v0.2.19 - Arma-style grid format for OPORD Recall

package.json

@@ -1,6 +1,6 @@
 {
   "name": "polaris-task-force",
-  "version": "0.2.18",
+  "version": "0.2.19",
   "description": "Web app for the Arma 3 unit Polaris Task Force. Uses Next.js for client- and server-side rendering, with a Postgres database and some other neat libraries.",
   "license": "MIT",
   "type": "module",

src/lib/opord-recall.ts

@@ -188,7 +188,7 @@ export interface OpordScenario {
   readonly operationName: string;
   /** e.g. "TRIDENT" */
   readonly objective: string;
-  /** Eight-digit grid as digits only, e.g. "03467219". */
+  /** Six-digit grid as digits only, e.g. "034672". */
   readonly grid: string;
   /** Three-digit degrees, e.g. 47. */
   readonly azimuth: number;
@@ -217,9 +217,9 @@ export interface OpordScenario {
   readonly enRouteMin: number;
 }
 
-/** Formats an 8-digit grid as two 4-digit halves, e.g. "0346 7219". */
+/** Formats a 6-digit grid Arma map style: three digits, hyphen, three digits, e.g. "034-672". */
 export function formatOpordGrid(grid: string): string {
-  return grid.length === 8 ? `${grid.slice(0, 4)} ${grid.slice(4)}` : grid;
+  return grid.length === 6 ? `${grid.slice(0, 3)}-${grid.slice(3)}` : grid;
 }
 
 /** Buckets a 1-359 azimuth onto the eight winds; 359 and 1 both resolve to NORTH. */
@@ -231,7 +231,7 @@ export function generateOpordScenario(seed: number): OpordScenario {
   const rng = mulberry32(seed);
   const operationName = `${pick(rng, OPERATION_ADJECTIVES)} ${pick(rng, OPERATION_NOUNS)}`;
   const objective = pick(rng, OBJECTIVE_NAMES);
-  const grid = Array.from({ length: 8 }, () => Math.floor(rng() * 10)).join("");
+  const grid = Array.from({ length: 6 }, () => Math.floor(rng() * 10)).join("");
   const azimuth = pickInt(rng, 1, 359);
   const distanceKm = pickInt(rng, 4, 24);
   const hHourMinutes = pickInt(rng, 0, 23) * 100 + pick(rng, [0, 15, 30, 45]);
@@ -327,22 +327,31 @@ export function buildOpordQuestions(
     CODEWORDS.filter((word) => word !== scenario.codeword && word !== scenario.abortCodeword),
   ).slice(0, 3);
 
+  const gridVariants = [
+    scenario.grid.split("").reverse().join(""),
+    scenario.grid.slice(3) + scenario.grid.slice(0, 3),
+    scenario.grid
+      .split("")
+      .map((digit) => String((Number(digit) + 1) % 10))
+      .join(""),
+    scenario.grid
+      .split("")
+      .map((digit) => String((Number(digit) + 2) % 10))
+      .join(""),
+  ];
+  // A palindrome or half-repeating grid collapses one variant onto the answer;
+  // dedupe first so the question always shows four distinct options.
+  const gridDistractors = gridVariants
+    .filter((value, index) => value !== scenario.grid && gridVariants.indexOf(value) === index)
+    .slice(0, 3);
+
   const gridBuilder = () =>
     // The objective grid is the core skill: always asked first.
     choiceQuestion(
       "grid",
-      "What is the 8-digit grid of the objective?",
+      "What is the 6-digit grid of the objective?",
       formatOpordGrid(scenario.grid),
-      [
-        formatOpordGrid(scenario.grid.split("").reverse().join("")),
-        formatOpordGrid(scenario.grid.slice(4) + scenario.grid.slice(0, 4)),
-        formatOpordGrid(
-          scenario.grid
-            .split("")
-            .map((digit) => String((Number(digit) + 1) % 10))
-            .join(""),
-        ),
-      ],
+      gridDistractors.map((value) => formatOpordGrid(value)),
       rng,
     );