#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
schedule_load_single(MDB_txn *mdb_txn, MDB_dbi mdb_dbi, db_key_schedule_e key_schedule, uint8_t relay_num, uint8_t weekday, MDB_val *value)
{
    int err;

    size_t key_size = sizeof(db_key_schedule_e) + (2 * sizeof(uint8_t)); 
    uint8_t *key_data = malloc(key_size);
    uint8_t *key_data_writer = key_data;
    memmove(key_data_writer, &relay_num, sizeof(uint8_t));
    key_data_writer += sizeof(uint8_t);
    memmove(key_data_writer, &weekday, sizeof(uint8_t));
    key_data_writer += sizeof(uint8_t);
    memmove(key_data_writer, &key_schedule, sizeof(db_key_schedule_e));

    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;
}

schedule_t*
schedule_load(MDB_env *mdb_env, uint8_t relay_num, uint8_t weekday)
{
    int err;
    MDB_txn *mdb_txn;
    MDB_dbi mdb_dbi;
    
    schedule_t *new_schedule;

    uuid_t off_id;
    memset(off_id, 0, sizeof(uuid_t));
    memcpy(off_id, "off", 3);

    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 schedule_create(off_id, weekday, 0, NULL);
    }

    if((err = mdb_dbi_open(mdb_txn, "schedules", 0, &mdb_dbi)) != 0)
    {
        switch(err)
        {
            case MDB_NOTFOUND:
                LOG_INFO("no schedule db found in db. returning new one (no schedules db)\n");
                mdb_txn_abort(mdb_txn);
                break;
            default:
                LOG_ERROR("mdb_txn_begin error %s\n", mdb_strerror(err));
        }
        return schedule_create(off_id, weekday, 0, NULL);
    }

    MDB_val value;

    if((err = schedule_load_single(mdb_txn, mdb_dbi, DB_KEY_SCHEDULE_ID, relay_num, weekday, &value)) != 0)
    {
        LOG_INFO("no schedule for relay %d and weekday %d found in db. returning new one\n", relay_num, weekday);
        mdb_txn_abort(mdb_txn); // transaction is read only
        return schedule_create(off_id, weekday, 0, NULL);
    }
    uuid_t *schedule_id = (uuid_t*)value.mv_data;

    if((err = schedule_load_single(mdb_txn, mdb_dbi, DB_KEY_SCHEDULE_PERIODS, relay_num, weekday, &value)) != 0)
    {
        LOG_INFO("no schedule for relay %d and weekday %d found in db. returning new one\n", relay_num, weekday);
        mdb_txn_abort(mdb_txn); // transaction is read only
        return schedule_create(off_id, weekday, 0, NULL);
    }
    uint16_t schedule_periods_length = ((uint16_t*)value.mv_data)[0];
    uint16_t *schedule_periods = ((uint16_t*)value.mv_data) + 1;

    new_schedule = schedule_create(*schedule_id, weekday, schedule_periods_length, schedule_periods);

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