#!/usr/bin/env python
# Generate links in the root filesystem for appropriate packages.
# This assumes that /bin and /sbin are symlinks to /usr/bin and /usr/sbin.

packages = [
	"awk",
	"bash",
	"busybox",  # not that anything relies on it, but for fixing things
	"coreutils",
	"debianutils",
	"diffutils",
	"e2fsprogs",
	"ed",
	"file",
	"gawk",
	"grep",
	"gzip",
	"iproute2",
	"m4",
	"mawk",
	"mksh",
	"module-init-tools",
	"net-tools",
	"procps",
	"psmisc",
	"sed",
	"shadow",
	"sysvinit",
	"tar",
	"udev",
	"upstart",
	"util-linux",
	]
specials = {
	# Provided by glibc.
	# (ldconfig and sln are actually installed in /sbin by glibc.)
	"/usr/bin/catchsegv": None,
	"/usr/bin/gencat": None,
	"/usr/bin/getconf": None,
	"/usr/bin/getent": None,
	"/usr/bin/glibcbug": None,
	"/usr/bin/iconv": None,
	"/usr/bin/ldd": None,
	"/usr/bin/lddlibc4": None,
	"/usr/bin/locale": None,
	"/usr/bin/localedef": None,
	"/usr/bin/mtrace": None,
	"/usr/bin/memusage": None,
	"/usr/bin/memusagestat": None,
	"/usr/bin/pcprofiledump": None,
	"/usr/bin/rpcgen": None,
	"/usr/bin/sprof": None,
	"/usr/bin/tzselect": None,
	"/usr/bin/xtrace": None,
	"/usr/sbin/iconvconfig": None,
	"/usr/sbin/ldconfig": None,
	"/usr/sbin/nscd": None,
	"/usr/sbin/nscd_nischeck": None,
	"/usr/sbin/rpcinfo": None,
	"/usr/sbin/sln": None,
	"/usr/sbin/zdump": None,
	"/usr/sbin/zic": None,

	# An oddity -- this is the only binary still left in /lib on modern
	# Linux systems. (No good reason for that that I can see...)
	"/lib/cpp": "bin/cpp",

	"/usr/bin/cc": "bin/cc",
	"/usr/bin/cpp": "bin/cpp",
	"/usr/bin/gcc": "bin/gcc",
	"/usr/bin/ld": "bin/ld",

	"/usr/bin/expect": "bin/expect",
	"/usr/bin/runhaskell": "bin/runhaskell",
	"/usr/bin/python": "bin/python",
	"/usr/bin/perl": "bin/perl",
	"/usr/bin/tcl": "bin/tcl",
	"/usr/bin/tcl.real": "bin/tcl.real",
	"/usr/bin/tclsh": "bin/tclsh",
	"/usr/bin/wish": "bin/wish",
	"/usr/bin/wishx": "bin/wishx",
	"/usr/bin/wishx.real": "bin/wishx.real",

	"/usr/bin/sendmail": "bin/exim",
	"/usr/sbin/sendmail": "bin/exim",
	# ... and this is the only binary in /usr/lib:
	"/usr/lib/sendmail": "bin/exim",
	"/usr/bin/mail": "bin/mail",
	"/usr/bin/mailx": "bin/mailx",

	"/usr/sbin/fsck.jfs": "sbin/fsck.jfs",
	"/usr/sbin/fsck.reiser4": "sbin/fsck.reiser4",
	"/usr/sbin/fsck.xfs": "sbin/fsck.xfs",

	"/usr/sbin/mount.cifs": "sbin/mount.cifs",
	"/usr/sbin/umount.cifs": "sbin/umount.cifs",
	"/usr/sbin/mount.nfs": "sbin/mount.nfs",
	"/usr/sbin/umount.nfs": "sbin/umount.nfs",
	"/usr/sbin/mount.nfs4": "sbin/mount.nfs4",
	"/usr/sbin/umount.nfs4": "sbin/umount.nfs4",
	"/usr/sbin/mount.ntfs-3g": "sbin/mount.ntfs-3g",
	"/usr/sbin/umount.ntfs-3g": "sbin/umount.ntfs-3g",

	# Provided by linux.
	"/usr/include/asm": "include/asm",
	"/usr/include/asm-generic": "include/asm-generic",
	"/usr/include/linux": "include/linux",
	"/usr/include/mtd": "include/mtd",
	"/usr/include/rdma": "include/rdma",
	"/usr/include/sound": "include/sound",
	"/usr/include/video": "include/video",

	"/usr/share/icons": "share/icons",
	"/usr/share/mime": "share/mime",
	"/usr/share/themes": "share/themes",

	"/lib/udev": "lib/udev",
	}

import sys, os, optparse
from garstowlib.packages import *

def ensure_symlink(src, dest, options):
	"""Ensure that symlink dest exists, pointing to src."""
	try:
		if os.readlink(in_root(dest)) == src:
			return
	except OSError:
		pass
	print "  link " + in_root(dest) + " -> " + src
	if not options.dryrun:
		try:
			os.unlink(in_root(dest))
		except OSError:
			pass
		os.symlink(src, in_root(dest))

def update_dir(src, dest, options):
	print "Updating " + dest

	pd = get_packages_dir()

	files = {}
	for p in packages:
		d = pd + "/" + p + "/" + src
		try:
			for f in os.listdir(in_root(d)):
				files[f] = d + "/" + f
		except OSError:
			pass

	to_remove = []
	for f in os.listdir(in_root(dest)):
		df = dest + "/" + f
		if not (f in files or df in specials):
			to_remove.append(f)

	to_remove.sort()
	for f in to_remove:
		df = dest + "/" + f
		print "  remove " + in_root(df)
		if not options.dryrun:
			os.unlink(in_root(df))

	for (t, s) in files.items():
		df = dest + "/" + t
		ensure_symlink(s, df, options)

	print

def main(args):
	usage = "usage: %prog [options]"
	parser = optparse.OptionParser(usage=usage)
	parser.add_option("-n", action="store_true", dest="dryrun",
	                  help="show what will be done, rather than doing it")
	parser.add_option("--root", dest="root", metavar="DIR",
	                  help="specify root directory of system to operate on")
	options, args = parser.parse_args(args)

	if args != []:
		parser.error("no arguments necessary")
	if options.root is not None:
		set_root_dir(options.root)

	update_dir("bin", "/usr/bin", options)
	update_dir("sbin", "/usr/sbin", options)

	print "Making symlinks"
	sd = get_stow_dir()
	for (s, t) in specials.items():
		if t is None:
			continue
		target = sd + "/" + t
		ensure_symlink(target, s, options)

if __name__ == "__main__":
	main(sys.argv[1:])