824 lines
24 KiB
Rust

/*
DrCr: Web-based double-entry bookkeeping framework
Copyright (C) 2022-2025 Lee Yingtong Li (RunasSudo)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
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/>.
*/
//! Implements Australian individual income tax calculations
// TODO: Ideally this would be separated into its own plugin
use std::collections::HashMap;
use std::fmt::Display;
use async_trait::async_trait;
use tokio::sync::RwLock;
use crate::account_config::kinds_for_account;
use crate::model::transaction::{Posting, Transaction, TransactionWithPostings};
use crate::reporting::calculator::ReportingGraphDependencies;
use crate::reporting::dynamic_report::{
entries_for_kind, CalculatableDynamicReport, CalculatableDynamicReportEntry,
CalculatableSection, CalculatedRow, DynamicReport, LiteralRow,
};
use crate::reporting::executor::ReportingExecutionError;
use crate::reporting::steps::AllTransactionsExceptEarningsToEquityBalances;
use crate::reporting::types::{
BalancesBetween, DateStartDateEndArgs, ReportingContext, ReportingProductId,
ReportingProductKind, ReportingProducts, ReportingStep, ReportingStepArgs, ReportingStepId,
Transactions, VoidArgs,
};
use crate::util::sofy_from_eofy;
use crate::{QuantityInt, INCOME_TAX, INCOME_TAX_CONTROL};
// Constants and tax calculations
fn get_grossedup_rfb(taxable_value: QuantityInt) -> QuantityInt {
// FIXME: May vary from year to year
((taxable_value as f64) * 2.0802) as QuantityInt
}
fn get_base_income_tax(net_taxable: QuantityInt) -> QuantityInt {
// FIXME: May vary from year to year
if net_taxable <= 18200_00 {
0
} else if net_taxable <= 45000_00 {
(0.16 * (net_taxable - 18200_00) as f64) as QuantityInt
} else if net_taxable <= 135000_00 {
4288_00 + (0.30 * (net_taxable - 45000_00) as f64) as QuantityInt
} else if net_taxable <= 190000_00 {
31288_00 + (0.37 * (net_taxable - 135000_00) as f64) as QuantityInt
} else {
51638_00 + (0.45 * (net_taxable - 190000_00) as f64) as QuantityInt
}
}
// fn get_medicare_levy(net_taxable: QuantityInt) -> QuantityInt {
// todo!()
// }
// fn get_medicare_levy_surcharge(
// net_taxable: QuantityInt,
// rfb_grossedup: QuantityInt,
// ) -> QuantityInt {
// todo!()
// }
/// Call [ReportingContext::register_lookup_fn] for all steps provided by this module
pub fn register_lookup_fns(context: &mut ReportingContext) {
CalculateIncomeTax::register_lookup_fn(context);
}
/// Calculates income tax
///
/// [Transactions] product represents income tax charge for the year.
/// [DynamicReport] product represents the tax summary report.
#[derive(Debug)]
pub struct CalculateIncomeTax {}
impl CalculateIncomeTax {
fn register_lookup_fn(context: &mut ReportingContext) {
context.register_lookup_fn(
"CalculateIncomeTax",
&[ReportingProductKind::Transactions],
Self::takes_args,
Self::from_args,
);
}
fn takes_args(args: &Box<dyn ReportingStepArgs>) -> bool {
args.is::<VoidArgs>()
}
fn from_args(_args: Box<dyn ReportingStepArgs>) -> Box<dyn ReportingStep> {
Box::new(CalculateIncomeTax {})
}
}
impl Display for CalculateIncomeTax {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.write_fmt(format_args!("{}", self.id()))
}
}
#[async_trait]
impl ReportingStep for CalculateIncomeTax {
fn id(&self) -> ReportingStepId {
ReportingStepId {
name: "CalculateIncomeTax",
product_kinds: &[
ReportingProductKind::DynamicReport,
ReportingProductKind::Transactions,
],
args: Box::new(VoidArgs {}),
}
}
fn requires(&self, context: &ReportingContext) -> Vec<ReportingProductId> {
// CalculateIncomeTax depends on CombineOrdinaryTransactions
vec![ReportingProductId {
name: "CombineOrdinaryTransactions",
kind: ReportingProductKind::BalancesBetween,
args: Box::new(DateStartDateEndArgs {
date_start: sofy_from_eofy(context.eofy_date),
date_end: context.eofy_date.clone(),
}),
}]
}
fn after_init_graph(
&self,
