#include "environment.h"
#include "gc.h"
#include "errors.h"

Environment *
env_create(Environment *parent) {
    Environment *env = alloc_env();
    env->parent = parent;
    env->marked = false;
    env->table = ht_init();
    return env;
}

void
env_add_symbol(Environment *env, Object *symbol, Object *value) {
    if (symbol->type != OBJ_TYPE_SYMBOL) {
        error_push((Error){
            .type = ERR_TYPE_RUNTIME,
            .value = ERR_NOT_A_SYMBOL,
            .line = 0,
            .col = 0,
        });
        return;
    }
    ht_insert(env->table, symbol, value);
}

Object *
env_lookup(Environment *env, Object *symbol) {
    while (env != NULL) {
        Object *obj = ht_lookup(env->table, symbol);
        if (obj != NULL) {
            return obj;
        }
        env = env->parent;
    }
    return obj_err;
}

Object *
env_update(Environment *env, Object *symbol, Object *value) {
    while (env != NULL) {
        Object *obj = ht_lookup(env->table, symbol);
        if (obj != NULL) {
            ht_insert(env->table, symbol, value);
            return obj_nil;
        }
        env = env->parent;
    }
    error_push((Error){
        .type = ERR_TYPE_RUNTIME,
        .value = ERR_SYMBOL_NOT_FOUND,
    });
    return obj_err;
}

void
env_add_or_update_current(Environment *env, Object *symbol, Object *value) {
    ht_insert(env->table, symbol, value);
}

Environment *
env_extend(Environment *parent, Environment *extra) {
    Environment *env = parent;
    HashTablePair *pairs = extra->table->pairs;
    for (size_t i = 0; i < array_cap(pairs); i++) {
        if (pairs[i].key != NULL) {
            ht_insert(env->table, pairs[i].key, pairs[i].value);
        }
    }
    return env;
}