use chrono::{DateTime, Utc};
use serde::{Deserialize, Serialize};
use sqlx::Postgres;
use uuid::Uuid;

#[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
#[serde(tag = "t", content = "c")]
pub enum Datum {
    Text(Option<String>),
    Timestamp(Option<DateTime<Utc>>),
    Uuid(Option<Uuid>),
}

impl Datum {
    // TODO: Can something similar be achieved with a generic return type?
    /// Bind this as a parameter to a sqlx query.
    pub fn bind_onto<'a>(
        self,
        query: sqlx::query::Query<'a, Postgres, <sqlx::Postgres as sqlx::Database>::Arguments<'a>>,
    ) -> sqlx::query::Query<'a, Postgres, <sqlx::Postgres as sqlx::Database>::Arguments<'a>> {
        match self {
            Self::Text(value) => query.bind(value),
            Self::Timestamp(value) => query.bind(value),
            Self::Uuid(value) => query.bind(value),
        }
    }

    /// Transform the contained value into a serde_json::Value.
    pub fn inner_as_value(&self) -> serde_json::Value {
        let serialized = serde_json::to_value(self).unwrap();
        #[derive(Deserialize)]
        struct Tagged {
            c: serde_json::Value,
        }
        let deserialized: Tagged = serde_json::from_value(serialized).unwrap();
        deserialized.c
    }

    pub fn is_none(&self) -> bool {
        match self {
            Self::Text(None) | Self::Timestamp(None) | Self::Uuid(None) => true,
            Self::Text(_) | Self::Timestamp(_) | Self::Uuid(_) => false,
        }
    }
}