#!/usr/bin/env python3

#   cryptomator-utils: Python utilities for inspecting Cryptomator drives
#   Copyright (C) 2024  Lee Yingtong Li (RunasSudo)
#
#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU Affero 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 Affero General Public License for more details.
#
#   You should have received a copy of the GNU Affero General Public License
#   along with this program.  If not, see <https://www.gnu.org/licenses/>.

from lib_cryptomator_utils.cryptomator import decrypt_file, directory_path_to_id, encrypt_filename, hash_directory_id, load_vault_config

import os
import sys

def main():
	if len(sys.argv) < 3:
		print('Decrypts a single file from a Cryptomator drive and prints to standard output', file=sys.stderr)
		print('', file=sys.stderr)
		print('Usage: {} /path/to/vault.cryptomator /plaintext/path/within/drive'.format(sys.argv[0]), file=sys.stderr)
		sys.exit(1)
	
	# Parse CLI arguments
	vault_config_path = sys.argv[1]
	target_directory = sys.argv[2]
	
	vault_path = os.path.split(vault_config_path)[0]
	
	# Load vault config (asks for password)
	primary_master_key, hmac_master_key = load_vault_config(vault_config_path)
	
	# Resolve the parent directory of the file
	target_directory_parts = target_directory.strip('/').split('/')
	directory_id = directory_path_to_id(vault_path, primary_master_key, hmac_master_key, '/'.join(target_directory_parts[:-1]))
	
	# Decrypt the file
	hashed_directory_id = hash_directory_id(primary_master_key, hmac_master_key, directory_id)
	encrypted_filename = encrypt_filename(primary_master_key, hmac_master_key, directory_id, target_directory_parts[-1])
	content = decrypt_file(vault_path, primary_master_key, hashed_directory_id, encrypted_filename)
	
	# Print to stdout
	sys.stdout.buffer.write(content)
	sys.stdout.buffer.flush()

if __name__ == '__main__':
	main()