#!/bin/bash

# Download Freetz packages from a randomly chosen mirror server. There is
# an empty input field for a user-defined server in 'menuconfig'. Additionally,
# another download source maybe specified on the command line as $3. $2 is the name
# of the file to be downloaded.
#
# This script is designed to be called by makefile includes (*.mk), but can
# also be called directly. It expects to find a file with necessary variables
# at a relative location '../.config' to this script. The variables are:
#   - FREETZ_DL_SITE_USER     (URL, e.g. http://my.server.org)

# XXX: Temporarily use system's md5sum if busybox applet is not yet build (see #1535)
MD5SUM=$(dirname $0)/md5sum
[ ! -x $MD5SUM ] && MD5SUM="$(which md5sum)"

DOT_CONFIG=$FREETZ_BASE_DIR/.config
FREETZ_DL_SITE_1="http://freetz.magenbrot.net"
FREETZ_DL_SITE_2="http://freetz.3dfxatwork.de"
FREETZ_DL_SITE_3="http://freetz.wirsind.info"

helpmsg()
{
cat << 'EOF'
freetz_download - download Freetz packages

Usage: freetz_download (-?|--help) | [--no-append-servers] ( (<download-dir> | check) <filename> [<main-url>] [<md5>])
    check         - check download
    download-dir  - target directory for download file
    filename      - download file name
    main-url      - url without filename for primary download
    md5           - md5 of file
    -?, --help    - print this help text

Examples:
    freetz_download dl package.tar.bz2
    freetz_download dl package.tar.bz2 http://myserver.com/freetz

Debugging: just set DEBUG=1, like this:
    DEBUG=1 freetz_download dl package.tar.bz2
EOF
}

do_download()
{
	# $1 = target directory, $2 = full download URL
	echo
	if [ "$DEBUG" == "1" ]; then echo "wget -nd -t3 --timeout=20 --no-check-certificate --passive-ftp -P \"$1\" \"$2\""; fi
	wget -nd -t3 --timeout=20 --no-check-certificate --passive-ftp -P "$1" "$2"
	wget_result=$?
	if [ "$wget_result" != "0" ]; then
		echo "Download failed - \"$2\"  ->  error code $wget_result" >&2
		fname=$(basename $2)
		rm -f $1/$fname
		return $wget_result
	fi
	echo "Download succeeded - \"$2\"  ->  saved to folder \"$1\""
}

do_check()
{
	wget --quiet -t3 --timeout=20 --no-check-certificate --passive-ftp --spider "$1"
	wget_result=$?
	return $wget_result
}

# $1 - url
# $2 - subdir
# $3 - version
do_checkout_cvs()
{
	local module_name
	module_name="${2/-$3/}"
	(cvs -d:"$1" export -D "$3" "$module_name" || cvs -d:"$1" export -r "$3" "$module_name") && mv "$module_name" "$2"
}
do_checkout_svn()
{
	local extra_flags
	svn help export | grep -q trust-server-cert && extra_flags="--trust-server-cert"
	svn export --non-interactive $extra_flags -r$3 "$1" "$2"
}
do_checkout_git()
{
	git clone "$1" "$2" || return $?
	(
		cd "$2" && git checkout "$3" || return $?
		if [ -f ".gitmodules" ]; then
			git submodule init && git submodule update || return $?
		fi
		rm -rf .git
	)
}
# Note: remote repository must support "git archive" command
# $1 is expected to have the following format:
#    repository_url,path1,path2,...,pathN
# where
#    repository_url - a repository url supporting archive command, e.g. git://repo.or.cz/git.git
#    pathX - a path to any file or directory within the repository
# Only path1,...,pathN will be transmitted saving both bandwidth and processing power.
do_checkout_git_archive()
{
	local repository paths
	repository=$(echo "$1" | cut -d , -f 1)
	paths=$(echo "$1" | cut -d , -f 2- | tr , " ")
	git archive --format=tar --remote="$repository" --prefix="$2/" "$3" $paths | tar -x
}
do_checkout_bzr()
{
	bzr export -r"$3" "$2" "$1"
}
do_checkout_hg()
{
	hg clone -r "$3" "$1" "$2" && (cd "$2" && rm -rf .hg .hgignore .hgtags)
}
do_checkout_darcs()
{
	darcs get -t "$3" "$1" "$2" && (cd "$2" && rm -rf _darcs)
}


