From bcdb5a58408d366245fbc81128870273866c0461 Mon Sep 17 00:00:00 2001
From: "Brennan Wilkes (Text Groove)" <brennan@textgroove.com>
Date: Mon, 2 Feb 2026 22:19:05 -0800
Subject: [PATCH] feat: Rank DISC

---
 tools/rank_discrepency.js | 150 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 150 insertions(+)
 create mode 100644 tools/rank_discrepency.js

diff --git a/tools/rank_discrepency.js b/tools/rank_discrepency.js
new file mode 100644
index 0000000..f157124
--- /dev/null
+++ b/tools/rank_discrepency.js
@@ -0,0 +1,150 @@
+#!/usr/bin/env node
+"use strict";
+
+/*
+  Compare rank placement between AB and BC "common_listings_*_top*.json" reports.
+
+  Usage:
+    node scripts/rank_discrepency.js \
+      --ab reports/common_listings_ab_top1000.json \
+      --bc reports/common_listings_bc_top1000.json \
+      --top 50
+
+  Notes:
+  - Rank = index in payload.rows (1-based).
+  - Only compares SKUs that exist in BOTH files (unless --include-missing).
+*/
+
+const fs = require("fs");
+const path = require("path");
+
+function readJson(p) {
+  return JSON.parse(fs.readFileSync(p, "utf8"));
+}
+
+function parseArgs(argv) {
+  const out = {
+    ab: "reports/common_listings_ab_top1000.json",
+    bc: "reports/common_listings_bc_top1000.json",
+    top: 50,
+    includeMissing: false,
+    minDiscrep: 1,
+  };
+  for (let i = 0; i < argv.length; i++) {
+    const a = argv[i];
+    if (a === "--ab" && argv[i + 1]) out.ab = argv[++i];
+    else if (a === "--bc" && argv[i + 1]) out.bc = argv[++i];
+    else if (a === "--top" && argv[i + 1]) out.top = Number(argv[++i]) || out.top;
+    else if (a === "--min" && argv[i + 1]) out.minDiscrep = Number(argv[++i]) || out.minDiscrep;
+    else if (a === "--include-missing") out.includeMissing = true;
+  }
+  return out;
+}
+
+function buildRankMap(payload) {
+  const rows = Array.isArray(payload?.rows) ? payload.rows : [];
+  const map = new Map();
+  for (let i = 0; i < rows.length; i++) {
+    const r = rows[i];
+    if (!r || !r.canonSku) continue;
+    map.set(String(r.canonSku), { rank: i + 1, row: r });
+  }
+  return map;
+}
+
+function fmtMoney(n) {
+  return Number.isFinite(n) ? `$${n.toFixed(2)}` : "";
+}
+
+function main() {
+  const args = parseArgs(process.argv.slice(2));
+  const repoRoot = process.cwd();
+
+  const abPath = path.isAbsolute(args.ab) ? args.ab : path.join(repoRoot, args.ab);
+  const bcPath = path.isAbsolute(args.bc) ? args.bc : path.join(repoRoot, args.bc);
+
+  const ab = readJson(abPath);
+  const bc = readJson(bcPath);
+
+  const abMap = buildRankMap(ab);
+  const bcMap = buildRankMap(bc);
+
+  const keys = new Set([...abMap.keys(), ...bcMap.keys()]);
+  const diffs = [];
+
+  for (const canonSku of keys) {
+    const a = abMap.get(canonSku);
+    const b = bcMap.get(canonSku);
+
+    if (!args.includeMissing && (!a || !b)) continue;
+
+    const rankAB = a ? a.rank : null;
+    const rankBC = b ? b.rank : null;
+
+    const discrep =
+      rankAB !== null && rankBC !== null ? Math.abs(rankAB - rankBC) : Infinity;
+
+    if (discrep !== Infinity && discrep < args.minDiscrep) continue;
+
+    const rep = (a?.row?.representative || b?.row?.representative) ?? null;
+    const name = rep?.name || "";
+    const priceNum = rep?.priceNum;
+    const url = rep?.url || "";
+
+    diffs.push({
+      canonSku,
+      discrep,
+      rankAB,
+      rankBC,
+      storeCountAB: a?.row?.storeCount ?? null,
+      storeCountBC: b?.row?.storeCount ?? null,
+      name,
+      price: fmtMoney(priceNum),
+      url,
+    });
+  }
+
+  diffs.sort((x, y) => {
+    if (y.discrep !== x.discrep) return y.discrep - x.discrep;
+    // tie-breaker: best average rank (smaller is "higher")
+    const ax = (x.rankAB ?? 1e9) + (x.rankBC ?? 1e9);
+    const ay = (y.rankAB ?? 1e9) + (y.rankBC ?? 1e9);
+    if (ax !== ay) return ax - ay;
+    return String(x.canonSku).localeCompare(String(y.canonSku));
+  });
+
+  const top = diffs.slice(0, args.top);
+
+  console.log(
+    `AB: ${path.relative(repoRoot, abPath)} (rows=${ab?.rows?.length ?? 0})`
+  );
+  console.log(
+    `BC: ${path.relative(repoRoot, bcPath)} (rows=${bc?.rows?.length ?? 0})`
+  );
+  console.log(
+    `Showing top ${top.length} by |rankAB-rankBC| (min=${args.minDiscrep})\n`
+  );
+
+  for (const d of top) {
+    const ra = d.rankAB === null ? "—" : String(d.rankAB);
+    const rb = d.rankBC === null ? "—" : String(d.rankBC);
+    const sca = d.storeCountAB === null ? "—" : String(d.storeCountAB);
+    const scb = d.storeCountBC === null ? "—" : String(d.storeCountBC);
+
+    console.log(
+      [
+        `Δ=${d.discrep}`,
+        `AB#${ra} (stores=${sca})`,
+        `BC#${rb} (stores=${scb})`,
+        `sku=${d.canonSku}`,
+        d.price ? `rep=${d.price}` : "",
+        d.name ? `name="${d.name.replace(/\s+/g, " ").trim().slice(0, 120)}"` : "",
+      ]
+        .filter(Boolean)
+        .join(" | ")
+    );
+    if (d.url) console.log(`  ${d.url}`);
+  }
+}
+
+main();