#!/bin/sh

CONFIG_DIR=/var/config
RUN_CONF_DIR=/run/config

CONFIG_PARTITION="Config"
OEM_PARTITION="OEM Config"
TABLE=$'\n'"$(cat /proc/mtd)"
if [[ $TABLE =~ [[:space:]]mtd([[:digit:]]+)[^\"]*\"$CONFIG_PARTITION\" ]] ; then
   CONFIG_MTDC=/dev/mtd${BASH_REMATCH[1]}
   CONFIG_MTDB=/dev/mtdblock${BASH_REMATCH[1]}
else
   echo "Cannot find a ${CONFIG_PARTITION} partition"
   exit 0
fi
if [[ $TABLE =~ [[:space:]]mtd([[:digit:]]+)[^\"]*\"$OEM_PARTITION\" ]] ; then
   OEM_MTDC=/dev/mtd${BASH_REMATCH[1]}
   OEM_MTDB=/dev/mtdblock${BASH_REMATCH[1]}
else
   echo "Cannot find a ${OEM_PARTITION} partition"
   exit 0
fi

CONFIG_DIR=/var/config
OEM_DIR=/var/oem

FILES="network/interfaces \
ppp/options \
ppp/pap-secrets \
ppp/chap-secrets \
ppp/peers \
"

# Files used by bluetooth or wifi.
BTWIFIFILES="\
bluetooth/ \
default/ \
dnsmasq.d/ \
hosts \
hostname \
hostapd.conf \
modprobe.d/ \
wpa_supplicant.conf \
"

# File hidden so it is not removed on hardware reset
WIFITAR=".defaults2.tar.gz"

mount_config() {
	echo "Mounting ${CONFIG_DIR}"
	mkdir -p ${CONFIG_DIR}
	mount ${CONFIG_DIR}

	# Prepare flash for JFFS2 or EXT4 if mount fails
	if [ $? -ne 0 ]; then
		echo "Creating ${CONFIG_DIR}"
		fs=$(mount -fvn ${CONFIG_DIR})
		if [[ $fs =~ [[:space:]]*(/dev/(...)[^[:space:]]*) ]] ; then
			if [[ ${BASH_REMATCH[2]} == mmc ]] ; then
				# One more check for empty
				mdev="${BASH_REMATCH[1]}"
				if [[ $(dd if=$mdev count=4 2>/dev/null | tr -d '\0' | wc -c) == 0 ]] ; then
					mkfs.ext4 -O 64bit ${mdev}
				fi
			else
				flash_erase -j ${CONFIG_MTDC} 0 0
			fi
		fi
		mount ${CONFIG_DIR}
	fi
}

mount_oem() {
	echo "Mounting ${OEM_DIR}"
	mkdir -p ${OEM_DIR}
	mount ${OEM_DIR}

	# Prepare flash for JFFS2 or EXT4 if mount fails
	# Prepare flash for JFFS2 or EXT4 if mount fails
	if [ $? -ne 0 ]; then
		echo "Creating ${OEM_DIR}"
		fs=$(mount -fvn ${OEM_DIR})
		if [[ $fs =~ [[:space:]]*(/dev/(...)[^[:space:]]*) ]] ; then
			if [[ ${BASH_REMATCH[2]} == mmc ]] ; then
				mdev="${BASH_REMATCH[1]}"
				if  [[ $(dd if=$mdev count=4 2>/dev/null | tr -d '\0' | wc -c) == 0 ]] ; then
					mkfs.ext4 -O 64bit ${mdev}
				fi
			else
				flash_erase -j ${OEM_MTDC} 0 0
			fi
		fi
		mount ${OEM_DIR}
	fi
}

# Create symlinks in directory $2
# that point to non-directory items
# in directory $1
# No recursion.
#
# /etc/default/rcS must be in the
# root file system
#
function linkdir {
    from="$1"
    to="$2"
    newdir=$(basename "$from")
    savedir=$(pwd)
    cd "${from}"
    for f in * ; do
        if [[ ${to} == /etc/default ]] && [[ $f == rcS ]] ; then
            continue
        fi
        if [[ $f == volatiles ]] ; then
            continue
        fi
        if [[ $f == \* ]] ; then
            break
        fi

        if ! [[ -h ${to}/${f} ]] ; then
            ln -sf "${from}/${f}" "${to}/${f}"
        fi
    done
    cd "$savedir"
}

