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//! Implements utility type for JSON, JSONB field handling in diesel
use diesel::deserialize::FromSqlRow;
use diesel::expression::AsExpression;
use diesel::pg::{Pg, PgValue};
use diesel::sql_types;
use diesel::{deserialize::FromSql, serialize::ToSql};
use serde::de::DeserializeOwned;
use serde::Deserialize;
use serde::Serialize;
use std::ops::{Deref, DerefMut};

/// Wrapper type that implements Json data handling for postgres diesel connection
///
/// Use as wrapper for fields that are stored in Jsonb format
/// ```ignore
/// #[derive(serde::Serialize, serde::Deserialize, Debug)]
/// pub struct ComplexStruct {
///   // ...
/// }
///
/// #[derive(serde::Serialize, serde::Deserialize,
///          diesel::Queryable, diesel::Insertable)]
/// pub struct ExampleTable {
///     // Field that will be stored in Json, Jsonb format
///     pub jsonb_field: diesel_json::Json<ComplexStruct>,
/// }
/// ```
#[derive(FromSqlRow, AsExpression, Serialize, Deserialize, Debug, Clone)]
#[serde(transparent)]
#[diesel(sql_type = sql_types::Jsonb)]
pub struct Json<T: Sized>(pub T);

impl<T> Json<T> {
    pub fn new(value: T) -> Json<T> {
        Json(value)
    }
}

impl<T> Deref for Json<T> {
    type Target = T;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl<T> DerefMut for Json<T> {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.0
    }
}

impl<T> AsRef<T> for Json<T> {
    fn as_ref(&self) -> &T {
        &self.0
    }
}

impl<T> AsMut<T> for Json<T> {
    fn as_mut(&mut self) -> &mut T {
        &mut self.0
    }
}

impl<T> FromSql<sql_types::Jsonb, Pg> for Json<T>
where
    T: std::fmt::Debug + DeserializeOwned,
{
    fn from_sql(bytes: PgValue) -> diesel::deserialize::Result<Self> {
        let value = <serde_json::Value as FromSql<sql_types::Jsonb, Pg>>::from_sql(bytes)?;
        Ok(Json(serde_json::from_value::<T>(value)?))
    }
}

impl<T> ToSql<sql_types::Jsonb, Pg> for Json<T>
where
    T: std::fmt::Debug + Serialize,
{
    fn to_sql(&self, out: &mut diesel::serialize::Output<Pg>) -> diesel::serialize::Result {
        let value = serde_json::to_value(self)?;
        <serde_json::Value as ToSql<sql_types::Jsonb, Pg>>::to_sql(&value, &mut out.reborrow())
    }
}

impl<T> PartialEq for Json<T>
where
    T: PartialEq,
{
    fn eq(&self, other: &Self) -> bool {
        self.0 == other.0
    }
}

impl<T> Default for Json<T>
where
    T: Default,
{
    fn default() -> Self {
        Json(T::default())
    }
}