ModuleByFile{$file} = $ModuleByPat{$file}
	        if exists $ModuleByPat{$file};
	}

	# If still unresolved files...
	if (my @ToDo = grep { !defined $ModuleByFile{$_} } keys %ModuleByFile) {

	    # Cannot match what isn't there.
	    @ToDo = grep { -e $_ } @ToDo;

	    if (@ToDo) {
		# Try prefix matching.

		# Remove trailing slashes.
		for (@ToDo) { s|/$|| }

		my %ToDo;
		@ToDo{@ToDo} = ();

		for my $pat (keys %ModuleByPat) {
		    last unless keys %ToDo;
		    if (-d $pat) {
			my @Done;
			for my $file (keys %ToDo) {
			    if ($file =~ m|^$pat|i) {
				$ModuleByFile{$file} = $ModuleByPat{$pat};
				push @Done, $file;
			    }
			}
			delete @ToDo{@Done};
		    }
		}
	    }
	}

	for my $file (@Files) {
	    if (defined $ModuleByFile{$file}) {
		my $module     = $ModuleByFile{$file};
		my $maintainer = $Modules{$ModuleByFile{$file}}{MAINTAINER};
		printf "%-15s $module $maintainer $Maintainers{$maintainer}\n", $file;
	    } else {
		printf "%-15s ?\n", $file;
	    }
	}
    }
    elsif ($Check) {
	duplicated_maintainers();
    }
    else {
	usage();
    }
}

sub duplicated_maintainers {
    my %files;
    for my $k (keys %Modules) {
	for my $f (get_module_files($k)) {
	    ++$files{$f};
	}
    }
    for my $f (keys %files) {
	if ($files{$f} > 1) {
	    warn "File $f appears $files{$f} times in Maintainers.pl\n";
	}
    }
}

1;