/*=============================================================================
    Copyright (c) 2001-2011 Joel de Guzman

    Distributed under the Boost Software License, Version 1.0. (See accompanying
    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/
#if !defined(BOOST_SPIRIT_CONJURE_COMPILER_HPP)
#define BOOST_SPIRIT_CONJURE_COMPILER_HPP

#include "ast.hpp"
#include "error_handler.hpp"
#include <vector>
#include <map>
#include <boost/function.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/phoenix/core.hpp>
#include <boost/phoenix/function.hpp>
#include <boost/phoenix/operator.hpp>

namespace client { namespace code_gen
{
    ///////////////////////////////////////////////////////////////////////////
    //  The Function
    ///////////////////////////////////////////////////////////////////////////
    struct function
    {
        function(std::vector<int>& code, int nargs)
          : code(code), address(code.size()), size_(0), nargs_(nargs) {}

        void op(int a);
        void op(int a, int b);
        void op(int a, int b, int c);

        int& operator[](std::size_t i) { return code[address+i]; }
        int const& operator[](std::size_t i) const { return code[address+i]; }
        std::size_t size() const { return size_; }
        std::size_t get_address() const { return address; }

        int nargs() const { return nargs_; }
        int nvars() const { return variables.size(); }
        int const* find_var(std::string const& name) const;
        void add_var(std::string const& name);
        void link_to(std::string const& name, std::size_t address);

        void print_assembler() const;

    private:

        std::map<std::string, int> variables;
        std::map<std::size_t, std::string> function_calls;
        std::vector<int>& code;
        std::size_t address;
        std::size_t size_;
        std::size_t nargs_;
    };

    ///////////////////////////////////////////////////////////////////////////
    //  The Compiler
    ///////////////////////////////////////////////////////////////////////////
    struct compiler
    {
        typedef bool result_type;

        template <typename ErrorHandler>
        compiler(ErrorHandler& error_handler_)
          : current(0)
        {
            using namespace boost::phoenix::arg_names;
            namespace phx = boost::phoenix;
            using boost::phoenix::function;

            error_handler = function<ErrorHandler>(error_handler_)(
                "Error! ", _2, phx::cref(error_handler_.iters)[_1]);
        }

        bool operator()(ast::nil) { BOOST_ASSERT(0); return false; }
        bool operator()(unsigned int x);
        bool operator()(bool x);
        bool operator()(ast::identifier const& x);
        bool operator()(ast::optoken const& x);
        bool operator()(ast::unary const& x);
        bool operator()(ast::function_call const& x);
        bool operator()(ast::expression const& x);
        bool operator()(ast::assignment const& x);
        bool operator()(ast::variable_declaration const& x);
        bool operator()(ast::statement_list const& x);
        bool operator()(ast::statement const& x);
        bool operator()(ast::if_statement const& x);
        bool operator()(ast::while_statement const& x);
        bool operator()(ast::return_statement const& x);
        bool operator()(ast::function const& x);
        bool operator()(ast::function_list const& x);

        void print_assembler() const;

        boost::shared_ptr<code_gen::function>
        find_function(std::string const& name) const;

        std::vector<int>& get_code() { return code; }
        std::vector<int> const& get_code() const { return code; }

    private:

        bool compile_expression(
            int min_precedence,
            std::list<ast::operation>::const_iterator& rbegin,
            std::list<ast::operation>::const_iterator rend);

        typedef std::map<std::string, boost::shared_ptr<code_gen::function> > function_table;

        std::vector<int> code;
        code_gen::function* current;
        std::string current_function_name;
        function_table functions;
        bool void_return;

        boost::function<
            void(int tag, std::string const& what)>
        error_handler;
    };
}}

#endif
