//! Identifiers.
//!
//! Newtypes rather than bare `String`s, so a feed id cannot be passed where a
//! user id belongs. They are stored as TEXT: v1 declared
//! `external_calendars.user_id INTEGER` against a TEXT `users.id`, and because
//! SQLite does not enforce foreign key types the constraint silently could
//! never match.

use serde::{Deserialize, Serialize};
use std::fmt;

macro_rules! id_type {
    ($name:ident, $entity:literal) => {
        #[doc = concat!("The identity of a ", $entity, ".")]
        #[derive(
            Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Serialize, Deserialize, sqlx::Type,
        )]
        #[serde(transparent)]
        #[sqlx(transparent)]
        pub struct $name(pub String);

        impl $name {
            /// A fresh random identifier.
            pub fn new() -> Self {
                Self(uuid::Uuid::new_v4().to_string())
            }

            pub fn as_str(&self) -> &str {
                &self.0
            }
        }

        impl Default for $name {
            fn default() -> Self {
                Self::new()
            }
        }

        impl fmt::Display for $name {
            fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
                f.write_str(&self.0)
            }
        }

        impl From<String> for $name {
            fn from(value: String) -> Self {
                Self(value)
            }
        }

        impl From<&str> for $name {
            fn from(value: &str) -> Self {
                Self(value.to_owned())
            }
        }
    };
}

id_type!(UserId, "user");
id_type!(FeedId, "subscribed feed");