#!/bin/sh
# ------------------------------------------------------------------------------
#
# git-qgoto: Implements the "git qgoto" extension command.
#
# This is derived from git-qgoto.shar, which provides each of the qit-qgoto,
# git-qpush, and git-qpop extension commands, for manipulation of the applied
# patch sequence, and unapplied patch queue.
#
# $Id$
# ------------------------------------------------------------------------------
#
# I'd have liked to call this a "SYNOPSIS", (which is what it is), but git's
# git-sh-setup script requires the much less appropriate name "OPTIONS_SPEC",
# (which describes only a small subset of its actual content).
#
OPTIONS_SPEC="\
git qgoto [[-f | --force [--no-backup]] | --keep-changes] <patch>
git qgoto [[-f | --force [--no-backup]] | --keep-changes] <index>

Push or pop patches, until the nominated patch becomes topmost on
the applied patch stack
--
f,force!       backup locally modified files, and discard changes
no-backup!     do not save any backup files from this invocation
keep-changes!  tolerate non-conflicting local changes"
#
# ------------------------------------------------------------------------------
#
# $Id$
#
# Written by Keith Marshall <keith@users.osdn.me>
# Copyright (C) 2018-2020, 2022, Keith Marshall
#
#
# This file is part of the Git-MQ program suite.
#
# The Git-MQ program suite is free software: you can redistribute it
# and/or modify it under the terms of the GNU General Public Licence
# as published by the Free Software Foundation, either version 3 of
# the Licence, or (at your option) any later version.
#
# The Git-MQ program suite 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 Licence for more details.
#
# You should have received a copy of the GNU General Public Licence
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
# ------------------------------------------------------------------------------
#
# Although they may not always have any effect, all Git-MQ commands, like
# their hg counterparts, are expected to accept the global verbosity, and
# colour control options; ensure that they are declared:
#
OPTIONS_SPEC="$OPTIONS_SPEC
colour?*     generic output colour control -- may have no effect"
${OPTION_VERBOSE_DEFINED-false} || OPTIONS_SPEC="$OPTIONS_SPEC
v,verbose!*  generic verbosity selector -- may have no effect"

# For Git-MQ options, such as "--colour", we prefer a spelling convention
# which conforms to "World English" standards; however, git itself adopts
# "US English" convention.  Thus, we must also accommodate users who will
# specify "--color" instead of "--colour", without creating any ambiguity
# in the possible abbreviations; to achieve this, we check for "--color",
# among the command-line arguments, replacing it with "--colour", BEFORE
# we allow git to parse them.
#
for mq_argv
do case "$mq_argv" in
     --color*) mq_argv=`echo $mq_argv | sed 's/^--colo/&u/'` ;;
     --no-color) mq_argv="--no-colour" ;;
   esac
   ${mq_argv_init-true} && { set -- "$mq_argv"; mq_argv_init=false
   } || set -- "$@" "$mq_argv"
done

# Now, we may let git parse the command line, and set up its shell script
# processing environment, for use within a git working directory tree.
#
SUBDIRECTORY_OK=true . "`git --exec-path`/git-sh-setup" && require_work_tree

libexecdir=`dirname "$0"`
test `basename "$libexecdir"` = bin && libexecdir=`dirname "$libexecdir"`
libexecdir="$libexecdir/libexec/git-mq/${VERSION=1.0}"

mq_require(){ test -f "$1" || die "fatal: '$1' not found."; . "$1"; }
mq_require "$libexecdir/git-mq-setup.sh"

mq_facility='git qgoto'
. $libexecdir/git-qgoto-init.sh

# The "git goto <dest>" operation is effectively equivalent to either
# "git qpush <dest>", when <dest> follows the current topmost applied
# patch in the series, or to "git qpop <dest>", when <dest> precedes
# this topmost patch; (either is suitable, if <dest> is the topmost
# patch).  The following awk script attempts to choose the appropriate
# equivalence, (favouring "git qpush", in the ambiguous case), before
# delegating to the chosen backend handler script.
#
mq_goto_direction="`awk "$mq_series $mq_status $mq_error_handler"'
  END { $0 = "'"$1"'";'"$mq_series_index_lookup"'
    if( entry[$1] >= applied ) print "qpush"; else print "qpop";
  }' $mq_series_file $mq_status_file`"
case $mq_goto_direction in qpush | qpop)
  . $libexecdir/git-${mq_goto_direction}-backend.sh ;;

# In the event of the awk script failing to identify a valid <dest>
# patch reference, it will leave an error diagnostic in place of the
# backend handler selection; report this, and abort.
#
  *) echo >&2 "$mq_goto_direction"; exit 1 ;;
esac
#
# ------------------------------------------------------------------------------
# $RCSfile$: end of file
