#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include "parser.h"
#include "builtin.h"
#include "eval.h"

int varcount = 0;
luckyvar *variables[10000];

int funccount= 0;
luckytree *functions[10000];

int argcount(luckyval *tree){
	if (tree == NULL) return 0;
	else return 1 + argcount(tree->nextelement);
}

bool checkargcount(luckytree *tree, int i){
	return !(argcount(tree->arguments) == i);
}

void argcounterror(luckytree *tree, int expected){
		if (checkargcount(tree, expected)) {
			printf("expected %d args to function %s, got %d\n",expected, tree->function, argcount(tree->arguments));
			exit(1);
		}
}

luckyval *lookupvar(char *name){
	for (int i = 0; i < 10000; i++){
		if (variables[i] != NULL && strcmp(variables[i]->name, name) == 0){
			return variables[i]->val;
		}
	}
	printf("no such variable %s exists!\n", name);
	exit(1);
}

luckyval *eval(luckytree *tree){
	int i = 0;
	for (luckyval *current = tree->arguments; i < argcount(tree->arguments); current = current->nextelement){
		if (current->type == LUCKYTREE){
			luckyval *var = malloc(sizeof(luckyval));
			var = eval(current->tree);
			memcpy(&current->d, &var->d, sizeof(double));
			current->type = var->type;
			free(var);
		}
		else if (strcmp(tree->function, "let") != 0) {
			if (current->type == LUCKYVAR){
				luckyval *tmp = lookupvar(current->var);		
				memcpy(&current->d, &tmp->d, sizeof(double));
				current->type = tmp->type;
			}
		}
		i++;
	}

	luckyval *out = malloc(sizeof(luckyval));

	if (arithmetic(tree, out)) return out;
	else if (io(tree, out)) return out;
	else if (variableops(tree, out)) return out;

	printf("Unknown function!\n");
	exit(1);
}