add csv module with Row struct and make_checksum fn

Cargo.toml

@@ -4,3 +4,6 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+chrono = "0.4.44"
+rand = "0.10.0"
+ratatui = "0.30.0"

src/csv.rs

@@ -0,0 +1,73 @@
+pub struct Row {
+    name: String,
+    hut_type: String,
+    path: String,
+    tare: f64,
+    mat_id: String,
+    quantity: f64,
+    lot_id: String,
+    uom: String,
+    lot_status: String,
+    born: chrono::DateTime<chrono::Local>,
+    expire: chrono::DateTime<chrono::Local>,
+}
+
+impl Row {
+    pub fn new(
+        name: &str,
+        hut_type: &str,
+        path: &str,
+        tare: f64,
+        mat_id: &str,
+        quantity: f64,
+        uom: &str,
+        lot_status: &str,
+        checksum: bool,
+    ) -> Self {
+        let born = chrono::Local::now();
+        let expire = born
+            .checked_add_days(chrono::Days::new(365))
+            .expect("A valid date time");
+        let name = match checksum {
+            true => make_checksum(),
+            false => name.to_ascii_uppercase(),
+        };
+        Self {
+            name: name.clone(),
+            hut_type: hut_type.to_ascii_uppercase(),
+            path: path.to_ascii_uppercase(),
+            tare,
+            mat_id: mat_id.to_ascii_uppercase(),
+            quantity,
+            lot_id: format!("{}-{}", name, mat_id).to_ascii_uppercase(),
+            uom: uom.to_ascii_uppercase(),
+            lot_status: lot_status.to_ascii_uppercase(),
+            born,
+            expire,
+        }
+    }
+}
+
+fn make_checksum() -> String {
+    let base = rand::random_range(10000..99999).to_string();
+    let expect = "a valid character in the base checksum";
+
+    let split = format!(
+        "{}{}{}{}{}",
+        base.chars().next().expect(expect),
+        base.chars().nth(2).expect(expect),
+        base.chars().nth(4).expect(expect),
+        base.chars().nth(1).expect(expect),
+        base.chars().nth(3).expect(expect)
+    )
+    .repeat(2);
+
+    let sum: u32 = split
+        .chars()
+        .map(|c| c.to_digit(10).expect("a valid integer value"))
+        .sum();
+
+    let last = (10 - (sum % 10)) % 10;
+
+    format!("{}{}", base, last)
+}

src/main.rs

@@ -1,3 +1,5 @@
+mod csv;
+
 fn main() {
     println!("Hello, world!");
 }