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    // Copyright 2015-2017 Parity Technologies (UK) Ltd.
    // This file is part of Parity.

    // Parity 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.

    // Parity 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 Parity.  If not, see <http://www.gnu.org/licenses/>.

    use hash::H256;
    use sha3::Hashable;
    use hashdb::HashDB;
    use super::triedb::TrieDB;
    use super::{Trie, TrieItem, TrieIterator, Query};

    /// A `Trie` implementation which hashes keys and uses a generic `HashDB` backing database.
    ///
    /// Use it as a `Trie` trait object. You can use `raw()` to get the backing `TrieDB` object.
    pub struct SecTrieDB<'db> {
    	raw: TrieDB<'db>
    }

    impl<'db> SecTrieDB<'db> {
    	/// Create a new trie with the backing database `db` and empty `root`
    	///
    	/// Initialise to the state entailed by the genesis block.
    	/// This guarantees the trie is built correctly.
    	/// Returns an error if root does not exist.
    	pub fn new(db: &'db HashDB, root: &'db H256) -> super::Result<Self> {
    		Ok(SecTrieDB { raw: TrieDB::new(db, root)? })
    	}

    	/// Get a reference to the underlying raw `TrieDB` struct.
    	pub fn raw(&self) -> &TrieDB {
    		&self.raw
    	}

    	/// Get a mutable reference to the underlying raw `TrieDB` struct.
    	pub fn raw_mut(&mut self) -> &mut TrieDB<'db> {
    		&mut self.raw
    	}
    }

    impl<'db> Trie for SecTrieDB<'db> {
    	fn iter<'a>(&'a self) -> super::Result<Box<TrieIterator<Item = TrieItem> + 'a>> {
    		TrieDB::iter(&self.raw)
    	}

    	fn root(&self) -> &H256 { self.raw.root() }

    	fn contains(&self, key: &[u8]) -> super::Result<bool> {
    		self.raw.contains(&key.sha3())
    	}

    	fn get_with<'a, 'key, Q: Query>(&'a self, key: &'key [u8], query: Q) -> super::Result<Option<Q::Item>>
    		where 'a: 'key
    	{
    		self.raw.get_with(&key.sha3(), query)
    	}
    }

    #[test]
    fn trie_to_sectrie() {
    	use memorydb::MemoryDB;
    	use hashdb::DBValue;
    	use super::triedbmut::TrieDBMut;
    	use super::super::TrieMut;

    	let mut memdb = MemoryDB::new();
    	let mut root = H256::default();
    	{
    		let mut t = TrieDBMut::new(&mut memdb, &mut root);
    		t.insert(&(&[0x01u8, 0x23]).sha3(), &[0x01u8, 0x23]).unwrap();
    	}
    	let t = SecTrieDB::new(&memdb, &root).unwrap();
    	assert_eq!(t.get(&[0x01u8, 0x23]).unwrap().unwrap(), DBValue::from_slice(&[0x01u8, 0x23]));
    }

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