bazzar/actors/database_manager/src/lib.rs

use actix::{Actor, Context};
use config::SharedAppConfig;
use sqlx::PgPool;
use sqlx_core::arguments::Arguments;

pub use crate::account_orders::*;
pub use crate::accounts::*;
pub use crate::addresses::*;
pub use crate::order_items::*;
pub use crate::photos::*;
pub use crate::product_photos::*;
pub use crate::products::*;
pub use crate::shopping_cart_items::*;
pub use crate::shopping_carts::*;
pub use crate::stocks::*;
pub use crate::tokens::*;

pub mod account_orders;
pub mod accounts;
pub mod addresses;
pub mod order_items;
pub mod photos;
pub mod product_photos;
pub mod products;
pub mod shopping_cart_items;
pub mod shopping_carts;
pub mod stocks;
pub mod tokens;

#[macro_export]
macro_rules! db_async_handler {
    ($msg: ty, $async: ident, $res: ty) => {
        impl actix::Handler<$msg> for crate::Database {
            type Result = actix::ResponseActFuture<Self, Result<$res>>;

            fn handle(&mut self, msg: $msg, _ctx: &mut Self::Context) -> Self::Result {
                use actix::WrapFuture;
                let pool = self.pool.clone();
                Box::pin(async { $async(msg, pool).await }.into_actor(self))
            }
        }
    };
    ($msg: ty, $async: ident, $res: ty, $inner_async: ident) => {
        async fn $inner_async(msg: $msg, pool: sqlx::PgPool) -> Result<$res> {
            let mut t = pool.begin().await?;
            match $async(msg, &mut t).await {
                Ok(res) => {
                    t.commit().await?;
                    Ok(res)
                }
                Err(e) => {
                    let _ = t.rollback().await;
                    Err(e)
                }
            }
        }

        impl actix::Handler<$msg> for crate::Database {
            type Result = actix::ResponseActFuture<Self, Result<$res>>;

            fn handle(&mut self, msg: $msg, _ctx: &mut Self::Context) -> Self::Result {
                use actix::WrapFuture;
                let pool = self.pool.clone();
                Box::pin(async { $inner_async(msg, pool).await }.into_actor(self))
            }
        }
    };
}

#[macro_export]
macro_rules! query_db {
    ($db: expr, $msg: expr, default $fail: expr) => {
        match $db.send($msg).await {
            Ok(Ok(r)) => r,
            Ok(Err(e)) => {
                log::error!("{e}");
                $fail
            }
            Err(e) => {
                log::error!("{e:?}");
                $fail
            }
        }
    };

    ($db: expr, $msg: expr, $fail: expr) => {
        $crate::query_db!($db, $msg, $fail, $fail)
    };

    ($db: expr, $msg: expr, $db_fail: expr, $act_fail: expr) => {
        match $db.send($msg).await {
            Ok(Ok(r)) => r,
            Ok(Err(e)) => {
                log::error!("{e}");
                return Err($db_fail);
            }
            Err(e) => {
                log::error!("{e:?}");
                return Err($act_fail);
            }
        }
    };

    ($db: expr, $msg: expr, passthrough $db_fail: expr, $act_fail: expr) => {
        match $db.send($msg).await {
            Ok(Ok(r)) => r,
            Ok(Err(e)) => {
                log::error!("{e}");
                return Err($db_fail(e.into()));
            }
            Err(e) => {
                log::error!("{e:?}");
                return Err($act_fail);
            }
        }
    };
}

