#!/usr/bin/perl -w

use strict;
use Cwd;

$| = 1; # autoflush stdout after each print, to avoid output after die

my $defaultrepo;
my @packages;
my $verbose = 2;
my $try_to_resume = 0;
my $ignore_failure = 0;
my $checked_out_flag = 0; # NOT the opposite of bare_flag (describes remote repo state)
my $get_mode;
my $bare_flag = ""; # NOT the opposite of checked_out_flag (describes local repo state)

my %tags;

# Figure out where to get the other repositories from.
sub getrepo {
    my $repo;

    if (defined($defaultrepo)) {
        $repo = $defaultrepo;
        chomp $repo;
    } else {
        # Figure out where to get the other repositories from,
        # based on where this GHC repo came from.
        my $git_dir = $bare_flag ? "--git-dir=ghc.git" : "";
        my $branch  = `git $git_dir branch | grep "\* " | sed "s/^\* //"`; chomp $branch;
        my $remote  = `git $git_dir config branch.$branch.remote`;         chomp $remote;
        if ($remote eq "") {
            # remotes are not mandatory for branches (e.g. not recorded by default for bare repos)
            $remote = "origin";
        }
        $repo       = `git $git_dir config remote.$remote.url`;            chomp $repo;
    }

    my $repo_base;
    my $checked_out_tree;

    if ($repo =~ /^...*:/) {
        # HTTP or SSH
        # Above regex says "at least two chars before the :", to avoid
        # catching Win32 drives ("C:\").
        $repo_base = $repo;

        # --checked-out is needed if you want to use a checked-out repo
        # over SSH or HTTP
        if ($checked_out_flag) {
            $checked_out_tree = 1;
        } else {
            $checked_out_tree = 0;
        }

        # Don't drop the last part of the path if specified with -r, as
        # it expects repos of the form:
        #
        #   http://darcs.haskell.org
        #
        # rather than
        #
        #   http://darcs.haskell.org/ghc
        #
        if (!$defaultrepo) {
            $repo_base =~ s#/[^/]+/?$##;
        }
    }
    elsif ($repo =~ /^\/|\.\.\/|.:(\/|\\)/) {
        # Local filesystem, either absolute (C:/ or /) or relative (../) path
        $repo_base = $repo;
        if (-f "$repo/HEAD") {
            # assume a local mirror:
            $checked_out_tree = 0;
            $repo_base =~ s#/[^/]+/?$##;
        } elsif (-d "$repo/ghc.git") {
            # assume a local mirror:
            $checked_out_tree = 0;
        } else {
            # assume a checked-out tree:
            $checked_out_tree = 1;
        }
    }
    else {
        die "Couldn't work out repo";
    }

    return $repo_base, $checked_out_tree;
}

sub parsePackages {
    my @repos;
    my $lineNum;

    open IN, "< packages.conf"
        or open IN, "< packages" # clashes with packages directory when using --bare
        or die "Can't open packages file (or packages.conf)";
    @repos = <IN>;
    close IN;

    @packages = ();
    $lineNum = 0;
    foreach (@repos) {
        chomp;
        $lineNum++;
        if (/^([^# ]+) +([^ ]+) +([^ ]+) +([^ ]+)$/) {
            my %line;
            $line{"localpath"}  = $1;
            $line{"tag"}        = $2;
            $line{"remotepath"} = $3;
            $line{"vcs"}        = $4;
            push @packages, \%line;
        }
        elsif (! /^(#.*)?$/) {
            die "Bad content on line $lineNum of packages file: $_";
        }
    }
}

sub message {
    if ($verbose >= 2) {
        print "@_\n";
    }
}

sub warning {
    if ($verbose >= 1) {
        print "warning: @_\n";
    }
}

sub scm {
    my $dir = shift;
    my $scm = shift;
    my $pwd;

    if ($dir eq '.') {
        message "== running $scm @_";
    } else {
        message "== $dir: running $scm @_";
        $pwd = getcwd();
        chdir($dir);
    }

    system ($scm, @_) == 0
        or $ignore_failure
        or die "$scm failed: $?";

    if ($dir ne '.') {
        chdir($pwd);
    }
}

sub scmall {
    my $command = shift;

    my $localpath;
    my $tag;
    my $remotepath;
    my $scm;
    my $line;
    my $branch_name;
    my $subcommand;

    my $path;
    my $wd_before = getcwd;

    my $pwd;
    my @args;

    my $started;
    my $doing;
    my $start_repo;

    my ($repo_base, $checked_out_tree) = getrepo();

    my $is_github_repo = $repo_base =~ m/(git@|git:\/\/|https:\/\/)github.com/;

    parsePackages;

