Final refactor before doing actual work

1 files changed, 112 insertions, 88 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 66ebe32..bef9ffe 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,14 +1,33 @@
 use std::collections::HashMap;
 use std::fmt;
+use std::ops::AddAssign;
+
+#[derive(Clone, Copy)]
+pub struct Capital {
+    principal: f64,
+    interest: f64,
+}
+
+impl Capital {
+    fn total(&self) -> f64 {
+        self.principal + self.interest
+    }
+}
+
+// TODO generate other operations using macros
+impl AddAssign for Capital {
+    fn add_assign(&mut self, other: Self) {
+        self.principal += other.principal;
+        self.interest += other.interest;
+    }
+}
 
 pub struct Simulation {
-    mortgage: Mortgage,
-    updates: MortgageUpdates,
+    st: SimState,
+    updates: SimUpdates,
     history: Vec<Quota>,
-    topay_total: f64,
-    topay_interest: f64,
-    payed_principal: f64,
-    payed_interest: f64,
+    topay: Capital,
+    payed: Capital,
     payed_amortized: f64,
 }
 
@@ -17,50 +36,53 @@ impl Simulation {
         let pending_quotas = years * 12;
         let i12 = i1 / 12.0;
 
-        let mortgage = Mortgage {
+        let mut st = SimState {
             period: 0,
             principal,
             i12,
-            monthly: Mortgage::monthly(principal, i12, pending_quotas),
+            monthly: 0.,
             pending_quotas,
         };
+        st.calculate_monthly();
 
-        let topay_total = mortgage.monthly * pending_quotas as f64;
+        let topay_total = st.monthly * pending_quotas as f64;
 
         Simulation {
-            mortgage,
-            topay_total,
-            topay_interest: topay_total - principal,
-            payed_principal: 0.,
-            payed_interest: 0.,
+            st,
+            topay: Capital {
+                principal,
+                interest: topay_total - principal,
+            },
+            payed: Capital {
+                principal: 0.,
+                interest: 0.,
+            },
             payed_amortized: 0.,
             history: vec![],
             updates: HashMap::new(),
         }
     }
 
-    pub fn run(&mut self, updates: MortgageUpdates) {
+    pub fn run(&mut self, updates: SimUpdates) {
         self.updates = updates;
-        let mut mortgage = self.mortgage.clone();
-        while mortgage.pending_quotas > 0 && mortgage.principal > 0. {
-            let quota = mortgage.step();
-            self.payed_principal += quota.principal;
-            self.payed_interest += quota.interest;
+        let mut st = self.st.clone();
+        while st.pending_quotas > 0 && st.principal > 0. {
+            let quota = st.step();
+            self.payed += quota.payed;
             self.history.push(quota);
-            self.apply_updates(&mut mortgage);
+            self.apply_updates(&mut st);
         }
     }
 
-    fn apply_updates(&mut self, mortgage: &mut Mortgage) {
-        match self.updates.get_mut(&mortgage.period) {
-            Some(MortgageUpdate::Amortize(principal)) => {
-                if *principal > mortgage.principal {
-                    *principal = mortgage.principal;
+    fn apply_updates(&mut self, st: &mut SimState) {
+        match self.updates.get_mut(&st.period) {
+            Some(SimUpdate::Amortize(principal)) => {
+                if *principal > st.principal {
+                    *principal = st.principal;
                 };
-                mortgage.principal -= *principal;
-                mortgage.monthly =
-                    Mortgage::monthly(mortgage.principal, mortgage.i12, mortgage.pending_quotas);
-
+                st.principal -= *principal;
+                st.calculate_monthly();
+                self.payed.principal += *principal;
                 self.payed_amortized += *principal;
             }
             None => (),
@@ -68,82 +90,57 @@ impl Simulation {
     }
 
     pub fn render_table(&self) {
-        let mortgage = &self.mortgage;
+        let st = &self.st;
 
         println!("\n========================================================");
         println!(
             "=== HIPOTECA: {}€, A {} AÑOS, INTERÉS FIJO {:.2}% ===",
-            mortgage.principal,
-            mortgage.pending_quotas / 12,
-            mortgage.i12 * 12. * 100.,
+            st.principal,
+            st.pending_quotas / 12,
+            st.i12 * 12. * 100.,
         );
         println!("========================================================");
 
         println!("\n\n# SIMULACIÓN CUOTAS\n");
         println!("Year | Mon |   Quota ( Amrtzd +  Intrst) |    Pending");
-        for mortgage in self.history.iter() {
-            print!("{mortgage}");
-            if let Some(update) = self.updates.get(&mortgage.period) {
+        for st in self.history.iter() {
+            print!("{st}");
+            if let Some(update) = self.updates.get(&st.period) {
                 print!(" {update}");
             }
             println!();
         }
 
