chore: refactor

This commit is contained in:
Aravinth Manivannan 2023-08-17 02:30:57 +05:30
parent 7fff3aaaaf
commit a2cb5f2e6d
Signed by: realaravinth
GPG key ID: AD9F0F08E855ED88
5 changed files with 330 additions and 307 deletions

61
src/actor.rs Normal file
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use uuid::Uuid;
use crate::expense::Split;
pub trait Actor {
fn spends(&mut self, i: Split);
fn owes(&mut self, i: Split);
// name must be unique in a namespace
fn name(&self) -> &str;
fn id(&self) -> &Uuid;
}
impl PartialEq for dyn Actor {
fn eq(&self, other: &Self) -> bool {
self.id() == other.id()
}
}
pub struct Person {
name: String,
spent: Vec<Split>,
owes: Vec<Split>,
id: Uuid,
}
impl Person {
pub fn new(name: String, id: Uuid) -> Self {
let owes = Vec::default();
let spent = Vec::default();
Self {
name,
spent,
owes,
id,
}
}
}
impl Actor for Person {
fn spends(&mut self, split: Split) {
if split.purchase.paid_by().name() == self.name() {
self.spent.push(split);
} else {
unimplemented!("Raise error: Actor didn't pay for purchase")
}
}
fn owes(&mut self, split: Split) {
if split.purchase.paid_by().name() == self.name() {
unimplemented!("Raise error: Actor didn't paid for purchase; can't own money")
} else {
self.owes.push(split);
}
}
fn name(&self) -> &str {
&self.name
}
fn id(&self) -> &Uuid {
&self.id
}
}

173
src/expense.rs Normal file
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use std::rc::Rc;
use rust_decimal::prelude::*;
use rust_decimal_macros::dec;
use crate::actor::*;
use crate::purchase::*;
use crate::strategy::*;
#[derive(Clone)]
pub struct Split {
pub(crate) purchase: Rc<dyn Purchasable>,
pub(crate) split_strategy: SplitStrategy,
pub(crate) parties: Vec<Rc<dyn Actor>>,
}
impl Split {
pub fn new(
purchase: Rc<dyn Purchasable>,
split_strategy: SplitStrategy,
parties: Vec<Rc<dyn Actor>>,
) -> Self {
Self {
split_strategy,
parties,
purchase,
}
}
pub fn money_owed(&self) -> ShareHashMap {
match &self.split_strategy {
SplitStrategy::Unequal(shares) => {
let mut s = shares.clone();
let payer = self.purchase.paid_by();
if let Some((_, money)) = s.get_mut(payer.name()) {
*money = dec!(0.0);
}
s
}
SplitStrategy::Equal => {
let mut shares = ShareHashMap::default();
let cost = self.purchase.cost();
let total_parties = Decimal::new(self.parties.len() as i64, 0);
for actor in self.parties.iter() {
if *actor == self.purchase.paid_by() {
shares.insert(actor.name().to_owned(), (actor.clone(), dec!(0.00)));
} else {
shares.insert(
actor.name().to_owned(),
(actor.clone(), cost / total_parties),
);
}
}
shares
}
SplitStrategy::Shares(c) => {
let mut shares = ShareHashMap::default();
let cost = self.purchase.cost();
for (actor_name, (actor, share)) in c.iter() {
//if actor.name() == split.purchase.paid_by().name() {
if *actor == self.purchase.paid_by() {
shares.insert(actor_name.clone(), (actor.clone(), dec!(0.00)));
} else {
shares.insert(actor_name.clone(), (actor.clone(), cost * share));
}
}
shares
}
}
}
pub fn get(&mut self, actor: Rc<dyn Actor>) -> Option<Decimal> {
unimplemented!();
// if let Some((_actor, cost)) = self.shares.get(actor.name()) {
// Some(*cost)
// } else {
// None
// }
}
pub fn validate(&self) -> bool {
self.split_strategy.validate(self.purchase.as_ref())
}
}
//impl Actor for Person {
// fn spends<P: Purchasable>(&self, i: &I);
// fn owes<T: Actor>(&self, amount: usize);
//}
#[cfg(test)]
mod tests {
use super::*;
use uuid::Uuid;
#[test]
fn split_works() {
let person1: Rc<dyn Actor> = Rc::new(Person::new("person1".into(), Uuid::new_v4()));
let person2: Rc<dyn Actor> = Rc::new(Person::new("person2".into(), Uuid::new_v4()));
let person3: Rc<dyn Actor> = Rc::new(Person::new("person3".into(), Uuid::new_v4()));
let person4: Rc<dyn Actor> = Rc::new(Person::new("person4".into(), Uuid::new_v4()));