# Regular use: help parameter -> exit without error
if [ "$1" == "-?" -o "$1" == "--help" ]; then
	helpmsg
	exit 0
fi

opt_append_servers=y
while [ $# -gt 1 ]; do
	case "$1" in
		--no-append-servers)
			opt_append_servers=n
			shift
			;;
		*)
			break
			;;
	esac
done

# Wrong number of parameters -> exit with error
if [ $# -lt 2 -o $# -gt 4 ]; then
	helpmsg >&2
	exit 1
fi

DL_DIR="$1"
DL_FILE="$2"
MAIN_URL="$3"
MD5="$4"

# Import Freetz config variables
[ -e $DOT_CONFIG ] && . $DOT_CONFIG

if [ "$DEBUG" == "1" ]; then
	echo "freetz_download parameters:"
	echo "    DL_DIR=$DL_DIR"
	echo "    DOT_CONFIG=$DOT_CONFIG"
	echo "    DL_FILE=$DL_FILE"
	echo "    MAIN_URL=$MAIN_URL"
	echo "    MD5=$MD5"
fi

num_sites=0
# Fill array 'sites' with download server URLs, first primary site (if specified)
if [ -n "$MAIN_URL" ]; then
	# give sourceforge a few more tries, because it redirects to different mirrors
	if [ ${MAIN_URL:0:3} == "@SF" ]; then
		MAIN_URL=${MAIN_URL/@SF\//}
		for (( n=0; n < 5; n++ )); do
			sites[$num_sites]=http://downloads.sourceforge.net/$MAIN_URL
			(( num_sites++ ))
		done
	elif [ ${MAIN_URL:0:4} == "@AVM" ]; then
		MAIN_URL=${MAIN_URL/@AVM\//}
		sites[0]=ftp://ftp.avm.de/fritz.box/$MAIN_URL
		sites[1]=http://download.avm.de/fritz.box/$MAIN_URL
		sites[2]=ftp://service.avm.de/$MAIN_URL
		num_sites=3
	elif [ ${MAIN_URL:0:4} == "@GNU" ]; then
		MAIN_URL=${MAIN_URL/@GNU\//}
		sites[0]=http://ftpmirror.gnu.org/$MAIN_URL # automatically chooses a nearby and up-to-date mirror
		sites[1]=http://ftp.gnu.org/gnu/$MAIN_URL
		num_sites=2
	elif [ ${MAIN_URL:0:7} == "@KERNEL" ]; then
		MAIN_URL=${MAIN_URL/@KERNEL\//}
		sites[0]=http://ftp.de.kernel.org/pub/$MAIN_URL
		sites[1]=http://ftp.kernel.org/pub/$MAIN_URL
		num_sites=2
	elif [ ${MAIN_URL:0:8} == "@TELEKOM" ]; then
		MAIN_URL=${MAIN_URL/@TELEKOM\//}
		sites[0]=http://www.telekom.de/dlp/eki/downloads/$MAIN_URL
		sites[1]=http://www.t-home.de/dlp/eki/downloads/$MAIN_URL
		sites[2]=http://hilfe.telekom.de/dlp/eki/downloads/$MAIN_URL
		num_sites=3
	elif [ ${MAIN_URL:0:7} == "@APACHE" ]; then
		MAIN_URL=${MAIN_URL/@APACHE\//}
		sites[0]=http://www.eu.apache.org/dist/$MAIN_URL
		sites[1]=http://www.apache.org/dist/$MAIN_URL
		sites[2]=http://apache.openmirror.de/$MAIN_URL
		sites[3]=http://archive.apache.org/dist/$MAIN_URL
		num_sites=4
	else
		supportedVCSs="cvs|svn|git|git_archive|bzr|hg|darcs"
		VCS="$(echo "${MAIN_URL}" | sed -nr -e "s,^(${supportedVCSs})(@|://).*,\1,p")"
		if [ -n "${VCS}" ]; then
			MAIN_URL="$(echo "${MAIN_URL}" | sed -r -e "s,^(${supportedVCSs})@(.*),\2,")"
			num_sites=0
			MD5=""
		else
			sites[$num_sites]=$MAIN_URL
			(( num_sites++ ))
		fi
	fi
fi

