#define RANGE_NUM 100
#define TRANS_NUM_PER_RAGE 15  /* 每个数据段分布15个事务 */
#define UPDATE_NUM_PER_TRANS 10 /* 每个事务更新十行数据 */

/* 不同的cn节点 */
enum cn_port {
    cn01 = 11111,
    cn02,
    cn03,
    cn04,
    cn05
};

void *thread_func(void *arg) {
    PGconn *conn;
    PGresult *res;
    char conn_info[100];

    int cur_port = rand() % 5 + cn01;

    snprintf(conn_info, sizeof(conn_info),
            "dbname = postgres user = wanxdz password = 129212351GTFgtf_ host = 127.0.0.1 port = %d", cur_port);
    
    conn = PQconnectdb(conn_info);
    if (PQstatus(conn) != CONNECTION_OK) {
        fprintf(stderr, "%lu connection to database failed: %s", pthread_self(), PQerrorMessage(conn));
        PQfinish(conn);
        pthread_exit(NULL);
    }

    /* 开启事务 */
    res = PQexec(conn, "BEGIN");
    if (PQresultStatus(res) != PGRES_COMMAND_OK) {
        fprintf(stderr, "%lu BEGIN failed: %s", pthread_self(), PQerrorMessage(conn));
        PQclear(res);
        PQfinish(conn);
        pthread_exit(NULL);
    }
    PQclear(res);

    int begin_id = (int) arg;
    int row_id;
    for (int i = 0; i < UPDATE_NUM_PER_TRANS; ++i) {
        char new_uuid[37];
        uuid_t uuid;
        char update_query[100];
        uuid_generate_random(uuid);
        uuid_unparse(uuid, new_uuid);
        row_id = rand() % 100 + begin_id; //从 begin_id 开始到 begin_id + 100 - 1的范围取一个随机数值
        snprintf(update_query, sizeof(update_query), "UPDATE foo SET str = '%s' WHERE id = %d", new_uuid, row_id);

        res = PQexec(conn, update_query);
        /* 更新成功后，将更新信息保存到日志内 */
        if (PQresultStatus(res) == PGRES_COMMAND_OK) {
            pthread_rwlock_wrlock(&rwlock);
            fp = fopen(update_log, "a+");
            fprintf(fp, "%lu\t\t%d\t\t%s\n", pthread_self(), row_id, new_uuid);  /* 线程id    更新的行id    更新的uuid */
            fclose(fp);
            pthread_rwlock_unlock(&rwlock);
        } else {
            fprintf(stderr, "%lu UPDATE failed: %s", pthread_self(), PQerrorMessage(conn));
            PQclear(res);
            PQfinish(conn);
            pthread_exit(NULL);
        }

        PQclear(res);
    }

    res = PQexec(conn, "END");
    if (PQresultStatus(res) != PGRES_COMMAND_OK) {
        fprintf(stderr, "%lu END failed: %s", pthread_self(), PQerrorMessage(conn));
        PQclear(res);
        PQfinish(conn);
        pthread_exit(NULL);
    }
    PQclear(res);
    PQfinish(conn);
    return NULL;
}

int main(int argc, char *argv[]) {
    /* 初始化写锁 */
    int err = pthread_rwlock_init(&rwlock, NULL);
    if (err != 0) {
        fprintf(stderr, "Can't init rwlock, the err result is %d", err);
        return 0;
    }

    /* 初始化pthread数组 */
    pthread_t **tid;
    tid = (pthread_t **) malloc(sizeof(pthread_t *) * RANGE_NUM);
    for (int i = 0; i < 2; ++i) {       /* 分100段 */
        tid[i] = (pthread_t *) malloc(sizeof(pthread_t) * TRANS_NUM_PER_RAGE);
        int begin_row = i + 1;
        for (int j = 0; j < TRANS_NUM_PER_RAGE; ++j) {    /* 每段15个事务 */
            pthread_create(&tid[i][j], NULL, (void *) thread_func, (void *) (begin_row * RANGE_NUM + 1));
            pthread_detach(tid[i][j]);
        }
    }
    while (1) {
        /* 这里防止main退出 */
    }

    return 0;
}