/*
	This file is part of cpp-ethereum.

	cpp-ethereum 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.

	cpp-ethereum 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 cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
*/
/** @file CodeFragment.h
 * @author Gav Wood <i@gavwood.com>
 * @date 2014
 */

#pragma once

#include <libethsupport/Common.h>
#include <libethcore/Instruction.h>
#include "CodeLocation.h"
#include "Exceptions.h"

namespace boost { namespace spirit { class utree; } }
namespace sp = boost::spirit;

namespace eth
{

class CompilerState;

class CodeFragment
{
	friend class CodeLocation;

public:
	CodeFragment(sp::utree const& _t, CompilerState& _s, bool _allowASM = false);
	CodeFragment(bytes const& _c = bytes()): m_code(_c) {}

	static CodeFragment compile(std::string const& _src, CompilerState& _s);

	/// Consolidates data and returns code.
	bytes const& code() { optimise(); consolidateData(); return m_code; }

	unsigned appendPush(u256 _l);
	void appendFragment(CodeFragment const& _f);
	void appendFragment(CodeFragment const& _f, unsigned _i);
	void appendInstruction(Instruction _i);

	CodeLocation appendPushLocation(unsigned _l = 0);
	void appendPushLocation(CodeLocation _l) { assert(_l.m_f == this); appendPushLocation(_l.m_pos); }
	void appendPushDataLocation(bytes const& _data);

	CodeLocation appendJump() { auto ret = appendPushLocation(0); appendInstruction(Instruction::JUMP); return ret; }
	CodeLocation appendJumpI() { auto ret = appendPushLocation(0); appendInstruction(Instruction::JUMPI); return ret; }
	CodeLocation appendJump(CodeLocation _l) { auto ret = appendPushLocation(_l.m_pos); appendInstruction(Instruction::JUMP); return ret; }
	CodeLocation appendJumpI(CodeLocation _l) { auto ret = appendPushLocation(_l.m_pos); appendInstruction(Instruction::JUMPI); return ret; }

	void appendFile(std::string const& _fn);

	std::string asPushedString() const;

	void onePath() { assert(!m_totalDeposit && !m_baseDeposit); m_baseDeposit = m_deposit; m_totalDeposit = INT_MAX; }
	void otherPath() { donePath(); m_totalDeposit = m_deposit; m_deposit = m_baseDeposit; }
	void donePaths() { donePath(); m_totalDeposit = m_baseDeposit = 0; }
	void ignored() { m_baseDeposit = m_deposit; }
	void endIgnored() { m_deposit = m_baseDeposit; m_baseDeposit = 0; }

	bool operator==(CodeFragment const& _f) const { return _f.m_code == m_code && _f.m_data == m_data; }
	bool operator!=(CodeFragment const& _f) const { return !operator==(_f); }
	unsigned size() const { return m_code.size(); }

	void consolidateData();
	void optimise();

private:
	template <class T> void error() const { throw T(); }
	void constructOperation(sp::utree const& _t, CompilerState& _s);

	void donePath() { if (m_totalDeposit != INT_MAX && m_totalDeposit != m_deposit) error<InvalidDeposit>(); }

	int m_deposit = 0;
	int m_baseDeposit = 0;
	int m_totalDeposit = 0;
	bytes m_code;
	std::vector<unsigned> m_locs;
	std::multimap<bytes, unsigned> m_data;
};

static const CodeFragment NullCodeFragment;

}