#! /usr/bin/env bash

#  This script is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License version 2 as
#  published by the Free Software Foundation.
#
#  See the COPYING and AUTHORS files for more details.

usage()
{
	printf $"Usage: quilt refresh [-p n|-p ab] [-u|-U num|-c|-C num] [-z[new_name]] [-f] [--no-timestamps] [--no-index] [--diffstat] [--sort] [--backup] [--strip-trailing-whitespace] [patch]\n"

	if [ x$1 = x-h ]
	then
		printf $"
Refreshes the specified patch, or the topmost patch by default.
Documentation that comes before the actual patch in the patch file is
retained.

It is possible to refresh patches that are not on top.  If any patches
on top of the patch to refresh modify the same files, the script aborts
by default.  Patches can still be refreshed with -f.  In that case this
script will print a warning for each shadowed file, changes by more
recent patches will be ignored, and only changes in files that have not
been modified by any more recent patches will end up in the specified
patch.

-p n	Create a -p n style patch (-p0 or -p1 supported).

-p ab	Create a -p1 style patch, but use a/file and b/file as the
	original and new filenames instead of the default
	dir.orig/file and dir/file names.

-u, -U num, -c, -C num
	Create a unified diff (-u, -U) with num lines of context. Create
	a context diff (-c, -C) with num lines of context. The number of
	context lines defaults to 3.

-z[new_name]
	Create a new patch containing the changes instead of refreshing the
	topmost patch. If no new name is specified, \`-2' is added to the
	original patch name, etc. (See the fork command.)

--no-timestamps
	Do not include file timestamps in patch headers.

--no-index
	Do not output Index: lines.

--diffstat
	Add a diffstat section to the patch header, or replace the
	existing diffstat section.

-f	Enforce refreshing of a patch that is not on top.

--backup
	Create a backup copy of the old version of a patch as patch~.

--sort	Sort files by their name instead of preserving the original order.

--strip-trailing-whitespace
	Strip trailing whitespace at the end of lines.
"
		exit 0
	else
		exit 1
	fi
}

die()
{
	local status=$1
	[ -n "$tmp_patch" ] && rm -f $tmp_patch
	[ -n "$tmp_result" ] && rm -f $tmp_result
	[ -n "$workdir" ] && rm -rf "$workdir"
	exit $status
}

options=`getopt -o p:uU:cC:fz::h --long no-timestamps,diffstat,backup,sort \
				 --long no-index \
				 --long strip-trailing-whitespace -- "$@"`

if [ $? -ne 0 ]
then
	usage
fi

eval set -- "$options"

opt_format=-u
while true
do
	case "$1" in
	-p)
		opt_strip_level=$2
		shift 2 ;;
	-f)
		opt_force=1
		shift ;;
	-u|-c)
		opt_format=$1
		shift ;;
	-U|-C)
		opt_format="$1 $2"
		shift 2 ;;
	-z)
		opt_fork=1
		opt_new_name=$2
		shift 2 ;;
	-h)
		usage -h ;;
	--no-timestamps)
		QUILT_NO_DIFF_TIMESTAMPS=1
		shift ;;
	--no-index)
		QUILT_NO_DIFF_INDEX=1
		shift ;;
	--diffstat)
		opt_diffstat=1
		shift ;;
	--backup)
		QUILT_BACKUP=1
		shift ;;
	--sort)
		opt_sort=1
		shift ;;
	--strip-trailing-whitespace)
		opt_strip_whitespace=1
		shift ;;
	--)
		shift
		break ;;
	esac
done

if [ $# -gt 1 ]
then
	usage
fi

# Read in library functions
if ! [ -r $QUILT_DIR/scripts/patchfns ]
then
	echo "Cannot read library $QUILT_DIR/scripts/patchfns" >&2
	exit 1
fi
. $QUILT_DIR/scripts/patchfns

QUILT_DIFF_OPTS="$QUILT_DIFF_OPTS $opt_format"

patch=$(find_applied_patch "$1") || exit 1

# Properly handle spaces in file names
saved_IFS=$IFS
IFS=$'\n'

if [ -z "$opt_sort" ]
then
	files=( $(files_in_patch_ordered $patch) )
else
	files=( $(files_in_patch $patch | sort) )
fi

IFS=$saved_IFS

if [ -n "$opt_fork" -a $# -ne 0 ]
then
	printf $"Can only refresh the topmost patch with -z currently\n" >&2
	exit 1
fi

if [ -n "$opt_fork" ]; then
	old_patch=$patch
	old_patch_args=$(patch_args "$old_patch")
	if [ -n "$opt_new_name" ]
	then
		patch=$opt_new_name
	else
		patch=$(next_filename "$patch")
	fi
	if [ -e "$(patch_file_name "$patch")" ]; then
		printf $"Patch %s exists already\n" "$(print_patch "$patch")" >&2
		exit 1
	fi
fi

if [ -z "$opt_strip_level" ]
then
	opt_strip_level=$(patch_strip_level "$patch")
fi
case "$opt_strip_level" in
0 | 1)
	num_strip_level=$opt_strip_level
	;;
ab)
	num_strip_level=1
	;;
*)
	printf $"Cannot refresh patches with -p%s, please specify -p0, -p1, or -pab instead\n" \
	       "$opt_strip_level" >&2
	exit 1
	;;
esac

