/*
	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 main.cpp
 * @author Gav Wood <i@gavwood.com>
 * @date 2014
 * RLP tool.
 */
#include <fstream>
#include <iostream>
#include <boost/regex.hpp>
#include <boost/algorithm/string.hpp>
#include "../test/JsonSpiritHeaders.h"
#include <libdevcore/CommonIO.h>
#include <libdevcore/RLP.h>
#include <libdevcrypto/SHA3.h>
#include <libethereum/Client.h>
using namespace std;
using namespace dev;
namespace js = json_spirit;

void help()
{
	cout
		<< "Usage abi enc <method_name> (<arg1>, (<arg2>, ... ))" << endl
		<< "      abi enc -a <abi.json> <method_name> (<arg1>, (<arg2>, ... ))" << endl
		<< "      abi dec -a <abi.json> [ <signature> | <unique_method_name> ]" << endl
		<< "Options:" << endl
		<< "    -a,--abi-file <filename>  Specify the JSON ABI file." << endl
		<< "    -h,--help  Print this help message and exit." << endl
		<< "    -V,--version  Show the version and exit." << endl
		<< "Input options:" << endl
		<< "    -p,--prefix  Require all input formats to be prefixed e.g. 0x for hex, . for decimal, @ for binary." << endl
		<< "    -P,--no-prefix  Require no input format to be prefixed." << endl
		<< "    -t,--typing  Require all arguments to be typed e.g. b32: (bytes32), u64: (uint64), b[]: (byte[]), i: (int256)." << endl
		<< "    -T,--no-typing  Require no arguments to be typed." << endl
		<< "Output options:" << endl
		<< "    -i,--index <n>  Output only the nth (counting from 0) return value." << endl
		<< "    -d,--decimal  All data should be displayed as decimal." << endl
		<< "    -x,--hex  Display all data as hex." << endl
		<< "    -b,--binary  Display all data as binary." << endl
		<< "    -p,--prefix  Prefix by a base identifier." << endl
		<< "    -z,--no-zeroes  Remove any leading zeroes from the data." << endl
		<< "    -n,--no-nulls  Remove any trailing nulls from the data." << endl
		;
	exit(0);
}

void version()
{
	cout << "abi version " << dev::Version << endl;
	exit(0);
}

enum class Mode
{
	Encode,
	Decode
};

enum class Encoding
{
	Auto,
	Decimal,
	Hex,
	Binary,
};

enum class Tristate
{
	False = false,
	True = true,
	Mu
};

enum class Format
{
	Binary,
	Hex,
	Decimal
};

struct InvalidUserString: public Exception {};
struct InvalidFormat: public Exception {};

enum class Base
{
	Unknown,
	Bytes,
	Address,
	Int,
	Uint,
	Fixed
};

static const map<Base, string> s_bases =
{
	{ Base::Bytes, "bytes" },
	{ Base::Address, "address" },
	{ Base::Int, "int" },
	{ Base::Uint, "uint" },
	{ Base::Fixed, "fixed" }
};

struct ABIType
{
	Base base = Base::Unknown;
	unsigned size = 32;
	unsigned ssize = 0;
	vector<int> dims;
	string name;
	ABIType() = default;
	ABIType(std::string const& _type, std::string const& _name):
		name(_name)
	{
		string rest;
		for (auto const& i: s_bases)
			if (boost::algorithm::starts_with(_type, i.second))
			{
				base = i.first;
				rest = _type.substr(i.second.size());
			}
		if (base == Base::Unknown)
			throw InvalidFormat();
		boost::regex r("(\\d*)(x(\\d+))?((\\[\\d*\\])*)");
		boost::smatch res;
		boost::regex_match(rest, res, r);
		size = res[1].length() > 0 ? stoi(res[1]) : 0;
		ssize = res[3].length() > 0 ? stoi(res[3]) : 0;
		boost::regex r2("\\[(\\d*)\\](.*)");
		for (rest = res[4]; boost::regex_match(rest, res, r2); rest = res[2])
			dims.push_back(!res[1].length() ? -1 : stoi(res[1]));
	}

