#include "control_parser.h"

#include <stdlib.h>
#include <stdio.h>

typedef control_parser_ctx context;

static void extract(context *ctx, char *fpc) {
	gsize len = (fpc - ctx->buffer->str) - ctx->mark;
	g_string_truncate(ctx->tmp, 0);
	g_string_append_len(ctx->tmp, ctx->buffer->str + ctx->mark, len);
	ctx->read += len;
}

static double extract_double(context *ctx, char *fpc) {
	extract(ctx, fpc);
	return strtod(ctx->tmp->str, NULL);
}

%%{

	machine control_parser;
	variable cs ctx->cs;

	action done { fbreak; }
	action mark { ctx->mark = fpc - ctx->buffer->str; }
	action telemetrystart { }
	action vehicle { }

	SP = " ";

	double = (digit | '.')*;
	
	dx = double >mark % { t->map.dx = extract_double(ctx, fpc); };
	dy = double >mark % { t->map.dy = extract_double(ctx, fpc); };
	min_sensor = double >mark % { t->map.min_sensor = extract_double(ctx, fpc); };
	max_sensor = double >mark % { t->map.max_sensor = extract_double(ctx, fpc); };
	max_speed = double >mark % { t->map.max_speed = extract_double(ctx, fpc); };
	max_turn = double >mark % { t->map.max_turn = extract_double(ctx, fpc); };
	max_hard_turn = double >mark % { t->map.max_hard_turn = extract_double(ctx, fpc); };

	init = "I" SP dx SP dy SP double SP min_sensor SP max_sensor SP max_speed SP max_turn SP max_hard_turn SP ";";

	x = double;
	y = double;
	r = double;
	dir = double;
	speed = double;
	ctl = [ab\-] [Ll\-rR];
	timestamp = double;

	boulder = "b" SP x SP y SP r SP;
	crater = "b" SP x SP y SP r SP;
	homebase = "b" SP x SP y SP r SP;
	martian = "m" SP x SP y SP dir SP speed SP;
	object = boulder | crater | homebase | martian;
	objects = object*;
	telemetry = ( ("T" SP timestamp SP ctl SP x SP y SP dir SP speed SP) %vehicle objects) >telemetrystart ";";

	main := init @ done;
}%%

%% write data;

static int control_parser_has_error(context *ctx) {
	return ctx->cs == control_parser_error;
}

static int control_parser_is_finished(context *ctx) {
	return ctx->cs >= control_parser_first_final;
}

void control_parser_new(trial *t) {
	context *ctx = t->parse_ctx = g_slice_new(context);
	%% write init;
	ctx->buffer = g_string_sized_new(0);
	ctx->tmp = g_string_sized_new(0);
}

void control_parser_reset(trial *t) {
	context *ctx = t->parse_ctx;
	%% write init;
	g_string_truncate(ctx->tmp, 0);
}

void control_parser_free(trial *t) {
	g_string_free(t->parse_ctx->buffer, TRUE);
	g_string_free(t->parse_ctx->tmp, TRUE);
	g_slice_free(context, t->parse_ctx);
}

run_t control_parse(trial *t) {
	context *ctx = t->parse_ctx;
	gsize wehave;

	if (0 < (wehave = ctx->buffer->len - ctx->read)) {
		char *p, *pe;

		p = ctx->buffer->str + ctx->read;
		pe = p + wehave;

		%% write exec;

		g_string_erase(ctx->buffer, 0, ctx->read);
		ctx->mark -= ctx->read;
		ctx->read = 0;
	}

	if (control_parser_has_error(ctx)) {
		fprintf(stderr, "Parse error\n");
		return RUN_ERROR;
	}
	if (control_parser_is_finished(ctx)) return RUN_DONE;
	return RUN_GO_ON;
}