#!/usr/bin/perl
#############################################################################
##
## Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
## Contact: http://www.qt-project.org/
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## This file is part of the utilities of the Qt Toolkit.
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## rights. These rights are described in the Nokia Qt LGPL Exception
## version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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## Alternatively, this file may be used under the terms of the GNU General
## Public License version 3.0 as published by the Free Software Foundation
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## file. Please review the following information to ensure the GNU General
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#############################################################################

use v5.008;
use strict;
use warnings;

package Qt::Build;

use Carp         qw( confess             );
use English      qw( -no_match_vars      );
use Getopt::Long qw( GetOptionsFromArray );
use Pod::Usage   qw( pod2usage           );
use Cwd          qw( getcwd              );
use File::Spec   qw( path catfile        );
use Config;

# Like `system', but possibly log the command, and die on non-zero exit code
sub exe
{
    my ($self, @cmd) = @_;

    print "+ @cmd\n" unless ($self->{quiet});

    if (system(@cmd) != 0) {
        confess "@cmd exited with status $CHILD_ERROR";
    }

    return 0;
}

sub dropPrivileges()
{
    my ($self) = @_;

    if ($> == 0) { # EUID == 0: must drop if possible
        local $! = undef;
        if ($< != 0) { # UID != 0 (run through setuid). swap UID with EUID
            ($(, $)) = ($), $();
            die "Cannot lower gid privileges: $!" if $!;
            ($<, $>) = ($>, $<);
            die "Cannot lower uid privileges: $!" if $!;
        } else { # UID == 0: run through sudo?
            if (defined $ENV{SUDO_GID}) {
                $) = "$ENV{SUDO_GID} $ENV{SUDO_GID}";
                die "Cannot lower gid privileges: $!" if $!;
            }
            if (defined $ENV{SUDO_UID}) {
                $> = $ENV{SUDO_UID};
                die "Cannot lower uid privileges: $!" if $!;
            }
        }
    }
}

sub exeHighPriv()
{
    my ($self, @cmd) = @_;
    return $self->exe(@cmd);
}

sub exeLowPriv()
{
    my ($self, @cmd) = @_;

    if ("$Config{osname}" =~ /mswin/i) {
        # Just like exeHighPriv for now
        return $self->exe(@cmd);
    } else {
        my $ret;
        my $pid = fork();
        die "Couldn't fork" unless defined $pid;
        if ($pid == 0) {
            $self->dropPrivileges;
            $self->exe(@cmd);
            exit 0;
        } else {
            waitpid($pid, 0);
            return $?;
        }
    }
}

sub new
{
    my ($class, @arguments) = @_;

    my $self = {};
    bless $self, $class;

    $self->parse_arguments(@arguments);
    $self->detect_configuration;

    my $depfile = "build.dependencies";
    my $result;
    our (%build_dependencies, %build_commands, %install_commands, @nondefault_modules);

    # following variables may be expanded in the evaluation below
    my $MAKEOPTS = $self->{'MAKEOPTS'};
    my $MAKE = $self->{'MAKE'};

    unless ($result = do $depfile) {
        die "build couldn't parse $depfile: $@" if $@;
        die "build couldn't execute $depfile: $!" unless defined $result;
    }

    $self->{'deps'} = \%build_dependencies;
    $self->{'buildcmds'} = \%build_commands;
    $self->{'instcmds'} = \%install_commands;
    $self->{'nondefault'} = \@nondefault_modules;

    return $self;
}

sub parse_arguments
{
    my ($self, @args) = @_;

    %{$self} = (%{$self},
        'verbose'             => 0,
        'continue'            => 0,
        'jobs'                => -1,
        'force_qmake'         => 0,
        'build-submodules'    => [],
    );

