tktax-transaction-category 0.2.2

// ---------------- [ File: tktax-transaction-category/src/transaction_category_prediction.rs ]
crate::ix!();

#[derive(Getters,Debug, PartialEq)]
#[getset(get="pub")]
pub struct TransactionCategoryPrediction<TxCat:TransactionCategory> {
    category: TxCat,
    score:    Decimal,
}

impl<TxCat:TransactionCategory> PartialOrd for TransactionCategoryPrediction<TxCat> {

    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        other.score.partial_cmp(&self.score)
    }
}

impl<TxCat:TransactionCategory> Eq for TransactionCategoryPrediction<TxCat> {}

impl<TxCat:TransactionCategory> Ord for TransactionCategoryPrediction<TxCat> {

    fn cmp(&self, other: &Self) -> Ordering {
        other.score.partial_cmp(&self.score).unwrap()
    }
}

pub fn predict_category<TxCat:TransactionCategory>(desc: &str, category_map: &CategoryMap<TxCat>) -> Vec<TransactionCategoryPrediction<TxCat>> {

    let desc = desc.to_lowercase();

    let stemmed_tokens = preprocess_vendor_description(&desc);

    let mut category_scores = HashMap::new();

    for token in stemmed_tokens {

        if let Some(categories) = category_map.get(&StemmedToken::from_str(&token).unwrap()) {

            let n_categories = categories.len();

            for category in categories {
                let score = Decimal::ONE / Decimal::from(n_categories);
                *category_scores.entry(category).or_insert(Decimal::ZERO) += score;
            }
        }
    }

    let mut predictions: Vec<_> = category_scores
        .iter()
        .map(|(&category, &score)| TransactionCategoryPrediction {
            category: *category,
            score,
        })
        .collect();

    predictions.sort_by(|a, b| b.score.partial_cmp(&a.score).unwrap());
    predictions
}

/*
#[cfg(test)]
mod tests {

    use super::*;

    #[test] fn test_category_map() {

        println!("{:#?}", *CATEGORY_MAP);

        let result = predict_category("Bicycle bank food food chipotle", &*CATEGORY_MAP);

        println!("{:#?}", result);
    }
}
*/