#include "parse.h"
#include "util.h"
#include <assert.h>

static mpc_ast_t *_parse_dbc_string(const char *file_name, const char *string);
static mpc_ast_t *_parse_dbc_file_by_handle(const char *name, FILE *handle);

#define X_MACRO_PARSE_VARS\
	X(spaces,               "s")\
	X(newline,              "n")\
	X(sign,                 "sign")\
	X(flt,                  "float")\
	X(ident,                "ident")\
	X(integer,              "integer")\
	X(factor,               "factor")\
	X(offset,               "offset")\
	X(range,                "range")\
	X(length,               "length")\
	X(node,                 "node")\
	X(nodes,                "nodes")\
	X(stringp,              "string")\
	X(unit,                 "unit")\
	X(startbit,             "startbit")\
	X(endianess,            "endianess")\
	X(y_mx_c,               "y_mx_c")\
	X(name,                 "name")\
	X(ecu,                  "ecu")\
	X(dlc,                  "dlc")\
	X(id,                   "id")\
	X(multiplexor,          "multiplexor")\
	X(signal,               "signal")\
	X(message,              "message")\
	X(messages,             "messages")\
	X(types,                "types")\
	X(version,              "version")\
	X(ecus,                 "ecus")\
	X(symbols,              "symbols")\
	X(bs,                   "bs")\
	X(sigtype,              "sigtype")\
	X(sigval,               "sigval")\
	X(whatever,             "whatever")\
	X(values,               "values")\
	X(val_item,             "val_item")\
	X(val,                  "val")\
	X(vals,                 "vals")\
	X(attribute_definition, "attribute_definition")\
	X(attribute_value,      "attribute_value")\
	X(comment,              "comment")\
	X(comments,             "comments")\
	X(comment_string,       "comment_string")\
	X(dbc,                  "dbc")

/* TODO: Be more lax in what is acceptable */
static const char *dbc_grammar =
" s                    : /[ \\t]/ ; \n"
" n                    : /\\r?\\n/ ; \n"
" sign                 : '+' | '-' ; \n"
" float                : /[-+]?[0-9]+(\\.[0-9]+)?([eE][-+]?[0-9]+)?/ ; \n"
" ident                : /[a-zA-Z_][a-zA-Z0-9_]*/ ;\n"
" integer              : <sign>? /[0-9]+/ ; \n"
" factor               : <float> | <integer> ; \n"
" offset               : <float> | <integer> ; \n"
" length               : /[0-9]+/ ; \n"
" range                : '[' ( <float> | <integer> ) '|' ( <float> | <integer> ) ']' ;\n"
" node                 : <ident> ; \n"
" nodes                : <node> <s>* ( ',' <s>* <node>)* ; \n"
" string               : '\"' /((\\\\\")|[^\"])*/ '\"' \n; "
" unit                 : <string> ; \n"
" startbit             : <integer> ; \n"
" endianess            : '0' | '1' ; \n" /* for the endianess; 0 = Motorola, 1 = Intel */
" y_mx_c               : '(' <factor> ',' <offset> ')' ; \n"
" name                 : <ident> ; \n"
" ecu                  : <ident> ; \n"
" dlc                  : <integer> ; \n"
" id                   : <integer> ; \n"
" multiplexor          : 'M' | 'm' <s>* <integer> ; \n"
" signal               : <s>* \"SG_\" <s>+ <name> <s>* <multiplexor>? <s>* ':' <s>* <startbit> <s>* '|' <s>* \n"
"                        <length> <s>* '@' <s>* <endianess> <s>* <sign> <s>* <y_mx_c> <s>* \n"
"                        <range> <s>* <unit> <s>* <nodes> <s>* <n> ; \n"
" message              : \"BO_\" <s>+ <id> <s>+ <name>  <s>* ':' <s>* <dlc> <s>+ <ecu> <s>* <n> <signal>* ; \n"
" messages             : (<message> <n>*)* ; \n"
" version              : \"VERSION\" <s> <string> <n>+ ; \n"
" ecus                 : \"BU_\" <s>* ':' (<ident>|<s>)* <n> ; \n"
" symbols              : \"NS_\" <s>* ':' <s>* <n> ('\t'|' '* <ident> <n>)* <n> ; \n"
" sigtype              : <integer>  ;\n"
" sigval               : <s>* \"SIG_VALTYPE_\" <s>+ <id> <s>+ <name> <s>* \":\" <s>* <sigtype> <s>* ';' <n>* ; \n"
" whatever             : (<ident>|<string>|<integer>|<float>) ; \n"
" bs                   : \"BS_\" <s>* ':' <s>* <n>+ ; "
" types                : <s>* <ident> (<whatever>|<s>)+ ';' <n> ; \n"
" values               : \"VAL_TABLE_\" (<whatever>|<s>)* ';' <n> ; \n"
" val_cnt              : <integer> ; \n"
" val_name             : <string> ; \n"
" val_index            : <integer> ; \n"
" attribute_definition : \"BA_DEF_\" (<whatever>|<s>|',')* ';' <n> ; \n"
" attribute_value      : \"BA_\" (<whatever>|<s>|',')* ';' <n> ; \n"
" val_item             : (<s>+ <integer> <s>+ <string>) ; \n"
" val                  : \"VAL_\" <s>+ <id> <s>+ <name> <val_item>* ';' <n> ; \n"
" vals                 : <val>* ; \n"
" env_var_name         : <ident> ; \n"
" comment_string       : <string> ; \n"
" comment              : \"CM_\" <s>+ "
"                        ( "
"                             \"SG_\" <s>+ <id> <s>+ <name> <s>+ <comment_string> "
"                        |    \"BU_\" <s>+ <name> <s>+ <comment_string> "
"                        |    \"BO_\" <s>+ <id> <s>+ <comment_string> "
"                        |    \"EV_\" <s>+ <env_var_name> <s>+ <comment_string> "
"                        |    <comment_string> "
"                        ) <s>* ';' <n> ;\n "
" comments              : <comment>* ; "
" dbc       : <version> <symbols> <bs> <ecus> <values>* <n>* <messages> <comments> <sigval>* <attribute_definition>* <attribute_value>* <vals>  ; \n" ;

