refactor(api): extract rate card match support

packages/api/src/router/rate-card-match-support.ts

@@ -0,0 +1,78 @@
+type MatchKey = "roleId" | "chapter" | "location" | "seniority" | "workType";
+
+type MatchableRateCardLine = Partial<Record<MatchKey, string | null>>;
+type RateCardLineMatchCriteria = Partial<Record<MatchKey, string | undefined>>;
+type RateCardLineMatchWeights = Partial<Record<MatchKey, number>>;
+
+type RateCardLineMatchResult<TLine> = {
+  line: TLine;
+  score: number;
+  mismatch: boolean;
+};
+
+function normalizeRateCardMatchValue(
+  value: string,
+  caseInsensitive: boolean,
+): string {
+  return caseInsensitive ? value.toLowerCase() : value;
+}
+
+function rateCardMatchValuesEqual(input: {
+  lineValue: string;
+  criteriaValue: string;
+  caseInsensitive: boolean;
+}): boolean {
+  return normalizeRateCardMatchValue(input.lineValue, input.caseInsensitive) ===
+    normalizeRateCardMatchValue(input.criteriaValue, input.caseInsensitive);
+}
+
+export function scoreRateCardLineMatch<TLine extends MatchableRateCardLine>(
+  line: TLine,
+  input: {
+    criteria: RateCardLineMatchCriteria;
+    weights: RateCardLineMatchWeights;
+    caseInsensitiveKeys?: readonly MatchKey[];
+  },
+): RateCardLineMatchResult<TLine> {
+  const caseInsensitiveKeys = new Set(input.caseInsensitiveKeys ?? []);
+  let score = 0;
+  let mismatch = false;
+
+  for (const [key, criteriaValue] of Object.entries(input.criteria) as Array<[MatchKey, string | undefined]>) {
+    const lineValue = line[key];
+    if (!criteriaValue || !lineValue) {
+      continue;
+    }
+
+    if (rateCardMatchValuesEqual({
+      lineValue,
+      criteriaValue,
+      caseInsensitive: caseInsensitiveKeys.has(key),
+    })) {
+      score += input.weights[key] ?? 0;
+      continue;
+    }
+
+    mismatch = true;
+  }
+
+  return { line, score, mismatch };
+}
+
+export function pickBestRateCardLineMatch<
+  TLine extends MatchableRateCardLine,
+>(
+  lines: TLine[],
+  input: {
+    criteria: RateCardLineMatchCriteria;
+    weights: RateCardLineMatchWeights;
+    caseInsensitiveKeys?: readonly MatchKey[];
+  },
+): TLine | null {
+  const candidates = lines
+    .map((line) => scoreRateCardLineMatch(line, input))
+    .filter((candidate) => !candidate.mismatch)
+    .sort((left, right) => right.score - left.score);
+
+  return candidates[0]?.line ?? null;
+}