	ABIType(std::string const& _s)
	{
		if (_s.size() < 1)
			return;
		switch (_s[0])
		{
		case 'b': base = Base::Bytes; break;
		case 'a': base = Base::Address; break;
		case 'i': base = Base::Int; break;
		case 'u': base = Base::Uint; break;
		case 'f': base = Base::Fixed; break;
		default: throw InvalidFormat();
		}
		if (_s.size() < 2)
		{
			if (base == Base::Fixed)
				size = ssize = 16;
			else if (base == Base::Address || base == Base::Bytes)
				size = 0;
			else
				size = 32;
			return;
		}
		strings d;
		boost::algorithm::split(d, _s, boost::is_any_of("*"));
		string s = d[0];
		if (s.find_first_of('x') == string::npos)
			size = stoi(s.substr(1));
		else
		{
			size = stoi(s.substr(1, s.find_first_of('x') - 1));
			ssize = stoi(s.substr(s.find_first_of('x') + 1));
		}
		for (unsigned i = 1; i < d.size(); ++i)
			if (d[i].empty())
				dims.push_back(-1);
			else
				dims.push_back(stoi(d[i]));
	}

	string canon() const
	{
		string ret;
		switch (base)
		{
		case Base::Bytes: ret = "bytes" + (size > 0 ? toString(size) : ""); break;
		case Base::Address: ret = "address"; break;
		case Base::Int: ret = "int" + toString(size); break;
		case Base::Uint: ret = "uint" + toString(size); break;
		case Base::Fixed: ret = "fixed" + toString(size) + "x" + toString(ssize); break;
		default: throw InvalidFormat();
		}
		for (int i: dims)
			ret += "[" + ((i > -1) ? toString(i) : "") + "]";
		return ret;
	}

	void noteHexInput(unsigned _nibbles) { if (base == Base::Unknown) { if (_nibbles == 40) base = Base::Address; else { base = Base::Bytes; size = _nibbles / 2; } } }
	void noteBinaryInput() { if (base == Base::Unknown) { base = Base::Bytes; size = 32; } }
	void noteDecimalInput() { if (base == Base::Unknown) { base = Base::Uint; size = 32; } }
};

bytes aligned(bytes const& _b, ABIType _t, Format _f, unsigned _length)
{
	(void)_t;
	bytes ret = _b;
	while (ret.size() < _length)
		if (_f == Format::Binary)
			ret.push_back(0);
		else
			ret.insert(ret.begin(), 0);
	while (ret.size() > _length)
		if (_f == Format::Binary)
			ret.pop_back();
		else
			ret.erase(ret.begin());
	return ret;
}

tuple<bytes, ABIType, Format> fromUser(std::string const& _arg, Tristate _prefix, Tristate _typing)
{
	ABIType type;
	string val;
	if (_typing == Tristate::True || (_typing == Tristate::Mu && _arg.find(':') != string::npos))
	{
		if (_arg.find(':') == string::npos)
			throw InvalidUserString();
		type = ABIType(_arg.substr(0, _arg.find(':')));
		val = _arg.substr(_arg.find(':') + 1);
	}
	else
		val = _arg;

	if (_prefix != Tristate::False)
	{
		if (val.substr(0, 2) == "0x")
		{
			type.noteHexInput(val.size() - 2);
			return make_tuple(fromHex(val), type, Format::Hex);
		}
		if (val.substr(0, 1) == "+")
		{
			type.noteDecimalInput();
			return make_tuple(toCompactBigEndian(bigint(val.substr(1))), type, Format::Decimal);
		}
		if (val.substr(0, 1) == "@")
		{
			type.noteBinaryInput();
			return make_tuple(asBytes(val.substr(1)), type, Format::Binary);
		}
	}
	if (_prefix != Tristate::True)
	{
		if (_arg.find_first_not_of("0123456789") == string::npos)
		{
			type.noteDecimalInput();
			return make_tuple(toCompactBigEndian(bigint(val)), type, Format::Decimal);
		}
		if (_arg.find_first_not_of("0123456789abcdefABCDEF") == string::npos)
		{
			type.noteHexInput(val.size());
			return make_tuple(fromHex(val), type, Format::Hex);
		}
		type.noteBinaryInput();
		return make_tuple(asBytes(_arg), type, Format::Binary);
	}
	throw InvalidUserString();
}

struct ABIMethod
{
	string name;
	vector<ABIType> ins;
	vector<ABIType> outs;
	bool isConstant = false;

	// isolation *IS* documentation.