let item = Item::new("test item".into(), dec!(240.00), person1.clone());
let actors = vec![
person1.clone(),
person2.clone(),
person3.clone(),
person4.clone(),
];
// equal split
let strategy = SplitStrategy::Equal;
let mut split = Split::new(Rc::new(item), strategy, actors);
assert!(split.validate());
let dues = split.money_owed();
for (_actor_name, (actor, due)) in dues.iter() {
if split.purchase.paid_by().name() == actor.name() {
assert_eq!(*due, dec!(0.00));
} else {
assert_eq!(
*due,
split.purchase.cost() / Decimal::new(split.parties.len() as i64, 0)
);
}
}
// share split
let mut shares = ShareHashMap::default();
shares.insert(person1.name().to_owned(), (person1.clone(), dec!(0.3)));
shares.insert(person2.name().to_owned(), (person2.clone(), dec!(0.4)));
shares.insert(person3.name().to_owned(), (person3.clone(), dec!(0.2)));
shares.insert(person4.name().to_owned(), (person4.clone(), dec!(0.1)));
let strategy = SplitStrategy::Shares(shares.clone());
split.split_strategy = strategy;
assert!(split.validate());
let dues = split.money_owed();
for (actor_name, (actor, due)) in dues.iter() {
println!("Testing for actor: {actor_name} with due: {due}");
if split.purchase.paid_by().name() == actor.name() {
assert_eq!(*due, dec!(0.00));
} else {
let (_, share) = shares.get(actor_name).unwrap();
assert_eq!(*due, split.purchase.cost() * *share);
}
}
// Unequal split
let mut shares = ShareHashMap::default();
shares.insert(
person1.name().to_owned(),
(person1.clone(), dec!(0.3) * split.purchase.cost()),
);
shares.insert(
person2.name().to_owned(),
(person2.clone(), dec!(0.4) * split.purchase.cost()),
);
shares.insert(
person3.name().to_owned(),
(person3.clone(), dec!(0.2) * split.purchase.cost()),
);
shares.insert(
person4.name().to_owned(),
(person4.clone(), dec!(0.1) * split.purchase.cost()),
);
let strategy = SplitStrategy::Unequal(shares);
split.split_strategy = strategy;
assert!(split.validate());
}
}

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@ -14,310 +14,7 @@
* You should have received a copy of the GNU Affero General Public License * You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>. * along with this program. If not, see <https://www.gnu.org/licenses/>.
*/ */
use std::collections::HashMap; pub mod actor;
use std::rc::Rc; pub mod expense;
pub mod purchase;
use rust_decimal::prelude::*; pub mod strategy;
use rust_decimal_macros::dec;
use uuid::Uuid;
pub trait Purchasable {
fn cost(&self) -> Decimal;
fn name(&self) -> &str;
fn paid_by(&self) -> Rc<dyn Actor>;
}
#[derive(Clone)]
pub struct Split {
purchase: Rc<dyn Purchasable>,
split_strategy: SplitStrategy,
parties: Vec<Rc<dyn Actor>>,
}
impl Split {
pub fn new(
purchase: Rc<dyn Purchasable>,
split_strategy: SplitStrategy,
parties: Vec<Rc<dyn Actor>>,
) -> Self {
Self {
split_strategy,
parties,
purchase,
}
}
pub fn money_owed(&self) -> ShareHashMap {
match &self.split_strategy {
SplitStrategy::Unequal(shares) => {
let mut s = shares.clone();
let payer = self.purchase.paid_by();
if let Some((_, money)) = s.get_mut(payer.name()) {
*money = dec!(0.0);
}
s
}
SplitStrategy::Equal => {
let mut shares = ShareHashMap::default();
let cost = self.purchase.cost();
let total_parties = Decimal::new(self.parties.len() as i64, 0);
for actor in self.parties.iter() {
if *actor == self.purchase.paid_by() {
shares.insert(actor.name().to_owned(), (actor.clone(), dec!(0.00)));
} else {
shares.insert(
actor.name().to_owned(),
(actor.clone(), cost / total_parties),
);
}
}
shares
}
SplitStrategy::Shares(c) => {
let mut shares = ShareHashMap::default();
let cost = self.purchase.cost();
for (actor_name, (actor, share)) in c.iter() {
//if actor.name() == split.purchase.paid_by().name() {
if *actor == self.purchase.paid_by() {
shares.insert(actor_name.clone(), (actor.clone(), dec!(0.00)));
} else {
shares.insert(actor_name.clone(), (actor.clone(), cost * share));