const char *parse_get_grammar(void)
{
	return dbc_grammar;
}

mpc_ast_t *parse_dbc_file_by_name(const char *name)
{
	assert(name);
	mpc_ast_t *ast = NULL;
	FILE *input = fopen(name, "rb");
	if (!input)
		goto end;
	ast = _parse_dbc_file_by_handle(name, input);
end:
	if (input)
		fclose(input);
	return ast;
}

mpc_ast_t *parse_dbc_file_by_handle(FILE *handle)
{
	assert(handle);
	return _parse_dbc_file_by_handle("<FILE*>", handle);
}

static mpc_ast_t *_parse_dbc_file_by_handle(const char *name, FILE *handle)
{
	assert(name);
	assert(handle);
	mpc_ast_t *ast = NULL;
	char *istring = NULL;
	if (!(istring = slurp(handle)))
		goto end;
	ast = _parse_dbc_string(name, istring);
end:
	free(istring);
	return ast;
}

mpc_ast_t *parse_dbc_string(const char *string)
{
	assert(string);
	return _parse_dbc_string("<string>", string);
}

enum cleanup_length_e
{
#define X(CVAR, NAME) _ignore_me_ ## CVAR,
	X_MACRO_PARSE_VARS
	CLEANUP_LENGTH
#undef X
};

static mpc_ast_t *_parse_dbc_string(const char *file_name, const char *string)
{
	assert(file_name);
	assert(string);
	#define X(CVAR, NAME) mpc_parser_t *CVAR = mpc_new((NAME));
	X_MACRO_PARSE_VARS
	#undef X

	#define X(CVAR, NAME) CVAR,
	mpc_err_t *language_error = mpca_lang(MPCA_LANG_WHITESPACE_SENSITIVE, dbc_grammar, X_MACRO_PARSE_VARS NULL);
	#undef X

	if (language_error != NULL) {
		mpc_err_print(language_error);
		mpc_err_delete(language_error);
		exit(EXIT_FAILURE);
	}

	mpc_result_t r;
	mpc_ast_t *ast = NULL;
	if (mpc_parse(file_name, string, dbc, &r)) {
		ast = r.output;
	} else {
		mpc_err_print(r.error);
		mpc_err_delete(r.error);
	}

#define X(CVAR, NAME) CVAR,
	mpc_cleanup(CLEANUP_LENGTH,
		X_MACRO_PARSE_VARS NULL
		);
#undef X
	return ast;
}