    GetOptionsFromArray(\@args,
        'verbose|v:1'   =>  \$self->{'verbose'},
        'continue'      =>  \$self->{'continue'},
        'jobs|j:1'      =>  \$self->{'jobs'},
        'force-qmake'   =>  \$self->{'force_qmake'},
        'help|?'        =>  sub { pod2usage(1); },
    ) || pod2usage(2);

    push(@{$self->{'build-submodules'}}, @args) if (@args);

    return;
}

sub which {
    my ($self, $exe) = @_;

    foreach my $path (File::Spec->path()) {
        my $file = File::Spec->catfile($path, $exe);
        return $file if -x $file;
    }
    return;
}

sub detect_configuration
{
    my ($self) = @_;

    die "You need to configure Qt before you try to build it, aborting." if (!-e 'qtbase/.qmake.cache');

    use Cwd qw(abs_path);
    use Env qw(@PATH);

    my $abs_path = abs_path('qtbase/bin');
    unshift @PATH, $abs_path;

    if ($self->{'jobs'} >= 0) {
        $self->{'MAKEOPTS'} = "-j $self->{'jobs'}";
    } else {
        $self->{'MAKEOPTS'} = "";
    }
    $self->{'MAKE'} = $ENV{MAKE} || "make";

    if ("$Config{osname}" =~ /mswin/i) {
        my $exe = $self->which("nmake.exe");
        $exe = $self->which("jom.exe") if (defined $exe && $self->which("jom.exe"));
        $exe = $self->which("mingw32-make.exe") if (!defined $exe);

         # Use the /MP compiler option, if using nmake, to use all CPU threads when compiling
        if ($exe =~ 'nmake') {
            my $cl = $ENV{'CL'};
            if (defined $cl) {
                $cl .= ' /MP';
            } else {
                $cl = '/MP';
            }
            $ENV{'CL'} = $cl;
        }

        $self->{'MAKE'} = "\"$exe\"" if (defined $exe);
        $self->{'MAKEOPTS'} = "" if (defined $exe && $exe =~ /nmake/);

        # Tools needed for building QtWebKit/Windows (Bison, Flex, gperf, iconv)
        my $abs_path = abs_path('gnuwin32/bin');
        unshift @PATH, "$abs_path";
    }
}

sub find_pro_file
{
    my ($self, $dir) = @_;
    my $D;
    if (opendir($D,$dir)) {
        ($dir =~ /\/$/) || ($dir .= "/");
        foreach my $file (sort readdir($D)) {
            if ($file  =~ /^.*\.pro$/) {
                closedir($D);
                return $file;
            }
        }
        closedir($D);
    }
}

sub eliminate_empty_modules
{
    my ($self) = @_;
    foreach my $repo (keys(%{$self->{'deps'}})) {
        if (!$self->find_pro_file($repo)) {
            printf "Missing module %s, ignored\n", $repo;
            delete $self->{'deps'}->{$repo};
        }
    }
}

sub check_build_module
{
    my ($self, $module) = @_;
    my @missing_link;
    foreach my $submod (split(/,/, $self->{'deps'}->{$module})) {
        next if ($submod =~ /:s$/);  # Soft dependency
        if (defined $self->{'deps'}->{$submod}) {
            push(@missing_link, $self->check_build_module($submod));
        } else {
            push(@missing_link, $submod);
        }
    }
    return @missing_link;
}

sub check_build_modules
{
    my ($self, $fail) = @_;
    my $letsdie = 0;
    foreach my $module (@{$self->{'build-submodules'}}) {
        if (defined $self->{'deps'}->{$module}) {
            my @missing_link = $self->check_build_module($module);
            if (scalar @missing_link) {
                $letsdie = 1;
                my $mods = join(", ", @missing_link);
                print STDERR "Ignoring module '$module': requires $mods\n";
            }
        } else {
            print STDERR "No module named '$module'\n";
            $letsdie = 1;
        }
    }
    die "FAIL: Missing module dependencies, build aborted." if ($letsdie && $fail);
}

sub resolve_soft_dependencies
{
    my ($self) = @_;

    my @nondefault = @{$self->{'nondefault'}};
    foreach my $module (keys(%{$self->{'deps'}})) {
        my @deps = split(/,/, $self->{'deps'}->{$module});
        my @newdeps;
        foreach my $dep (@deps) {
            if ($dep =~ /(.*):s$/) {
                my $mod = $1;
                if (defined $self->{'deps'}->{$mod}
                    && !grep {$_ eq $mod} @nondefault) {
                    push(@newdeps, $mod);
                }
            } else {
                push(@newdeps, $dep);
            }
        }
        $self->{'deps'}->{$module} = join(",", @newdeps);
    }
}