steps: &Vec<Box<dyn ReportingStep>>,
dependencies: &mut ReportingGraphDependencies,
_context: &ReportingContext,
) {
for other in steps {
if let Some(other) =
other.downcast_ref::<AllTransactionsExceptEarningsToEquityBalances>()
{
// AllTransactionsExceptEarningsToEquity depends on CalculateIncomeTax
dependencies.add_dependency(
other.id(),
ReportingProductId {
name: self.id().name,
kind: other.product_kinds[0],
args: if other.product_kinds[0] == ReportingProductKind::Transactions {
Box::new(VoidArgs {})
} else {
other.id().args
},
},
);
}
}
}
async fn execute(
&self,
context: &ReportingContext,
_steps: &Vec<Box<dyn ReportingStep>>,
_dependencies: &ReportingGraphDependencies,
products: &RwLock<ReportingProducts>,
) -> Result<ReportingProducts, ReportingExecutionError> {
let products = products.read().await;
// Get balances for current year
let balances = &products
.get_or_err(&ReportingProductId {
name: "CombineOrdinaryTransactions",
kind: ReportingProductKind::BalancesBetween,
args: Box::new(DateStartDateEndArgs {
date_start: sofy_from_eofy(context.eofy_date),
date_end: context.eofy_date.clone(),
}),
})?
.downcast_ref::<BalancesBetween>()
.unwrap()
.balances;
// Get taxable income and deduction accounts
let kinds_for_account =
kinds_for_account(context.db_connection.get_account_configurations().await);
// Pre-compute taxable value of reportable fringe benefits (required for MLS)
let rfb_taxable = balances
.iter()
.filter(|(acc, _)| {
kinds_for_account
.get(*acc)
.map(|kinds| kinds.iter().any(|k| k == "austax.rfb"))
.unwrap_or(false)
})
.map(|(_, bal)| *bal)
.sum();
// Generate tax summary report
let report = CalculatableDynamicReport::new(
"Tax summary".to_string(),
vec!["$".to_string()],
vec![
CalculatableDynamicReportEntry::CalculatableSection(CalculatableSection::new(
"Salary or wages (1)".to_string(),
Some("income1".to_string()),
true,
true,
{
let mut entries = entries_for_kind_floor(
"austax.income1",
true,
&vec![balances],
&kinds_for_account,
100,
);
entries.push(CalculatableDynamicReportEntry::CalculatedRow(
CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Total item 1".to_string(),
quantity: report.subtotal_for_id("income1").unwrap(),
id: Some("total_income1".to_string()),
visible: true,
auto_hide: true,
link: None,
heading: true,
bordered: true,
},
},
));
// Add spacer as child of the Section so it is hidden if the Section is hidden
entries.push(CalculatableDynamicReportEntry::Spacer);
entries
},
)),
CalculatableDynamicReportEntry::CalculatableSection(CalculatableSection::new(
"Australian Government allowances and payments (5)".to_string(),
Some("income5".to_string()),
true,
true,
{
let mut entries = entries_for_kind(
"austax.income5",
true,
&vec![balances],
&kinds_for_account,
);
entries.push(CalculatableDynamicReportEntry::CalculatedRow(
CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Total item 5".to_string(),
quantity: floor_quantity(
report.subtotal_for_id("income5").unwrap(),
100,
),
id: Some("total_income5".to_string()),
visible: true,
auto_hide: true,
link: None,
heading: true,
bordered: true,
},
},
));
entries.push(CalculatableDynamicReportEntry::Spacer);
entries
},
)),
CalculatableDynamicReportEntry::CalculatableSection(CalculatableSection::new(
"Gross interest (10)".to_string(),
Some("income10".to_string()),
true,
true,
{
let mut entries = entries_for_kind(
"austax.income10",
true,
&vec![balances],
&kinds_for_account,
);
entries.push(CalculatableDynamicReportEntry::CalculatedRow(
CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Total item 10".to_string(),
quantity: floor_quantity(
report.subtotal_for_id("income10").unwrap(),
100,
),
id: Some("total_income10".to_string()),
visible: true,
auto_hide: true,
link: None,
heading: true,
bordered: true,
},
},
));
entries.push(CalculatableDynamicReportEntry::Spacer);
entries
},
)),
