#!/bin/sh

###########################################################################

mappers=""
scanners=""
version="unknown"

register_mapper()
{
    mappers="${mappers}${mappers:+ }$1"
}

register_scanner()
{
    scanners="${scanners}${scanners:+ }$1"
}

load()
{
    for lib in `ls "$1"/[0-9][0-9]_*.sh | sort`; do
	source $lib
    done
}

# Map device/sector through blockdevice mappings (e.g. lvm)

run()
{
    local found
    foundm=1
    while [ -n "$found" ]; do
	found=""
	for name in "$@"; do
	    if detect_$name; then
		found=1
		if do_$name; then
		    return
		fi
		break
	    fi
	done
    done
}

###########################################################################

unset LANG

#### Find library directory and load library files

name="`basename "$0"`"
X="`dirname "$0"`"
if [ "`basename "$X"`" == "bin" ]; then # `"
    libdir="`dirname "$X"`/lib/$name" #`"
fi
if [ -z "$libdir" -o ! -d "$libdir" ]; then
    libdir="$X/lib"
fi

if [ ! -d "$libdir" ]; then
    echo "! Library directory not found" 1>&2
    exit 1
fi

load "$libdir"

#### Parse command line arguments

X=`getopt -o "hV" --long "help,noscan,version" -n "$name" -- "$@"`
if [ $? != 0 ]; then exit 1; fi
eval set -- "$X"

noscan=""
help=""

while true; do
    case "$1" in
	-h|--help) help="0"; shift ;;
	--noscan) noscan="0"; shift ;;
	-V|--version) echo "$name $version"; exit 0 ;;
	--) shift; break ;;
	*) echo "! internal error"; exit 1 ;;
    esac
done

if [ -n "$help" -o -z "$2" ]; then
    cat <<EOF
Usage: $name [-h|--help] [--noscan] <device> <sector>"

mapsector -- Map sector numbers to file name(s)

Given a device and a sector number, mapsector will try to find the
file name(s) mapping to this sector. It will try to gather as much
information about the given sector as possible.

mapsector currently has support for the following mapping schemes:

EOF
    for mapper in $mappers; do
	describe_$mapper
    done
    cat <<EOF

mapsector currently supports the following filesystems

EOF
    for scanner in $scanners; do
	describe_$scanner
    done
cat <<EOF

mapsector will try it's best to find an associated file name but
depending on the filesystem state and the type of sector (e.g. if
the sector is part of a filesystem metadata block) this may not be
possible.

For mapsector to work, the filesystem must be currently active
(e.g. LVM must be running, crypted devices must have been set up). The
filesystem must not necessarily be mounted (though if mounted,
mapsector will give you the mountpoint).

if '--noscan' is given, the possibly lengthy (!!) filesystem scan for
filenames is skipped.

-- mapsector Version $version
EOF
    exit "${help:-1}"
fi

device="$1"
sector="$2"

echo "device $device"
echo "sector $sector"

run $mappers
if [ -z "$noscan" ]; then
    run $scanners
fi