#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <uuid/uuid.h>

#include <models/relay.h>
#include <macros.h>

static int
relay_load_single(MDB_txn *mdb_txn, MDB_dbi mdb_dbi, db_key_relay_e key_relay, uint8_t num, MDB_val *value)
{
    int err;

    size_t key_size = sizeof(db_key_relay_e) + sizeof(uint8_t); 
    void *key_data = malloc(key_size);
    memmove((uint8_t*)key_data, &key_relay, sizeof(db_key_relay_e));
    memmove((uint8_t*)key_data + sizeof(db_key_relay_e), &num, sizeof(uint8_t));

    MDB_val key;
    key.mv_size = key_size;
    key.mv_data = key_data;

    if((err = mdb_get(mdb_txn, mdb_dbi, &key, value)) != 0)
    {
        LOG_ERROR("mdb_get error %s\n", mdb_strerror(err));
        mdb_txn_abort(mdb_txn);
        free(key_data);
        return 1;
    }
    free(key_data);
    return 0;
}

relay_t*
relay_load(MDB_env *mdb_env, uint8_t num)
{
    int err;
    MDB_txn *mdb_txn;
    MDB_dbi mdb_dbi;
    
    relay_t *new_relay;

    if((err = mdb_txn_begin(mdb_env, NULL, MDB_RDONLY, &mdb_txn)) != 0)
    {
        LOG_ERROR("mdb_txn_begin error %s\n", mdb_strerror(err));
        return relay_create(num);
    }

    if((err = mdb_dbi_open(mdb_txn, "relays", 0, &mdb_dbi)) != 0)
    {
        switch(err)
        {
            case MDB_NOTFOUND:
                LOG_INFO("no relay for num %d found in db. returning new one (no relays db)\n", num);
                mdb_txn_abort(mdb_txn);
                return relay_create(num);
            default:
                LOG_ERROR("mdb_txn_begin error %s\n", mdb_strerror(err));
                return relay_create(num);
        }
    }

    new_relay = malloc(sizeof(relay_t));
    new_relay->number = num;

    MDB_val value;

    if((err = relay_load_single(mdb_txn, mdb_dbi, DB_KEY_RELAY_NAME, num, &value)) != 0)
    {
        LOG_INFO("no relay for num %d found in db. returning new one\n", num);
        mdb_txn_abort(mdb_txn); // transaction is read only
        return relay_create(num);
    }
    strncpy(new_relay->name, (char*)value.mv_data, MAX_NAME_LENGTH);
    new_relay->name[MAX_NAME_LENGTH] = '\0';

    if((err = relay_load_single(mdb_txn, mdb_dbi, DB_KEY_RELAY_SCHEDULE_ID, num, &value)) != 0)
    {
        LOG_INFO("no relay for num %d found in db. returning new one\n", num);
        mdb_txn_abort(mdb_txn); // transaction is read only
        return relay_create(num);
    }
    uuid_t *schedule_id = (uuid_t*)value.mv_data;

    if((err = relay_load_single(mdb_txn, mdb_dbi, DB_KEY_RELAY_SCHEDULE_PERIODS, num, &value)) != 0)
    {
        LOG_INFO("no relay for num %d found in db. returning new one\n", num);
        mdb_txn_abort(mdb_txn); // transaction is read only
        return relay_create(num);
    }
    uint16_t schedule_periods_length = ((uint16_t*)value.mv_data)[0];
    uint16_t *schedule_periods = ((uint16_t*)value.mv_data) + 1;

    new_relay->schedule = schedule_create(*schedule_id, schedule_periods_length, schedule_periods);

    mdb_txn_abort(mdb_txn); // transaction is read only
    
    return new_relay;
}