CalculatableDynamicReportEntry::CalculatableSection(CalculatableSection::new(
"Partnerships and trusts (13)".to_string(),
Some("income13".to_string()),
true,
true,
{
let mut entries = entries_for_kind(
"austax.income13",
true,
&vec![balances],
&kinds_for_account,
);
entries.push(CalculatableDynamicReportEntry::CalculatedRow(
CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Total item 13".to_string(),
quantity: floor_quantity(
report.subtotal_for_id("income13").unwrap(),
100,
),
id: Some("total_income13".to_string()),
visible: true,
auto_hide: true,
link: None,
heading: true,
bordered: true,
},
},
));
entries.push(CalculatableDynamicReportEntry::Spacer);
entries
},
)),
CalculatableDynamicReportEntry::CalculatableSection(CalculatableSection::new(
"Foreign source income and foreign assets or property (20)".to_string(),
Some("income20".to_string()),
true,
true,
{
let mut entries = entries_for_kind(
"austax.income20",
true,
&vec![balances],
&kinds_for_account,
);
entries.push(CalculatableDynamicReportEntry::CalculatedRow(
CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Total item 20".to_string(),
quantity: floor_quantity(
report.subtotal_for_id("income20").unwrap(),
100,
),
id: Some("total_income20".to_string()),
visible: true,
auto_hide: true,
link: None,
heading: true,
bordered: true,
},
},
));
entries.push(CalculatableDynamicReportEntry::Spacer);
entries
},
)),
CalculatableDynamicReportEntry::CalculatableSection(CalculatableSection::new(
"Other income (24)".to_string(),
Some("income24".to_string()),
true,
true,
{
let mut entries = entries_for_kind(
"austax.income24",
true,
&vec![balances],
&kinds_for_account,
);
entries.push(CalculatableDynamicReportEntry::CalculatedRow(
CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Total item 24".to_string(),
quantity: floor_quantity(
report.subtotal_for_id("income24").unwrap(),
100,
),
id: Some("total_income24".to_string()),
visible: true,
auto_hide: true,
link: None,
heading: true,
bordered: true,
},
},
));
entries.push(CalculatableDynamicReportEntry::Spacer);
entries
},
)),
CalculatableDynamicReportEntry::CalculatedRow(CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Total assessable income".to_string(),
quantity: vec![
report
.quantity_for_id("total_income1")
.map(|v| v[0])
.unwrap_or(0) + report
.quantity_for_id("total_income5")
.map(|v| v[0])
.unwrap_or(0) + report
.quantity_for_id("total_income10")
.map(|v| v[0])
.unwrap_or(0) + report
.quantity_for_id("total_income13")
.map(|v| v[0])
.unwrap_or(0) + report
.quantity_for_id("total_income20")
.map(|v| v[0])
.unwrap_or(0) + report
.quantity_for_id("total_income24")
.map(|v| v[0])
.unwrap_or(0),
],
id: Some("total_income".to_string()),
visible: true,
auto_hide: false,
link: None,
heading: true,
bordered: true,
},
}),
CalculatableDynamicReportEntry::Spacer,
CalculatableDynamicReportEntry::CalculatableSection(CalculatableSection::new(
"Work-related travel expenses (D2)".to_string(),
Some("d2".to_string()),
true,
true,
{
let mut entries = entries_for_kind(
"austax.d2",
false,
&vec![balances],
&kinds_for_account,
);
entries.push(CalculatableDynamicReportEntry::CalculatedRow(
CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Total item D2".to_string(),
quantity: floor_quantity(
report.subtotal_for_id("d2").unwrap(),
100,
),
id: Some("total_d2".to_string()),
visible: true,
auto_hide: true,
link: None,
heading: true,
bordered: true,
},
},
));
entries.push(CalculatableDynamicReportEntry::Spacer);
entries
},
)),
CalculatableDynamicReportEntry::CalculatableSection(CalculatableSection::new(
"Work-related self-education expenses (D4)".to_string(),
Some("d4".to_string()),
true,
true,
{
let mut entries = entries_for_kind(
"austax.d4",
false,
&vec![balances],
&kinds_for_account,
);
entries.push(CalculatableDynamicReportEntry::CalculatedRow(
CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Total item D4".to_string(),
