From 097a8fba3c46ca83104763e897ee8dc035722071 Mon Sep 17 00:00:00 2001
From: Guillermo Ramos
Date: Sun, 26 Jan 2025 19:28:58 +0100
Subject: Basic simulator

---
 src/lib.rs | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 src/lib.rs

(limited to 'src/lib.rs')

diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..a0e1e61
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,68 @@
+use std::fmt;
+
+#[derive(Debug)]
+pub struct MortgageState {
+    period: u32,
+    capital: f64,
+    i12: f64,
+    quota: f64,
+    quotas: u32,
+}
+
+impl fmt::Display for MortgageState {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "{:5} | {:4.2}\t{:.2}\t{:.2}\t{:.2}",
+            self.period,
+            self.quota,
+            self.interests(),
+            self.amortized(),
+            self.capital
+        )
+    }
+}
+
+pub fn quota(capital: f64, i12: f64, quotas: u32) -> f64 {
+    capital * i12 / (1.0 - (1.0 + i12).powi(-(quotas as i32)))
+}
+
+impl MortgageState {
+    fn new(capital: f64, i1: f64, years: u32) -> Self {
+        let quotas = years * 12;
+        let i12 = i1 / 12.0;
+        MortgageState {
+            period: 0,
+            capital,
+            i12,
+            quota: quota(capital, i12, quotas),
+            quotas,
+        }
+    }
+
+    pub fn step(&mut self) {
+        self.period += 1;
+        self.quotas -= 1;
+        self.capital = (1.0 + self.i12) * self.capital - self.quota;
+    }
+
+    pub fn interests(&self) -> f64 {
+        self.i12 * self.capital
+    }
+
+    pub fn amortized(&self) -> f64 {
+        self.quota - self.interests()
+    }
+}
+
+pub fn run_mortgage(capital: f64, i12: f64, years: u32) {
+    let mut state = MortgageState::new(capital, i12, years);
+
+    println!("Total a pagar: {}\n\n", state.quota * state.quotas as f64);
+
+    println!("Cuota | c\tIn\tAn\tCn");
+    while state.quotas > 0 {
+        println!("{state}");
+        state.step();
+    }
+}
-- 
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