#!/bin/sh
"""": # -*-python-*-
bup_exec="$(dirname "$0")/bup-exec" || exit $?
exec "$bup_exec" "$0" ${1+"$@"}
"""

from __future__ import absolute_import, print_function
import os.path, sys

from bup.compat import argv_bytes, get_argvb
from bup.helpers import handle_ctrl_c, readpipe
from bup.io import byte_stream
from bup import options


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

handle_ctrl_c()

o = options.Options(optspec)
opt, flags, extra = o.parse_bytes(get_argvb()[1:])

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

tree_hash = argv_bytes(extra[0])
path = [argv_bytes(x) for x in extra[1:]]

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

if path:
    sys.exit(1)

sys.stdout.flush()
out = byte_stream(sys.stdout)
out.write(tree_hash + b'\n')