quantity: floor_quantity(
report.subtotal_for_id("d4").unwrap(),
100,
),
id: Some("total_d4".to_string()),
visible: true,
auto_hide: true,
link: None,
heading: true,
bordered: true,
},
},
));
entries.push(CalculatableDynamicReportEntry::Spacer);
entries
},
)),
CalculatableDynamicReportEntry::CalculatableSection(CalculatableSection::new(
"Other work-related expenses (D5)".to_string(),
Some("d5".to_string()),
true,
true,
{
let mut entries = entries_for_kind(
"austax.d5",
false,
&vec![balances],
&kinds_for_account,
);
entries.push(CalculatableDynamicReportEntry::CalculatedRow(
CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Total item D5".to_string(),
quantity: floor_quantity(
report.subtotal_for_id("d5").unwrap(),
100,
),
id: Some("total_d5".to_string()),
visible: true,
auto_hide: true,
link: None,
heading: true,
bordered: true,
},
},
));
entries.push(CalculatableDynamicReportEntry::Spacer);
entries
},
)),
CalculatableDynamicReportEntry::CalculatableSection(CalculatableSection::new(
"Gifts or donations (D9)".to_string(),
Some("d9".to_string()),
true,
true,
{
let mut entries = entries_for_kind(
"austax.d9",
false,
&vec![balances],
&kinds_for_account,
);
entries.push(CalculatableDynamicReportEntry::CalculatedRow(
CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Total item D9".to_string(),
quantity: floor_quantity(
report.subtotal_for_id("d9").unwrap(),
100,
),
id: Some("total_d9".to_string()),
visible: true,
auto_hide: true,
link: None,
heading: true,
bordered: true,
},
},
));
entries.push(CalculatableDynamicReportEntry::Spacer);
entries
},
)),
CalculatableDynamicReportEntry::CalculatableSection(CalculatableSection::new(
"Other deductions (D15)".to_string(),
Some("d15".to_string()),
true,
true,
{
let mut entries = entries_for_kind(
"austax.d15",
false,
&vec![balances],
&kinds_for_account,
);
entries.push(CalculatableDynamicReportEntry::CalculatedRow(
CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Total item D15".to_string(),
quantity: floor_quantity(
report.subtotal_for_id("d15").unwrap(),
100,
),
id: Some("total_d15".to_string()),
visible: true,
auto_hide: true,
link: None,
heading: true,
bordered: true,
},
},
));
entries.push(CalculatableDynamicReportEntry::Spacer);
entries
},
)),
CalculatableDynamicReportEntry::CalculatedRow(CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Total deductions".to_string(),
quantity: vec![
report
.quantity_for_id("total_d2")
.map(|v| v[0])
.unwrap_or(0) + report
.quantity_for_id("total_d4")
.map(|v| v[0])
.unwrap_or(0) + report
.quantity_for_id("total_d5")
.map(|v| v[0])
.unwrap_or(0) + report
.quantity_for_id("total_d9")
.map(|v| v[0])
.unwrap_or(0) + report
.quantity_for_id("total_d15")
.map(|v| v[0])
.unwrap_or(0),
],
id: Some("total_deductions".to_string()),
visible: true,
auto_hide: false,
link: None,
heading: true,
bordered: true,
},
}),
CalculatableDynamicReportEntry::Spacer,
CalculatableDynamicReportEntry::CalculatedRow(CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Net taxable income".to_string(),
quantity: vec![
report.quantity_for_id("total_income").unwrap()[0]
- report.quantity_for_id("total_deductions").unwrap()[0],
],
id: Some("net_taxable".to_string()),
visible: true,
auto_hide: false,
link: None,
heading: true,
bordered: true,
},
}),
// Precompute RFB amount as this is required for MLS
CalculatableDynamicReportEntry::LiteralRow(LiteralRow {
text: "Taxable value of reportable fringe benefits".to_string(),
quantity: vec![rfb_taxable],
id: Some("rfb_taxable".to_string()),
visible: false,
auto_hide: false,
link: None,
heading: false,
bordered: false,
}),
CalculatableDynamicReportEntry::CalculatedRow(CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Grossed-up value".to_string(),
quantity: vec![get_grossedup_rfb(
report.quantity_for_id("rfb_taxable").unwrap()[0],
)],
