#include "symtable.h"

void entry_init(struct entry* self,
                char const* name,
                size_t addr,
                bool is_local)
{
    assert(self);
    self->name = strdup(name);
    self->addr = addr;
    self->is_local = is_local;
}

void entry_free(struct entry* self)
{
    assert(self);
    free(self->name);
}

void env_init(struct env* self, struct env* parent)
{
    assert(self);
    vec_init(&self->entries);
    self->parent = parent;
}

void env_free(struct env* self)
{
    assert(self);

    if (self->parent)
    {
        env_free(self->parent);
        free(self->parent);
        self->parent = NULL;
    }

    vec_free_elements(&self->entries, (void*) entry_free);
    vec_free(&self->entries);
}

struct entry* env_try_get(struct env* self, char* name)
{
    assert(self);
    assert(name);

    for (size_t i=0; i<self->entries.size; i++)
    {
        struct entry* entry = self->entries.data[i];

        if (strcmp(entry->name, name) == 0)
        {
            return entry;
        }
    }

    if (self->parent)
    {
        return env_try_get(self->parent, name);
    }

    return NULL;
}

void symtable_init(struct symtable* self)
{
    assert(self);
    self->root = malloc(sizeof(struct env));
    env_init(self->root, NULL);
}

void symtable_free(struct symtable* self)
{
    assert(self);
    env_free(self->root);
    free(self->root);
}

void symtable_declare(struct symtable* self,
                      char* name,
                      size_t addr,
                      bool is_local)
{
    assert(self);
    assert(name);
    assert(self->root);

    struct entry* entry = malloc(sizeof(struct entry));
    entry_init(entry, name, addr, is_local);

    vec_push(&self->root->entries, entry);
}

struct entry* symtable_try_get(struct symtable* self, char* name)
{
    assert(self);
    assert(name);

    return env_try_get(self->root, name);

}

void symtable_open_scope(struct symtable* self)
{
    struct env* env = malloc(sizeof(struct env));
    env_init(env, self->root);

    self->root = env;
}

void symtable_close_scope(struct symtable* self)
{
    assert(self);
    assert(self->root);

    struct env* env = self->root->parent;
    self->root->parent = NULL;

    env_free(self->root);
    free(self->root);

    self->root = env;
}