#include <string.h>
#include <stdio.h>

#include "types.h"

typedef struct val {
	type t;
	char *name;
	union {
		int i;
	};
} val;

val *vars[4096];
int varcount = 0;

values *eval(ast *a);

values *getval(ast *a, int index, type t) { 
	values *tmp;
	if (t == INT && a->vals->ts[index] == INT)
		return a->vals;
	else if  ((tmp = eval(a->vals->as[index]))->ts[0] == t)
		return tmp;
	else
		fprintf(stderr, "expected value, but got nothing\n");
}

void checkcount(ast *a, int argc) {
	if (a->vals->argc != argc)
		fprintf(stderr, "incorrect number of args given!\n");
}

values *eval(ast *a) {
	values *v = malloc(sizeof(values));

	if (strcmp(a->fname, "print") == 0) {
		checkcount(a, 1);
		printf("%d\n", getval(a, 0, INT)->is[0]);
		return NULL;
	} 

	else if (strcmp(a->fname, "set") == 0) {
		checkcount(a, 2);
		printf("%d\n", getval(a, 0, INT)->is[0]);
		return NULL;
	} 

	else if (strcmp(a->fname, "+") == 0) {
		v->is[0] = getval(a, 0, INT)->is[0];
		for (int i = 1; i < a->vals->argc; i++) 
			v->is[0] += getval(a, i, INT)->is[i];

		v->ts[0] = INT;
		v->argc++;
	}
	else if (strcmp(a->fname, "-") == 0) {
		if (a->vals->argc == 1) 
			v->is[0] = -getval(a, 0, INT)->is[0];
		else {
			v->is[0] = getval(a, 0, INT)->is[0];
			for (int i = 1; i < a->vals->argc; i++) 
				v->is[0] -= getval(a, i, INT)->is[i];
		}

		v->ts[0] = INT;
		v->argc++;
	}
	else if (strcmp(a->fname, "*") == 0) {
		v->is[0] = getval(a, 0, INT)->is[0]; 
		for (int i = 1; i < a->vals->argc; i++) 
			v->is[0] *= getval(a, i, INT)->is[i];

		v->ts[0] = INT;
		v->argc++;
	}
	else if (strcmp(a->fname, "/") == 0) {
		v->is[0] = getval(a, 0, INT)->is[0];
		for (int i = 1; i < a->vals->argc; i++) 
			v->is[0] /= getval(a, i, INT)->is[i];

		v->ts[0] = INT;
		v->argc++;
	}
	else if (strcmp(a->fname, "%") == 0) {
		v->is[0] = getval(a, 0, INT)->is[0] % getval(a, 1, INT)->is[1];
		v->ts[0] = INT;
		v->argc++;
	}

	return v;
}