import { createRequire } from "node:module";
import type { Page } from "@playwright/test";

const requireFromMapLibre = createRequire(import.meta.resolve("maplibre-gl"));
const { fromVectorTileJs } = requireFromMapLibre("@maplibre/vt-pbf") as {
  fromVectorTileJs(tile: unknown): Uint8Array;
};

// Exercise the same MVT worker path as GeoServer, including a dense pipe inventory.
export async function mockPipeVectorTiles(page: Page) {
  const tiles = new Map<string, Buffer>();
  await page.route("**/tjwater_next:pipes/WebMercatorQuad/**", (route) => {
    const path = new URL(route.request().url()).pathname.split("/");
    const [zoom, tileY, tileX] = path.slice(-3).map(Number);
    const key = `${zoom}/${tileY}/${tileX}`;
    let body = tiles.get(key);
    if (!body) {
      const project = (longitude: number, latitude: number) => {
        const sin = Math.sin(latitude * Math.PI / 180);
        return {
          x: Math.round(((longitude + 180) / 360 * 2 ** zoom - tileX) * 4096),
          y: Math.round(((0.5 - Math.log((1 + sin) / (1 - sin)) / (4 * Math.PI)) * 2 ** zoom - tileY) * 4096)
        };
      };
      const features = Array.from({ length: 2001 }, (_, index) => {
        const latitude = index === 0 ? 30.91 : 30.918 + Math.floor((index - 1) / 100) * 0.0004;
        const longitude = index === 0 ? 121.45 : 121.45 + (index - 1) % 100 * 0.0003;
        const geometry = [[project(longitude, latitude),
          project(index === 0 ? 121.48 : longitude + 0.00025, latitude)]];
        const [start, end] = geometry[0];
        if (start.y < -256 || start.y > 4352 || end.x < -256 || start.x > 4352) return [];
        return [{ type: 2, id: index + 1, extent: 4096,
          properties: { id: index + 1, diameter: index === 0 ? 800 : 100,
            status: index % 5 === 4 ? "closed" : "open" },
          loadGeometry: () => geometry }];
      }).flat();
      body = Buffer.from(fromVectorTileJs({ layers: { pipes: {
        version: 2, name: "pipes", extent: 4096, length: features.length,
        feature: (index: number) => features[index]
      } } }));
      tiles.set(key, body);
    }
    return route.fulfill({ body, contentType: "application/vnd.mapbox-vector-tile",
      headers: { "Access-Control-Allow-Origin": "*" } });
  });
}