	ABIMethod() = default;

	ABIMethod(js::mObject _o)
	{
		name = _o["name"].get_str();
		isConstant = _o["constant"].get_bool();
		if (_o.count("inputs"))
			for (auto const& i: _o["inputs"].get_array())
			{
				js::mObject a = i.get_obj();
				ins.push_back(ABIType(a["type"].get_str(), a["name"].get_str()));
			}
		if (_o.count("outputs"))
			for (auto const& i: _o["outputs"].get_array())
			{
				js::mObject a = i.get_obj();
				outs.push_back(ABIType(a["type"].get_str(), a["name"].get_str()));
			}
	}

	ABIMethod(string const& _name, vector<ABIType> const& _args)
	{
		name = _name;
		ins = _args;
	}

	string sig() const
	{
		string methodArgs;
		for (auto const& arg: ins)
			methodArgs += (methodArgs.empty() ? "" : ",") + arg.canon();
		return name + "(" + methodArgs + ")";
	}
	FixedHash<4> id() const { return FixedHash<4>(sha3(sig())); }

	std::string solidityDeclaration() const
	{
		ostringstream ss;
		ss << "function " << name << "(";
		int f = 0;
		for (ABIType const& i: ins)
			ss << (f++ ? ", " : "") << i.canon() << " " << i.name;
		ss << ") ";
		if (isConstant)
			ss << "constant ";
		if (!outs.empty())
		{
			ss << "returns (";
			f = 0;
			for (ABIType const& i: outs)
				ss << (f ? ", " : "") << i.canon() << " " << i.name;
			ss << ")";
		}
		return ss.str();
	}

	bytes encode(vector<pair<bytes, Format>> const& _params) const
	{
		bytes ret = name.empty() ? bytes() : id().asBytes();
		unsigned pi = 0;
		vector<unsigned> inArity;
		for (ABIType const& i: ins)
		{
			unsigned arity = 1;
			for (auto j: i.dims)
				if (j == -1)
				{
					ret += aligned(_params[pi].first, ABIType(), Format::Decimal, 32);
					arity *= fromBigEndian<unsigned>(_params[pi].first);
					pi++;
				}
				else
					arity *= j;
			inArity.push_back(arity);
		}
		unsigned ii = 0;
		for (ABIType const& i: ins)
		{
			for (unsigned j = 0; j < inArity[ii]; ++j)
			{
				if (i.base == Base::Bytes && !i.size)
				{
					ret += _params[pi].first;
					while (ret.size() % 32 != 0)
						ret.push_back(0);
				}
				else
					ret += aligned(_params[pi].first, i, _params[pi].second, 32);
				++pi;
			}
			++ii;
		}
		return ret;
	}
	string decode(bytes const& _data, int _index = -1)
	{
		stringstream out;
		if (_index == -1)
			out << "[";
		(void)_data;
		if (_index == -1)
			out << "]";
		return out.str();
	}
};

string canonSig(string const& _name, vector<ABIType> const& _args)
{
	string methodArgs;
	for (auto const& arg: _args)
		methodArgs += (methodArgs.empty() ? "" : ",") + arg.canon();
	return _name + "(" + methodArgs + ")";
}

struct UnknownMethod: public Exception {};
struct OverloadedMethod: public Exception {};

class ABI
{
public:
	ABI() = default;
	ABI(std::string const& _json)
	{
		js::mValue v;
		js::read_string(_json, v);
		for (auto const& i: v.get_array())
		{
			js::mObject o = i.get_obj();
			if (o["type"].get_str() != "function")
				continue;
			ABIMethod m(o);
			m_methods[m.id()] = m;
		}
	}

	ABIMethod method(string _nameOrSig, vector<ABIType> const& _args) const
	{
		auto id = FixedHash<4>(sha3(_nameOrSig));
		if (!m_methods.count(id))
			id = FixedHash<4>(sha3(canonSig(_nameOrSig, _args)));
		if (!m_methods.count(id))
			for (auto const& m: m_methods)
				if (m.second.name == _nameOrSig)
				{
					if (m_methods.count(id))
						throw OverloadedMethod();
					id = m.first;
				}
		if (m_methods.count(id))
			return m_methods.at(id);
		throw UnknownMethod();
	}

	friend ostream& operator<<(ostream& _out, ABI const& _abi);

private:
	map<FixedHash<4>, ABIMethod> m_methods;
};

ostream& operator<<(ostream& _out, ABI const& _abi)
{
	_out << "contract {" << endl;
	for (auto const& i: _abi.m_methods)
		_out << "  " << i.second.solidityDeclaration() << "; // " << i.first.abridged() << endl;
	_out << "}" << endl;
	return _out;
}

