even more drop stuff

site/drop-tables.js

@@ -16,6 +16,8 @@
     },
   };
 
+  const RARE_MODIFIER_VERSIONS = new Set(["v2", "bb"]);
+
   function esc(value) {
     return String(value ?? "")
       .replaceAll("&", "&")
@@ -38,6 +40,88 @@
     box.innerHTML = `<div class="drops-status ${kind ? `drops-status--${kind}` : ""}">${esc(message)}</div>`;
   }
 
+  function currentVersion() {
+    return qs("#drops-version")?.value || "v1";
+  }
+
+  function rareModifierEnabled() {
+    return RARE_MODIFIER_VERSIONS.has(currentVersion());
+  }
+
+  function currentRareModifier() {
+    const select = qs("#drops-rare-modifier");
+    const pct = rareModifierEnabled() ? Number(select?.value || 0) : 0;
+    const label = select?.selectedOptions?.[0]?.textContent || "No modifier";
+    return { pct, label, multiplier: 1 + (pct / 100) };
+  }
+
+  function modifierMultiplierLabel(modifier) {
+    return `x${modifier.multiplier.toFixed(3).replace(/0+$/, "").replace(/\.$/, "")}`;
+  }
+
+  function updateRareModifierControls() {
+    const wrap = qs("#drops-rare-modifier-wrap");
+    const v2Note = qs("#drops-v2-note");
+    const select = qs("#drops-rare-modifier");
+    const enabled = rareModifierEnabled();
+
+    if (wrap) wrap.hidden = !enabled;
+    if (v2Note) v2Note.hidden = currentVersion() !== "v2";
+
+    if (!enabled && select) {
+      select.value = "0";
+    }
+  }
+
+  function formatOddsDenominator(value) {
+    if (!Number.isFinite(value) || value <= 0) return "—";
+
+    if (value >= 1000) {
+      return Math.round(value).toLocaleString();
+    }
+
+    if (value >= 100) {
+      return value.toFixed(1).replace(/\.0$/, "");
+    }
+
+    return value.toFixed(2).replace(/0+$/, "").replace(/\.$/, "");
+  }
+
+  function adjustedRate(rate) {
+    const text = String(rate || "");
+    const match = text.match(/^(\d+)\/(\d+)$/);
+    if (!match) return text || "—";
+
+    const num = Number(match[1]);
+    const den = Number(match[2]);
+    const modifier = currentRareModifier();
+
+    if (!rareModifierEnabled() || modifier.pct <= 0) {
+      return text;
+    }
+
+    const baseProbability = num / den;
+    const adjustedProbability = Math.min(1, baseProbability * modifier.multiplier);
+
+    if (adjustedProbability >= 1) {
+      return "1/1";
+    }
+
+    return `1/${formatOddsDenominator(1 / adjustedProbability)}`;
+  }
+
+  function rateCellHtml(rate) {
+    const base = String(rate || "—");
+    const adjusted = adjustedRate(base);
+    const modifier = currentRareModifier();
+
+    if (!rareModifierEnabled() || modifier.pct <= 0 || adjusted === base) {
+      return esc(base);
+    }
+
+    return esc(adjusted);
+  }
+
   async function fetchJson(path) {
     const res = await fetch(path, { cache: "no-store" });
     if (!res.ok) throw new Error(`${path}: HTTP ${res.status}`);
@@ -149,7 +233,7 @@
           <td data-label="Source">${esc(labelValue(row.source || "—"))}</td>
           <td data-label="Item">${esc(item)}</td>
           <td data-label="Item Code">${esc(itemCode)}</td>
-          <td data-label="Rate">${esc(row.rate || "—")}</td>
+          <td data-label="Rate">${rateCellHtml(row.rate || "—")}</td>
         </tr>
       `;
     }).join("");
@@ -157,12 +241,17 @@
     const truncation = rows.length > shown.length
       ? ` Showing first ${shown.length.toLocaleString()}.`
       : "";
+    const modifier = currentRareModifier();
+    const modifierNote = rareModifierEnabled() && modifier.pct > 0
+      ? `<span>Rate modifier: ${esc(modifier.label)} / ${esc(modifierMultiplierLabel(modifier))}</span>`
+      : "";
 
     box.innerHTML = `
       <div class="drops-summary">
         <div>
           <strong>Peeps ${esc(tableLabel)} drop table</strong>
           <span>${rows.length.toLocaleString()} matching rows.${truncation}</span>
+          ${modifierNote}
         </div>
         <span>${state.rows.length.toLocaleString()} total rows</span>
       </div>
@@ -214,6 +303,7 @@
     if (qs("#drops-search")) qs("#drops-search").value = "";
 
     populateFilters(state.rows);
+    updateRareModifierControls();
 
     if (qs("#drops-rare-mode")) qs("#drops-rare-mode").value = "";
     if (qs("#drops-episode")) qs("#drops-episode").value = "";
@@ -245,6 +335,7 @@
   document.addEventListener("DOMContentLoaded", () => {
     qs("#drops-mode")?.addEventListener("change", updateMode);
     qs("#drops-version")?.addEventListener("change", loadPeeps);
+    qs("#drops-rare-modifier")?.addEventListener("change", renderTable);
 
     qs("#drops-rare-mode")?.addEventListener("change", (event) => {
       state.filters.mode = event.target.value;