    @args = ();

    if ($command =~ /^remote$/) {
        while (@_ > 0 && $_[0] =~ /^-/) {
            push(@args,shift);
        }
        if (@_ < 1) { help(1); }
        $subcommand = shift;
        if ($subcommand ne 'add' && $subcommand ne 'rm' && $subcommand ne 'set-url') {
            help(1);
        }
        while (@_ > 0 && $_[0] =~ /^-/) {
            push(@args,shift);
        }
        if (($subcommand eq 'add' || $subcommand eq 'rm') && @_ < 1) {
            help(1);
        } elsif (@_ < 1) { # set-url
            $branch_name = 'origin';
        } else {
            $branch_name = shift;
        }
    } elsif ($command eq 'new') {
        if (@_ < 1) {
            $branch_name = 'origin';
        } else {
            $branch_name = shift;
        }
    }

    push(@args, @_);

    # $doing is a good enough approximation to what we are doing that
    # we can use it to check that --resume is resuming the right command
    $doing = join(" ", ($command, @args));
    $started = 1;
    if ($try_to_resume && -f "resume") {
        my $what;
        open RESUME, "< resume"
            or die "Can't open resume file";
        $start_repo = <RESUME>;
        chomp $start_repo;
        $what = <RESUME>;
        chomp $what;
        close RESUME;
        if ($what eq $doing) {
            $started = 0;
        }
    }

    for $line (@packages) {
        $tag        = $$line{"tag"};
        $scm        = $$line{"vcs"};
        # Use the "remote" structure for bare git repositories
        $localpath  = ($bare_flag && $scm eq "git") ?
                      $$line{"remotepath"} : $$line{"localpath"};
        $remotepath = ($checked_out_tree) ?
                      $$line{"localpath"}  : $$line{"remotepath"};

        if (!$started) {
            if ($start_repo eq $localpath) {
                $started = 1;
            }
            else {
                next;
            }
        }

        open RESUME, "> resume.tmp";
        print RESUME "$localpath\n";
        print RESUME "$doing\n";
        close RESUME;
        rename "resume.tmp", "resume";

        # Check the SCM is OK as early as possible
        die "Unknown SCM: $scm" if (($scm ne "darcs") and ($scm ne "git"));

        # We can't create directories on GitHub, so we translate
        # "packages/foo" into "package-foo".
        if ($is_github_repo) {
            $remotepath =~ s/\//-/;
        }

        # Construct the path for this package in the repo we pulled from
        $path = "$repo_base/$remotepath";

        if ($command =~ /^(?:g|ge|get)$/) {
            # Skip any repositories we have not included the tag for
            if (not defined($tags{$tag})) {
                $tags{$tag} = 0;
            }
            if ($tags{$tag} == 0) {
                next;
            }

            if (-d $localpath) {
                warning("$localpath already present; omitting")
                    if $localpath ne ".";
                if ($scm eq "git") {
                    scm ($localpath, $scm, "config", "core.ignorecase", "true");
                }
                next;
            }

            # Note that we use "." as the path, as $localpath
            # doesn't exist yet.
            if ($scm eq "darcs") {
                # The first time round the loop, default the get-mode
                if (not defined($get_mode)) {
                    warning("adding --partial, to override use --complete");
                    $get_mode = "--partial";
                }
                scm (".", $scm, "get", $get_mode, $path, $localpath, @args);
            }
            else {
                my @argsWithBare = @args;
                push @argsWithBare, $bare_flag if $bare_flag;
                scm (".", $scm, "clone", $path, $localpath, @argsWithBare);
                scm ($localpath, $scm, "config", "core.ignorecase", "true");
            }
            next;
        }

        my $darcs_repo_present = 1 if -d "$localpath/_darcs";
        my $git_repo_present = 1 if -d "$localpath/.git" || ($bare_flag && -d "$localpath");
        if ($darcs_repo_present) {
            if ($git_repo_present) {
                die "Found both _darcs and .git in $localpath";
            }
            $scm = "darcs";
        } elsif ($git_repo_present) {
            $scm = "git";
        } elsif ($tag eq "") {
            die "Required repo $localpath is missing";
        } else {
             message "== $localpath repo not present; skipping";
             next;
        }

