#include "../arena-lib/arena.h"
#include <stdio.h>

typedef enum {
    BIN_OP_SUMA,
    BIN_OP_RESTA,
    BIN_OP_MULTIPLY,
    BIN_OP_DIVISION
} BinaryOps;

typedef enum {
    NODE_NUMBER,
    NODE_OPERATION
} NodeKind;

typedef struct Node{
    union {
        BinaryOps operation;
        int number;
    }value;
    NodeKind type;
    struct Node* left;
    struct Node* right;
} Node;

Node* create_number(Arena* arena_ref, int n){
    Node* node = (Node*)arena_alloc(arena_ref, sizeof(Node));
    if(node == NULL){
        return NULL;
    }
    node->type = NODE_NUMBER;
    node->value.number = n;
    node->left = NULL;
    node->right = NULL;
    return node;
}

Node* create_operation(Arena* ref_arena, BinaryOps op, Node* l, Node* r){
    Node* node = (Node*)arena_alloc(ref_arena, sizeof(Node));
    if(node == NULL){
        return NULL;
    }
    node->type = NODE_OPERATION;
    node->value.operation = op;
    node->left = l;
    node->right = r;
    return node;
}

int node_compute(Node* node){
    if(node->type == NODE_OPERATION){
        int r1 = node_compute(node->left);
        int r2 = node_compute(node->right);
        int result = 0;
        switch (node->value.operation) {
            case BIN_OP_SUMA:
                result = r1 + r2;
                break;
            case BIN_OP_RESTA:
                result  = r1 -  r2;
                break;
            case BIN_OP_MULTIPLY:
                result = r1 * r2;
                break;
            case BIN_OP_DIVISION:
                result = (r2 != 0) ? r1 / r2 : 0;
                break;
            default:
                result = 0;
                break;
        }
        return result;
    }

    return node->value.number;
}

int main(void){

    Arena arena = arena_create(32);

    printf("Memory struct information\n");
    printf("=========================\n");
    printf("sizeof(Node):%zu\n", sizeof(Node));
    printf("align(Node): %zu\n", _Alignof(Node));

    //Creamos el arbol para 3 + (4 - 1)
    Node* t1 = create_number(&arena, 3);
    Node* t21 = create_number(&arena, 4);
    Node* t22 = create_number(&arena, 1);
    Node* t2 = create_operation(&arena, BIN_OP_RESTA, t21, t22);
    Node* root = create_operation(&arena, BIN_OP_SUMA, t1, t2);

    printf("Node compute\n");
    printf("============\n");

    printf("result: %d\n", node_compute(root));

    arena_free(&arena);

    return 0;
}