sub mark_as_finished
{
    my ($self, $doneModule) = @_;

    delete $self->{'deps'}->{$doneModule};
    foreach my $module (keys(%{$self->{'deps'}})) {
        my @deps = split(/,/, $self->{'deps'}->{$module});
        @deps = grep { $_ !~ /$doneModule/ } @deps;
        $self->{'deps'}->{$module} = join(",", @deps);
    }
}

sub get_next_modules
{
    my ($self, $module) = @_;

    my @nextModules;
    my $deps = $self->{'deps'}->{$module};
    return if (!defined $deps);
    $self->{'seenHash'}->{$module}++;
    if ($deps eq '') {
        push (@nextModules, $module);
        return @nextModules;
     }

    foreach my $dep (split(/,/, $deps)) {
        push (@nextModules, $self->get_next_modules($dep)) unless $self->{'seenHash'}->{$dep};
    }

    return @nextModules;
}

sub get_all_next_modules
{
    my ($self) = @_;

    $self->{'seenHash'} = ();

    my @nextModules;
    foreach my $module (@{$self->{'build-submodules'}}) {
        my @mods = $self->get_next_modules($module);
        push(@nextModules, @mods);
    }

    my %seen = ();
    my @uniqModules;
    foreach my $item (@nextModules) {
        push(@uniqModules, $item) unless $seen{$item}++;
    }

    return @uniqModules;
}

sub build_project
{
    my ($self, $module) = @_;
    my $build_command = $self->{'buildcmds'}->{$module};
    my $install_command = $self->{'instcmds'}->{$module};
    if (!defined $build_command) {
        if (!-e "$module/Makefile") {
            $self->exeLowPriv("cd $module && qmake -r") && die "'cd $module && $build_command' failed: $?";
        }
        $build_command = "$self->{MAKE} $self->{MAKEOPTS}" if (!defined $build_command);
    }
    $self->exeLowPriv("cd $module && $build_command") && die "'cd $module && $build_command' failed: $?";
    $install_command = "$self->{MAKE} install" if (!defined $install_command);
    ### TODO: Should be fixed after the alpha
    unless ("$Config{osname}" =~ /(dar|ms)win/i) {
        $self->exeHighPriv("cd $module && $install_command") && die "'cd $module && $install_command failed: $?";
    }
    $self->mark_as_finished($module);
    return 0;
}

sub build_qt
{
    my ($self) = @_;

    printf "OS Name ........ %s\n", $Config{osname};
    printf "Verbose ........ %s\n", ($self->{'verbose'} ? $self->{'verbose'} : "no");
    printf "Continue ....... %s\n", ($self->{'continue'} ? "yes" : "no");
    printf "Force qmake..... %s\n", ($self->{'force_qmake'} ? "yes" : "no");
    printf "Jobs ........... %s\n", ($self->{'jobs'} >= 0 ? $self->{'jobs'} : "unset");

    my $path = $ENV{'PATH'};
    print "PATH $path\n";

    print "Modules to build:\n";
    my $mods = "(all present)";
    $mods = join(", ", @{$self->{'build-submodules'}}) if (@{$self->{'build-submodules'}});
    print "    $mods\n";

    while (my @modules = $self->get_all_next_modules) {
        foreach my $module (@modules) {
            print "build $module...\n";
            $self->build_project($module);
        }
    }

    print "build done!\n";

    return 0;
}

sub run
{
    my ($self) = @_;

    $self->eliminate_empty_modules;

    if (scalar @{$self->{'build-submodules'}} > 0) {
        $self->check_build_modules(1);
    } else {
        my @default = keys(%{$self->{'deps'}});
        my @nondefault = @{$self->{'nondefault'}};
        foreach my $item (@nondefault) {
            @default = grep { $_ ne $item } @default;
        }
        push(@{$self->{'build-submodules'}}, @default);
        $self->check_build_modules(0);
    }

    $self->resolve_soft_dependencies;

    $self->build_qt;

#    print Dumper($self);

    return;
}

#==============================================================================

Qt::Build->new(@ARGV)->run if (!caller);
1;