okane_core/report/
balance.rs

1use std::collections::HashMap;
2
3use super::{
4    context::Account,
5    eval::{Amount, EvalError, PostingAmount},
6    ReportContext,
7};
8
9/// Error related to [Balance] operations.
10#[derive(Debug, thiserror::Error, PartialEq, Eq)]
11pub enum BalanceError {
12    #[error("balance = 0 cannot deduce posting amount when balance has multi commodities")]
13    MultiCommodityWithPartialSet(#[from] EvalError),
14}
15
16/// Accumulated balance of accounts.
17#[derive(Debug, Default, PartialEq, Eq, Clone)]
18pub struct Balance<'ctx> {
19    accounts: HashMap<Account<'ctx>, Amount<'ctx>>,
20}
21
22impl<'ctx> FromIterator<(Account<'ctx>, Amount<'ctx>)> for Balance<'ctx> {
23    /// Constructs [Balance] instance out of Iterator.
24    fn from_iter<T>(iter: T) -> Self
25    where
26        T: IntoIterator<Item = (Account<'ctx>, Amount<'ctx>)>,
27    {
28        Self {
29            accounts: iter.into_iter().collect(),
30        }
31    }
32}
33
34impl<'ctx> Balance<'ctx> {
35    /// Adds a particular account value, and returns the updated balance.
36    pub fn add_amount(&mut self, account: Account<'ctx>, amount: Amount<'ctx>) -> &Amount<'ctx> {
37        let curr: &mut Amount = self.accounts.entry(account).or_default();
38        *curr += amount;
39        curr.remove_zero_entries();
40        curr
41    }
42
43    /// Adds a particular account value with the specified commodity, and returns the updated balance.
44    pub(super) fn add_posting_amount(
45        &mut self,
46        account: Account<'ctx>,
47        amount: PostingAmount<'ctx>,
48    ) -> &Amount<'ctx> {
49        let curr: &mut Amount = self.accounts.entry(account).or_default();
50        *curr += amount;
51        curr.remove_zero_entries();
52        curr
53    }
54
55    /// Tries to set the particular account's balance with the specified commodity,
56    /// and returns the delta which should have caused the difference.
57    pub(super) fn set_partial(
58        &mut self,
59        account: Account<'ctx>,
60        amount: PostingAmount<'ctx>,
61    ) -> Result<PostingAmount<'ctx>, BalanceError> {
62        match amount {
63            PostingAmount::Zero => {
64                let prev: Amount<'ctx> = self
65                    .accounts
66                    .insert(account, Amount::zero())
67                    .unwrap_or_default();
68                (&prev)
69                    .try_into()
70                    .map_err(BalanceError::MultiCommodityWithPartialSet)
71            }
72            PostingAmount::Single(single_amount) => {
73                let prev = self
74                    .accounts
75                    .entry(account)
76                    .or_default()
77                    .set_partial(single_amount);
78                Ok(PostingAmount::Single(prev))
79            }
80        }
81    }
82
83    /// Gets the balance of the given account.
84    pub fn get(&self, account: &Account<'ctx>) -> Option<&Amount<'ctx>> {
85        self.accounts.get(account)
86    }
87
88    /// Rounds the balance following the context.
89    pub fn round(&mut self, ctx: &ReportContext<'ctx>) {
90        for amount in self.accounts.values_mut() {
91            amount.round_mut(ctx);
92        }
93    }
94
95    /// Returns unordered iterator for the account and the amount.
96    pub(crate) fn iter(&self) -> impl Iterator<Item = (&Account<'ctx>, &Amount<'ctx>)> {
97        self.accounts.iter()
98    }
99
100    /// Constructs sorted vec of account and commodity tuple.
101    pub fn into_vec(self) -> Vec<(Account<'ctx>, Amount<'ctx>)> {
102        let mut ret: Vec<(Account<'ctx>, Amount<'ctx>)> = self.accounts.into_iter().collect();
103        ret.sort_unstable_by_key(|(a, _)| a.as_str());
104        ret
105    }
106}
107
108#[cfg(test)]
109mod tests {
110    use super::*;
111
112    use bumpalo::Bump;
113    use pretty_assertions::assert_eq;
114    use rust_decimal_macros::dec;
115
116    use super::super::context::ReportContext;
117
118    #[test]
119    fn balance_gives_zero_amount_when_not_initalized() {
120        let arena = Bump::new();
121        let mut ctx = ReportContext::new(&arena);
122
123        let balance = Balance::default();
124        assert_eq!(balance.get(&ctx.accounts.ensure("Expenses")), None);
125    }
126
127    #[test]
128    fn test_balance_increment_adds_value() {
129        let arena = Bump::new();
130        let mut ctx = ReportContext::new(&arena);
131
132        let mut balance = Balance::default();
133        let updated = balance
134            .add_posting_amount(
135                ctx.accounts.ensure("Expenses"),
136                PostingAmount::from_value(dec!(1000), ctx.commodities.ensure("JPY")),
137            )
138            .clone();
139
140        assert_eq!(
141            updated,
142            Amount::from_value(dec!(1000), ctx.commodities.ensure("JPY"))
143        );
144        assert_eq!(
145            balance.get(&ctx.accounts.ensure("Expenses")),
146            Some(&updated)
147        );
148
149        let updated = balance
150            .add_posting_amount(
151                ctx.accounts.ensure("Expenses"),
152                PostingAmount::from_value(dec!(-1000), ctx.commodities.ensure("JPY")),
153            )
154            .clone();
155
156        assert_eq!(updated, Amount::zero());
157        assert_eq!(
158            balance.get(&ctx.accounts.ensure("Expenses")),
159            Some(&updated)
160        );
161    }
162
163    #[test]
164    fn test_balance_set_partial_from_absolute_zero() {
165        let arena = Bump::new();
166        let mut ctx = ReportContext::new(&arena);
167        let mut balance = Balance::default();
168
169        let prev = balance
170            .set_partial(
171                ctx.accounts.ensure("Expenses"),
172                PostingAmount::from_value(dec!(1000), ctx.commodities.ensure("JPY")),
173            )
174            .unwrap();
175
176        // Note it won't be PostingAmount::zero(),
177        // as set_partial is called with commodity amount.
