okane_core/report/
balance.rs

1use std::collections::HashMap;
2
3use crate::report::eval::EvalError;
4
5use super::{
6    context::Account,
7    eval::{Amount, OwnedEvalError, PostingAmount},
8    ReportContext,
9};
10
11/// Error related to [Balance] operations.
12#[derive(Debug, thiserror::Error, PartialEq, Eq)]
13pub enum BalanceError {
14    #[error("balance = 0 cannot deduce posting amount when balance has multi commodities")]
15    MultiCommodityWithPartialSet(#[from] OwnedEvalError),
16}
17
18/// Accumulated balance of accounts.
19#[derive(Debug, Default, PartialEq, Eq, Clone)]
20pub struct Balance<'ctx> {
21    accounts: HashMap<Account<'ctx>, Amount<'ctx>>,
22}
23
24impl<'ctx> FromIterator<(Account<'ctx>, Amount<'ctx>)> for Balance<'ctx> {
25    /// Constructs [Balance] instance out of Iterator.
26    fn from_iter<T>(iter: T) -> Self
27    where
28        T: IntoIterator<Item = (Account<'ctx>, Amount<'ctx>)>,
29    {
30        Self {
31            accounts: iter.into_iter().collect(),
32        }
33    }
34}
35
36impl<'ctx> Balance<'ctx> {
37    /// Adds a particular account value, and returns the updated balance.
38    pub fn add_amount(&mut self, account: Account<'ctx>, amount: Amount<'ctx>) -> &Amount<'ctx> {
39        let curr: &mut Amount = self.accounts.entry(account).or_default();
40        *curr += amount;
41        curr.remove_zero_entries();
42        curr
43    }
44
45    /// Adds a particular account value with the specified commodity, and returns the updated balance.
46    pub(super) fn add_posting_amount(
47        &mut self,
48        account: Account<'ctx>,
49        amount: PostingAmount<'ctx>,
50    ) -> &Amount<'ctx> {
51        let curr: &mut Amount = self.accounts.entry(account).or_default();
52        *curr += amount;
53        curr.remove_zero_entries();
54        curr
55    }
56
57    /// Tries to set the particular account's balance with the specified commodity,
58    /// and returns the delta which should have caused the difference.
59    pub(super) fn set_partial(
60        &mut self,
61        ctx: &ReportContext<'ctx>,
62        account: Account<'ctx>,
63        amount: PostingAmount<'ctx>,
64    ) -> Result<PostingAmount<'ctx>, BalanceError> {
65        match amount {
66            PostingAmount::Zero => {
67                let prev: Amount<'ctx> = self
68                    .accounts
69                    .insert(account, Amount::zero())
70                    .unwrap_or_default();
71                (&prev).try_into().map_err(|e: EvalError<'_>| {
72                    BalanceError::MultiCommodityWithPartialSet(e.into_owned(ctx))
73                })
74            }
75            PostingAmount::Single(single_amount) => {
76                let prev = self
77                    .accounts
78                    .entry(account)
79                    .or_default()
80                    .set_partial(single_amount);
81                Ok(PostingAmount::Single(prev))
82            }
83        }
84    }
85
86    /// Gets the balance of the given account.
87    pub fn get(&self, account: &Account<'ctx>) -> Option<&Amount<'ctx>> {
88        self.accounts.get(account)
89    }
90
91    /// Rounds the balance following the context.
92    pub fn round(&mut self, ctx: &ReportContext<'ctx>) {
93        for amount in self.accounts.values_mut() {
94            amount.round_mut(ctx);
95        }
96    }
97
98    /// Returns unordered iterator for the account and the amount.
99    pub(crate) fn iter(&self) -> impl Iterator<Item = (&Account<'ctx>, &Amount<'ctx>)> {
100        self.accounts.iter()
101    }
102
103    /// Constructs sorted vec of account and commodity tuple.
104    pub fn into_vec(self) -> Vec<(Account<'ctx>, Amount<'ctx>)> {
105        let mut ret: Vec<(Account<'ctx>, Amount<'ctx>)> = self.accounts.into_iter().collect();
106        ret.sort_unstable_by_key(|(a, _)| a.as_str());
107        ret
108    }
109}
110
111#[cfg(test)]
112mod tests {
113    use super::*;
114
115    use bumpalo::Bump;
116    use pretty_assertions::assert_eq;
117    use rust_decimal_macros::dec;
118
119    use super::super::context::ReportContext;
120
121    #[test]
122    fn balance_gives_zero_amount_when_not_initalized() {
123        let arena = Bump::new();
124        let mut ctx = ReportContext::new(&arena);
125
126        let balance = Balance::default();
127        assert_eq!(balance.get(&ctx.accounts.ensure("Expenses")), None);
128    }
129
130    #[test]
131    fn test_balance_increment_adds_value() {
132        let arena = Bump::new();
133        let mut ctx = ReportContext::new(&arena);
134
135        let mut balance = Balance::default();
136        let updated = balance
137            .add_posting_amount(
138                ctx.accounts.ensure("Expenses"),
139                PostingAmount::from_value(dec!(1000), ctx.commodities.ensure("JPY")),
140            )
141            .clone();
142
143        assert_eq!(
144            updated,
145            Amount::from_value(dec!(1000), ctx.commodities.ensure("JPY"))
146        );
147        assert_eq!(
148            balance.get(&ctx.accounts.ensure("Expenses")),
149            Some(&updated)
150        );
151
152        let updated = balance
153            .add_posting_amount(
154                ctx.accounts.ensure("Expenses"),
155                PostingAmount::from_value(dec!(-1000), ctx.commodities.ensure("JPY")),
156            )
157            .clone();
158
159        assert_eq!(updated, Amount::zero());
160        assert_eq!(
161            balance.get(&ctx.accounts.ensure("Expenses")),
162            Some(&updated)
163        );
164    }
165
166    #[test]
167    fn test_balance_set_partial_from_absolute_zero() {
168        let arena = Bump::new();
169        let mut ctx = ReportContext::new(&arena);
170        let mut balance = Balance::default();
171
172        let expenses = ctx.accounts.ensure("Expenses");
173        let jpy = ctx.commodities.insert("JPY").unwrap();
174        let prev = balance
175            .set_partial(&ctx, expenses, PostingAmount::from_value(dec!(1000), jpy))
176            .unwrap();
177
178        // Note it won't be PostingAmount::zero(),
179        // as set_partial is called with commodity amount.
