use serde::{Deserialize, Deserializer, Serialize, Serializer};
use std::marker::PhantomData;
use crate::error::{Error, Result};
use crate::model::Model;
use crate::query::QueryBuilder;
use super::helpers::{build_self_ref_tree_sql, cached_ref, preserve_cached_value};
use super::require_scalar_relation_key;
#[derive(Debug, Clone)]
pub struct SelfRef<E: Model> {
pub foreign_key: &'static str,
pub local_key: &'static str,
cached: Option<Box<E>>,
fk_value: Option<serde_json::Value>,
_marker: PhantomData<E>,
}
impl<E: Model> SelfRef<E> {
pub fn new(foreign_key: &'static str, local_key: &'static str) -> Self {
Self {
foreign_key,
local_key,
cached: None,
fk_value: None,
_marker: PhantomData,
}
}
pub fn with_fk_value(mut self, fk: serde_json::Value) -> Self {
self.fk_value = Some(fk);
self
}
#[doc(hidden)]
pub fn preserve_runtime_state_from(&mut self, previous: &Self) {
preserve_cached_value(
&mut self.cached,
&previous.cached,
previous.fk_value.is_none(),
self.foreign_key == previous.foreign_key
&& self.local_key == previous.local_key
&& self.fk_value == previous.fk_value,
);
}
pub async fn load(&self) -> Result<Option<E>> {
if let Some(cached) = &self.cached {
return Ok(Some((**cached).clone()));
}
let fk = match &self.fk_value {
Some(v) if !v.is_null() => require_scalar_relation_key(v, "SelfRef::load")?,
_ => return Ok(None),
};
E::query()
.where_eq(self.local_key, fk.clone())
.first()
.await
}
pub async fn load_with<F>(&self, constraint_fn: F) -> Result<Option<E>>
where
F: FnOnce(QueryBuilder<E>) -> QueryBuilder<E> + Send,
{
let fk = match &self.fk_value {
Some(v) if !v.is_null() => require_scalar_relation_key(v, "SelfRef::load_with")?,
_ => return Ok(None),
};
let query = E::query().where_eq(self.local_key, fk.clone());
constraint_fn(query).first().await
}
pub async fn exists(&self) -> Result<bool> {
let fk = match &self.fk_value {
Some(v) if !v.is_null() => require_scalar_relation_key(v, "SelfRef::exists")?,
_ => return Ok(false),
};
E::query()
.where_eq(self.local_key, fk.clone())
.exists()
.await
}
pub fn get_cached(&self) -> Option<&E> {
cached_ref(&self.cached)
}
}
impl<E: Model> Default for SelfRef<E> {
fn default() -> Self {
Self {
foreign_key: "parent_id",
local_key: "id",
cached: None,
fk_value: None,
_marker: PhantomData,
}
}
}
impl<E: Model + Serialize> Serialize for SelfRef<E> {
fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
where
S: Serializer,
{
self.cached.serialize(serializer)
}
}
impl<'de, E: Model> Deserialize<'de> for SelfRef<E> {
fn deserialize<D>(deserializer: D) -> std::result::Result<Self, D::Error>
where
D: Deserializer<'de>,
{
let cached = Option::<E>::deserialize(deserializer)?;
Ok(Self {
cached: cached.map(Box::new),
..Self::default()
})
}
}
#[derive(Debug, Clone)]
pub struct SelfRefMany<E: Model> {
pub foreign_key: &'static str,
pub local_key: &'static str,
cached: Option<Vec<E>>,
parent_pk: Option<serde_json::Value>,
_marker: PhantomData<E>,
}
impl<E: Model> SelfRefMany<E> {
pub fn new(foreign_key: &'static str, local_key: &'static str) -> Self {
Self {
foreign_key,
local_key,
cached: None,
parent_pk: None,
_marker: PhantomData,
}
}
pub fn with_parent_pk(mut self, pk: serde_json::Value) -> Self {
self.parent_pk = Some(pk);
self
}
#[doc(hidden)]
pub fn preserve_runtime_state_from(&mut self, previous: &Self) {
preserve_cached_value(
&mut self.cached,
&previous.cached,
previous.parent_pk.is_none(),
self.foreign_key == previous.foreign_key
&& self.local_key == previous.local_key
&& self.parent_pk == previous.parent_pk,
);
}
pub async fn load(&self) -> Result<Vec<E>> {
if let Some(cached) = &self.cached {
return Ok(cached.clone());
}
let pk = self.parent_pk.as_ref().ok_or_else(|| {
Error::query(String::from(
"Parent primary key not set for self-reference",
))
})?;
let pk = require_scalar_relation_key(pk, "SelfRefMany::load")?;
E::query()
.where_eq(self.foreign_key, pk.clone())
.get()
.await
}
pub async fn load_with<F>(&self, constraint_fn: F) -> Result<Vec<E>>
where
F: FnOnce(QueryBuilder<E>) -> QueryBuilder<E> + Send,
{
let pk = self.parent_pk.as_ref().ok_or_else(|| {
Error::query(String::from(
"Parent primary key not set for self-reference",
))
})?;
let pk = require_scalar_relation_key(pk, "SelfRefMany::load_with")?;
let query = E::query().where_eq(self.foreign_key, pk.clone());
constraint_fn(query).get().await
}
pub async fn count(&self) -> Result<u64> {
let pk = self.parent_pk.as_ref().ok_or_else(|| {
Error::query(String::from(
"Parent primary key not set for self-reference",
))
})?;
let pk = require_scalar_relation_key(pk, "SelfRefMany::count")?;
E::query()
.where_eq(self.foreign_key, pk.clone())
.count()
.await
}
pub async fn exists(&self) -> Result<bool> {
let pk = self.parent_pk.as_ref().ok_or_else(|| {
Error::query(String::from(
"Parent primary key not set for self-reference",
))
})?;
let pk = require_scalar_relation_key(pk, "SelfRefMany::exists")?;
E::query()
.where_eq(self.foreign_key, pk.clone())
.exists()
.await
}
pub fn get_cached(&self) -> Option<&[E]> {
cached_ref(&self.cached)
}
pub async fn load_tree(&self, max_depth: usize) -> Result<Vec<E>> {
if max_depth == 0 {
return Ok(Vec::new());
}
let pk = self.parent_pk.as_ref().ok_or_else(|| {
Error::query(String::from(
"Parent primary key not set for self-reference",
))
})?;
let pk = require_scalar_relation_key(pk, "SelfRefMany::load_tree")?;
let db = crate::database::__current_db()?;
let (sql, params) = build_self_ref_tree_sql::<E>(
self.foreign_key,
self.local_key,
pk,
max_depth,
db.backend(),
)?;
db.__raw_with_params::<E>(&sql, params).await
}
}
impl<E: Model> Default for SelfRefMany<E> {
fn default() -> Self {
Self {
foreign_key: "parent_id",
local_key: "id",
cached: None,
parent_pk: None,
_marker: PhantomData,
}
}
}
impl<E: Model + Serialize> Serialize for SelfRefMany<E> {
fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
where
S: Serializer,
{
self.cached.serialize(serializer)
}
}
impl<'de, E: Model> Deserialize<'de> for SelfRefMany<E> {
fn deserialize<D>(deserializer: D) -> std::result::Result<Self, D::Error>
where
D: Deserializer<'de>,
{
let cached = Option::<Vec<E>>::deserialize(deserializer)?;
Ok(Self {
cached,
..Self::default()
})
}
}