path: root/IkiWiki/Plugin/darcs.pm

#!/usr/bin/perl
package IkiWiki::Plugin::darcs;

use warnings;
use strict;
use IkiWiki;

sub import {
    hook(type => "checkconfig", id => "darcs", call => \&checkconfig);
    hook(type => "getsetup", id => "darcs", call => \&getsetup);
    hook(type => "rcs", id => "rcs_update", call => \&rcs_update);
    hook(type => "rcs", id => "rcs_prepedit", call => \&rcs_prepedit);
    hook(type => "rcs", id => "rcs_commit", call => \&rcs_commit);
    hook(type => "rcs", id => "rcs_commit_staged", call => \&rcs_commit_staged);
    hook(type => "rcs", id => "rcs_add", call => \&rcs_add);
    hook(type => "rcs", id => "rcs_remove", call => \&rcs_remove);
    hook(type => "rcs", id => "rcs_rename", call => \&rcs_rename);
    hook(type => "rcs", id => "rcs_recentchanges", call => \&rcs_recentchanges);
    hook(type => "rcs", id => "rcs_diff", call => \&rcs_diff);
    hook(type => "rcs", id => "rcs_getctime", call => \&rcs_getctime);
    hook(type => "rcs", id => "rcs_getmtime", call => \&rcs_getmtime);
}

sub silentsystem (@) {
    open(SAVED_STDOUT, ">&STDOUT");
    open(STDOUT, ">/dev/null");
    my $ret = system @_;
    open(STDOUT, ">&SAVED_STDOUT");
    return $ret;
}

sub darcs_info ($$$) {
    my $field = shift;
    my $repodir = shift;
    my $file = shift; # Relative to the repodir.

    my $child = open(DARCS_CHANGES, "-|");
    if (! $child) {
        exec('darcs', 'changes', '--repodir', $repodir, '--xml-output', $file) or
            error("failed to run 'darcs changes'");
    }

    # Brute force for now.  :-/
    while (<DARCS_CHANGES>) {
        last if /^<\/created_as>$/;
    }
    ($_) = <DARCS_CHANGES> =~ /$field=\'([^\']+)/;
    $field eq 'hash' and s/\.gz//; # Strip away the '.gz' from 'hash'es.

    close(DARCS_CHANGES);

    return $_;
}

sub file_in_vc ($$) {
    my $repodir = shift;
    my $file = shift;

    my $child = open(DARCS_MANIFEST, "-|");
    if (! $child) {
        exec('darcs', 'query', 'manifest', '--repodir', $repodir) or
            error("failed to run 'darcs query manifest'");
    }
    my $found=0;
    while (<DARCS_MANIFEST>) {
        $found = 1 if /^(\.\/)?$file$/;
    }
    close(DARCS_MANIFEST) or error("'darcs query manifest' exited " . $?);

    return $found;
}

sub darcs_rev ($) {
    my $file = shift; # Relative to the repodir.
    my $repodir = $config{srcdir};

    return "" unless file_in_vc($repodir, $file);
    my $hash = darcs_info('hash', $repodir, $file);
    return defined $hash ? $hash : "";
}

sub checkconfig () {
    if (defined $config{darcs_wrapper} && length $config{darcs_wrapper}) {
        push @{$config{wrappers}}, {
            wrapper => $config{darcs_wrapper},
            wrappermode => (defined $config{darcs_wrappermode} ? $config{darcs_wrappermode} : "06755"),
        };
    }
}

sub getsetup () {
    return
        plugin => {
            safe => 0, # rcs plugin
            rebuild => undef,
            section => "rcs",
        },
        darcs_wrapper => {
            type => "string",
            example => "/darcs/repo/_darcs/ikiwiki-wrapper",
            description => "wrapper to generate (set as master repo apply hook)",
            safe => 0, # file
            rebuild => 0,
        },
        darcs_wrappermode => {
            type => "string",
            example => '06755',
            description => "mode for darcs_wrapper (can safely be made suid)",
            safe => 0,
            rebuild => 0,
        },
        historyurl => {
            type => "string",
            example => "http://darcs.example.com/darcsweb.cgi?r=wiki;a=filehistory;f=[[file]]",
            description => "darcsweb url to show file history ([[file]] substituted)",
            safe => 1,
            rebuild => 1,
        },
        diffurl => {
            type => "string",
            example => "http://darcs.example.com/darcsweb.cgi?r=wiki;a=filediff;h=[[hash]];f=[[file]]",
            description => "darcsweb url to show a diff ([[hash]] and [[file]] substituted)",
            safe => 1,
            rebuild => 1,
        },
}

sub rcs_update () {
    silentsystem('darcs', "pull", "--repodir", $config{srcdir}, "-qa")
}

sub rcs_prepedit ($) {
    # Prepares to edit a file under revision control.  Returns a token that
    # must be passed to rcs_commit() when the file is to be commited.  For us,
    # this token the hash value of the latest patch that modifies the file,
    # i.e. something like its current revision.

