/// __  ___ __ ___   ___ ___  ___ ___  ___  _ __
/// \ \/ / '__/ _ \ / __/ _ \/ __/ __|/ _ \| '__|
///  >  <| | | (_) | (_|  __/\__ \__ \ (_) | |
/// /_/\_\_|  \___/ \___\___||___/___/\___/|_|
///
/// Copyright (c) 1997 - Ognjen 'xolatile' Milan Robovic
///
/// xolatile@chud.cyou - xrocessor - Probably the most minimalistic general preprocessor aimed at EAXHLA language syntax.
///
/// This program is free software, free as in freedom and as in free beer, 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 any later version if you wish...
///
/// This program is distributed in the hope that it will be useful, but it is probably not, and without any warranty, without even the implied
/// warranty of merchantability or fitness for a particular purpose, because it is pointless. Please see the GNU (Geenoo) General Public License
/// for more details, if you dare, it is a lot of text that nobody wants to read...

static natural processor_parse_comment (character * buffer);
static natural processor_parse_include (character * buffer);
static natural processor_parse_use     (character * buffer);
static natural processor_parse_alias   (character * buffer);
static natural processor_parse_macro   (character * buffer);
static natural processor_parse_scope   (character * buffer);
static natural processor_parse_unscope (character * buffer);
static natural processor_parse_default (character * buffer);

static procedure processor_parse_buffer (character * buffer, natural limit);

typedef enum {
	processor_token_comment,        processor_token_include,        processor_token_use,            processor_token_alias,
	processor_token_macro,          processor_token_scope,          processor_token_unscope,        processor_token_default,
	processor_token_count
} processor_token_enumeration;

static character * processor_token_key [processor_token_count - 1] = {
	"---",          "include ",     "use ",         "alias ",       "macro ",       "scope ",       "unscope "
};

static natural (* processor_parse_key [processor_token_count]) (character * buffer) = {
	processor_parse_comment,        processor_parse_include,        processor_parse_use,            processor_parse_alias,
	processor_parse_macro,          processor_parse_scope,          processor_parse_unscope,        processor_parse_default
};

typedef struct {
	natural       count;
	natural       limit;
	character * * token_array_data;
	natural     * token_array_size;
	natural     * token_array_type;
} processor_structure;

static natural processor_parse_default (character * buffer) {
	for (natural select = 0; select < token_count; ++select) {
		if (string_compare_limit (buffer, token_array [select]->data, token_array [select]->size) == true) {
			if (token_array [select]->type == token_alias) {
				if (character_is_separator (buffer [-1])                         == false) continue;
				if (character_is_separator (buffer [token_array [select]->size]) == false) continue;

				output (token_value [select]->data, token_value [select]->size);

				return (token_array [select]->size);
			}

			if (token_array [select]->type == token_macro) {
				if (character_is_separator (buffer [-1])                         == false) continue;
				if (character_is_separator (buffer [token_array [select]->size]) == false) continue;

				processor_parse_buffer (token_value [select]->data, token_value [select]->size);

				return (token_array [select]->size);
			}
		}
	}

	output (buffer, 1);

	return (1);
}

static natural processor_parse_comment (character * buffer) {
	for (natural offset = 3; buffer [offset] != '\0'; ++offset) {
		if (buffer [offset] == '\n') break;
	}

	return (offset + 1);
}

static natural processor_parse_use (character * buffer) {
	natural length = 0;

	for (natural offset = 4; (buffer [offset] != '\0') && (character_is_blank (buffer [offset]) == true); ++offset);

	++token_count;

	token_array [token_count - 1] = arena_add (sizeof (* * token_array));

	token_array [token_count - 1]->data = & buffer [offset];
	token_array [token_count - 1]->type = token_use;

	for (length = 0; (buffer [offset + length] != '\0') && (character_is_blank (buffer [offset + length]) == false); ++length);

	token_array [token_count - 1]->size = length;

	return (offset + length + 1);
}

static natural processor_parse_include (character * buffer) {
	natural     length = 0;
	natural     offset = 0;
	character * data   = null;

	for (offset = 8; (buffer [offset] != '\0') && (character_is_blank (buffer [offset]) == true); ++offset);

	fatal_failure (buffer [offset] != '"', "processor_parse_include: Not a string.");

	++token_count;

	token_array [token_count - 1] = arena_add (sizeof (* * token_array));

	token_array [token_count - 1]->data = & buffer [offset + 1];
	token_array [token_count - 1]->type = token_include;

	for (length = 1; (buffer [offset + length] != '\0') && (buffer [offset + length] != '"'); ++length);

	token_array [token_count - 1]->size = length - 1;

	data = arena_add_file (token_array [token_count - 1]->data, token_array [token_count - 1]->size);

	processor_parse_buffer (data, -1);

	return (offset + length + 1);
}

static natural processor_parse_alias (character * buffer) {
	natural offset = 0;
	natural length = 0;

	for (offset = 6; (buffer [offset] != '\0') && (character_is_blank (buffer [offset]) == true); ++offset);

