/*
  Copyright (c) 2013-2015, Matthias Schiffer <mschiffer@universe-factory.net>
  All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are met:

    1. Redistributions of source code must retain the above copyright notice,
       this list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright notice,
       this list of conditions and the following disclaimer in the documentation
       and/or other materials provided with the distribution.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/


#pragma once

#include <cstdio>
#include <memory>
#include <sstream>
#include <string>
#include <vector>

namespace solar {

class nocopy_t {
private:
	nocopy_t(const nocopy_t &o) = delete;
	nocopy_t(nocopy_t &&o) = delete;
	nocopy_t & operator=(const nocopy_t &o) = delete;
	nocopy_t & operator=(nocopy_t &&o) = delete;

protected:
	nocopy_t() {}
};

class codegen_t : private nocopy_t {
public:
	struct variable_t {
		std::string str;
		std::string name;


		variable_t(const std::pair<std::string, std::string> &value, bool func = false) : str(value.first), name(value.second) {
			if (!func) {
				char last = str[str.length()-1];
				if (last != '*' && last != '&')
					str += ' ';

				str += name;
			}
		}
	};

	struct function_t {
		variable_t type_name;
		std::vector<variable_t> args;

		void add_arg(const std::pair<std::string, std::string> &value, bool func = false) {
			args.emplace_back(value, func);
		}

		void add_arg(const std::string &str, const std::string &name, bool func = false) {
			add_arg({str, name}, func);
		}

		function_t(const std::string &type, const std::string &name) : type_name({type + ' ' + name, name}, true) {}
	};

private:
	FILE *file;
	unsigned level;


	template<typename... Args> void open_block(Args ...args) {
		write_line(args..., " {");
		level++;
	}

	template<typename... Args> void close_block(Args ...args) {
		level--;
		write_line("}", args...);
	}


	static void handle_arg(std::ostringstream *s, bool is_call, const variable_t &var) {
		if (is_call)
			*s << var.name;
		else
			*s << var.str;
	}

	static void handle_arg(std::ostringstream *s, bool is_call, const std::vector<variable_t> &vars) {
		bool first = true;
		for (const variable_t &var : vars) {
			if (!first)
				*s << ", ";

			handle_arg(s, is_call, var);
			first = false;
		}
	}

	static void handle_arg(std::ostringstream *s, bool is_call, const function_t &f) {
		handle_arg(s, is_call, f.type_name);

		*s << "(";

		if (f.args.empty() && !is_call)
			*s << "void";
		else
			handle_arg(s, is_call, f.args);

		*s << ")";
	}

	template<typename T> static void handle_arg(std::ostringstream *s, __attribute__((unused)) bool is_call, T arg) {
		*s << arg;
	}

	static void handle_args(__attribute__((unused)) std::ostringstream *s, __attribute__((unused)) bool is_call) {
	}

	template<typename T, typename... Args> static void handle_args(std::ostringstream *s, bool is_call, T arg, Args ...args) {
		handle_arg(s, is_call, arg);
		handle_args(s, is_call, args...);
	}

	template<typename... Args> void write_offset(int offset, Args ...args) {
		for (int i = 0; i < int(level) + offset; i++)
			std::fputc('\t', file);

		std::fputs(combine(args...).c_str(), file);
	}

	void write_line_offset(__attribute__((unused)) int offset) {
		std::fputs("\n", file);
	}

	template<typename... Args> void write_line_offset(int offset, Args ...args) {
		write_offset(offset, args..., "\n");
	}

public:
	class block_t : private nocopy_t {
	private:
		codegen_t *codegen;
		std::string close_string;

	public:
		template<typename... Args> block_t(codegen_t *codegen0, Args ...args) : codegen(codegen0) {
			codegen->open_block(args...);
		}

		template<typename... Args> void close(Args ...args) {
			close_string = combine(args...);
		}

		template<typename... Args> void close_(Args ...args) {
			close(args..., ";");
		}

		~block_t() {
			codegen->close_block(close_string);
		}
	};

	codegen_t(const char *filename);
	~codegen_t();

	template<typename... Args> static std::string combine(Args ...args) {
		std::ostringstream s;
		handle_args(&s, false, args...);
		return s.str();
	}

	template<typename... Args> static std::string call(Args ...args) {
		std::ostringstream s;
		handle_args(&s, true, args...);
		return s.str();
	}

	template<typename... Args> void write_line(Args ...args) {
		write_line_offset(0, args...);
	}

	template<typename... Args> void write_line_(Args ...args) {
		write_line(args..., ";");
	}

	template<typename... Args> void _write_line(Args ...args) {
		write_line_offset(1, args...);
	}

	template<typename... Args> void _write_line_(Args ...args) {
		write_line_offset(1, args..., ";");
	}

	template<typename... Args> void write_case(Args ...args) {
		write_line_offset(-1, "case ", args..., ":");
	}

	template<typename... Args> void write_default() {
		write_line_offset(-1, "default:");
	}
};

}