#! /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.

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

usage()
{
	printf $"Usage: quilt import [-p num] [-R] [-P patch] [-f] [-d {o|a|n}] patchfile ...\n"
	if [ x$1 = x-h ]
	then
		printf $"
Import external patches.  The patches will be inserted following the
current top patch, and must be pushed after import to apply them.

-p num
	Number of directory levels to strip when applying (default=1)

-R
	Apply patch in reverse.

-P patch
	Patch filename to use inside quilt. This option can only be
	used when importing a single patch.

-f	Overwrite/update existing patches.

-d {o|a|n}
	When overwriting in existing patch, keep the old (o), all (a), or
	new (n) patch header. If both patches include headers, this option
	must be specified. This option is only effective when -f is used.
"
		exit 0
	else
		exit 1
	fi
}

find_patch_file()
{
	local name="$1"

	if [ ${name:0:1} = / ]
	then
		# Patch has absolute path
		if [ -r "$name" ]
		then
			echo "$name"
			return
		fi
	else
		# Patch has a relative path
		if [ -r "$SUBDIR$name" ]
		then
			echo "$SUBDIR$name"
			return
		fi
	fi

	printf $"Patch %s does not exist\n" "$name" >&2
	return 1
}

merge_patches()
{
	local old="$1" new="$2"
	local old_desc=$(gen_tempfile) new_desc=$(gen_tempfile)

	cat_file "$old" | patch_header | strip_diffstat > $old_desc
	cat_file "$new" | patch_header | strip_diffstat > $new_desc

	if [ -z "$opt_desc" ]
	then
		[ -s $old_desc ] || opt_desc=n
		[ -z "$opt_desc" -a ! -s $new_desc ] && opt_desc=o

		if [ -z "$opt_desc" ]
		then
			local diff=$(diff -u $old_desc $new_desc \
				     | sed -e '1,2d')
			if [ -n "$diff" ]
			then
				printf $"Patch headers differ:\n" >&2
				echo "$diff" >&2
				printf \
$"Please use -d {o|a|n} to specify which patch header(s) to keep.\n" >&2
				rm -f $old_desc $new_desc
				return 1
			fi
		fi
	fi

	[ "$opt_desc" = n ] || cat "$old_desc"
	[ "$opt_desc" = a ] && echo '---'
	if [ "$opt_desc" = o ]
	then
		cat_file "$new" | patch_body
	else
		cat_file "$new"
	fi
	rm -f $old_desc $new_desc
}

die()
{
	local status=$1
	[ "$merged_patch_file" != "$patch_file" ] && rm -f "$merged_patch_file"
	exit $status
}

options=`getopt -o P:d:fp:Rh -- "$@"`

if [ $? -ne 0 ]
then
	usage
fi

eval set -- "$options"

while true
do
	case "$1" in
	-P)
		opt_patch=${2#$QUILT_PATCHES/}
		shift 2 ;;
	-p)
		opt_strip=$2
		shift 2 ;;
	-R)
		opt_reverse=1
		shift ;;
	-d)
		case "$2" in
			o|n|a) opt_desc=$2 ;;
			*) usage ;;
		esac
		shift 2 ;;
	-f)
		opt_force=1
		shift ;;
	-h)
		usage -h ;;
	--)
		shift
		break ;;
	esac
done

if [ $# -gt 1 -a -n "$opt_patch" ]
then
	printf $"Option \`-P' can only be used when importing a single patch\n" >&2
	exit 1
fi

[ -n "$opt_strip" ] && patch_args="-p$opt_strip"
if [ -n "$opt_reverse" ]
then
	if [ -n "$patch_args" ]
	then
		patch_args="$patch_args -R"
	else
		patch_args="-R"
	fi
fi

before=$(patch_after "$(top_patch)")
for orig_patch_file in "$@"
do
	if [ -n "$opt_patch" ]
	then
		patch=$opt_patch
	else
		patch=${orig_patch_file##*/}
	fi

	patch_file=$(find_patch_file "$orig_patch_file") || exit 1
	merged_patch_file="$patch_file"

	if is_applied $patch
	then
		printf $"Patch %s is applied\n" "$(print_patch $patch)" >&2
		exit 1
	fi

	dest=$(patch_file_name $patch)
	if patch_in_series "$patch"
	then
		if [ "$patch_file" = "$dest" ]
		then
			printf $"Patch %s already exists in series.\n" \
			       "$(print_patch $patch)" >&2
			exit 1
		fi
		if [ -z "$opt_force" ]
		then
			printf $"Patch %s exists. Replace with -f.\n" \
			       "$(print_patch $patch)" >&2
			exit 1
		fi
		if [ "$opt_desc" != n ]
		then
			merged_patch_file=$(gen_tempfile)
			merge_patches "$dest" "$patch_file" \
				      > $merged_patch_file \
				|| die 1
		fi
		printf $"Replacing patch %s with new version\n" \
		       "$(print_patch $patch)" >&2
	elif [ -e "$dest" ]
	then
		printf $"Importing patch %s\n" "$(print_patch $patch)"
	else
		printf $"Importing patch %s (stored as %s)\n" \
		       "$orig_patch_file" \
		       "$(print_patch $patch)"

		mkdir -p "${dest%/*}"
	fi

	if [ "$merged_patch_file" != "$dest" ] && \
	   (( [ "$merged_patch_file" != "$patch_file" ] && \
	      ! cat_to_new_file "$dest" < "$merged_patch_file" ) || \
	    ( [ "$merged_patch_file" = "$patch_file" ] && \
	      ! cp "$merged_patch_file" "$dest" ))
	then
		printf $"Failed to import patch %s\n" "$(print_patch $patch)" >&2
		die 1
	fi

	[ "$merged_patch_file" != "$patch_file" ] && rm -f "$merged_patch_file"

	if ! patch_in_series $patch &&
	   ! insert_in_series $patch "$patch_args" "$before"
	then
		printf $"Failed to insert patch %s into file series\n" \
		       "$(print_patch $patch)" >&2
		exit 1
	fi

	rm -rf $QUILT_PC/$patch
done