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|
use actix::{Handler, Message};
use chrono::NaiveDateTime;
use diesel::{BoolExpressionMethods, ExpressionMethods, JoinOnDsl, QueryDsl, RunQueryDsl};
use diesel::{Connection, MysqlConnection};
use crate::error::ServiceError;
use crate::model::{DbExecutor, NewTransaction, User};
use crate::schema::transactions::{columns as transaction_columns, dsl::transactions};
use crate::schema::users::{columns as user_columns, dsl::users};
#[derive(Debug, Clone, Queryable)]
struct TempTransaction {
pub id: u64,
pub date: NaiveDateTime,
pub sender: String,
pub receiver: u64,
pub amount: u64,
pub sender_balance: u64,
pub receiver_balance: u64,
pub purpose: String,
}
#[derive(Debug, Clone)]
pub struct Transaction {
pub id: u64,
pub date: NaiveDateTime,
pub sender: String,
pub receiver: String,
pub amount: u64,
pub sender_balance: u64,
pub receiver_balance: u64,
pub purpose: String,
}
pub struct TransactionsRequest {
id: u64,
}
impl TransactionsRequest {
pub fn new(id: u64) -> Self {
Self { id }
}
}
impl Message for TransactionsRequest {
type Result = Result<Vec<Transaction>, ServiceError>;
}
impl Handler<TransactionsRequest> for DbExecutor {
type Result = Result<Vec<Transaction>, ServiceError>;
fn handle(&mut self, req: TransactionsRequest, _: &mut Self::Context) -> Self::Result {
let conn: &MysqlConnection = &self.0.get().unwrap();
use transaction_columns as t_cols;
let temp = transactions
.filter(
transaction_columns::sender
.eq(req.id)
.or(transaction_columns::receiver.eq(req.id)),
)
.inner_join(users.on(transaction_columns::sender.eq(user_columns::id)))
.select((
t_cols::id,
t_cols::date,
user_columns::name,
t_cols::receiver,
t_cols::amount,
t_cols::sender_balance,
t_cols::receiver_balance,
t_cols::purpose,
))
.order(transaction_columns::date.desc())
.load::<TempTransaction>(conn)
.map_err(|_| ServiceError::NotFound)?;
let recv_ids = temp.iter().map(|t| t.receiver).collect::<Vec<_>>();
let receivers = users
.select((user_columns::id, user_columns::name))
.filter(user_columns::id.eq_any(recv_ids))
.load::<(u64, String)>(conn)?;
let mut output = Vec::with_capacity(temp.len());
for t in temp {
let (_, name) = receivers
.iter()
.find(|(id, _)| id == &t.receiver)
.expect("oh no");
let t = Transaction {
id: t.id,
date: t.date,
sender: t.sender,
receiver: name.to_owned(),
amount: t.amount,
sender_balance: t.sender_balance,
receiver_balance: t.receiver_balance,
purpose: t.purpose,
};
output.push(t);
}
Ok(output)
}
}
pub struct TransferRequest {
pub from: String,
pub to: String,
pub amount: u64,
pub purpose: String,
}
impl Message for TransferRequest {
type Result = Result<(), ServiceError>;
}
impl Handler<TransferRequest> for DbExecutor {
type Result = Result<(), ServiceError>;
fn handle(&mut self, req: TransferRequest, _: &mut Self::Context) -> Self::Result {
let conn: &MysqlConnection = &self.0.get().unwrap();
Ok(conn.transaction::<_, diesel::result::Error, _>(|| {
// Lock the user record to avoid modification by other threads
users
.filter(
user_columns::name
.eq(&req.from)
.or(user_columns::name.eq(&req.to)),
)
.for_update()
.execute(conn)?;
let sender = users
.filter(user_columns::name.eq(&req.from))
.first::<User>(conn)?;
let new_sender_balance = sender
.balance
.checked_sub(req.amount)
.ok_or(diesel::result::Error::RollbackTransaction)?;
diesel::update(users.find(sender.id))
.set(user_columns::balance.eq(new_sender_balance))
.execute(conn)?;
let receiver = users
.filter(user_columns::name.eq(&req.to))
.first::<User>(conn)?;
let new_receiver_balance = receiver
.balance
.checked_add(req.amount)
.ok_or(diesel::result::Error::RollbackTransaction)?;
diesel::update(users.find(receiver.id))
.set(user_columns::balance.eq(new_receiver_balance))
.execute(conn)?;
let t = NewTransaction {
sender: sender.id,
receiver: receiver.id,
amount: req.amount,
sender_balance: new_sender_balance,
receiver_balance: new_receiver_balance,
purpose: &req.purpose,
};
diesel::insert_into(transactions).values(&t).execute(conn)?;
Ok(())
})?)
}
}
|