#[derive(Debug, thiserror::Error)]
pub enum Error {
    #[error("Failed to connect to database. {0:?}")]
    Connect(#[from] sqlx::Error),
    #[error("{0}")]
    Account(#[from] accounts::Error),
    #[error("{0}")]
    AccountOrder(#[from] account_orders::Error),
    #[error("{0}")]
    Product(#[from] products::Error),
    #[error("{0}")]
    Stock(#[from] stocks::Error),
    #[error("{0}")]
    OrderItem(#[from] order_items::Error),
    #[error("{0}")]
    ShoppingCart(#[from] shopping_carts::Error),
    #[error("{0}")]
    ShoppingCartItem(#[from] shopping_cart_items::Error),
    #[error("{0}")]
    Token(#[from] tokens::Error),
    #[error("{0}")]
    Photo(#[from] photos::Error),
    #[error("{0}")]
    ProductPhoto(#[from] product_photos::Error),
    #[error("{0}")]
    AccountAddress(#[from] addresses::Error),
}

pub type Result<T> = std::result::Result<T, Error>;

pub struct Database {
    pool: PgPool,
}

pub type SharedDatabase = actix::Addr<Database>;

impl Clone for Database {
    fn clone(&self) -> Self {
        Self {
            pool: self.pool.clone(),
        }
    }
}

impl Database {
    pub async fn build(config: SharedAppConfig) -> Result<Self> {
        let url = config.lock().database().url();
        let pool = sqlx::PgPool::connect(&url).await.map_err(Error::Connect)?;
        Ok(Database { pool })
    }

    pub fn pool(&self) -> &PgPool {
        &self.pool
    }
}

impl Actor for Database {
    type Context = Context<Self>;
}

/// Multi-query load for large amount of records to read
///
/// Examples
///
/// ```
/// # use database_manager::photos::Error;
/// async fn load() {
///     # let pool: sqlx::PgPool::connect("").await.unwrap();
///     use database_manager::MultiLoad;
///     let t = pool.begin().await.unwrap();
///     let mut multi = MultiLoad::new(
///         &mut t,
///         "SELECT id, name FROM products WHERE ",
///         " id = "
///     );
///     multi.load(4, vec![1,2,3,4], |_| Error::All.into());
///     t.commit().await.unwrap();
/// }
/// ```
pub struct MultiLoad<'transaction, 'transaction2, 'header, 'condition, T> {
    pool: &'transaction mut sqlx::Transaction<'transaction2, sqlx::Postgres>,
    header: &'header str,
    condition: &'condition str,
    __phantom: std::marker::PhantomData<T>,
}

impl<'transaction, 'transaction2, 'header, 'condition, T>
    MultiLoad<'transaction, 'transaction2, 'header, 'condition, T>
where
    T: for<'r> sqlx::FromRow<'r, sqlx::postgres::PgRow> + Send + Unpin,
{
    pub fn new(
        pool: &'transaction mut sqlx::Transaction<'transaction2, sqlx::Postgres>,
        header: &'header str,
        condition: &'condition str,
    ) -> Self {
        Self {
            pool,
            header,
            condition,
            __phantom: Default::default(),
        }
    }

    pub async fn load<'query, Error, Ids>(
        &mut self,
        len: usize,
        items: Ids,
        on_error: Error,
    ) -> std::result::Result<Vec<T>, crate::Error>
    where
        Ids: Iterator<Item = model::RecordId>,
        Error: Fn(sqlx::Error) -> crate::Error,
    {
        let mut res = Vec::new();

        for ids in items.fold(
            Vec::<Vec<model::RecordId>>::with_capacity(len),
            |mut v, id| {
                if matches!(v.last().map(|v| v.len()), Some(20) | None) {
                    v.push(Vec::with_capacity(20));
                }
                v.last_mut().unwrap().push(id);
                v
            },
        ) {
            let query: String = self.header.into();
            let query = ids.iter().enumerate().fold(query, |mut q, (idx, _id)| {
                if idx != 0 {
                    q.push_str(" OR");
                }
                q.push_str(&format!(" {} ${}", self.condition, idx + 1));
                q
            });
            let q = sqlx::query_as_with(
                query.as_str(),
                ids.into_iter()
                    .fold(sqlx::postgres::PgArguments::default(), |mut args, id| {
                        args.add(id);
                        args
                    }),
            );

            let records: Vec<T> = match q.fetch_all(&mut *self.pool).await {
                Ok(rec) => rec,
                Err(e) => return Err(on_error(e)),
            };
            res.extend(records);
        }

        Ok(res)
    }
}