void userOutput(ostream& _out, bytes const& _data, Encoding _e)
{
	switch (_e)
	{
	case Encoding::Binary:
		_out.write((char const*)_data.data(), _data.size());
		break;
	default:
		_out << toHex(_data) << endl;
	}
}

template <unsigned n, class T> vector<typename std::remove_reference<decltype(get<n>(T()))>::type> retrieve(vector<T> const& _t)
{
	vector<typename std::remove_reference<decltype(get<n>(T()))>::type> ret;
	for (T const& i: _t)
		ret.push_back(get<n>(i));
	return ret;
}

int main(int argc, char** argv)
{
	Encoding encoding = Encoding::Auto;
	Mode mode = Mode::Encode;
	string abiFile;
	string method;
	Tristate prefix = Tristate::Mu;
	Tristate typePrefix = Tristate::Mu;
	bool clearZeroes = false;
	bool clearNulls = false;
	bool verbose = false;
	int outputIndex = -1;
	vector<pair<bytes, Format>> params;
	vector<ABIType> args;

	for (int i = 1; i < argc; ++i)
	{
		string arg = argv[i];
		if (arg == "-h" || arg == "--help")
			help();
		else if (arg == "enc" && i == 1)
			mode = Mode::Encode;
		else if (arg == "dec" && i == 1)
			mode = Mode::Decode;
		else if ((arg == "-a" || arg == "--abi") && argc > i)
			abiFile = argv[++i];
		else if ((arg == "-i" || arg == "--index") && argc > i)
			outputIndex = atoi(argv[++i]);
		else if (arg == "-p" || arg == "--prefix")
			prefix = Tristate::True;
		else if (arg == "-P" || arg == "--no-prefix")
			prefix = Tristate::False;
		else if (arg == "-t" || arg == "--typing")
			typePrefix = Tristate::True;
		else if (arg == "-T" || arg == "--no-typing")
			typePrefix = Tristate::False;
		else if (arg == "-z" || arg == "--no-zeroes")
			clearZeroes = true;
		else if (arg == "-n" || arg == "--no-nulls")
			clearNulls = true;
		else if (arg == "-v" || arg == "--verbose")
			verbose = true;
		else if (arg == "-x" || arg == "--hex")
			encoding = Encoding::Hex;
		else if (arg == "-d" || arg == "--decimal" || arg == "--dec")
			encoding = Encoding::Decimal;
		else if (arg == "-b" || arg == "--binary" || arg == "--bin")
			encoding = Encoding::Binary;
		else if (arg == "-v" || arg == "--verbose")
			version();
		else if (arg == "-V" || arg == "--version")
			version();
		else if (method.empty())
			method = arg;
		else
		{
			auto u = fromUser(arg, prefix, typePrefix);
			args.push_back(get<1>(u));
			params.push_back(make_pair(get<0>(u), get<2>(u)));
		}
	}

	string abiData;
	if (abiFile.empty())
		abiData = contentsString(abiFile);

	if (mode == Mode::Encode)
	{
		ABIMethod m;
		if (abiData.empty())
			m = ABIMethod(method, args);
		else
		{
			ABI abi(abiData);
			if (verbose)
				cerr << "ABI:" << endl << abi;
			try {
				m = abi.method(method, args);
			}
			catch(...)
			{
				cerr << "Unknown method in ABI." << endl;
				exit(-1);
			}
		}
		userOutput(cout, m.encode(params), encoding);
	}
	else if (mode == Mode::Decode)
	{
		if (abiData.empty())
		{
			cerr << "Please specify an ABI file." << endl;
			exit(-1);
		}
		else
		{
			ABI abi(abiData);
			ABIMethod m;
			if (verbose)
				cerr << "ABI:" << endl << abi;
			try {
				m = abi.method(method, args);
			}
			catch(...)
			{
				cerr << "Unknown method in ABI." << endl;
				exit(-1);
			}
			string encoded;
			for (int i = cin.get(); i != -1; i = cin.get())
				encoded.push_back((char)i);
			cout << m.decode(fromHex(encoded));
		}

		// TODO: read abi to determine output format.
		(void)encoding;
		(void)clearZeroes;
		(void)clearNulls;
		(void)outputIndex;
	}

	return 0;
}