        # Work out the arguments we should give to the SCM
        if ($command =~ /^(?:w|wh|wha|what|whats|whatsn|whatsne|whatsnew|status)$/) {
            if ($scm eq "darcs") {
                $command = "whatsnew";
            }
            elsif ($scm eq "git") {
                $command = "status";
            }
            else {
                die "Unknown scm";
            }

            # Hack around 'darcs whatsnew' failing if there are no changes
            $ignore_failure = 1;
            scm ($localpath, $scm, $command, @args);
        }
        elsif ($command =~ /^commit$/) {
            # git fails if there is nothing to commit, so ignore failures
            $ignore_failure = 1;
            scm ($localpath, $scm, "commit", @args);
        }
        elsif ($command =~ /^(?:pus|push)$/) {
            scm ($localpath, $scm, "push", @args);
        }
        elsif ($command =~ /^(?:pul|pull)$/) {
            scm ($localpath, $scm, "pull", @args);
        }
        elsif ($command =~ /^(?:s|se|sen|send)$/) {
            if ($scm eq "darcs") {
                $command = "send";
            }
            elsif ($scm eq "git") {
                $command = "send-email";
            }
            else {
                die "Unknown scm";
            }
            scm ($localpath, $scm, $command, @args);
        }
        elsif ($command =~ /^fetch$/) {
            scm ($localpath, $scm, "fetch", @args);
        }
        elsif ($command =~ /^new$/) {
            my @scm_args = ("log", "$branch_name..");
            scm ($localpath, $scm, @scm_args, @args);
        }
        elsif ($command =~ /^log$/) {
            scm ($localpath, $scm, "log", @args);
        }
        elsif ($command =~ /^remote$/) {
            my @scm_args;
            $ignore_failure = 1;
            if ($subcommand eq 'add') {
                @scm_args = ("remote", "add", $branch_name, $path);
            } elsif ($subcommand eq 'rm') {
                @scm_args = ("remote", "rm", $branch_name);
            } elsif ($subcommand eq 'set-url') {
                @scm_args = ("remote", "set-url", $branch_name, $path);
            }
            scm ($localpath, $scm, @scm_args, @args);
        }
        elsif ($command =~ /^checkout$/) {
            # Not all repos are necessarily branched, so ignore failure
            $ignore_failure = 1;
            scm ($localpath, $scm, "checkout", @args)
                unless $scm eq "darcs";
        }
        elsif ($command =~ /^grep$/) {
            # Hack around 'git grep' failing if there are no matches
            $ignore_failure = 1;
            scm ($localpath, $scm, "grep", @args)
                unless $scm eq "darcs";
        }
        elsif ($command =~ /^diff$/) {
            scm ($localpath, $scm, "diff", @args)
                unless $scm eq "darcs";
        }
        elsif ($command =~ /^clean$/) {
            scm ($localpath, $scm, "clean", @args)
                unless $scm eq "darcs";
        }
        elsif ($command =~ /^reset$/) {
            scm ($localpath, $scm, "reset", @args)
                unless $scm eq "darcs";
        }
        elsif ($command =~ /^branch$/) {
            scm ($localpath, $scm, "branch", @args)
                unless $scm eq "darcs";
        }
        elsif ($command =~ /^config$/) {
            scm ($localpath, $scm, "config", @args)
                unless $scm eq "darcs";
        }
        elsif ($command =~ /^repack$/) {
            scm ($localpath, $scm, "repack", @args)
                if $scm eq "git"
        }
        elsif ($command =~ /^format-patch$/) {
            scm ($localpath, $scm, "format-patch", @args)
                if $scm eq "git"
        }
        elsif ($command =~ /^gc$/) {
            scm ($localpath, $scm, "gc", @args)
                unless $scm eq "darcs";
        }
        elsif ($command =~ /^tag$/) {
            scm ($localpath, $scm, "tag", @args);
        }
        else {
            die "Unknown command: $command";
        }
    }

    unlink "resume";
}

sub help
{
        my $exit = shift;

        # Get the built in help
        my $help = <<END;
Usage:

./sync-all [-q] [-s] [--ignore-failure] [-r repo] [--checked-out] [--bare]
           [--nofib] [--extra] [--testsuite] [--resume] cmd [git flags]

Applies the command "cmd" to each repository in the tree.

