#!/bin/sh
"""": # -*-python-*-
bup_python="$(dirname "$0")/../cmd/bup-python" || exit $?
exec "$bup_python" "$0" ${1+"$@"}
"""
# end of bup preamble

from __future__ import absolute_import
import os, sys

from bup.helpers import handle_ctrl_c, readpipe
from bup import options


optspec = """
subtree-hash ROOT_HASH [PATH_ITEM...]
--
"""

handle_ctrl_c()

o = options.Options(optspec)
(opt, flags, extra) = o.parse(sys.argv[1:])

if len(extra) < 1:
    o.fatal('must specify a root hash')

tree_hash = extra[0]
path = extra[1:]

while path:
    target_name = path[0]
    subtree_items = readpipe(['git', 'ls-tree', '-z', tree_hash])
    target_hash = None
    for entry in subtree_items.split('\0'):
        if not entry:
            break
        info, name = entry.split('\t', 1)
        if name == target_name:
            _, _, target_hash = info.split(' ')
            break
    if not target_hash:
        print >> sys.stderr, "Can't find %r in %s" % (target_name, tree_hash)
        break
    tree_hash = target_hash
    path = path[1:]

if path:
    sys.exit(1)

print tree_hash