#include "symtab.h"

static u32_t hash_func(const void* _key) {
    const symtab_key_t* key = (symtab_key_t*)_key;
    return rt_strhash(key->strp_name);
}

static int key_cmp(const void* _key1, const void* _key2) {
    const symtab_key_t* key1 = (symtab_key_t*)_key1;
    const symtab_key_t* key2 = (symtab_key_t*)_key2;
    if (rt_strcmp(key1->strp_name, key2->strp_name) == 0) {
        return 0;
    }
    return 1;
}

void init_symtab(symtab_t* symtab) {
    symtab->cur_scope = NULL;
    symtab->gid = 1;
    init_hashtable(&symtab->global_table);
    symtab->global_table.hash_func = hash_func;
    symtab->global_table.key_cmp = key_cmp;
    init_hashtable(&symtab->local_table);
    symtab->local_table.hash_func = hash_func;
    symtab->local_table.key_cmp = key_cmp;
}

void symtab_destroy(symtab_t* symtab) {
    // TODO
}

void symtab_enter_scope(symtab_t* symtab) {
    scope_t *scope = (scope_t*)salloc_alloc(sizeof(scope_t));
    scope->parent = symtab->cur_scope;
    scope->uid = symtab->gid++;
    init_hashtable(&scope->table);

    scope->table.hash_func = hash_func;
    scope->table.key_cmp = key_cmp;
    symtab->cur_scope = scope;
}

void symtab_leave_scope(symtab_t* symtab) {
    Assert(symtab->cur_scope != NULL);
    scope_t *parent = symtab->cur_scope->parent;
    hashtable_destory(&symtab->cur_scope->table);
    salloc_free(symtab->cur_scope);
    symtab->cur_scope = parent;
}

void* symtab_get(symtab_t* symtab, symtab_key_t* key) {
    for (scope_t* scope = symtab->cur_scope; scope != NULL; scope = scope->parent) {
        void* val = hashtable_get(&scope->table, key);
        if (val != NULL) {
            return val;
        }
    }
    return NULL;
}
void* symtab_add(symtab_t* symtab, symtab_key_t* key, void* val) {
    return hashtable_set(&symtab->cur_scope->table, key, val);
}