initial commit

backend/src/filter.ts

@@ -0,0 +1,49 @@
+export type MatchMode = 'any' | 'all';
+
+export function parseIdList(value: unknown): number[] {
+  if (typeof value !== 'string' || value.trim() === '') {
+    return [];
+  }
+
+  return value
+    .split(',')
+    .map((item) => Number(item.trim()))
+    .filter((item) => Number.isInteger(item) && item > 0);
+}
+
+export function parseMatchMode(value: unknown): MatchMode {
+  return value === 'all' ? 'all' : 'any';
+}
+
+export function sqlForRelationFilter(
+  ids: number[],
+  mode: MatchMode,
+  relationTable: string,
+  ownerColumn: string,
+  targetColumn: string,
+  ownerExpression: string,
+  params: unknown[]
+): string {
+  if (ids.length === 0) {
+    return '';
+  }
+
+  params.push(ids);
+  const paramIndex = params.length;
+
+  if (mode === 'all') {
+    return `(
+      SELECT count(DISTINCT ${targetColumn})
+      FROM ${relationTable}
+      WHERE ${ownerColumn} = ${ownerExpression}
+        AND ${targetColumn} = ANY($${paramIndex}::int[])
+    ) = ${ids.length}`;
+  }
+
+  return `EXISTS (
+    SELECT 1
+    FROM ${relationTable}
+    WHERE ${ownerColumn} = ${ownerExpression}
+      AND ${targetColumn} = ANY($${paramIndex}::int[])
+  )`;
+}