// Covers the region-select drag tool (mousedown/mousemove/mouseup handlers wired in map.js's
// startRegionSelect/updateRegionPreview/finishRegionSelect) and the client-side glTF export
// pipeline (export-worker.js) — the second UI surface flagged throughout MCMapper's Phase 5 work
// as verified only via a headless pipeline run against seeded data, never an actual browser
// drag gesture. See README's e2e section.
//
// The seeded dataset (see global-setup.ts) fills a 5x5-chunk solid terrain footprint centered on
// the world origin — where the map's default view is centered — so a drag anywhere near the
// visible center reliably selects real, meshable terrain without computing exact Leaflet
// pixel<->world math.
import { test, expect, type Page } from "@playwright/test";

async function waitForMapReady(page: Page) {
  await page.goto("/");
  await expect(page.getByTestId("region-toggle")).toBeVisible();
  await page.locator("#map.leaflet-container").waitFor();
}

async function dragOnMap(page: Page, fromFrac: number, toFrac: number) {
  const box = await page.locator("#map").boundingBox();
  if (!box) throw new Error("#map has no bounding box");
  const start = { x: box.x + box.width * fromFrac, y: box.y + box.height * fromFrac };
  const end = { x: box.x + box.width * toFrac, y: box.y + box.height * toFrac };
  await page.mouse.move(start.x, start.y);
  await page.mouse.down();
  await page.mouse.move((start.x + end.x) / 2, (start.y + end.y) / 2, { steps: 5 });
  await page.mouse.move(end.x, end.y, { steps: 5 });
  await page.mouse.up();
}

test("dragging on the map selects a region and reports the chunk count", async ({ page }) => {
  await waitForMapReady(page);
  await page.getByTestId("region-toggle").click();

  await dragOnMap(page, 0.4, 0.6);

  await expect(page.getByTestId("region-status")).toHaveText(/^\d+ chunks? selected$/);
  await expect(page.getByTestId("region-export")).toBeVisible();
});

test("exporting a selected region downloads a non-empty .glb file", async ({ page }) => {
  await waitForMapReady(page);
  await page.getByTestId("region-toggle").click();
  await dragOnMap(page, 0.35, 0.65);
  await expect(page.getByTestId("region-status")).toHaveText(/^\d+ chunks? selected$/);

  const [download] = await Promise.all([
    page.waitForEvent("download"),
    page.getByTestId("region-export").click(),
  ]);

  expect(download.suggestedFilename()).toMatch(/\.glb$/);
  const path = await download.path();
  expect(path).not.toBeNull();
  const { statSync } = await import("node:fs");
  const size = statSync(path!).size;
  // A well-formed GLB has at minimum a 12-byte header + JSON chunk header — real seeded terrain
  // should produce something far larger (actual mesh geometry), so this also catches an
  // accidentally-empty export, not just a missing file.
  expect(size).toBeGreaterThan(200);
});

test("an oversized selection is rejected with a clear message instead of exporting", async ({ page }) => {
  await waitForMapReady(page);

  // Zoom out to the map's minimum (minZoom: -4, see map.js's init()) so many more chunks fit in
  // the same viewport, making it easy to drag past the 64-chunk cap without needing to compute
  // exact pixel<->world math. Leaflet's zoom-out control gains `leaflet-disabled` once at
  // minZoom — waiting for that (rather than a fixed click count) avoids racing the zoom
  // animation, which silently drops clicks fired faster than it can keep up.
  const zoomOut = page.locator(".leaflet-control-zoom-out");
  for (let i = 0; i < 8; i++) {
    if (await zoomOut.evaluate((el) => el.classList.contains("leaflet-disabled"))) break;
    await zoomOut.click();
    await page.waitForTimeout(300);
  }

  await page.getByTestId("region-toggle").click();
  // Not 0.02 — that lands the mousedown on Leaflet's own top-left zoom control, which stops
  // event propagation before it reaches the map's mousedown listener (startRegionSelect never
  // fires). Starting past that corner still covers a huge area at minZoom.
  await dragOnMap(page, 0.15, 0.95);

  await expect(page.getByTestId("region-status")).toHaveText(/too large/);
  // x-show hides via CSS rather than removing the node, so assert visibility, not DOM count.
  await expect(page.getByTestId("region-export")).not.toBeVisible();
});