178        assert_eq!(
179            prev,
180            PostingAmount::from_value(dec!(0), ctx.commodities.ensure("JPY"))
181        );
182        assert_eq!(
183            balance.get(&ctx.accounts.ensure("Expenses")),
184            Some(&Amount::from_value(
185                dec!(1000),
186                ctx.commodities.ensure("JPY")
187            ))
188        );
189    }
190
191    #[test]
192    fn test_balance_set_partial_hit_same_commodity() {
193        let arena = Bump::new();
194        let mut ctx = ReportContext::new(&arena);
195        let mut balance = Balance::default();
196        balance.add_posting_amount(
197            ctx.accounts.ensure("Expenses"),
198            PostingAmount::from_value(dec!(1000), ctx.commodities.ensure("JPY")),
199        );
200
201        let prev = balance
202            .set_partial(
203                ctx.accounts.ensure("Expenses"),
204                PostingAmount::from_value(dec!(-1000), ctx.commodities.ensure("JPY")),
205            )
206            .unwrap();
207
208        assert_eq!(
209            prev,
210            PostingAmount::from_value(dec!(1000), ctx.commodities.ensure("JPY"))
211        );
212        assert_eq!(
213            balance.get(&ctx.accounts.ensure("Expenses")),
214            Some(&Amount::from_value(
215                dec!(-1000),
216                ctx.commodities.ensure("JPY")
217            ))
218        );
219    }
220
221    #[test]
222    fn test_balance_set_partial_multi_commodities() {
223        let arena = Bump::new();
224        let mut ctx = ReportContext::new(&arena);
225        let mut balance = Balance::default();
226        balance.add_posting_amount(
227            ctx.accounts.ensure("Expenses"),
228            PostingAmount::from_value(dec!(1000), ctx.commodities.ensure("JPY")),
229        );
230        balance.add_posting_amount(
231            ctx.accounts.ensure("Expenses"),
232            PostingAmount::from_value(dec!(200), ctx.commodities.ensure("CHF")),
233        );
234
235        let prev = balance
236            .set_partial(
237                ctx.accounts.ensure("Expenses"),
238                PostingAmount::from_value(dec!(100), ctx.commodities.ensure("CHF")),
239            )
240            .unwrap();
241
242        assert_eq!(
243            prev,
244            PostingAmount::from_value(dec!(200), ctx.commodities.ensure("CHF"))
245        );
246        assert_eq!(
247            balance.get(&ctx.accounts.ensure("Expenses")),
248            Some(&Amount::from_values([
249                (dec!(1000), ctx.commodities.ensure("JPY")),
250                (dec!(100), ctx.commodities.ensure("CHF")),
251            ]))
252        );
253    }
254
255    #[test]
256    fn test_balance_set_partial_zero_on_zero() {
257        let arena = Bump::new();
258        let mut ctx = ReportContext::new(&arena);
259        let mut balance = Balance::default();
260
261        let prev = balance
262            .set_partial(ctx.accounts.ensure("Expenses"), PostingAmount::zero())
263            .unwrap();
264
265        assert_eq!(prev, PostingAmount::zero());
266        assert_eq!(
267            balance.get(&ctx.accounts.ensure("Expenses")),
268            Some(&Amount::zero())
269        );
270    }
271
272    #[test]
273    fn test_balance_set_partial_zero_on_single_commodity() {
274        let arena = Bump::new();
275        let mut ctx = ReportContext::new(&arena);
276        let mut balance = Balance::default();
277        balance.add_posting_amount(
278            ctx.accounts.ensure("Expenses"),
279            PostingAmount::from_value(dec!(1000), ctx.commodities.ensure("JPY")),
280        );
281
282        let prev = balance
283            .set_partial(ctx.accounts.ensure("Expenses"), PostingAmount::zero())
284            .unwrap();
285
286        assert_eq!(
287            prev,
288            PostingAmount::from_value(dec!(1000), ctx.commodities.ensure("JPY"))
289        );
290        assert_eq!(
291            balance.get(&ctx.accounts.ensure("Expenses")),
292            Some(&Amount::zero())
293        );
294    }
295
296    #[test]
297    fn test_balance_set_partial_zero_fails_on_multi_commodities() {
298        let arena = Bump::new();
299        let mut ctx = ReportContext::new(&arena);
300        let mut balance = Balance::default();
301        balance.add_posting_amount(
302            ctx.accounts.ensure("Expenses"),
303            PostingAmount::from_value(dec!(1000), ctx.commodities.ensure("JPY")),
304        );
305        balance.add_posting_amount(
306            ctx.accounts.ensure("Expenses"),
307            PostingAmount::from_value(dec!(200), ctx.commodities.ensure("CHF")),
308        );
309
310        let err = balance
311            .set_partial(ctx.accounts.ensure("Expenses"), PostingAmount::zero())
312            .unwrap_err();
313
314        assert_eq!(
315            err,
316            BalanceError::MultiCommodityWithPartialSet(EvalError::PostingAmountRequired)
317        );
318    }
319}
okane_core/report/balance.rs

okane_core/report/
balance.rs
