import test from 'node:test';
import assert from 'node:assert/strict';
import vm from 'node:vm';
import { readFileSync } from 'node:fs';
import { spawnSync } from 'node:child_process';
import { patchPdfClient, prelude, workerPrefix } from './install-webview-compat.mjs';

function realm() {
  const ctx = vm.createContext({ assert });
  vm.runInContext('delete Map.prototype.getOrInsert; delete Map.prototype.getOrInsertComputed;', ctx);
  return ctx;
}

test('reproduces missing API, then caches one Promise per key', async () => {
  const ctx = realm();
  assert.throws(() => vm.runInContext('new Map().getOrInsertComputed("x", () => 1)', ctx), /not a function/);
  vm.runInContext(prelude, ctx);
  await vm.runInContext(
    '(async () => { const map = new Map(); let calls = 0; const create = key => { assert.equal(key, "metadata"); calls++; return Promise.resolve(42); }; const a = map.getOrInsertComputed("metadata", create); const b = map.getOrInsertComputed("metadata", create); assert.equal(a, b); assert.equal(await a, 42); assert.equal(calls, 1); })()', ctx);
});

test('preserves falsy values, callback semantics, key identity and exceptions', () => {
  const ctx = realm();
  vm.runInContext(prelude, ctx);
  vm.runInContext(
    'const map = new Map(); for (const v of [undefined, null, false, 0, ""]) { map.set("x", v); assert.equal(map.getOrInsertComputed("x", () => { throw Error("unexpected"); }), v); assert.equal(map.getOrInsert("x", 99), v); }' +
    'assert.throws(() => map.getOrInsertComputed("x", null), /callable/); assert.throws(() => Map.prototype.getOrInsert.call({}, "x", 1));' +
    'const key = {}; assert.equal(map.getOrInsertComputed(key, k => k), key); assert.equal(map.getOrInsertComputed(NaN, () => 3), 3); assert.equal(map.getOrInsertComputed(NaN, () => 4), 3);' +
    'map.getOrInsertComputed(-0, k => { assert.equal(Object.is(k, -0), false); return 0; });' +
    'assert.throws(() => map.getOrInsertComputed("error", () => { throw Error("boom"); }), /boom/); assert.equal(map.has("error"), false);' +
    'assert.equal(map.getOrInsertComputed("reentrant", () => { map.set("reentrant", 1); return 2; }), 2); assert.equal(map.get("reentrant"), 2);' +
    'map.getOrInsertComputed("this", function () { "use strict"; assert.equal(this, undefined); });' +
    'assert.equal(Object.getOwnPropertyDescriptor(Map.prototype, "getOrInsertComputed").enumerable, false);', ctx);
});

test('does not replace existing implementations and is safe to run twice', () => {
  const ctx = realm();
  vm.runInContext(prelude, ctx);
  vm.runInContext('const original = Map.prototype.getOrInsertComputed; const direct = Map.prototype.getOrInsert;', ctx);
  vm.runInContext(prelude, ctx);
  vm.runInContext('assert.equal(Map.prototype.getOrInsertComputed, original); assert.equal(Map.prototype.getOrInsert, direct);', ctx);
});

const nl = String.fromCharCode(10);
const worker = '/* pdfjsVersion = 6.3.289 */' + nl + 'globalThis.result = new Map().getOrInsertComputed("worker", () => 7);';
const fixture = '// this.#methodPromises.getOrInsertComputed(' + nl + workerPrefix + JSON.stringify(worker) + ';';
const patch = source => patchPdfClient(source, '0.2.1-rc.2', '0.2.1-rc.2');

test('patch initializes both page and isolated embedded worker before use', () => {
  const output = patch(fixture);
  const page = realm();
  vm.runInContext(output, page);
  const isolated = realm();
  vm.runInContext(page._dsh_pdf_worker_default, isolated);
  assert.equal(isolated.result, 7);
  assert.ok(output.startsWith(prelude));
});

test('rejects version drift, missing/duplicate worker and repeated patch', () => {
  assert.throws(() => patchPdfClient(fixture, 'other', 'other'), /unsupported/);
  assert.throws(() => patchPdfClient(fixture, '0.2.1-rc.2', 'other'), /unsupported/);
  assert.throws(() => patch(''), /expected/);
  assert.throws(() => patch(fixture + nl + fixture), /exactly one/);
  assert.throws(() => patch(fixture.replace('6.3.289', '0.0.0')), /unexpected/);
  assert.throws(() => patch(patch(fixture)), /already applied/);
});

test('actual installed PDF bundle and embedded worker patch and parse', { skip: !process.env.DSH_PDF_CLIENT }, () => {
  const source = readFileSync(process.env.DSH_PDF_CLIENT, 'utf8');
  const output = patch(source);
  const line = output.split(nl).find(line => line.startsWith(workerPrefix));
  const embedded = vm.runInNewContext(line.slice(workerPrefix.length, -1), {}, { timeout: 1000 });
  assert.ok(embedded.startsWith(prelude));
  for (const code of [output, embedded]) {
    const result = spawnSync(process.execPath, ['--input-type=module', '--check'], { input: code, encoding: 'utf8' });
    assert.equal(result.status, 0, result.stderr);
  }
  // Exercise the exact upstream cache method body with the API removed.
  const body = source.split('#cacheSimpleMethod(name, data = null) {')[1].split(nl)[1].trim();
  const ctx = realm();
  vm.runInContext(prelude, ctx);
  vm.runInContext('class Transport { #methodPromises = new Map(); calls = 0; messageHandler = { sendWithPromise: () => { this.calls++; return Promise.resolve(1); } }; cached(name, data = null) { ' + body + ' } } const t = new Transport(); assert.equal(t.cached("GetMetadata"), t.cached("GetMetadata")); assert.equal(t.calls, 1);', ctx);
});