#!/bin/bash
#
# arch-meta-hook - generic tla hook script
# Copyright (C) 2004 Hans Ulrich Niedermann
# 
#   This program is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or
#   (at your option) any later version.
#
#   This program 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 General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software
#   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# arch-meta-hook executes hook scripts from a directory structure like:
#
# +- ARCH_HOOKDIR
#  +- me@host--2004-me
#   +- category
#    +- category--branch
#     +- category--branch--version
#      +- category--branch--version--revision
#
# The ARCH_HOOKDIR is ~/.arch-hooks or ~/.arch-params/hooks - the
# first directory found is used.
#
# In each directory from ARCH_HOOKDIR downwards, there may
# be a directory structure like
#
# +- =ACTION
#  +- 10script1
#  +- 20script2
#  +- 30script3
#
# where ACTION is the tla action performed (e.g. "commit") and the
# ??script* may be arbitrarily named executables. However, the
# ??script* naming scheme allows to determine the call sequence
# easily.
#
# If the ARCH_HOOKDIR, archive, category, version, revision match
# (ARCH_HOOKDIR always matches) and the =ACTION subdirectory exists,
# all the hook scripts in the =ACTION subdirectory are called in sequence.
#
# Note that the more general hook scripts are called for each and
# every action on more specialized items - e.g. hooks in ARCH_HOOKDIR are
# called every time.
#
# All of these hook scripts are called with the following variables
# set (example values given):
#
#    ARCH_HOOK_ACTION the tla action, e.g. commit or make-pristine
#    ARCH_ARCHIVE     me@host--2004-me
#    ARCH_CATEGORY    category
#    ARCH_BRANCH      category--branch
#    ARCH_VERSION     category--branch--version
#    ARCH_REVISION    category--branch--version--revision
#
# Hook scripts must return 0 if the tla action is to succeed.
#
# An example script may be
#
# +- ARCH_HOOKDIR
#  +- me@host--2004-me
#   +- category
#    +- =commit
#     +- 50mirror
#
# with a simple content of
#
# tla archive-mirror \
#     "$ARCH_ARCHIVE" "${ARCH_ARCHIVE}-MIRROR" \
#     "${ARCH_CATEGORY}
#
# which updates only the category on the mirror of the
# me@host--2004-me archive.
#
# You may even symlink these kinds of scripts...

# If you want to bypass the hooks for whatever reason, do...
# NOHOOKS=1 tla cmd
if [ $NOHOOKS ]; then
    echo "Bypassing hooks"
    unset NOHOOKS
    exit 0
fi

# Default hook directory
ARCH_HOOKDIR="$(dirname "$0")/hooks"
# Override hook dir if found
for dir in \
	"$HOME/.arch-hooks"
do
	if [ -d "$dir" ]; then
		ARCH_HOOKDIR="$dir"
		break
	fi
done

# Set either of these if you want
verbose=false
# verbose=true

ARCH_HOOK_ACTION="$1"
export ARCH_HOOK_ACTION

# What can't be set at all, should be set to ""
if [ "$ARCH_REVISION" != "" ]; then
    export ARCH_REVISION 

    ARCH_ONLY_LEVEL="$(tla parse-package-name --lvl ${ARCH_REVISION})"
    ARCH_ONLY_VERSION="$(tla parse-package-name --vsn ${ARCH_REVISION})"
    ARCH_ONLY_BRANCH="$(tla parse-package-name --branch ${ARCH_REVISION})"
    ARCH_ONLY_CATEGORY="$(tla parse-package-name --category ${ARCH_REVISION})"
    export ARCH_ONLY_LEVEL ARCH_ONLY_VERSION
    export ARCH_ONLY_BRANCH ARCH_ONLY_CATEGORY

    ARCH_CATEGORY="${ARCH_ONLY_CATEGORY}"
    ARCH_BRANCH="${ARCH_CATEGORY}--${ARCH_ONLY_BRANCH}"
    ARCH_VERSION="${ARCH_BRANCH}--${ARCH_ONLY_VERSION}"
    export ARCH_VERSION ARCH_BRANCH ARCH_CATEGORY
else
    echo "ARCH_REVISION not set!"
    verbose=true
fi

# Debug output
if "$verbose"; then
    set | grep '^ARCH_'
fi

failed=0
succeeded=0
# Try to execute succeedingly specialized hooks
for dir in \
    "$ARCH_HOOKDIR" \
    "$ARCH_ARCHIVE" \
    "$ARCH_CATEGORY" \
    "$ARCH_BRANCH" \
    "$ARCH_VERSION" \
    "$ARCH_REVISION"
  do
  if cd "$dir" >& /dev/null; then
      if [ -d "=$ARCH_HOOK_ACTION" ]; then
	  # we may have actions
	  for hook in "=$ARCH_HOOK_ACTION/"*[^~]; do
	      if [ -x "$hook" ]; then
		  complete="$PWD/$hook"
		  name="${complete#$ARCH_HOOKDIR/}"
		  "$verbose" && \
		      echo "Executing $ARCH_HOOK_ACTION hook script: $name"
		  "$hook"
		  status="$?"
		  if [ "$status" -eq 0 ]; then
		      "$verbose" && echo "Hook script succeeded."
		      succeeded=$(( $succeeded + 1 ))
		  else
		      if ! $verbose; then
			  echo "Hook script $ARCH_HOOK_ACTION failed: $status"
		      else
			  echo "Hook script failed: $status"
			  verbose=true
		      fi		      
		      failed=$(( $failed + 1 ))
		  fi
	      fi
	  done
      fi
  else
      # no such directory
      # then descending further doesn't make sense either
      break
  fi
done

# Print statistics
if $verbose; then
    echo "$[ $failed + $succeeded ] $ARCH_HOOK_ACTION hooks executed in total:"
    echo "    $succeeded successful"
    echo "    $failed failed"
fi

# Fail if any hook script failed
if [ "$failed" -gt 0 ]; then
    exit 1
else
    exit 0
fi