}
}
shares
}
}
}
pub fn get(&mut self, actor: Rc<dyn Actor>) -> Option<Decimal> {
unimplemented!();
// if let Some((_actor, cost)) = self.shares.get(actor.name()) {
// Some(*cost)
// } else {
// None
// }
}
pub fn validate(&self) -> bool {
self.split_strategy.validate(self.purchase.as_ref())
}
}
// key is a string for getting Eq and PartialEq w object safety
pub type ShareHashMap = HashMap<String, (Rc<dyn Actor>, Decimal)>;
/*
* SPLITTING STRATEGIES:
* Unequal: Each actor's split is specified in specific amounts
* Shares: Each actor's split is specified in specific percentage
* Equal: Each actor's split is computed by splitting total expense among all participating actors
*/
#[derive(Clone)]
pub enum SplitStrategy {
Unequal(ShareHashMap),
Shares(ShareHashMap),
Equal,
}
impl SplitStrategy {
fn validate(&self, purchase: &dyn Purchasable) -> bool {
match self {
SplitStrategy::Unequal(shares) => {
let mut total = dec!(0.00);
for (_actor_str, (_actor_obj, share)) in shares.iter() {
total += share;
}
let cost = purchase.cost();
println!("Unequal sharing: expected {cost} got {total}");
total == cost
}
SplitStrategy::Shares(shares) => {
let mut total = dec!(0.00);
let cost = purchase.cost();
let mut total_shares = dec!(0.00);
for (_actor_str, (_actor_obj, share)) in shares.iter() {
total_shares += share;
total += cost * share;
println!("Shares: {:?}, total: {total_shares}", share);
}
println!("Unequal sharing: expected shares 1 got {total_shares}");
println!("Unequal sharing: expected {cost} got {total}");
total_shares == dec!(1.00) && total == cost
}
SplitStrategy::Equal => true,
}
}
}
pub trait Actor {
fn spends(&mut self, i: Split);
fn owes(&mut self, i: Split);
// name must be unique in a namespace
fn name(&self) -> &str;
fn id(&self) -> &Uuid;
}
impl PartialEq for dyn Actor {
fn eq(&self, other: &Self) -> bool {
self.id() == other.id()
}
}
pub struct Person {
name: String,
spent: Vec<Split>,
owes: Vec<Split>,
id: Uuid,
}
impl Person {
pub fn new(name: String, id: Uuid) -> Self {
let owes = Vec::default();
let spent = Vec::default();
Self {
name,
spent,
owes,
id,
}
}
}
impl Actor for Person {
fn spends(&mut self, split: Split) {
if split.purchase.paid_by().name() == self.name() {
self.spent.push(split);
} else {
unimplemented!("Raise error: Actor didn't pay for purchase")
}
}
fn owes(&mut self, split: Split) {
if split.purchase.paid_by().name() == self.name() {
unimplemented!("Raise error: Actor didn't paid for purchase; can't own money")
} else {
self.owes.push(split);
}
}
fn name(&self) -> &str {
&self.name
}
fn id(&self) -> &Uuid {
&self.id
}
}
pub struct Item {
cost: Decimal,
name: String,
payer: Rc<dyn Actor>,
}
impl Item {
pub fn new(name: String, cost: Decimal, payer: Rc<dyn Actor>) -> Self {
Self { cost, name, payer }
}
}
impl Purchasable for Item {
fn cost(&self) -> Decimal {
self.cost
}
fn name(&self) -> &str {
&self.name
}
fn paid_by(&self) -> Rc<dyn Actor> {
self.payer.clone()
}
}
//impl Actor for Person {
// fn spends<P: Purchasable>(&self, i: &I);
// fn owes<T: Actor>(&self, amount: usize);
//}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn split_works() {
let person1: Rc<dyn Actor> = Rc::new(Person::new("person1".into(), Uuid::new_v4()));
let person2: Rc<dyn Actor> = Rc::new(Person::new("person2".into(), Uuid::new_v4()));
let person3: Rc<dyn Actor> = Rc::new(Person::new("person3".into(), Uuid::new_v4()));
let person4: Rc<dyn Actor> = Rc::new(Person::new("person4".into(), Uuid::new_v4()));
let item = Item::new("test item".into(), dec!(240.00), person1.clone());
let actors = vec![
person1.clone(),
person2.clone(),
person3.clone(),
person4.clone(),
];
// equal split
let strategy = SplitStrategy::Equal;
let mut split = Split::new(Rc::new(item), strategy, actors);
assert!(split.validate());
let dues = split.money_owed();