# Get Freetz mirror sites in array
FREETZ_SITES=( $(
	for (( i=1; i <= 3 ; i++ )); do
		eval "echo \$FREETZ_DL_SITE_$i"
	done
	) )

# Add user-defined mirror
if [ -n "$FREETZ_DL_SITE_USER" ]; then
	FREETZ_SITES[3]=$FREETZ_DL_SITE_USER
fi

# Fill array 'sites' with download server URLs, add Freetz Mirrors, in random order
if [ "$opt_append_servers" = y ]; then
	for (( n=${#FREETZ_SITES[@]}; n > 0; n-- )); do
		p=$(( RANDOM % n ))
		sites[$num_sites]=${FREETZ_SITES[$p]}
		(( num_sites++ ))
		FREETZ_SITES[$p]=${FREETZ_SITES[$((n-1))]}
	done
fi

# Loop over servers until a download succeeds or all requests have failed.
IFS=$'\n'
for i in ${sites[@]}; do
	if [ ${DL_DIR:0:5} == "check" ]; then
		do_check "$i/$DL_FILE"
		if [ "$?" != "0" ]; then
			continue
		fi
	else
		do_download "$DL_DIR" "$i/$DL_FILE"
		if [ "$?" != "0" ]; then
			continue
		fi
		if [ -n "$MD5" -a -x "$MD5SUM" ]; then
			FILE_MD5=$($MD5SUM "$DL_DIR/$DL_FILE" | sed 's/ .*//')
			if [ "$(echo $MD5 | tr A-Z a-z)" != "$FILE_MD5" ]; then
				echo "MD5 mismatch for $DL_DIR/$DL_FILE: $MD5 $FILE_MD5" 1>&1
				rm -f "$DL_DIR/$DL_FILE"
				continue;
			else
				echo "MD5 verified for $DL_DIR/$DL_FILE: $FILE_MD5"
			fi
		fi
	fi
	exit 0
done
unset IFS

if [ -n "$VCS" ]; then
	echo
	case "$DL_FILE" in
		*.tar.gz) COMPRESSION_FLAG=z ;;
		*.tar.bz2) COMPRESSION_FLAG=j ;;
		*.tar.xz) COMPRESSION_FLAG=J ;;
		*) { echo "Failed to detect compression method from $DL_FILE"; exit 1; } ;;
	esac

	SUBDIR=$(echo "$DL_FILE" | sed -r -e 's,(.*)[.]tar[.](gz|bz2|xz)$,\1,')
	VERSION=$(echo "$SUBDIR" | sed -r -e 's,[^-]*-(.+),\1,')
	[ -n "$VERSION" ] || { echo "Failed to detect version from $DL_FILE"; exit 1; }

	TMP_DIR=$(mktemp -d -t freetzXXX) || { echo "Error creating temporary dir."; exit 1; }
	echo "Checking out files from the $VCS repository..." \
	&& ( \
		cd "$TMP_DIR" \
		&& rm -rf "$SUBDIR" \
		&& [ ! -d "$SUBDIR" ] \
		&& do_checkout_"$VCS" "$MAIN_URL" "$SUBDIR" "$VERSION" \
		&& echo "Packing checkout..." \
		&& tar c${COMPRESSION_FLAG}f "$DL_FILE" "$SUBDIR" \
	) \
	&& mv "$TMP_DIR/$DL_FILE" "$DL_DIR/" \
	&& rm -rf "$TMP_DIR" \
	&& exit 0

	rm -f "$DL_DIR/$DL_FILE"
	rm -rf "$TMP_DIR"
fi

exit 1