#!/usr/bin/env perl
#
# Copyright (C) 2005 Apple Inc.
# Copyright (C) 2006 Anders Carlsson <andersca@mac.com>
# 
# This file is part of WebKit
# 
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Library General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
# 
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Library General Public License for more details.
# 
# You should have received a copy of the GNU Library General Public License
# along with this library; see the file COPYING.LIB.  If not, write to
# the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
# Boston, MA 02110-1301, USA.
# 

# This script is a temporary hack. 
# Files are generated in the source directory, when they really should go
# to the DerivedSources directory.
# This should also eventually be a build rule driven off of .idl files
# however a build rule only solution is blocked by several radars:
# <rdar://problems/4251781&4251785>

use strict;
use warnings;
use FindBin;
use lib '.', $FindBin::Bin;

use English;
use File::Path;
use File::Basename;
use Getopt::Long;
use Text::ParseWords;
use Cwd;
use JSON::PP;

use IDLParser;
use CodeGenerator;

my @idlDirectories;
my $outputDirectory;
my $outputHeadersDirectory;
my $generator;
my $defines;
my $filename;
my $prefix;
my $preprocessor;
my $writeDependencies;
my $verbose;
my $supplementalDependencyFile;
my $additionalIdlFiles;
my $idlAttributesFile;

GetOptions('include=s@' => \@idlDirectories,
           'outputDir=s' => \$outputDirectory,
           'outputHeadersDir=s' => \$outputHeadersDirectory,
           'generator=s' => \$generator,
           'defines=s' => \$defines,
           'filename=s' => \$filename,
           'prefix=s' => \$prefix,
           'preprocessor=s' => \$preprocessor,
           'verbose' => \$verbose,
           'write-dependencies' => \$writeDependencies,
           'supplementalDependencyFile=s' => \$supplementalDependencyFile,
           'additionalIdlFiles=s' => \$additionalIdlFiles,
           'idlAttributesFile=s' => \$idlAttributesFile);

die('Must specify input file.') unless @ARGV;
die('Must specify generator') unless defined($generator);
die('Must specify output directory.') unless defined($outputDirectory);
die('Must specify IDL attributes file.') unless defined($idlAttributesFile);

if (!$outputHeadersDirectory) {
    $outputHeadersDirectory = $outputDirectory;
}

generateBindings($_) for (@ARGV);

sub generateBindings
{
    my ($targetIdlFile) = @_;

    $targetIdlFile = Cwd::realpath($targetIdlFile);
    if ($verbose) {
        print "$generator: $targetIdlFile\n";
    }
    my $targetInterfaceName = fileparse($targetIdlFile, ".idl");

    my $idlFound = 0;
    my @supplementedIdlFiles;
    if ($supplementalDependencyFile) {
        # The format of a supplemental dependency file:
        #
        # DOMWindow.idl P.idl Q.idl R.idl
        # Document.idl S.idl
        # Event.idl
        # ...
        #
        # The above indicates that DOMWindow.idl is supplemented by P.idl, Q.idl and R.idl,
        # Document.idl is supplemented by S.idl, and Event.idl is supplemented by no IDLs.
        # The IDL that supplements another IDL (e.g. P.idl) never appears in the dependency file.
        open FH, "< $supplementalDependencyFile" or die "Cannot open $supplementalDependencyFile\n";
        while (my $line = <FH>) {
            my ($idlFile, @followingIdlFiles) = split(/\s+/, $line);
            if ($idlFile and fileparse($idlFile) eq fileparse($targetIdlFile)) {
                $idlFound = 1;
                @supplementedIdlFiles = sort @followingIdlFiles;
            }
        }
        close FH;

        # $additionalIdlFiles is list of IDL files which should not be included in
        # DerivedSources*.cpp (i.e. they are not described in the supplemental
        # dependency file) but should generate .h and .cpp files.
        if (!$idlFound and $additionalIdlFiles) {
            my @idlFiles = shellwords($additionalIdlFiles);
            $idlFound = grep { $_ and fileparse($_) eq fileparse($targetIdlFile) } @idlFiles;
        }

        if (!$idlFound) {
            my $codeGen = CodeGenerator->new(\@idlDirectories, $generator, $outputDirectory, $outputHeadersDirectory, $preprocessor, $writeDependencies, $verbose);

            # We generate empty .h and .cpp files just to tell build scripts that .h and .cpp files are created.
            generateEmptyHeaderAndCpp($codeGen->FileNamePrefix(), $targetInterfaceName, $outputHeadersDirectory, $outputDirectory);
            return;
        }
    }

    my $input;
    {
        local $INPUT_RECORD_SEPARATOR;
        open(JSON, "<", $idlAttributesFile) or die "Couldn't open $idlAttributesFile: $!";
        $input = <JSON>;
        close(JSON);
    }

    my $jsonDecoder = JSON::PP->new->utf8;
    my $jsonHashRef = $jsonDecoder->decode($input);
    my $idlAttributes = $jsonHashRef->{attributes};

