#!/usr/bin/env node
/**
 * ObsiGate — Image viewer tests (roadmap #108-D).
 *
 * Pure helpers (clampImageZoom / isImagePath / buildImageUrl) are evaluated in
 * a VM sandbox to avoid importing the full browser-only viewer chain. The rest
 * are static checks on the source and CSS.
 *
 * Usage: node tests/frontend/image-viewer.test.mjs
 */

import { strict as assert } from "node:assert";
import { readFileSync } from "node:fs";
import vm from "node:vm";
import path from "node:path";
import { fileURLToPath } from "node:url";

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const ROOT = path.join(__dirname, "..", "..");

const viewer = readFileSync(path.join(ROOT, "frontend", "js", "viewer.js"), "utf8");
const utils = readFileSync(path.join(ROOT, "frontend", "js", "utils.js"), "utf8");
const css = readFileSync(path.join(ROOT, "frontend", "style.css"), "utf8");
const main = readFileSync(path.join(ROOT, "backend", "main.py"), "utf8");

function test(label, fn) {
  try {
    fn();
    console.log("  \u2713 " + label);
  } catch (err) {
    console.error("  \u2717 " + label + "\n    " + String(err.message).slice(0, 300));
    process.exitCode = 1;
  }
}

// ── Pure helpers (VM sandbox) ──────────────────────────────────────────────
const begin = viewer.indexOf("const IMAGE_EXTS");
const end = viewer.indexOf("function formatBytes");
assert.ok(begin !== -1 && end !== -1, "image viewer helper block not found");
const sandbox = {};
vm.createContext(sandbox);
vm.runInContext(
  `${viewer.slice(begin, end).replace(/\bexport /g, "")}\nglobalThis.clampImageZoom = clampImageZoom; globalThis.isImagePath = isImagePath; globalThis.buildImageUrl = buildImageUrl;`,
  sandbox,
);
const { clampImageZoom, isImagePath, buildImageUrl } = sandbox;

test("clampImageZoom bounds to [0.1, 8]", () => {
  assert.equal(clampImageZoom(0.01), 0.1);
  assert.equal(clampImageZoom(100), 8);
  assert.equal(clampImageZoom(2), 2);
  assert.equal(clampImageZoom(NaN), 1);
});

test("isImagePath recognises image extensions (case-insensitive)", () => {
  for (const p of ["a.png", "a.JPG", "dir/b.jpeg", "x/y/z.svg", "p.webp", "q.bmp", "r.ico", "g.gif"]) {
    assert.equal(isImagePath(p), true, p);
  }
  for (const p of ["a.md", "a.txt", "noext", "a.PDF", ""]) {
    assert.equal(isImagePath(p), false, p);
  }
});

test("buildImageUrl encodes vault and path", () => {
  const url = buildImageUrl("My Vault", "café image.png");
  assert.equal(url, "/api/image/My%20Vault?path=caf%C3%A9%20image.png");
});

// ── Static checks: viewer wiring ───────────────────────────────────────────
test("viewer.js dispatches is_image to renderImageViewer", () => {
  assert.match(viewer, /if \(data\.is_image\) \{\s*renderImageViewer\(area, data\);/);
});

test("renderImageViewer never uses the JSON raw endpoint as an image src", () => {
  const start = viewer.indexOf("export function renderImageViewer");
  const stop = viewer.indexOf("export function renderFile");
  assert.ok(start !== -1 && stop > start, "renderImageViewer block not found");
  const block = viewer.slice(start, stop);
  assert.doesNotMatch(block, /\/raw\?path=/, "images must be served by /api/image, not /raw");
  assert.match(block, /buildImageUrl\(vault, path\)/);
});

test("image viewer supports wheel zoom, drag pan and double-click reset", () => {
  assert.match(viewer, /stage\.addEventListener\("wheel"/);
  assert.match(viewer, /stage\.addEventListener\("pointerdown"/);
  assert.match(viewer, /stage\.addEventListener\("dblclick", resetView\)/);
  assert.match(viewer, /renderImageViewer/);
});

test("image viewer exposes thumbnail navigation via /api/media thumb", () => {
  assert.match(viewer, /\/api\/media\/\$\{encodeURIComponent\(vault\)\}\/thumb\?path=/);
  assert.match(viewer, /let siblings = \[\]/);
  assert.match(viewer, /siblings = \(res\.items \|\| \[\]\)/);
});

// BUG-072 — lightbox + metadata panel must survive ←/→ (and filmstrip) navigation.
test("image viewer persists lightbox + metadata state across navigation", () => {
  assert.match(viewer, /const _imageViewerState = \{ lightbox: false, meta: false \}/);
  assert.match(viewer, /let _imageViewerNavPending = false/);
  // Both navigation paths flag the next render as an image→image navigation.
  assert.match(viewer, /_imageViewerNavPending = true;\s*\n\s*openFile\(vault, siblings\[next\]\.path\)/);
  assert.match(viewer, /_imageViewerNavPending = true;\s*\n\s*openFile\(vault, s\.path\)/);
  // renderFile resets the state only when the next render is not a carried-over image.
  assert.match(viewer, /if \(!data\.is_image \|\| !_imageViewerNavPending\)/);
  // The persisted state drives the container class and the panel visibility.
  assert.match(viewer, /classList\.toggle\("lightbox", _imageViewerState\.lightbox\)/);
  assert.match(viewer, /metaPanel\.hidden = !_imageViewerState\.meta/);
});

// ── Static checks: CSS ─────────────────────────────────────────────────────
test("style.css defines the image viewer layout + lightbox", () => {
  assert.match(css, /\.image-stage\s*\{/);
  assert.match(css, /\.image-nav-strip\s*\{/);
  assert.match(css, /\.image-meta-panel\s*\{/);
  assert.match(css, /\.image-viewer-container\.lightbox\s*\{/);
});

// BUG-072 — metadata is a right-hand sidebar, not a strip under the filmstrip,
// and it stays visible in lightbox mode.
test("style.css lays the metadata panel out as a right sidebar", () => {
  assert.match(css, /\.image-viewer-body\s*\{[\s\S]*?display:\s*flex/);
  const meta = /\.image-meta-panel\s*\{([^}]*)\}/.exec(css);
  assert.ok(meta, ".image-meta-panel rule not found");
  assert.match(meta[1], /border-left:/);
  assert.doesNotMatch(meta[1], /border-top:/);
  // The lightbox hide rule targets the filmstrip only — not the metadata sidebar.
  assert.match(css, /\.image-viewer-container\.lightbox \.image-nav-strip\s*\{/);
  assert.doesNotMatch(css, /\.image-viewer-container\.lightbox[^{]*\.image-meta-panel/);
});

// ── Static checks: icon mapping + backend ──────────────────────────────────
test("utils.js maps image extensions to the Lucide 'image' icon", () => {
  assert.match(utils, /"\.png": "image"/);
  assert.match(utils, /"\.svg": "image"/);
});

test("backend api_file_view points <img> at /api/image", () => {
  assert.match(main, /img_url = f"\/api\/image\//);
  assert.match(main, /f'<img src="\{img_url\}"/);
});

if (process.exitCode) {
  console.error("\nImage viewer tests FAILED");
} else {
  console.log("\nAll image viewer tests passed.");
}