1 files changed, 168 insertions, 0 deletions
diff --git a/krebs/5pkgs/git-hooks/default.nix b/krebs/5pkgs/git-hooks/default.nix
new file mode 100644
index 000000000..5697c31be
--- /dev/null
+++ b/krebs/5pkgs/git-hooks/default.nix
@@ -0,0 +1,168 @@
+{ lib, pkgs, ... }:
+
+with lib;
+
+let
+  out = {
+    inherit irc-announce;
+  };
+
+  # TODO irc-announce should return a derivation
+  irc-announce = { nick, channel, server, port ? 6667, verbose ? false }: ''
+    #! /bin/sh
+    set -euf
+
+    export PATH=${makeSearchPath "bin" (with pkgs; [
+      coreutils
+      git
+      gnused
+    ])}
+
+    green()  { printf '\x0303,99%s\x0F' "$1"; }
+    red()    { printf '\x0304,99%s\x0F' "$1"; }
+    orange() { printf '\x0307,99%s\x0F' "$1"; }
+    pink()   { printf '\x0313,99%s\x0F' "$1"; }
+    gray()   { printf '\x0314,99%s\x0F' "$1"; }
+
+    unset message
+    add_message() {
+      message="''${message+$message
+    }$*"
+    }
+
+    nick=${escapeShellArg nick}
+    channel=${escapeShellArg channel}
+    server=${escapeShellArg server}
+    port=${toString port}
+
+    host=$nick
+    cgit_endpoint=http://cgit.$host
+
+    empty=0000000000000000000000000000000000000000
+
+    while read oldrev newrev ref; do
+
+      if [ $oldrev = $empty ]; then
+        receive_mode=create
+      elif [ $newrev = $empty ]; then
+        receive_mode=delete
+      elif [ "$(git merge-base $oldrev $newrev)" = $oldrev ]; then
+        receive_mode=fast-forward
+      else
+        receive_mode=non-fast-forward
+      fi
+
+      h=$(echo $ref | sed 's:^refs/heads/::')
+
+      # empty_tree=$(git hash-object -t tree /dev/null)
+      empty_tree=4b825dc6
+
+      id=$(echo $newrev | cut -b-7)
+      id2=$(echo $oldrev | cut -b-7)
+      if [ $newrev = $empty ]; then id=$empty_tree; fi
+      if [ $oldrev = $empty ]; then id2=$empty_tree; fi
+
+      case $receive_mode in
+        create)
+          link="$cgit_endpoint/$GIT_SSH_REPO/?h=$h"
+          ;;
+        delete)
+          link="$cgit_endpoint/$GIT_SSH_REPO/ ($h)"
+          ;;
+        fast-forward|non-fast-forward)
+          link="$cgit_endpoint/$GIT_SSH_REPO/diff/?h=$h&id=$id&id2=$id2"
+          ;;
+      esac
+
+      #$host $GIT_SSH_REPO $ref $link
+      add_message $(pink push) $link $(gray "($receive_mode)")
+
+      ${optionalString verbose ''
+        add_message "$(
+          git log \
+              --format="$(orange %h) %s $(gray '(%ar)')" \
+              --reverse \
+              $id2..$id
+
+          git diff --stat $id2..$id \
+            | sed '$!s/\(+*\)\(-*\)$/'$(green '\1')$(red '\2')'/'
+        )"
+      ''}
+
+    done
+
+    if test -n "''${message-}"; then
+      exec ${irc-announce-script} \
+        "$server" \
+        "$port" \
+        "$nick" \
+        "$channel" \
+        "$message"
+    fi
+  '';
+
+  irc-announce-script = pkgs.writeScript "irc-announce-script" ''
+    #! /bin/sh
+    set -euf
+
+    export PATH=${makeSearchPath "bin" (with pkgs; [
+      coreutils
+      gawk
+      gnused
+      netcat
+      nettools
+    ])}
+
+    IRC_SERVER=$1
+    IRC_PORT=$2
+    IRC_NICK=$3$$
+    IRC_CHANNEL=$4
+    message=$5
+
+    export IRC_CHANNEL # for privmsg_cat
+
+    # echo2 and cat2 are used output to both, stdout and stderr
+    # This is used to see what we send to the irc server. (debug output)
+    echo2() { echo "$*"; echo "$*" >&2; }
+    cat2() { tee /dev/stderr; }
+
+    # privmsg_cat transforms stdin to a privmsg
+    privmsg_cat() { awk '{ print "PRIVMSG "ENVIRON["IRC_CHANNEL"]" :"$0 }'; }
+
+    # ircin is used to feed the output of netcat back to the "irc client"
+    # so we can implement expect-like behavior with sed^_^
+    # XXX mkselfdestructingtmpfifo would be nice instead of this cruft
+    tmpdir="$(mktemp -d irc-announce_XXXXXXXX)"
+    cd "$tmpdir"
+    mkfifo ircin
+    trap "
+      rm ircin
+      cd '$OLDPWD'
+      rmdir '$tmpdir'
+      trap - EXIT INT QUIT
+    " EXIT INT QUIT
+
+    {
+      echo2 "USER $LOGNAME 0 * :$LOGNAME@$(hostname)"
+      echo2 "NICK $IRC_NICK"
+
+      # wait for MODE message
+      sed -n '/^:[^ ]* MODE /q'
+
+      echo2 "JOIN $IRC_CHANNEL"
+
+      printf '%s' "$message" \
+        | privmsg_cat \
+        | cat2
+
+      echo2 "PART $IRC_CHANNEL"
+
+      # wait for PART confirmation
+      sed -n '/:'"$IRC_NICK"'![^ ]* PART /q'
+
+      echo2 'QUIT :Gone to have lunch'
+    } < ircin \
+      | nc "$IRC_SERVER" "$IRC_PORT" | tee -a ircin
+  '';
+
+in out