A full repository tree is obtained by first cloning the ghc
repository, then getting the subrepositories with "sync-all get":

  \$ git clone http://darcs.haskell.org/ghc.git
  \$ cd ghc
  \$ ./sync-all get

After this, "./sync-all pull" will pull from the original repository
tree.

A remote pointing to another local repository tree can be added like
this:

  \$ ./sync-all -r /path/to/ghc remote add otherlocal

and then we can pull from this other tree with

  \$ ./sync-all pull otherlocal

-------------- Commands -----------------
get

    Clones all sub-repositories from the same place that the ghc
    repository was cloned from.  See "which repos to use" below
    for details of how the subrepositories are laid out.

    There are various --<package-tag> options that can be given
    before "get" that enable extra repositories.  The full list is
    given at the end of this help.  For example:

    ./sync-all --testsuite get

    would get the testsuite repository in addition to the usual set of
    subrepositories.

remote add <remote-name>
remote rm <remote-name>
remote set-url [--push] <remote-name>

    Runs a "git remote" command on each subrepository, adjusting the
    repository location in each case appropriately.  For example, to
    add a new remote pointing to the upstream repositories:

    ./sync-all -r http://darcs.haskell.org/ remote add upstream

    The -r flag points to the root of the repository tree (see "which
    repos to use" below).  For a repository on the local filesystem it
    would point to the ghc reposiroty, and for a remote repository it
    points to the directory containing "ghc.git".

These commands just run the equivalent git command on each repository, passing
any extra arguments to git:

  branch
  checkout
  clean
  commit
  config
  diff
  fetch
  format-patch
  gc
  grep
  log
  new
  pull
  push
  repack
  reset
  send
  status
  tag

-------------- Flags -------------------
  These flags are given *before* the command and modify the way
  sync-all behaves.  Flags given *after* the command are passed to
  git.

  -q says to be quiet, and -s to be silent.

  --resume will restart a command that failed, from the repo at which
  it failed. This means you don't need to wait while, e.g., "pull"
  goes through all the repos it's just pulled, and tries to pull them
  again.

  --ignore-failure says to ignore errors and move on to the next repository

  -r repo says to use repo as the location of package repositories

  --checked-out says that the remote repo is in checked-out layout, as
  opposed to the layout used for the main repo.  By default a repo on
  the local filesystem is assumed to be checked-out, and repos accessed
  via HTTP or SSH are assumed to be in the main repo layout; use
  --checked-out to override the latter.

  --bare says that the local repo is in bare layout, same as the main repo.
  It also means that these repos are bare. You only have to use this flag if
  you don't have a bare ghc.git in the current directory and would like to 'get'
  all of the repos bare. Requires packages.conf to be present in the current
  directory (a renamed packages file from the main ghc repo).

  Note: --checked-out and --bare flags are NOT the opposite of each other.
        --checked-out: describes the layout of the remote repository tree.
        --bare:        describes the layout of the local repository tree.

  --nofib, --testsuite also get the nofib and testsuite repos respectively


------------ Which repos to use -------------
  sync-all uses the following algorithm to decide which remote repos to use

  It always computes the remote repos from a single base, <repo_base>
  How is <repo_base> set?
    If you say "-r repo", then that's <repo_base>
    otherwise <repo_base> is set by asking git where the ghc repo came
    from, and removing the last component (e.g. /ghc.git/ or /ghc/).

  Then sync-all iterates over the package found in the file
  ./packages; see that file for a description of the contents.

    If <repo_base> looks like a local filesystem path, or if you give
    the --checked-out flag, sync-all works on repos of form
          <repo_base>/<local-path>
    otherwise sync-all works on repos of form
          <repo_base>/<remote-path>
    This logic lets you say
      both    sync-all -r http://darcs.haskell.org/ghc-6.12 remote add ghc-6.12
      and     sync-all -r ../working remote add working
    The latter is called a "checked-out tree".

  NB: sync-all *ignores* the defaultrepo of all repos other than the
  root one.  So the remote repos must be laid out in one of the two
  formats given by <local-path> and <remote-path> in the file 'packages'.