for (_actor_name, (actor, due)) in dues.iter() {
if split.purchase.paid_by().name() == actor.name() {
assert_eq!(*due, dec!(0.00));
} else {
assert_eq!(
*due,
split.purchase.cost() / Decimal::new(split.parties.len() as i64, 0)
);
}
}
// share split
let mut shares = ShareHashMap::default();
shares.insert(person1.name().to_owned(), (person1.clone(), dec!(0.3)));
shares.insert(person2.name().to_owned(), (person2.clone(), dec!(0.4)));
shares.insert(person3.name().to_owned(), (person3.clone(), dec!(0.2)));
shares.insert(person4.name().to_owned(), (person4.clone(), dec!(0.1)));
let strategy = SplitStrategy::Shares(shares.clone());
split.split_strategy = strategy;
assert!(split.validate());
let dues = split.money_owed();
for (actor_name, (actor, due)) in dues.iter() {
println!("Testing for actor: {actor_name} with due: {due}");
if split.purchase.paid_by().name() == actor.name() {
assert_eq!(*due, dec!(0.00));
} else {
let (_, share) = shares.get(actor_name).unwrap();
assert_eq!(*due, split.purchase.cost() * *share);
}
}
// Unequal split
let mut shares = ShareHashMap::default();
shares.insert(
person1.name().to_owned(),
(person1.clone(), dec!(0.3) * split.purchase.cost()),
);
shares.insert(
person2.name().to_owned(),
(person2.clone(), dec!(0.4) * split.purchase.cost()),
);
shares.insert(
person3.name().to_owned(),
(person3.clone(), dec!(0.2) * split.purchase.cost()),
);
shares.insert(
person4.name().to_owned(),
(person4.clone(), dec!(0.1) * split.purchase.cost()),
);
let strategy = SplitStrategy::Unequal(shares);
split.split_strategy = strategy;
assert!(split.validate());
}
}

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src/purchase.rs Normal file
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use std::rc::Rc;
use rust_decimal::prelude::*;
use crate::actor::*;
pub trait Purchasable {
fn cost(&self) -> Decimal;
fn name(&self) -> &str;
fn paid_by(&self) -> Rc<dyn Actor>;
}
pub struct Item {
cost: Decimal,
name: String,
payer: Rc<dyn Actor>,
}
impl Item {
pub fn new(name: String, cost: Decimal, payer: Rc<dyn Actor>) -> Self {
Self { cost, name, payer }
}
}
impl Purchasable for Item {
fn cost(&self) -> Decimal {
self.cost
}
fn name(&self) -> &str {
&self.name
}
fn paid_by(&self) -> Rc<dyn Actor> {
self.payer.clone()
}
}

56
src/strategy.rs Normal file
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use std::collections::HashMap;
use std::rc::Rc;
use rust_decimal::prelude::*;
use rust_decimal_macros::dec;
use crate::actor::*;
use crate::purchase::*;
// key is a string for getting Eq and PartialEq w object safety
pub type ShareHashMap = HashMap<String, (Rc<dyn Actor>, Decimal)>;
/*
* SPLITTING STRATEGIES:
* Unequal: Each actor's split is specified in specific amounts
* Shares: Each actor's split is specified in specific percentage
* Equal: Each actor's split is computed by splitting total expense among all participating actors
*/
#[derive(Clone)]
pub enum SplitStrategy {
Unequal(ShareHashMap),
Shares(ShareHashMap),
Equal,
}
impl SplitStrategy {
pub(crate) fn validate(&self, purchase: &dyn Purchasable) -> bool {
match self {
SplitStrategy::Unequal(shares) => {
let mut total = dec!(0.00);
for (_actor_str, (_actor_obj, share)) in shares.iter() {
total += share;
}
let cost = purchase.cost();
println!("Unequal sharing: expected {cost} got {total}");
total == cost
}
SplitStrategy::Shares(shares) => {
let mut total = dec!(0.00);
let cost = purchase.cost();
let mut total_shares = dec!(0.00);
for (_actor_str, (_actor_obj, share)) in shares.iter() {
total_shares += share;
total += cost * share;
println!("Shares: {:?}, total: {total_shares}", share);
}
println!("Unequal sharing: expected shares 1 got {total_shares}");
println!("Unequal sharing: expected {cost} got {total}");
total_shares == dec!(1.00) && total == cost
}
SplitStrategy::Equal => true,
}
}
}