From 10f24f65ac7d19bf82ee2966fa8bad2be68eb359 Mon Sep 17 00:00:00 2001
From: Piv <18462828+Piv200@users.noreply.github.com>
Date: Sat, 28 Jan 2023 11:07:13 +1030
Subject: [PATCH] Add movements between accounts and departments

---
 src/lib.rs | 76 +++++++++++++++++++++++++++++++-----------------------
 1 file changed, 44 insertions(+), 32 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 58174bd..beb69cf 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -4,13 +4,23 @@ use itertools::Itertools;
 use na::{DMatrix, Dynamic, LU};
 use std::{collections::HashMap, error::Error, ops::Mul};
 
-// TODO: Look into serde for serialisation, can also use it to serialise/deserialise
-// records from a csv file using the csv crate
+#[derive(Hash, Clone, Default, PartialEq, Eq)]
+pub struct Unit {
+    pub department: String,
+    pub account: String,
+}
+
 #[derive(Default)]
 pub struct MovementRule {
     // If the vectors are empty, then it means 'all'
-    pub from_units: Vec<String>,
-    pub to_units: Vec<String>,
+    pub from_departments: Vec<String>,
+    pub to_departments: Vec<String>,
+    pub all_from_departments: bool,
+    pub all_to_departments: bool,
+    pub from_accounts: Vec<String>,
+    pub to_accounts: Vec<String>,
+    pub all_from_accounts: bool,
+    pub all_to_accounts: bool,
     pub amount: f64,
     pub is_percent: bool,
     pub is_separator: bool,
@@ -19,16 +29,13 @@ pub struct MovementRule {
 impl MovementRule {
     pub fn pass_break() -> MovementRule {
         MovementRule {
-            from_units: vec![],
-            to_units: vec![],
-            amount: 0.0,
-            is_percent: false,
             is_separator: true,
+            ..MovementRule::default()
         }
     }
 
     pub fn validate(&self) -> bool {
-        if self.from_units.is_empty() && self.to_units.is_empty() {
+        if self.from_departments.is_empty() && self.to_departments.is_empty() {
             // Would be nice to have a decent message/error here as well
             return false;
         }
@@ -51,7 +58,7 @@ pub fn smush_rules(rules: Vec<MovementRule>) -> Vec<MovementRule> {
     // TODO: We could make this more advanced by only smushing per divider, so that only the departments
     // needed between each pass is actually required
     for rule in rules {
-        for department in rule.from_units {
+        for department in rule.from_departments {
             // ruleMapping.entry(department).or_insert(ruleMapping.len());
         }
     }
@@ -77,40 +84,45 @@ pub fn move_money_1() {}
 // Note that the movement happens on a line-by-line level. So we can stream the data from disk, and potentially apply this
 // to every. It's also much more memory efficient than approach 1.
 // TODO: Time both approaches to seee which is faster depending on the size of the input data/number of rules
-// TODO: Right now this only supports movements between departments, we also need to support movements between accounts.
-//      This would require an expansion so that we also have from/to accounts, and the hashmap will use some struct
-//      that combines an account/department, which is also how the totals will be loaded. (so when loading from disk,
-//      we load the whole GL into memory sum the account/department totals, and move these into a map line by line)
 pub fn move_money_2(
-    initial_totals: HashMap<String, f64>,
-    rules: Vec<MovementRule>,
-) -> HashMap<String, f64> {
+    initial_totals: HashMap<Unit, f64>,
+    rules: &Vec<MovementRule>,
+) -> HashMap<Unit, f64> {
     // TODO: Should probably validate that all the rules have departments that actually exist in initial_totals.
     // Note: It's potentially a bit more intensive to use cloned totals, but it's much simpler code and, and since we're only working line-by-line
     // it isn't really that much memory. in practice
     let mut running_total = HashMap::from(initial_totals);
-    let mut temp_total: HashMap<String, f64> = running_total.clone();
+    let mut temp_total = running_total.clone();
     for rule in rules {
         if rule.is_separator {
             running_total = temp_total.clone();
         } else {
             let mut sum_from = 0.;
-            for department in rule.from_units {
-                let previous_temp = running_total.get(&department).expect(
-                    "Failed to find department in temp totals, this should not be possible",
-                );
-                let added_amount = if rule.is_percent {
-                    *previous_temp * rule.amount
-                } else {
-                    rule.amount
-                };
-                sum_from += added_amount;
-                *temp_total.get_mut(&department).unwrap() -= added_amount;
+            for unit in &running_total {
+                if (rule.all_from_departments || rule.from_departments.contains(&unit.0.department))
+                    && (rule.all_from_accounts || rule.from_accounts.contains(&unit.0.account))
+                {
+                    let previous_temp = unit.1;
+                    let added_amount = if rule.is_percent {
+                        previous_temp * rule.amount
+                    } else {
+                        rule.amount
+                    };
+                    sum_from += added_amount;
+                    *temp_total.get_mut(&unit.0).unwrap() -= added_amount;
+                }
             }
 
-            let value_per_unit = sum_from / rule.to_units.len() as f64;
-            for department in rule.to_units {
-                *temp_total.get_mut(&department).unwrap() += value_per_unit;
+            let num_to_units = running_total
+                .keys()
+                .filter(|key| {
+                    (rule.all_to_accounts || rule.to_departments.contains(&key.department))
+                        && (rule.all_to_accounts || rule.to_accounts.contains(&key.account))
+                })
+                .count();
+            let value_per_unit = sum_from / num_to_units as f64;
+            for unit in running_total.keys() {
+                *temp_total.get_mut(&unit).unwrap() += value_per_unit;
             }
         }
     }