Add trains endpoint handler

src/modules/trains.ts

@@ -0,0 +1,34 @@
+import { ApiTrainsTrainByHeadcode } from '@owlboard/api-schema-types';
+import type { BaseClient, ApiResult } from '../lib/base.js';
+import { IsValidHeadcode, IsValidToc, IsValidDateStr } from '../lib/validation.js';
+import { ensureDateString } from 'src/lib/helpers.js';
+import { ValidationError } from '../lib/errors.js';
+
+export class TrainsModule {
+    constructor(private client: BaseClient) { }
+
+    async getByHeadcode(headcode: string, date: string | Date = new Date, toc: string = ""): Promise<ApiResult<ApiTrainsTrainByHeadcode.TrainByHeadcodeResponse[]>> {
+        if (!IsValidHeadcode(headcode)) {
+            throw new ValidationError("headcode", "Invalid headcode format")
+        }
+        if (toc !== "" && !IsValidToc(toc)) {
+            throw new ValidationError("TOC", "Invalid TOC Format, needs to be two characters");
+        }
+
+        const dateStr = ensureDateString(date);
+        if (!IsValidDateStr(dateStr)) {
+            throw new ValidationError("Date", "Invalid date format, need YYYY-MM-DD");
+        }
+
+        const searchParams = new URLSearchParams();
+        searchParams.append('d', dateStr);
+        searchParams.append('h', headcode);
+        if (toc) searchParams.append('t', toc);
+
+        const path = `/trains?${searchParams.toString()}`;
+
+        return this.client.request<ApiTrainsTrainByHeadcode.TrainByHeadcodeResponse[]>(path, {
+            method: 'GET',
+        });
+    }
+}