180        assert_eq!(prev, PostingAmount::from_value(dec!(0), jpy));
181        assert_eq!(
182            balance.get(&expenses),
183            Some(&Amount::from_value(dec!(1000), jpy))
184        );
185    }
186
187    #[test]
188    fn test_balance_set_partial_hit_same_commodity() {
189        let arena = Bump::new();
190        let mut ctx = ReportContext::new(&arena);
191        let mut balance = Balance::default();
192        balance.add_posting_amount(
193            ctx.accounts.ensure("Expenses"),
194            PostingAmount::from_value(dec!(1000), ctx.commodities.ensure("JPY")),
195        );
196
197        let expenses = ctx.accounts.ensure("Expenses");
198        let jpy = ctx.commodities.ensure("JPY");
199
200        let prev = balance
201            .set_partial(&ctx, expenses, PostingAmount::from_value(dec!(-1000), jpy))
202            .unwrap();
203
204        assert_eq!(
205            prev,
206            PostingAmount::from_value(dec!(1000), ctx.commodities.ensure("JPY"))
207        );
208        assert_eq!(
209            balance.get(&ctx.accounts.ensure("Expenses")),
210            Some(&Amount::from_value(
211                dec!(-1000),
212                ctx.commodities.ensure("JPY")
213            ))
214        );
215    }
216
217    #[test]
218    fn test_balance_set_partial_multi_commodities() {
219        let arena = Bump::new();
220        let mut ctx = ReportContext::new(&arena);
221        let mut balance = Balance::default();
222        balance.add_posting_amount(
223            ctx.accounts.ensure("Expenses"),
224            PostingAmount::from_value(dec!(1000), ctx.commodities.ensure("JPY")),
225        );
226        balance.add_posting_amount(
227            ctx.accounts.ensure("Expenses"),
228            PostingAmount::from_value(dec!(200), ctx.commodities.ensure("CHF")),
229        );
230
231        let expenses = ctx.accounts.ensure("Expenses");
232        let chf = ctx.commodities.ensure("CHF");
233
234        let prev = balance
235            .set_partial(&ctx, expenses, PostingAmount::from_value(dec!(100), chf))
236            .unwrap();
237
238        assert_eq!(
239            prev,
240            PostingAmount::from_value(dec!(200), ctx.commodities.ensure("CHF"))
241        );
242        assert_eq!(
243            balance.get(&ctx.accounts.ensure("Expenses")),
244            Some(&Amount::from_values([
245                (dec!(1000), ctx.commodities.ensure("JPY")),
246                (dec!(100), ctx.commodities.ensure("CHF")),
247            ]))
248        );
249    }
250
251    #[test]
252    fn test_balance_set_partial_zero_on_zero() {
253        let arena = Bump::new();
254        let mut ctx = ReportContext::new(&arena);
255        let mut balance = Balance::default();
256
257        let expenses = ctx.accounts.ensure("Expenses");
258
259        let prev = balance
260            .set_partial(&ctx, expenses, PostingAmount::zero())
261            .unwrap();
262
263        assert_eq!(prev, PostingAmount::zero());
264        assert_eq!(
265            balance.get(&ctx.accounts.ensure("Expenses")),
266            Some(&Amount::zero())
267        );
268    }
269
270    #[test]
271    fn test_balance_set_partial_zero_on_single_commodity() {
272        let arena = Bump::new();
273        let mut ctx = ReportContext::new(&arena);
274        let mut balance = Balance::default();
275        balance.add_posting_amount(
276            ctx.accounts.ensure("Expenses"),
277            PostingAmount::from_value(dec!(1000), ctx.commodities.ensure("JPY")),
278        );
279
280        let expenses = ctx.accounts.ensure("Expenses");
281
282        let prev = balance
283            .set_partial(&ctx, 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 expenses = ctx.accounts.ensure("Expenses");
311
312        let err = balance
313            .set_partial(&ctx, expenses, PostingAmount::zero())
314            .unwrap_err();
315
316        assert_eq!(
317            err,
318            BalanceError::MultiCommodityWithPartialSet(OwnedEvalError::PostingAmountRequired)
319        );
320    }
321}
okane_core/report/balance.rs

okane_core/report/
balance.rs