Available package-tags are:
END

        # Collect all the tags in the packages file
        my %available_tags;
        open IN, "< packages.conf"
            or open IN, "< packages" # clashes with packages directory when using --bare
            or die "Can't open packages file (or packages.conf)";
        while (<IN>) {
            chomp;
            if (/^([^# ]+) +(?:([^ ]+) +)?([^ ]+) +([^ ]+)/) {
                if (defined($2) && $2 ne "-") {
                    $available_tags{$2} = 1;
                }
            }
            elsif (! /^(#.*)?$/) {
                die "Bad line: $_";
            }
        }
        close IN;

        # Show those tags and the help text
        my @available_tags = keys %available_tags;
        print "$help@available_tags\n\n";
        exit $exit;
}

sub main {

    $tags{"-"} = 1;

    while ($#_ ne -1) {
        my $arg = shift;
        # We handle -q here as well as lower down as we need to skip over it
        # if it comes before the source-control command
        if ($arg eq "-q") {
            $verbose = 1;
        }
        elsif ($arg eq "-s") {
            $verbose = 0;
        }
        elsif ($arg eq "-r") {
            $defaultrepo = shift;
        }
        elsif ($arg eq "--resume") {
            $try_to_resume = 1;
        }
        elsif ($arg eq "--ignore-failure") {
            $ignore_failure = 1;
        }
        elsif ($arg eq "--complete" || $arg eq "--partial") {
            $get_mode = $arg;
        }
        # Use --checked-out if the _remote_ repos are a checked-out tree,
        # rather than the master trees.
        elsif ($arg eq "--checked-out") {
            $checked_out_flag = 1;
        }
        # Use --bare if the _local_ repos are bare repos,
        # rather than a checked-out tree.
        elsif ($arg eq "--bare") {
            $bare_flag = $arg;
        }
        elsif ($arg eq "--help") {
            help(0);
        }
        # --<tag> says we grab the libs tagged 'tag' with
        # 'get'. It has no effect on the other commands.
        elsif ($arg =~ m/^--no-(.*)$/) {
            $tags{$1} = 0;
        }
        elsif ($arg =~ m/^--(.*)$/) {
            $tags{$1} = 1;
        }
        else {
            unshift @_, $arg;
            if (grep /^-q$/, @_) {
                $verbose = 1;
            }
            last;
        }
    }

    # check for ghc repositories in cwd
    my $checked_out_found = 1 if (-d ".git" && -d "compiler");
    my $bare_found = 1 if (-d "ghc.git");

    if ($bare_flag && ! $bare_found && ! $defaultrepo) {
        die "error: bare repository ghc.git not found.\n"
          . "       Either clone a bare ghc repo first or specify the repo location. E.g.:\n"
          . "       ./sync-all --bare [--testsuite --nofib --extra] -r http://darcs.haskell.org/ get\n"
    }
    elsif ($bare_found) {
        $bare_flag = "--bare";
    }
    elsif (! $bare_flag && ! $checked_out_found) {
        die "error: sync-all must be run from the top level of the ghc tree.";
    }

    if ($#_ eq -1) {
        help(1);
    }
    else {
        # Give the command and rest of the arguments to the main loop
        scmall @_;
    }
}

END {
    my $ec = $?;
    my $pwd = getcwd();

    message "== Checking for old haddock repo";
    if (-d "utils/haddock/.git") {
        chdir("utils/haddock");
        if ((system "git log -1 87e2ca11c3d1b1bc49900fba0b5c5c6f85650718 > /dev/null 2> /dev/null") == 0) {
            print <<EOF;
============================
ATTENTION!

You have an old haddock repository in your GHC tree!

Please remove it (e.g. "rm -r utils/haddock"), and then run
"./sync-all get" to get the new repository.
============================
EOF
        }
        chdir($pwd);
    }

    message "== Checking for old binary repo";
    if (-d "libraries/binary/.git") {
        chdir("libraries/binary");
        if ((system "git log -1 749ac0efbde3b14901417364a872796598747aaf > /dev/null 2> /dev/null") == 0) {
            print <<EOF;
============================
ATTENTION!

You have an old binary repository in your GHC tree!

Please remove it (e.g. "rm -r libraries/binary"), and then run
"./sync-all get" to get the new repository.
============================
EOF
        }
        chdir($pwd);
    }

    $? = $ec;
}

main(@ARGV);