-        let payed_total = self.payed_principal + self.payed_interest + self.payed_amortized;
-
         println!("\n\n# A PRIORI\n");
         println!(
             "== Total a pagar: {:.2} ({:.2} cap + {:.2} int)",
-            self.topay_total, mortgage.principal, self.topay_interest
+            self.topay.total(),
+            self.topay.principal,
+            self.topay.interest
         );
         println!(
             "== Los intereses suponen un {:.2}% del total",
-            100. * self.topay_interest / self.topay_total
+            100. * self.topay.interest / self.topay.total()
         );
 
         println!("\n\n# RESULTADO FINAL\n");
         println!(
-            "== Total pagado: {:.2} ({:.2} cap + {:.2} int + {:.2} amortizado)",
-            payed_total, self.payed_principal, self.payed_interest, self.payed_amortized
+            "== Total pagado: {:.2} ({:.2} en cuotas + {:.2} int + {:.2} amortizado)",
+            self.payed.total(),
+            self.payed.principal - self.payed_amortized,
+            self.payed.interest,
+            self.payed_amortized
         );
         println!(
             "== Los intereses suponen un {:.2}% del total",
-            100. * self.payed_interest / payed_total
+            100. * self.payed.interest / self.payed.total()
         );
         println!();
     }
 }
 
 #[derive(Clone)]
-pub struct Quota {
-    period: u32,
-    interest: f64,
-    principal: f64,
-    pending_principal: f64,
-}
-
-impl fmt::Display for Quota {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(
-            f,
-            "{:4} | {:3} | {:7.2} ({:7.2} + {:7.2}) | {:10.2}",
-            if (self.period - 1) % 12 == 0 {
-                format!("Y{}", (self.period / 12) + 1)
-            } else {
-                // return Ok(());
-                "".to_string()
-            },
-            self.period,
-            self.interest + self.principal,
-            self.principal,
-            self.interest,
-            self.pending_principal
-        )
-    }
-}
-
-#[derive(Clone)]
-pub struct Mortgage {
+struct SimState {
     period: u32,
     principal: f64,
     i12: f64,
@@ -151,14 +148,23 @@ pub struct Mortgage {
     pending_quotas: u32,
 }
 
-impl Mortgage {
-    fn monthly(principal: f64, i12: f64, pending_quotas: u32) -> f64 {
-        principal * i12 / (1.0 - (1.0 + i12).powi(-(pending_quotas as i32)))
+impl SimState {
+    fn calculate_monthly(&mut self) {
+        self.monthly =
+            self.principal * self.i12 / (1.0 - (1.0 + self.i12).powi(-(self.pending_quotas as i32)))
+    }
+
+    fn capital(&self) -> Capital {
+        let interest = self.i12 * self.principal;
+        let principal = self.monthly - interest;
+        Capital {
+            principal,
+            interest,
+        }
     }
 
     fn step(&mut self) -> Quota {
-        let interest = self.quota_interest();
-        let principal = self.quota_principal();
+        let capital = self.capital();
 
         self.period += 1;
         self.pending_quotas -= 1;
@@ -166,29 +172,47 @@ impl Mortgage {
 
         Quota {
             period: self.period,
-            interest,
-            principal,
+            payed: capital,
             pending_principal: self.principal,
         }
     }
+}
 
-    fn quota_interest(&self) -> f64 {
-        self.i12 * self.principal
-    }
+#[derive(Clone)]
+pub struct Quota {
+    period: u32,
+    payed: Capital,
+    pending_principal: f64,
+}
 
-    fn quota_principal(&self) -> f64 {
-        self.monthly - self.quota_interest()
+impl fmt::Display for Quota {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "{:4} | {:3} | {:7.2} ({:7.2} + {:7.2}) | {:10.2}",
+            if (self.period - 1) % 12 == 0 {
+                format!("Y{}", (self.period / 12) + 1)
+            } else {
+                // return Ok(());
+                "".to_string()
+            },
+            self.period,
+            self.payed.total(),
+            self.payed.principal,
+            self.payed.interest,
+            self.pending_principal
+        )
     }
 }
 
-pub type MortgageUpdates = HashMap<u32, MortgageUpdate>;
+pub type SimUpdates = HashMap<u32, SimUpdate>;
 
 #[derive(Clone)]
-pub enum MortgageUpdate {
+pub enum SimUpdate {
     Amortize(f64),
 }
 
-impl fmt::Display for MortgageUpdate {
+impl fmt::Display for SimUpdate {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "[MORTGAGE UPDATE: ")?;
         match self {