// Copyright 2018 The Grin Developers
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use grin_chain as chain;
use grin_core as core;

use grin_store as store;
use grin_util as util;

use std::collections::HashSet;
use std::fs::{self, File, OpenOptions};
use std::iter::FromIterator;
use std::path::{Path, PathBuf};
use std::sync::Arc;
use std::time::{SystemTime, UNIX_EPOCH};

use crate::chain::store::ChainStore;
use crate::chain::txhashset;
use crate::core::core::BlockHeader;
use crate::util::file;

fn clean_output_dir(dir_name: &str) {
	let _ = fs::remove_dir_all(dir_name);
}

#[test]
fn test_unexpected_zip() {
	let now = SystemTime::now();
	let rand = now.duration_since(UNIX_EPOCH).unwrap().subsec_micros();

	let db_root = format!(".grin_txhashset_zip");
	clean_output_dir(&db_root);
	let db_env = Arc::new(store::new_env(db_root.clone()));
	let chain_store = ChainStore::new(db_env).unwrap();
	let store = Arc::new(chain_store);
	txhashset::TxHashSet::open(db_root.clone(), store.clone(), None).unwrap();
	// First check if everything works out of the box
	assert!(txhashset::zip_read(db_root.clone(), &BlockHeader::default(), Some(rand)).is_ok());
	let zip_path = Path::new(&db_root).join(format!("txhashset_snapshot_{}.zip", rand));
	let zip_file = File::open(&zip_path).unwrap();
	assert!(txhashset::zip_write(
		PathBuf::from(db_root.clone()),
		zip_file,
		&BlockHeader::default()
	)
	.is_ok());
	// Remove temp txhashset dir
	fs::remove_dir_all(Path::new(&db_root).join(format!("txhashset_zip_{}", rand))).unwrap();
	// Then add strange files in the original txhashset folder
	write_file(db_root.clone());
	assert!(txhashset::zip_read(db_root.clone(), &BlockHeader::default(), Some(rand)).is_ok());
	// Check that the temp dir dos not contains the strange files
	let txhashset_zip_path = Path::new(&db_root).join(format!("txhashset_zip_{}", rand));
	assert!(txhashset_contains_expected_files(
		format!("txhashset_zip_{}", rand),
		txhashset_zip_path.clone()
	));
	fs::remove_dir_all(Path::new(&db_root).join(format!("txhashset_zip_{}", rand))).unwrap();

	let zip_file = File::open(zip_path).unwrap();
	assert!(txhashset::zip_write(
		PathBuf::from(db_root.clone()),
		zip_file,
		&BlockHeader::default()
	)
	.is_ok());
	// Check that the txhashset dir dos not contains the strange files
	let txhashset_path = Path::new(&db_root).join("txhashset");
	assert!(txhashset_contains_expected_files(
		"txhashset".to_string(),
		txhashset_path.clone()
	));
	fs::remove_dir_all(Path::new(&db_root).join("txhashset")).unwrap();
}

fn write_file(db_root: String) {
	OpenOptions::new()
		.create(true)
		.write(true)
		.open(
			Path::new(&db_root)
				.join("txhashset")
				.join("kernel")
				.join("strange0"),
		)
		.unwrap();
	OpenOptions::new()
		.create(true)
		.write(true)
		.open(Path::new(&db_root).join("txhashset").join("strange1"))
		.unwrap();
	fs::create_dir(Path::new(&db_root).join("txhashset").join("strange_dir")).unwrap();
	OpenOptions::new()
		.create(true)
		.write(true)
		.open(
			Path::new(&db_root)
				.join("txhashset")
				.join("strange_dir")
				.join("strange2"),
		)
		.unwrap();
	fs::create_dir(
		Path::new(&db_root)
			.join("txhashset")
			.join("strange_dir")
			.join("strange_subdir"),
	)
	.unwrap();
	OpenOptions::new()
		.create(true)
		.write(true)
		.open(
			Path::new(&db_root)
				.join("txhashset")
				.join("strange_dir")
				.join("strange_subdir")
				.join("strange3"),
		)
		.unwrap();
}

fn txhashset_contains_expected_files(dirname: String, path_buf: PathBuf) -> bool {
	let list_zip_files = file::list_files(path_buf.into_os_string().into_string().unwrap());
	let zip_files_hashset: HashSet<_> = HashSet::from_iter(list_zip_files.iter().cloned());
	let expected_files = vec![
		dirname,
		"output".to_string(),
		"rangeproof".to_string(),
		"kernel".to_string(),
		"pmmr_hash.bin".to_string(),
		"pmmr_data.bin".to_string(),
	];
	let expected_files_hashset = HashSet::from_iter(expected_files.iter().cloned());
	let intersection: HashSet<_> = zip_files_hashset
		.difference(&expected_files_hashset)
		.collect();
	intersection.is_empty()
}