Dual simulation (only i1 + full)

2 files changed, 37 insertions, 26 deletions

diff --git a/front/src/Main.elm b/front/src/Main.elm
index fef4863..68ead13 100644
--- a/front/src/Main.elm
+++ b/front/src/Main.elm
@@ -206,7 +206,8 @@ capitalSumView { t, settings } { principal, interest } =
 type alias MortgageSim =
     { updates : SimUpdates
     , history : List Quota
-    , topay : Capital
+    , payed_noupdates : Capital
+    , payed_noprepays : Capital
     , payed : Capital
     , payed_amortized : Float
     }
@@ -214,10 +215,11 @@ type alias MortgageSim =
 
 simDecoder : JD.Decoder MortgageSim
 simDecoder =
-    JD.map5 MortgageSim
+    JD.map6 MortgageSim
         (JD.field "updates" simUpdatesDecoder)
         (JD.field "history" (JD.list quotaDecoder))
-        (JD.field "topay" capitalDecoder)
+        (JD.field "payed_noupdates" capitalDecoder)
+        (JD.field "payed_noprepays" capitalDecoder)
         (JD.field "payed" capitalDecoder)
         (JD.field "payed_amortized" JD.float)
 
@@ -1225,8 +1227,8 @@ simView m ( rawSpecs, sim ) =
                 , amountView [] currency vat
                 ]
             ]
-        , overview (t "Total to pay: ") sim.topay []
-        , if capitalSumView m sim.topay /= capitalSumView m sim.payed then
+        , overview (t "Total to pay: ") sim.payed_noprepays []
+        , if sim.payed_amortized > 0 then
             overview (t "Total after early payments: ") sim.payed <|
                 [ li []
                     [ text <| t "Payed early: "
@@ -1234,7 +1236,7 @@ simView m ( rawSpecs, sim ) =
                     ]
                 , li []
                     [ text <| t "Saved: "
-                    , amountView [] currency (sim.topay.interest - sim.payed.interest)
+                    , amountView [] currency (sim.payed_noprepays.interest - sim.payed.interest)
                     ]
                 ]
 
diff --git a/src/lib.rs b/src/lib.rs
index 6d95ff4..1637be7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -5,7 +5,7 @@ use std::ops::AddAssign;
 use serde::Deserialize;
 use serde::Serialize;
 
-#[derive(Clone, Copy, Serialize)]
+#[derive(Clone, Copy, Serialize, Default)]
 pub struct Capital {
     principal: f64,
     interest: f64,
@@ -30,7 +30,8 @@ pub struct Simulation {
     st: SimState,
     updates: SimUpdates,
     history: Vec<Quota>,
-    topay: Capital,
+    payed_noupdates: Capital,
+    payed_noprepays: Capital,
     payed: Capital,
     payed_amortized: f64,
 }
@@ -53,14 +54,12 @@ impl Simulation {
 
         Simulation {
             st,
-            topay: Capital {
+            payed_noupdates: Capital {
                 principal,
                 interest: topay_total - principal,
             },
-            payed: Capital {
-                principal: 0.,
-                interest: 0.,
-            },
+            payed_noprepays: Capital::default(),
+            payed: Capital::default(),
             payed_amortized: 0.,
             history: vec![],
             updates: SimUpdates::default(),
@@ -70,25 +69,35 @@ impl Simulation {
     pub fn run(&mut self, updates: SimUpdates) {
         self.updates = updates;
         let mut st = self.st.clone();
+        // Fist simulation: no prepayments
+        while st.pending_quotas > 0 && st.principal > 0. {
+            let quota = st.step();
+            self.payed_noprepays += quota.payed;
+            self.apply_updates(&mut st, false);
+        }
+        // Second simulation, the good one
+        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 st);
+            self.apply_updates(&mut st, true);
         }
     }
 
-    fn apply_updates(&mut self, st: &mut SimState) {
+    fn apply_updates(&mut self, st: &mut SimState, apply_prepays: bool) {
         for update in self.updates.get(st.period) {
             match update {
                 SimUpdate::Amortize(mut principal) => {
-                    if principal > st.principal {
-                        principal = st.principal;
-                    };
-                    st.principal -= principal;
-                    st.calculate_monthly();
-                    self.payed.principal += principal;
-                    self.payed_amortized += principal;
+                    if apply_prepays {
+                        if principal > st.principal {
+                            principal = st.principal;
+                        };
+                        st.principal -= principal;
+                        st.calculate_monthly();
+                        self.payed.principal += principal;
+                        self.payed_amortized += principal;
+                    }
                 }
                 SimUpdate::SetI1(i1) => {
                     st.i12 = i1 / 12.0;
@@ -123,13 +132,13 @@ impl Simulation {
         println!("\n\n# A PRIORI\n");
         println!(
             "== Total a pagar: {:.2} ({:.2} cap + {:.2} int)",
-            self.topay.total(),
-            self.topay.principal,
-            self.topay.interest
+            self.payed_noupdates.total(),
+            self.payed_noupdates.principal,
+            self.payed_noupdates.interest
         );
         println!(
             "== Los intereses suponen un {:.2}% del total",
-            100. * self.topay.interest / self.topay.total()
+            100. * self.payed_noupdates.interest / self.payed_noupdates.total()
         );
 
         println!("\n\n# RESULTADO FINAL\n");