    # Parse the target IDL file.
    my $targetParser = IDLParser->new(!$verbose);
    my $targetDocument = $targetParser->Parse($targetIdlFile, $defines, $preprocessor, $idlAttributes);

    foreach my $idlFile (@supplementedIdlFiles) {
        next if $idlFile eq $targetIdlFile;

        my $interfaceName = fileparse($idlFile, ".idl");
        my $parser = IDLParser->new(!$verbose);
        my $document = $parser->Parse($idlFile, $defines, $preprocessor, $idlAttributes);

        foreach my $interface (@{$document->interfaces}) {
            if (!$interface->isPartial || $interface->type->name eq $targetInterfaceName) {
                my $targetDataNode;
                my @targetGlobalContexts;
                foreach my $interface (@{$targetDocument->interfaces}) {
                    if ($interface->type->name eq $targetInterfaceName) {
                        $targetDataNode = $interface;
                        my $exposedAttribute = $targetDataNode->extendedAttributes->{"Exposed"} || "Window";
                        $exposedAttribute = substr($exposedAttribute, 1, -1) if substr($exposedAttribute, 0, 1) eq "(";
                        @targetGlobalContexts = split(",", $exposedAttribute);
                        last;
                    }
                }
                die "Not found an interface ${targetInterfaceName} in ${targetInterfaceName}.idl." unless defined $targetDataNode;

                # Support for attributes of partial interfaces.
                foreach my $attribute (@{$interface->attributes}) {
                    next unless shouldPropertyBeExposed($attribute, \@targetGlobalContexts);

                    # Record that this attribute is implemented by $interfaceName.
                    $attribute->extendedAttributes->{"ImplementedBy"} = $interfaceName if $interface->isPartial && !$attribute->extendedAttributes->{Reflect};

                    # Add interface-wide extended attributes to each attribute.
                    foreach my $extendedAttributeName (keys %{$interface->extendedAttributes}) {
                        $attribute->extendedAttributes->{$extendedAttributeName} = $interface->extendedAttributes->{$extendedAttributeName};
                    }
                    push(@{$targetDataNode->attributes}, $attribute);
                }

                # Support for methods of partial interfaces.
                foreach my $operation (@{$interface->operations}) {
                    next unless shouldPropertyBeExposed($operation, \@targetGlobalContexts);

                    # Record that this method is implemented by $interfaceName.
                    $operation->extendedAttributes->{"ImplementedBy"} = $interfaceName if $interface->isPartial;

                    # Add interface-wide extended attributes to each method.
                    foreach my $extendedAttributeName (keys %{$interface->extendedAttributes}) {
                        $operation->extendedAttributes->{$extendedAttributeName} = $interface->extendedAttributes->{$extendedAttributeName};
                    }
                    push(@{$targetDataNode->operations}, $operation);
                }

                # Support for constants of partial interfaces.
                foreach my $constant (@{$interface->constants}) {
                    next unless shouldPropertyBeExposed($constant, \@targetGlobalContexts);

                    # Record that this constant is implemented by $interfaceName.
                    $constant->extendedAttributes->{"ImplementedBy"} = $interfaceName if $interface->isPartial;

                    # Add interface-wide extended attributes to each constant.
                    foreach my $extendedAttributeName (keys %{$interface->extendedAttributes}) {
                        $constant->extendedAttributes->{$extendedAttributeName} = $interface->extendedAttributes->{$extendedAttributeName};
                    }
                    push(@{$targetDataNode->constants}, $constant);
                }
            } else {
                die "$idlFile is not a supplemental dependency of $targetIdlFile. There maybe a bug in the supplemental dependency generator (preprocess-idls.pl).\n";
            }
        }
    }

    # Generate desired output for the target IDL file.
    my $codeGen = CodeGenerator->new(\@idlDirectories, $generator, $outputDirectory, $outputHeadersDirectory, $preprocessor, $writeDependencies, $verbose, $targetIdlFile, $idlAttributes);
    $codeGen->ProcessDocument($targetDocument, $defines);
}

# Attributes / Operations / Constants of supplemental interfaces can have an [Exposed=XX] attribute which restricts
# on which global contexts they should be exposed.
sub shouldPropertyBeExposed
{
    my ($context, $targetGlobalContexts) = @_;

    my $exposed = $context->extendedAttributes->{Exposed};

    return 1 unless $exposed;

    $exposed = substr($exposed, 1, -1) if substr($exposed, 0, 1) eq "(";
    my @sourceGlobalContexts = split(",", $exposed);

    for my $targetGlobalContext (@$targetGlobalContexts) {
        return 1 if grep(/^$targetGlobalContext$/, @sourceGlobalContexts);
    }
    return 0;
}

sub generateEmptyHeaderAndCpp
{
    my ($prefix, $targetInterfaceName, $outputHeadersDirectory, $outputDirectory) = @_;

    my $headerName = "${prefix}${targetInterfaceName}.h";
    my $cppName = "${prefix}${targetInterfaceName}.cpp";
    my $contents = "/*
    This file is generated just to tell build scripts that $headerName and
    $cppName are created for ${targetInterfaceName}.idl, and thus
    prevent the build scripts from trying to generate $headerName and
    $cppName at every build. This file must not be tried to compile.
*/
";
    open FH, "> ${outputHeadersDirectory}/${headerName}" or die "Cannot open $headerName\n";
    print FH $contents;
    close FH;

    open FH, "> ${outputDirectory}/${cppName}" or die "Cannot open $cppName\n";
    print FH $contents;
    close FH;
}