    my $file = shift; # Relative to the repodir.
    my $rev = darcs_rev($file);
    return $rev;
}

sub commitauthor (@) {
    my %params=@_;
    
    my $author="anon\@web";
    if (defined $params{session}) {
        if (defined $params{session}->param("name")) {
            return $params{session}->param("name").'@web';
        }
        elsif (defined $params{session}->remote_addr()) {
            return $params{session}->remote_addr().'@web';
        }
    }
    return 'anon@web';
}

sub rcs_commit (@) {
    # Commit the page.  Returns 'undef' on success and a version of the page
    # with conflict markers on failure.
    my %params=@_;

    my ($file, $message, $token) =
        ($params{file}, $params{message}, $params{token});

    # Compute if the "revision" of $file changed.
    my $changed = darcs_rev($file) ne $token;

    # Yes, the following is a bit convoluted.
    if ($changed) {
        # TODO.  Invent a better, non-conflicting name.
        rename("$config{srcdir}/$file", "$config{srcdir}/$file.save") or
            error("failed to rename $file to $file.save: $!");

        # Roll the repository back to $token.

        # TODO.  Can we be sure that no changes are lost?  I think that
        # we can, if we make sure that the 'darcs push' below will always
        # succeed.
    
        # We need to revert everything as 'darcs obliterate' might choke
        # otherwise.
        # TODO: 'yes | ...' needed?  Doesn't seem so.
        silentsystem('darcs', "revert", "--repodir", $config{srcdir}, "--all") == 0 ||
            error("'darcs revert' failed");
        # Remove all patches starting at $token.
        my $child = open(DARCS_OBLITERATE, "|-");
        if (! $child) {
            open(STDOUT, ">/dev/null");
            exec('darcs', "obliterate", "--repodir", $config{srcdir},
               "--match", "hash " . $token) and
               error("'darcs obliterate' failed");
        }
        1 while print DARCS_OBLITERATE "y";
        close(DARCS_OBLITERATE);
        # Restore the $token one.
        silentsystem('darcs', "pull", "--quiet", "--repodir", $config{srcdir},
            "--match", "hash " . $token, "--all") == 0 ||
            error("'darcs pull' failed");
    
        # We're back at $token.  Re-install the modified file.
        rename("$config{srcdir}/$file.save", "$config{srcdir}/$file") or
            error("failed to rename $file.save to $file: $!");
    }

    # Record the changes.
    my $author=commitauthor(%params);
    if (!defined $message || !length($message)) {
        $message = "empty message";
    }
    silentsystem('darcs', 'record', '--repodir', $config{srcdir}, '--all',
            '-m', $message, '--author', $author, $file) == 0 ||
        error("'darcs record' failed");

    # Update the repository by pulling from the default repository, which is
    # master repository.
    silentsystem('darcs', "pull", "--quiet", "--repodir", $config{srcdir},
        "--all") == 0 || error("'darcs pull' failed");

    # If this updating yields any conflicts, we'll record them now to resolve
    # them.  If nothing is recorded, there are no conflicts.
    $token = darcs_rev($file);
    # TODO: Use only the first line here, i.e. only the patch name?
    writefile("$file.log", $config{srcdir}, 'resolve conflicts: ' . $message);
    silentsystem('darcs', 'record', '--repodir', $config{srcdir}, '--all',
        '-m', 'resolve conflicts: ' . $message, '--author', $author, $file) == 0 ||
        error("'darcs record' failed");
    my $conflicts = darcs_rev($file) ne $token;
    unlink("$config{srcdir}/$file.log") or
        error("failed to remove '$file.log'");

    # Push the changes to the main repository.
    silentsystem('darcs', 'push', '--quiet', '--repodir', $config{srcdir}, '--all') == 0 ||
        error("'darcs push' failed");
    # TODO: darcs send?

    if ($conflicts) {
        my $document = readfile("$config{srcdir}/$file");
        # Try to leave everything in a consistent state.
        # TODO: 'yes | ...' needed?  Doesn't seem so.
        silentsystem('darcs', "revert", "--repodir", $config{srcdir}, "--all") == 0 || 
            warn("'darcs revert' failed");
        return $document;
    }
    else {
        return undef;
    }
}

sub rcs_commit_staged (@) {
    my %params=@_;

    my $author=commitauthor(%params);
    if (!defined $params{message} || !length($params{message})) {
        $params{message} = "empty message";
    }

    silentsystem('darcs', "record", "--repodir", $config{srcdir},
        "-a", "-A", $author,
        "-m", $params{message},
    ) == 0 || error("'darcs record' failed");

