#include "transaction_manager.h"
#include "core_map.h"
#include "btree.h"

#define BOOST_TEST_MODULE BTreeTests
#include <boost/test/included/unit_test.hpp>

using namespace std;
using namespace boost;
using namespace persistent_data;

//----------------------------------------------------------------

namespace {
	block_address const NR_BLOCKS = 102400;

	transaction_manager::ptr
	create_tm() {
		block_manager<>::ptr bm(new block_manager<>("./test.data", NR_BLOCKS));
		space_map::ptr sm(new core_map(NR_BLOCKS));
		transaction_manager::ptr tm(new transaction_manager(bm, sm));
		return tm;
	}

	btree<1, uint64_traits>::ptr
	create_btree() {
		uint64_traits::ref_counter rc;

		return btree<1, uint64_traits>::ptr(
			new btree<1, uint64_traits>(create_tm(), rc));
	}

	// Checks that a btree is well formed.
	//
	// i) No block should be in the tree more than once.
	//
	class constraint_visitor : public btree<1, uint64_traits>::visitor {
	public:
	  bool visit_internal(unsigned level, bool is_root, btree_detail::node_ref<uint64_traits> const &n) {
			check_duplicate_block(n.get_location());
			return true;
		}

	  bool visit_internal_leaf(unsigned level, bool is_root, btree_detail::node_ref<uint64_traits> const &n) {
			check_duplicate_block(n.get_location());
			return true;
		}

	  bool visit_leaf(unsigned level, bool is_root, btree_detail::node_ref<uint64_traits> const &n) {
			check_duplicate_block(n.get_location());
			return true;
		}

	private:
		void check_duplicate_block(block_address b) {
			if (seen_.count(b)) {
				ostringstream out;
				out << "duplicate block in btree: " << b;
				throw runtime_error(out.str());
			}

			seen_.insert(b);
		}

		set<block_address> seen_;
	};

	void check_constraints(btree<1, uint64_traits>::ptr tree) {
		typedef btree<1, uint64_traits> tree_type;

		tree_type::visitor::ptr v(new constraint_visitor);
		tree->visit(v);
	}
}

//----------------------------------------------------------------

BOOST_AUTO_TEST_CASE(empty_btree_contains_nothing)
{
	auto tree = create_btree();
	check_constraints(tree);

	for (uint64_t i = 0; i < 1000; i++) {
		uint64_t key[1] = {i};
		BOOST_CHECK(!tree->lookup(key));
	}
}

BOOST_AUTO_TEST_CASE(insert_works)
{
	unsigned const COUNT = 100000;

	auto tree = create_btree();
	for (uint64_t i = 0; i < COUNT; i++) {
		uint64_t key[1] = {i * 7};
		uint64_t value = i;

		tree->insert(key, value);

		auto l = tree->lookup(key);
		BOOST_CHECK(l);
		BOOST_CHECK_EQUAL(*l, i);
	}

	check_constraints(tree);
}

//----------------------------------------------------------------