# parameter 1     Input directory
# parameter 2     Parent of output directory
#
# The basename (final component) of parameter 1
# is created as a directory in the directory
# of parameter 2.
#
# Any symlinks found are not copied, but instead
# updated to point to the "to" directory.
#
function copydir {
    from="$1"
    to="$2"
    newdir=$(basename "$from")
    links=()
    if rmdir $from >/dev/null 2>&1 ; then
        ln -sf  "$to/$newdir" "$from"
    else
        mkdir "$to/$newdir" >/dev/null 2>&1 || true
        savedir=$(pwd)
        cd "$from"
        for f in * ; do
            if [[ $f == \* ]] ; then
                break
            fi
            if [[ $f == volatiles ]] ; then
                continue
            fi
            if [[ -L ${f} ]] ; then
                 links+=(${f})
                 continue
            fi
            if ! [[ -f "$to/$f" ]] ; then
                cp -a "${f}" "$to/${newdir}/${f}"
            fi
        done
        for l in ${links[*]} ; do
            mylink=$(readlink "$l")
            if [[ $(dirname ${mylink}) == ${from} ]] ; then
                base=$(basename "${mylink}")
                if [[ $base != $l ]] ; then
                    echo "Writing symlink $to/$base $l"
                    ln -sf $to/${newdir}/$base $l
                fi
            fi
        done
        cd "$savedir"
    fi
}

case $1 in
	start)
		# mount config if not already mounted
		if ! grep -q " ${CONFIG_DIR} " /proc/mounts; then
			mount_config
		else
			echo "$CONFIG_DIR already mounted"
		fi

		# mount oem if specified in /etc/fstab and it isn't already mounted
		if mount -fvn "${OEM_DIR}" ; then
			if ! grep -q " ${OEM_DIR} " /proc/mounts; then
				mount_oem
			else
				echo "$OEM_DIR already mounted"
			fi
		fi

		# Default all config files if requested
		cd ${CONFIG_DIR}
		if [ -f force_defaults ]; then
			echo "Extracting default config files"
			tar -xf /etc/defaults.tar.gz
			if [[ -f ${WIFITAR} ]] ; then
				echo "Extract original wifi related files"
				tar -xf ${WIFITAR}
			fi
			rm -f force_defaults
		fi

		# Extract any missing files
		TARFILES=$(tar -tf /etc/defaults.tar.gz)
		for file in $TARFILES; do
			if [ ! -e $file ]; then
				tar -xf /etc/defaults.tar.gz $file
			fi
		done

		# Create links in /etc
		for file in $FILES; do
			if ! [[ -L /etc/$file ]] && ! [[ -d /etc/$file ]] ; then
				rm -rf /etc/$file
				ln -sf ${CONFIG_DIR}/$file /etc/$file
                        elif [[ -d /etc/$file ]] ; then
                            # JAK create links in directory.
                            linkdir "${CONFIG_DIR}/${file}" "/etc/${file}" 
			fi
		done
		
		# Move bluetooth wifi stuff to config directory.
		# We don't have factory defaults.
                ((dobackup=1))
		for file in ${BTWIFIFILES}; do
			if [[ -L /etc/$file ]]; then
                        	((dobackup=0))
                                break
			fi
		done
		if ((dobackup==1)) ; then
		        echo "Creating backup of Config files"
			tar -C /etc -czf ${CONFIG_DIR}/${WIFITAR} ${BTWIFIFILES}
		fi

		# For jffs2, you cannot remove a populated directory in an overlay.
                # We must copy individual files and create symlinks instead.
		for file in ${BTWIFIFILES}; do
                    isdir=0
                    # If last character is /, make the CONFIG directory.               
                    if [[ ${file: -1} == / ]] ; then
                            isdir=1
                            file=${file%?}
                            if ! [[ -d ${CONFIG_DIR}/$file ]] ; then   
                                    rm -f ${CONFIG_DIR}/$file 2>/dev/null || true
                                    mkdir ${CONFIG_DIR}/$file                    
                            fi                                                   
                            if [[ -d ${file} ]] ; then
                                copydir "/etc/${file}" "${CONFIG_DIR}"
                            fi
                    fi    
                    
                    if ((isdir == 0)); then
                            dir=$(dirname $file)
                            if [[ $dir != '.' ]] ; then
                                    mkdir -p "$dir"
                            fi
                            rm -rf old
                            mkdir old
                            if ! [[ -f $file ]] ; then
                                # Need to preserve old files which is difficult with busybox!
                                if [[ -d $file ]] || [[ -f $file ]] ; then
                                        cp --parents -a $file old || true
                                fi
                                (
                                    cd /etc
                                    if [[ -d $file ]] || [[ -f $file ]] ; then
                                        cp --parents -a $file ${CONFIG_DIR} || true
                                    fi
                                )
                                (
                                    cd old
                                    if [[ -d $file ]] || [[ -f $file ]] ; then
                                        cp --parents -a $file .. || true
                                    fi
                                )
                                rm -rf old
                            fi
                            rm -rf /etc/$file
                            ln -sf ${CONFIG_DIR}/$file /etc/$file
                    else
                        rm -f "/etc/${file}/*"
                        linkdir "${CONFIG_DIR}/${file}" "/etc/${file}"
                    fi
		done
	;;

	*)
		echo "Usage: $0 {start}"
		exit 2
	;;

esac