    # Push the changes to the main repository.
    silentsystem('darcs', 'push', '--quiet', '--repodir', $config{srcdir}, '--all') == 0 ||
        error("'darcs push' failed");
    # TODO: darcs send?

    return undef;
}

sub rcs_add ($) {
    my $file = shift; # Relative to the repodir.

    if(! file_in_vc($config{srcdir}, $file)) {
        # Intermediate directories will be added automagically.
        system('darcs', 'add', '--quiet', '--repodir', $config{srcdir},
            '--boring', $file) == 0 || error("'darcs add' failed");
    }
}

sub rcs_remove ($) {
    my $file = shift; # Relative to the repodir.

    unlink($config{srcdir}.'/'.$file);
}

sub rcs_rename ($$) {
    my $a = shift; # Relative to the repodir.
    my $b = shift; # Relative to the repodir.

    system('darcs', 'mv', '--repodir', $config{srcdir}, $a, $b) == 0 ||
        error("'darcs mv' failed");
}

sub rcs_recentchanges ($) {
    my $num=shift;
    my @ret;

    eval q{use Date::Parse};
    eval q{use XML::Simple};

    my $repodir=$config{srcdir};

    my $child = open(LOG, "-|");
    if (! $child) {
        $ENV{"DARCS_DONT_ESCAPE_ANYTHING"}=1;
        exec("darcs", "changes", "--xml", 
            "--summary",
             "--repodir", "$repodir",
             "--last", "$num")
        || error("'darcs changes' failed to run");
    }
    my $data;
    $data .= $_ while(<LOG>);
    close LOG;

    my $log = XMLin($data, ForceArray => 1);

    foreach my $patch (@{$log->{patch}}) {
        my $date=$patch->{local_date};
        my $hash=$patch->{hash};
        my $when=str2time($date);
        my (@pages, @files, @pg);
        push @pages, $_ foreach (@{$patch->{summary}->[0]->{modify_file}});
        push @pages, $_ foreach (@{$patch->{summary}->[0]->{add_file}});
        push @pages, $_ foreach (@{$patch->{summary}->[0]->{remove_file}});
        foreach my $f (@pages) {
            $f = $f->{content} if ref $f;
            $f =~ s,^\s+,,; $f =~ s,\s+$,,; # cut whitespace

            push @files, $f;
        }
        foreach my $p (@{$patch->{summary}->[0]->{move}}) {
            push @files, $p->{from};
        }

        foreach my $f (@files) {
            my $d = defined $config{'diffurl'} ? $config{'diffurl'} : "";
            $d =~ s/\[\[file\]\]/$f/go;
            $d =~ s/\[\[hash\]\]/$hash/go;

            push @pg, {
                page => pagename($f),
                diffurl => $d,
            };
        }
        next unless (scalar @pg > 0);

        my @message;
        push @message, { line => $_ } foreach (@{$patch->{name}});

        my $committype;
        my $author;
        if ($patch->{author} =~ /(.*)\@web$/) {
            $author = $1;
            $committype = "web";
        }
        else {
            $author=$patch->{author};
            $committype = "darcs";
        }

        push @ret, {
            rev => $patch->{hash},
            user => $author,
            committype => $committype,
            when => $when, 
            message => [@message],
            pages => [@pg],
        };
    }

    return @ret;
}

sub rcs_diff ($;$) {
    my $rev=shift;
    my $maxlines=shift;
    my @lines;
    my $repodir=$config{srcdir};
    foreach my $line (`darcs diff --repodir  $repodir --match 'hash $rev'`) {
        if (@lines || $line=~/^diff/) {
            last if defined $maxlines && @lines == $maxlines;
            push @lines, $line."\n";
        }
    }
    if (wantarray) {
        return @lines;
    }
    else {
        return join("", @lines);
    }
}

sub rcs_getctime ($) {
    my $file=shift;

    eval q{use Date::Parse};
    eval q{use XML::Simple};
    local $/=undef;

    my $child = open(LOG, "-|");
    if (! $child) {
        exec("darcs", "changes", "--xml", "--reverse",
            "--repodir", $config{srcdir}, $file)
        || error("'darcs changes $file' failed to run");
    }

    my $data;
    {
        local $/=undef;
        $data = <LOG>;
    }
    close LOG;

    my $log = XMLin($data, ForceArray => 1);

    my $datestr = $log->{patch}[0]->{local_date};

    if (! defined $datestr) {
        warn "failed to get ctime for $file";
        return 0;
    }

    my $date = str2time($datestr);
    
    debug("ctime for '$file': ". localtime($date));

    return $date;
}

sub rcs_getmtime ($) {
    error "rcs_getmtime is not implemented for darcs\n"; # TODO
}

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