id: Some("rfb_grossedup".to_string()),
visible: false,
auto_hide: false,
link: None,
heading: false,
bordered: false,
},
}),
CalculatableDynamicReportEntry::Spacer,
CalculatableDynamicReportEntry::CalculatedRow(CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Base income tax".to_string(),
quantity: vec![get_base_income_tax(
report.quantity_for_id("net_taxable").unwrap()[0],
)],
id: Some("tax_base".to_string()),
visible: true,
auto_hide: false,
link: None,
heading: false,
bordered: false,
},
}),
// CalculatableDynamicReportEntry::CalculatedRow(CalculatedRow {
// calculate_fn: |report| LiteralRow {
// text: "Medicare levy".to_string(),
// quantity: vec![get_medicare_levy(
// report.quantity_for_id("net_taxable").unwrap()[0],
// )],
// id: Some("tax_ml".to_string()),
// visible: true,
// auto_hide: true,
// link: None,
// heading: false,
// bordered: false,
// },
// }),
// CalculatableDynamicReportEntry::CalculatedRow(CalculatedRow {
// calculate_fn: |report| LiteralRow {
// text: "Medicare levy".to_string(),
// quantity: vec![get_medicare_levy_surcharge(
// report.quantity_for_id("net_taxable").unwrap()[0],
// report.quantity_for_id("rfb_grossedup").unwrap()[0],
// )],
// id: Some("tax_mls".to_string()),
// visible: true,
// auto_hide: true,
// link: None,
// heading: false,
// bordered: false,
// },
// }),
CalculatableDynamicReportEntry::CalculatedRow(CalculatedRow {
calculate_fn: |report| LiteralRow {
text: "Total income tax".to_string(),
quantity: vec![
report.quantity_for_id("tax_base").unwrap()[0], // + report.quantity_for_id("tax_ml").map(|v| v[0]).unwrap_or(0)
// + report.quantity_for_id("tax_mls").map(|v| v[0]).unwrap_or(0),
],
id: Some("total_tax".to_string()),
visible: true,
auto_hide: false,
link: None,
heading: true,
bordered: true,
},
}),
],
);
let mut report: DynamicReport = report.calculate();
report.auto_hide();
let total_tax = report.quantity_for_id("total_tax").unwrap()[0];
// Generate income tax transaction
let transactions = Transactions {
transactions: vec![TransactionWithPostings {
transaction: Transaction {
id: None,
dt: context
.db_connection
.metadata()
.eofy_date
.and_hms_opt(0, 0, 0)
.unwrap(),
description: "Estimated income tax".to_string(),
},
postings: vec![
Posting {
id: None,
transaction_id: None,
description: None,
account: INCOME_TAX.to_string(),
quantity: total_tax,
commodity: context.db_connection.metadata().reporting_commodity.clone(),
quantity_ascost: Some(total_tax),
},
Posting {
id: None,
transaction_id: None,
description: None,
account: INCOME_TAX_CONTROL.to_string(),
quantity: -total_tax,
commodity: context.db_connection.metadata().reporting_commodity.clone(),
quantity_ascost: Some(total_tax),
},
],
}],
};
// Store products
let mut result = ReportingProducts::new();
result.insert(
ReportingProductId {
name: self.id().name,
kind: ReportingProductKind::Transactions,
args: Box::new(VoidArgs {}),
},
Box::new(transactions),
);
result.insert(
ReportingProductId {
name: self.id().name,
kind: ReportingProductKind::DynamicReport,
args: Box::new(VoidArgs {}),
},
Box::new(report),
);
Ok(result)
}
}
/// Call [entries_for_kind] then round results down to next multiple of `floor`
fn entries_for_kind_floor(
kind: &str,
invert: bool,
balances: &Vec<&HashMap<String, QuantityInt>>,
kinds_for_account: &HashMap<String, Vec<String>>,
floor: QuantityInt,
) -> Vec<CalculatableDynamicReportEntry> {
let mut entries_for_kind = entries_for_kind(kind, invert, balances, kinds_for_account);
entries_for_kind.iter_mut().for_each(|e| match e {
CalculatableDynamicReportEntry::LiteralRow(row) => row
.quantity
.iter_mut()
.for_each(|v| *v = (*v / floor) * floor),
_ => unreachable!(),
});
entries_for_kind
}
fn floor_quantity(mut quantity: Vec<QuantityInt>, floor: QuantityInt) -> Vec<QuantityInt> {
quantity.iter_mut().for_each(|v| *v = (*v / floor) * floor);
quantity
}