trap "die 1" SIGTERM

if [ -n "$opt_fork" ]; then
	workdir=$(gen_tempfile -d "$PWD/quilt")
	apply_patch_temporarily "$workdir" "$old_patch" || exit 1
fi

tmp_patch=$(gen_tempfile)

for file in "${files[@]}"
do
	if [ -n "$opt_fork" ]; then
		old_file=$workdir/$file
		new_file=$file
	else
		old_file=$(backup_file_name "$patch" "$file")
		next_patch=$(next_patch_for_file "$patch" "$file")
		if [ -z "$next_patch" ]
		then
			new_file=$file
		else
			new_file=$(backup_file_name "$next_patch" "$file")
			files_were_shadowed=1
		fi
	fi
	if ! diff_file "$file" "$old_file" "$new_file"
	then
		die 1
	fi

	if [ -n "$files_were_shadowed" -a -z "$opt_force" ]
	then
		printf $"More recent patches modify files in patch %s. Enforce refresh with -f.\n" "$(print_patch "$patch")" >&2
		die 1
	fi

	if [ -n "$files_were_shadowed" -a -n "$opt_strip_whitespace" ]
	then
		printf $"Cannot use --strip-trailing-whitespace on a patch that has shadowed files.\n" >&2
	fi
done >> $tmp_patch

if [ -n "$opt_fork" -a ! -s $tmp_patch ]
then
	printf $"Nothing in patch %s\n" "$(print_patch "$patch")" >&2
	die 1
fi

# Check for trailing whitespace
if [ -z "$opt_strip_whitespace" ]
then
	$QUILT_DIR/scripts/remove-trailing-ws -n -p$num_strip_level \
	< $tmp_patch
else
	tmp_patch2=$(gen_tempfile)
	if $QUILT_DIR/scripts/remove-trailing-ws -p$num_strip_level \
				       < $tmp_patch > $tmp_patch2
	then
		rm -f $tmp_patch
		tmp_patch=$tmp_patch2
	fi
fi
# FIXME: no stripping of non-topmost patch !!!

patch_file=$(patch_file_name "$patch")

trap "" SIGINT

tmp_result=$(gen_tempfile) || die 1

prev_patch_file=$patch_file
[ -e "$prev_patch_file" ] || prev_patch_file=/dev/null

if [ -n "$opt_diffstat" ]
then
	cat_file "$prev_patch_file" | patch_header \
	| awk '
	    function print_diffstat(arr, i) {
	      if (system("diffstat '"$QUILT_DIFFSTAT_OPTS \
				     -p$num_strip_level \
				     $tmp_patch | sed -e s:^:"'" prefix ":"))
		exit 1
	    }
			{ prefix=""
			  if (index($0, "#") == 1)
			    prefix="#"
			}
	    /^#? .* \|  *[1-9][0-9]* /	{ eat = eat $0 "\n"
			  next }
	    /^#? .* files? changed(, .* insertions?\(\+\))?(, .* deletions?\(-\))?/ \
			{ print_diffstat()
			  diffstat_printed=1
			  eat = ""
			  next }
			{ print eat $0
			  eat = "" }
	    END		{ printf "%s", eat
			  if (!diffstat_printed) {
			    print "---"
			    print_diffstat()
			    print prefix
			  }
			}
	    ' > $tmp_result
else
	cat_file "$prev_patch_file" | patch_header \
	> $tmp_result
fi

cat $tmp_patch >> $tmp_result

mkdir -p $(dirname "$patch_file")

if [ -e "$patch_file" ] && \
   diff -q "$patch_file" $tmp_result > /dev/null
then
	printf $"Patch %s is unchanged\n" "$(print_patch "$patch")"
elif cat_to_new_file "$patch_file" $QUILT_BACKUP < $tmp_result
then
	if [ -n "$opt_fork" ]
	then
		if ! insert_in_series "$patch" "$old_patch_args"
		then
			printf $"Failed to insert patch %s into file series\n" \
			       "$(print_patch "$patch")" >&2
			rm -f "$patch_file"
			exit 1
		fi
		if ! rm -rf "$QUILT_PC/$patch" || \
		   ! mv "$workdir" "$QUILT_PC/$patch" || \
		   ! echo "$patch" >> $QUILT_PC/applied-patches
		then
			printf $"Failed to create patch %s\n" \
			       "$(print_patch "$patch")" >&2
			exit 1
		fi
		printf $"Fork of patch %s created as %s\n" \
			"$(print_patch "$old_patch")" \
			"$(print_patch "$patch")"
	else
		if [ -s $tmp_patch ]
		then
			printf $"Refreshed patch %s\n" "$(print_patch "$patch")"
		else
			printf $"Nothing in patch %s\n" "$(print_patch "$patch")"
		fi
	fi
	touch "$QUILT_PC/$patch/.timestamp"
else
	die 1
fi

rm -f "$QUILT_PC/$patch~refresh"
if ! change_db_strip_level -p$num_strip_level "$patch"
then
	die 1
fi
die 0