#ifndef VARIANT_PARSER_H
#define VARIANT_PARSER_H

#include "variant.h"
#include "os/file_access.h"
#include "resource.h"

class VariantParser {
public:

	struct Stream {

		virtual CharType get_char()=0;
		virtual bool is_utf8() const=0;
		virtual bool is_eof() const=0;

		CharType saved;

		Stream() { saved=0; }
		virtual ~Stream() {}
	};

	struct StreamFile : public Stream {

		FileAccess *f;

		virtual CharType get_char();
		virtual bool is_utf8() const;
		virtual bool is_eof() const;

		StreamFile() { f=NULL; }

	};

	typedef Error (*ParseResourceFunc)(void* p_self, Stream* p_stream,Ref<Resource>& r_res,int &line,String &r_err_str);

	struct ResourceParser {

		void *userdata;
		ParseResourceFunc func;
		ParseResourceFunc ext_func;
		ParseResourceFunc sub_func;

	};

	enum TokenType {
		TK_CURLY_BRACKET_OPEN,
		TK_CURLY_BRACKET_CLOSE,
		TK_BRACKET_OPEN,
		TK_BRACKET_CLOSE,
		TK_PARENTHESIS_OPEN,
		TK_PARENTHESIS_CLOSE,
		TK_IDENTIFIER,
		TK_STRING,
		TK_NUMBER,
		TK_COLON,
		TK_COMMA,
		TK_EQUAL,
		TK_EOF,
		TK_ERROR,
		TK_MAX
	};

	enum Expecting {

		EXPECT_OBJECT,
		EXPECT_OBJECT_KEY,
		EXPECT_COLON,
		EXPECT_OBJECT_VALUE,
	};

	struct Token {

		TokenType type;
		Variant value;
	};

	struct Tag {

		String name;
		Map<String,Variant> fields;
	};

private:
	static const char * tk_name[TK_MAX];

	template<class T>
	static Error _parse_construct(Stream *p_stream, Vector<T>& r_construct, int &line, String &r_err_str);
	static Error _parse_dictionary(Dictionary &object, Stream *p_stream, int &line, String &r_err_str,ResourceParser *p_res_parser=NULL);
	static Error _parse_array(Array &array, Stream *p_stream, int &line, String &r_err_str,ResourceParser *p_res_parser=NULL);
	static Error _parse_tag(Token& token,Stream *p_stream, int &line, String &r_err_str,Tag& r_tag,ResourceParser *p_res_parser=NULL);

public:

	static Error parse_tag(Stream *p_stream, int &line, String &r_err_str,Tag& r_tag,ResourceParser *p_res_parser=NULL);
	static Error parse_tag_assign_eof(Stream *p_stream, int &line, String &r_err_str, Tag& r_tag, String &r_assign, Variant &r_value,ResourceParser *p_res_parser=NULL);

	static Error parse_value(Token& token,Variant &value, Stream *p_stream, int &line, String &r_err_str,ResourceParser *p_res_parser=NULL);
	static Error get_token(Stream *p_stream,Token& r_token,int &line,String &r_err_str);
	static Error parse(Stream *p_stream, Variant &r_ret, String &r_err_str, int &r_err_line,ResourceParser *p_res_parser=NULL);
};

#endif // VARIANT_PARSER_H