	++token_count;

	token_array [token_count - 1] = arena_add (sizeof (* * token_array));
	token_value [token_count - 1] = arena_add (sizeof (* * token_value));

	token_array [token_count - 1]->data = & buffer [offset];
	token_array [token_count - 1]->type = token_alias;

	for (length = 0; (buffer [offset + length] != '\0') && (character_is_blank (buffer [offset + length]) == false); ++length);

	token_array [token_count - 1]->size = length;

	for (offset += length; (buffer [offset] != '\0') && (character_is_blank (buffer [offset]) == true); ++offset);

	token_value [token_count - 1]->data = & buffer [offset];
	token_value [token_count - 1]->type = token_alias;

	for (length = 0; (buffer [offset + length] != '\0') && (character_is_blank (buffer [offset + length]) == false); ++length);

	token_value [token_count - 1]->size = length;

	return (offset + length + 1);
}

static natural processor_parse_macro (character * buffer) {
	natural offset = 0;
	natural length = 0;

	for (offset = 6; (buffer [offset] != '\0') && (character_is_blank (buffer [offset]) == true); ++offset);

	++token_count;

	token_array [token_count - 1] = arena_add (sizeof (* * token_array));
	token_value [token_count - 1] = arena_add (sizeof (* * token_value));

	token_array [token_count - 1]->data = & buffer [offset];
	token_array [token_count - 1]->type = token_macro;

	for (length = 0; (buffer [offset + length] != '\0') && (character_is_blank (buffer [offset + length]) == false); ++length);

	token_array [token_count - 1]->size = length;

	for (offset += length; (buffer [offset] != '\0') && (character_is_blank (buffer [offset]) == true); ++offset);

	token_value [token_count - 1]->data = & buffer [offset];
	token_value [token_count - 1]->type = token_macro;

	for (length = 0; buffer [offset + length] != '\0'; ++length) {
		if (string_compare_limit (& buffer [offset + length], "end macro", 9) == true) {
			break;
		}
	}

	token_value [token_count - 1]->size = length;

	return (offset + length + 9 + 1);
}

static natural processor_parse_scope (character * buffer) {
	natural offset = 0;
	natural length = 0;
	natural select = 0;

	for (offset = 6; (buffer [offset] != '\0') && (character_is_blank (buffer [offset]) == true); ++offset);

	for (length = 0; (buffer [offset + length] != '\0') && (character_is_blank (buffer [offset + length]) == false); ++length);

	for (select = 0; select < token_count; ++select) {
		if ((string_compare_limit (token_array [select]->data, & buffer [offset], length) == true) && (token_array [select]->type == token_use)) {
			for (; buffer [offset + length] != '\0'; ++length) {
				if (string_compare_limit (& buffer [offset + length], "end scope", 9) == true) {
					return (offset + length + 9 + 1);
				}
			}
		}
	}

	return (offset + length + 1);
}

static natural processor_parse_unscope (character * buffer) {
	natural offset = 0;
	natural length = 0;
	natural select = 0;

	for (offset = 8; (buffer [offset] != '\0') && (character_is_blank (buffer [offset]) == true); ++offset);

	for (length = 0; (buffer [offset + length] != '\0') && (character_is_blank (buffer [offset + length]) == false); ++length);

	for (select = 0; select < token_count; ++select) {
		if ((string_compare_limit (token_array [select]->data, & buffer [offset], length) == true) && (token_array [select]->type == token_use)) {
			return (offset + length + 1);
		}
	}

	for (; buffer [offset + length] != '\0'; ++length) {
		if (string_compare_limit (& buffer [offset + length], "end unscope", 11) == true) {
			return (offset + length + 11 + 1);
		}
	}

	return (offset + length + 1);
}

static procedure processor_parse_buffer (character * buffer, natural limit) {
	for (natural length = 0, offset = 0; (buffer [offset] != '\0') && (offset != limit); offset += length) {
		natural select = 0;

		for (select = 0; select < token_default; ++select) {
			length = string_length (token_key [select]);
			if (string_compare_limit (& buffer [offset], token_key [select], length) == true) {
				break;
			}
		}

		if (string_compare_limit (& buffer [offset], "end macro", 9) == true) {
			length = 9;
			continue;
		}

		if (string_compare_limit (& buffer [offset], "end scope", 9) == true) {
			length = 9;
			continue;
		}

		if (string_compare_limit (& buffer [offset], "end unscope", 11) == true) {
			length = 11;
			continue;
		}

		length = processor_parse_key [select] (& buffer [offset]);
	}
}