#!/usr/bin/env python
#
# mmgen = Multi-Mode GENerator, command-line Bitcoin cold storage solution
# Copyright (C) 2013 by philemon <mmgen-py@yandex.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""
mmgen-walletchk: Check integrity of a mmgen deterministic wallet, display
                 information about it and export seed and mnemonic data
"""

import sys
from mmgen.Opts import *

from mmgen.util import *

help_data = {
	'prog_name': sys.argv[0].split("/")[-1],
	'desc':  """Check integrity of a %s deterministic wallet, display
                    its information and export seed and mnemonic data."""\
					% g.proj_name,
	'usage':   "[opts] [filename]",
	'options': """
-h, --help             Print this help message
-d, --outdir        d  Specify an alternate directory 'd' for output
-e, --echo-passphrase  Print passphrase to screen when typing it
-P, --passwd-file   f  Get passphrase from file 'f'
-q, --quiet            Suppress warnings; overwrite files without prompting
-S, --stdout           Print seed or mnemonic data to standard output
-v, --verbose          Produce more verbose output
-g, --export-incognito Export wallet to incognito format
-G, --hide-incog-data  f,o  Hide incognito data in existing file 'f'
                            at offset 'o' (comma-separated)
-m, --export-mnemonic  Export the wallet's mnemonic to file
-s, --export-seed      Export the wallet's seed to file
"""
}

short_opts = "hd:eP:qSvgG:ms"
long_opts  = "help","outdir=","echo_passphrase","passwd_file=","quiet",\
			"stdout","verbose",\
			"export_incognito","hide_incog_data=","export_mnemonic","export_seed"

opts,cmd_args = process_opts(sys.argv,help_data,short_opts,long_opts)
if 'quiet' in opts: g.quiet = True
if 'verbose' in opts: g.verbose = True
if 'hide_incog_data' in opts: opts['export_incognito'] = True

# Argument sanity checks and processing:
check_opts(opts,long_opts)

if len(cmd_args) != 1: usage(help_data)

check_infile(cmd_args[0])

if 'export_mnemonic' in opts:
	qmsg("Exporting mnemonic data to file by user request")
elif 'export_seed' in opts:
	qmsg("Exporting seed data to file by user request")
elif 'export_incognito' in opts:
	qmsg("Exporting wallet to incognito format by user request")

	d = get_data_from_wallet(cmd_args[0],silent=True)
	seed_id,key_id,preset,salt,enc_seed = \
			d[1][0], d[1][1], d[2].split(":")[0], d[3], d[4]

	passwd = get_mmgen_passphrase("Enter mmgen passphrase: ",opts)
	key = make_key(passwd, salt, preset, "main key")
	# We don't need the seed; just do this to verify password.
	if decrypt_seed(enc_seed, key, seed_id, key_id) == False:
		sys.exit(2)

	from Crypto import Random
	iv = Random.new().read(g.aesctr_iv_len)
	iv_id = make_chksum_8(iv)
	qmsg("IV ID: %s" % iv_id)

	from binascii import hexlify
	from hashlib import sha256
	# IV is used BOTH to initialize counter and to salt password!
	key = make_key(passwd, iv, preset, "wrapper key")
	incog_enc = encrypt_seed(salt + enc_seed, key, iv=int(hexlify(iv),16))

	if "hide_incog_data" in opts:
		fname,offset = opts['hide_incog_data'].split(",") # Already sanity-checked
		offset = int(offset)

		check_data_fits_file_at_offset(fname,offset,len(iv + incog_enc),"write")

		if not g.quiet: confirm_or_exit("","alter file '%s'" % fname)
		f = os.open(fname,os.O_RDWR)
		os.lseek(f, offset, os.SEEK_SET)
		os.write(f, iv + incog_enc)
		os.close(f)
		qmsg("Data written to file '%s' at offset %s" % (fname,offset),
				"Data written to file")
	else:
		fn = "%s-%s-%s[%s,%s].%s" % (seed_id, key_id, iv_id,
			len(enc_seed)*8, preset, g.incog_ext)
		export_to_file(fn, iv + incog_enc, "incognito wallet data", opts)

	sys.exit()

seed = get_seed_from_wallet(cmd_args[0], opts)
if seed: qmsg("Wallet is OK")
else:
	msg("Error opening wallet")
	sys.exit(2)

if 'export_mnemonic' in opts:
	wl = get_default_wordlist()
	from mmgen.mnemonic import get_mnemonic_from_seed
	p = True if g.debug else False
	mn = get_mnemonic_from_seed(seed, wl, g.default_wl, print_info=p)
	fn = "%s.%s" % (make_chksum_8(seed).upper(), g.mn_ext)
	export_to_file(fn, " ".join(mn)+"\n", "mnemonic data", opts)

elif 'export_seed' in opts:
	from mmgen.bitcoin import b58encode_pad
	data = col4(b58encode_pad(seed))
	chk = make_chksum_6(b58encode_pad(seed))
	fn = "%s.%s" % (make_chksum_8(seed).upper(), g.seed_ext)
	export_to_file(fn, "%s %s\n" % (chk,data), "seed data", opts)