// Copyright (c) 2012-2015 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include "dbwrapper.h"
#include "uint256.h"
#include "random.h"
#include "test/test_bitcoin.h"

#include <boost/assign/std/vector.hpp> // for 'operator+=()'
#include <boost/assert.hpp>
#include <boost/test/unit_test.hpp>
                    
using namespace std;
using namespace boost::assign; // bring 'operator+=()' into scope
using namespace boost::filesystem;
         
// Test if a string consists entirely of null characters
bool is_null_key(const vector<unsigned char>& key) {
    bool isnull = true;

    for (unsigned int i = 0; i < key.size(); i++)
        isnull &= (key[i] == '\x00');

    return isnull;
}
 
BOOST_FIXTURE_TEST_SUITE(dbwrapper_tests, BasicTestingSetup)
                       
BOOST_AUTO_TEST_CASE(dbwrapper)
{
    // Perform tests both obfuscated and non-obfuscated.
    for (int i = 0; i < 2; i++) {
        bool obfuscate = (bool)i;
        path ph = temp_directory_path() / unique_path();
        CDBWrapper dbw(ph, (1 << 20), true, false, obfuscate);
        char key = 'k';
        uint256 in = GetRandHash();
        uint256 res;

        // Ensure that we're doing real obfuscation when obfuscate=true
        BOOST_CHECK(obfuscate != is_null_key(dbw.GetObfuscateKey()));

        BOOST_CHECK(dbw.Write(key, in));
        BOOST_CHECK(dbw.Read(key, res));
        BOOST_CHECK_EQUAL(res.ToString(), in.ToString());
    }
}

// Test batch operations
BOOST_AUTO_TEST_CASE(dbwrapper_batch)
{
    // Perform tests both obfuscated and non-obfuscated.
    for (int i = 0; i < 2; i++) {
        bool obfuscate = (bool)i;
        path ph = temp_directory_path() / unique_path();
        CDBWrapper dbw(ph, (1 << 20), true, false, obfuscate);

        char key = 'i';
        uint256 in = GetRandHash();
        char key2 = 'j';
        uint256 in2 = GetRandHash();
        char key3 = 'k';
        uint256 in3 = GetRandHash();

        uint256 res;
        CDBBatch batch(&dbw.GetObfuscateKey());

        batch.Write(key, in);
        batch.Write(key2, in2);
        batch.Write(key3, in3);

        // Remove key3 before it's even been written
        batch.Erase(key3);

        dbw.WriteBatch(batch);

        BOOST_CHECK(dbw.Read(key, res));
        BOOST_CHECK_EQUAL(res.ToString(), in.ToString());
        BOOST_CHECK(dbw.Read(key2, res));
        BOOST_CHECK_EQUAL(res.ToString(), in2.ToString());

        // key3 never should've been written
        BOOST_CHECK(dbw.Read(key3, res) == false);
    }
}

BOOST_AUTO_TEST_CASE(dbwrapper_iterator)
{
    // Perform tests both obfuscated and non-obfuscated.
    for (int i = 0; i < 2; i++) {
        bool obfuscate = (bool)i;
        path ph = temp_directory_path() / unique_path();
        CDBWrapper dbw(ph, (1 << 20), true, false, obfuscate);

        // The two keys are intentionally chosen for ordering
        char key = 'j';
        uint256 in = GetRandHash();
        BOOST_CHECK(dbw.Write(key, in));
        char key2 = 'k';
        uint256 in2 = GetRandHash();
        BOOST_CHECK(dbw.Write(key2, in2));

        boost::scoped_ptr<CDBIterator> it(const_cast<CDBWrapper*>(&dbw)->NewIterator());

        // Be sure to seek past the obfuscation key (if it exists)
        it->Seek(key);

        char key_res;
        uint256 val_res;

        it->GetKey(key_res);
        it->GetValue(val_res);
        BOOST_CHECK_EQUAL(key_res, key);
        BOOST_CHECK_EQUAL(val_res.ToString(), in.ToString());

        it->Next();

        it->GetKey(key_res);
        it->GetValue(val_res);
        BOOST_CHECK_EQUAL(key_res, key2);
        BOOST_CHECK_EQUAL(val_res.ToString(), in2.ToString());

        it->Next();
        BOOST_CHECK_EQUAL(it->Valid(), false);
    }
}

// Test that we do not obfuscation if there is existing data.
BOOST_AUTO_TEST_CASE(existing_data_no_obfuscate)
{
    // We're going to share this path between two wrappers
    path ph = temp_directory_path() / unique_path();
    create_directories(ph);

    // Set up a non-obfuscated wrapper to write some initial data.
    CDBWrapper* dbw = new CDBWrapper(ph, (1 << 10), false, false, false);
    char key = 'k';
    uint256 in = GetRandHash();
    uint256 res;

    BOOST_CHECK(dbw->Write(key, in));
    BOOST_CHECK(dbw->Read(key, res));
    BOOST_CHECK_EQUAL(res.ToString(), in.ToString());

    // Call the destructor to free leveldb LOCK
    delete dbw;

    // Now, set up another wrapper that wants to obfuscate the same directory
    CDBWrapper odbw(ph, (1 << 10), false, false, true);

    // Check that the key/val we wrote with unobfuscated wrapper exists and 
    // is readable.
    uint256 res2;
    BOOST_CHECK(odbw.Read(key, res2));
    BOOST_CHECK_EQUAL(res2.ToString(), in.ToString());

    BOOST_CHECK(!odbw.IsEmpty()); // There should be existing data
    BOOST_CHECK(is_null_key(odbw.GetObfuscateKey())); // The key should be an empty string

    uint256 in2 = GetRandHash();
    uint256 res3;
 
    // Check that we can write successfully
    BOOST_CHECK(odbw.Write(key, in2));
    BOOST_CHECK(odbw.Read(key, res3));
    BOOST_CHECK_EQUAL(res3.ToString(), in2.ToString());
}
                        
// Ensure that we start obfuscating during a reindex.
BOOST_AUTO_TEST_CASE(existing_data_reindex)
{
    // We're going to share this path between two wrappers
    path ph = temp_directory_path() / unique_path();
    create_directories(ph);

    // Set up a non-obfuscated wrapper to write some initial data.
    CDBWrapper* dbw = new CDBWrapper(ph, (1 << 10), false, false, false);
    char key = 'k';
    uint256 in = GetRandHash();
    uint256 res;

    BOOST_CHECK(dbw->Write(key, in));
    BOOST_CHECK(dbw->Read(key, res));
    BOOST_CHECK_EQUAL(res.ToString(), in.ToString());

    // Call the destructor to free leveldb LOCK
    delete dbw;

    // Simulate a -reindex by wiping the existing data store
    CDBWrapper odbw(ph, (1 << 10), false, true, true);

    // Check that the key/val we wrote with unobfuscated wrapper doesn't exist
    uint256 res2;
    BOOST_CHECK(!odbw.Read(key, res2));
    BOOST_CHECK(!is_null_key(odbw.GetObfuscateKey()));

    uint256 in2 = GetRandHash();
    uint256 res3;
 
    // Check that we can write successfully
    BOOST_CHECK(odbw.Write(key, in2));
    BOOST_CHECK(odbw.Read(key, res3));
    BOOST_CHECK_EQUAL(res3.ToString(), in2.ToString());
}
 
BOOST_AUTO_TEST_SUITE_END()