use serde::{Serialize, Deserialize, Deserializer};
use std::fmt;
use rand::{thread_rng, Rng};
use chrono::prelude::{DateTime, Utc};

/// ID
#[derive(Clone, Deserialize, Serialize, Debug, PartialEq, Eq, Hash)]
pub struct Id(pub u64);
impl Id {
    pub fn to_string(&self) -> String {
        format!("{:x}", self.0)
    }
}
impl Into<String> for Id {
    fn into(self) -> String {
        format!("{:x}", self.0)
    }
}
impl fmt::Display for Id {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}", self.0)
    }
}

pub fn generate_id() -> Id {
    Id(thread_rng().gen())
}


pub fn deserialize_datetime<'de, D>(deserializer: D) -> Result<DateTime<Utc>, D::Error>
where
    D: Deserializer<'de>,
{
    let s = String::deserialize(deserializer)?;
    DateTime::parse_from_rfc3339(&s)
        .map_err(serde::de::Error::custom)
        .map(|dt| dt.with_timezone(&Utc))
}