From bcce61c8093d75212e6c5e365e3326781a0953c2 Mon Sep 17 00:00:00 2001
From: Mitchell M <mitchoah@gmail.com>
Date: Thu, 4 Jun 2026 19:21:56 -0500
Subject: [PATCH] add support for quanity

---
 src/main.rs | 93 +++++++++++++++++++++++++++++++++++++----------------
 src/pdf.rs  |  0
 2 files changed, 66 insertions(+), 27 deletions(-)
 create mode 100644 src/pdf.rs

diff --git a/src/main.rs b/src/main.rs
index 0ab5cd4..8ade7fd 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,5 @@
+pub mod pdf;
+
 use clap::{Parser, ValueEnum};
 use colored::*;
 
@@ -45,6 +47,10 @@ struct Args {
     /// Control terminal color output
     #[arg(long, default_value = "auto")]
     color: ColorChoice,
+
+    /// Number of casts to make simultaneously
+    #[arg(short = 'n', long, default_value_t = 1)]
+    quantity: u32,
 }
 
 fn main() {
@@ -57,7 +63,7 @@ fn main() {
         ColorChoice::Auto => {} // Respects standard stream capabilities (default)
     }
 
-    // Determine density and target wet weight
+    // Determine density and target wet weight for a SINGLE cast
     let density = args.density.or_else(|| {
         if (args.concentration - DEFAULT_CONCENTRATION).abs() < f64::EPSILON {
             Some(DEFAULT_DENSITY)
@@ -65,9 +71,11 @@ fn main() {
             None
         }
     });
-    let target_wet_weight = density.map(|d| (args.volume / 1000.0) * d);
 
-    let (plaster_nominal, water_nominal) = match target_wet_weight {
+    let single_wet_weight = density.map(|d| (args.volume / 1000.0) * d);
+    let total_wet_weight = single_wet_weight.map(|w| w * args.quantity as f64);
+
+    let (plaster_total, water_total) = match total_wet_weight {
         Some(wet_weight) => {
             let plaster = wet_weight / (1.0 + (args.concentration / PERCENT));
             let water = plaster * (args.concentration / PERCENT);
@@ -79,37 +87,56 @@ fn main() {
     // Output Header
     println!("--- Plaster Calculation Parameters ---");
     println!(
-        "Volume:        {}ml",
+        "Volume (per cast): {}ml",
         format!("{}", args.volume).color(COLOR_PARAM).bold()
     );
     println!(
-        "Concentration: {}g water per 100g plaster",
+        "Quantity:          {}",
+        format!("{}", args.quantity).color(COLOR_PARAM).bold()
+    );
+    println!(
+        "Concentration:     {}g water per 100g plaster",
         format!("{}", args.concentration).color(COLOR_PARAM).bold()
     );
 
     let density_str = density.map_or("Not provided/calculated".to_string(), |d| {
         format!("{}g/L", format!("{}", d).color(COLOR_PARAM).bold())
     });
-    println!("Density:       {}", density_str);
+    println!("Density:           {}", density_str);
     println!("--------------------------------------");
 
     // Output Mixing Amounts and Target Weights
-    if let (Some(p_nom), Some(w_nom)) = (plaster_nominal, water_nominal) {
-        let p_slack = p_nom * (1.0 + SLACK);
-        let w_slack = w_nom * (1.0 + SLACK);
-        let dry_weight = p_nom * DRY_WEIGHT_MULTIPLIER;
+    if let (Some(p_tot), Some(w_tot)) = (plaster_total, water_total) {
+        let p_slack = p_tot * (1.0 + SLACK);
+        let w_slack = w_tot * (1.0 + SLACK);
+
+        let single_plaster = p_tot / args.quantity as f64;
+        let single_dry_weight = single_plaster * DRY_WEIGHT_MULTIPLIER;
+        let total_dry_weight = single_dry_weight * args.quantity as f64;
+
+        if args.quantity > 1 {
+            println!("Combined Mixing Amounts (for {} casts):", args.quantity);
+            println!("  Nominal Total:");
+        } else {
+            println!("Mixing Amounts:");
+            println!("  Nominal:");
+        }
 
-        println!("Mixing Amounts:");
-        println!(" Nominal:");
         println!(
             "    Plaster:  {}g",
-            format!("{:.1}", p_nom).color(COLOR_PLASTER)
+            format!("{:.1}", p_tot).color(COLOR_PLASTER)
         );
         println!(
             "    Water:    {}g",
-            format!("{:.1}", w_nom).color(COLOR_WATER)
+            format!("{:.1}", w_tot).color(COLOR_WATER)
         );
-        println!(" {:2}% Slack:", SLACK * PERCENT);
+
+        if args.quantity > 1 {
+            println!("  {:2}% Slack Total:", SLACK * PERCENT);
+        } else {
+            println!("  {:2}% Slack:", SLACK * PERCENT);
+        }
+
         println!(
             "    Plaster:  {}g",
             format!("{:.1}", p_slack).color(COLOR_PLASTER).bold()
@@ -120,19 +147,31 @@ fn main() {
         );
 
         println!("\nTarget Weights:");
-        println!(
-            "    Wet Cast: {}g",
-            format!("{:.1}", target_wet_weight.unwrap())
-                .color(COLOR_TARGET)
-                .bold()
-        );
-        println!(
-            "    Dry Cast: {}g",
-            format!("{:.1}", dry_weight).color(COLOR_TARGET).bold()
-        );
+        if args.quantity > 1 {
+            println!("  Individual Cast:");
+        }
+            println!(
+                "    Wet Cast: {}g",
+                format!("{:.1}", single_wet_weight.unwrap()).color(COLOR_TARGET).bold()
+            );
+            println!(
+                "    Dry Cast: {}g",
+                format!("{:.1}", single_dry_weight).color(COLOR_TARGET).bold()
+            );
+        if args.quantity > 1 {
+            println!("  Total Batch:");
+            println!(
+                "    Wet Cast: {}g",
+                format!("{:.1}", total_wet_weight.unwrap()).color(COLOR_TARGET)
+            );
+            println!(
+                "    Dry Cast: {}g",
+                format!("{:.1}", total_dry_weight).color(COLOR_TARGET)
+            );
+        }
     } else {
-        println!("{}", 
-            "Target weights and mixing amounts cannot be calculated. Please specify a density with `-d` for any non-70 concentration.".red()
+        println!("{}",
+                 "Target weights and mixing amounts cannot be calculated. Please specify a density with `-d` for any non-70 concentration.".red()
         );
     }
 }
diff --git a/src/pdf.rs b/src/pdf.rs
new file mode 100644
index 0000000..e69de29