import { test } from 'node:test';
import assert from 'node:assert/strict';
import { createResourceView } from '../../src/lib/canvas-bindings/resource-view.ts';
const deferred = () => { let resolve, reject; const promise = new Promise((yes, no) => { resolve = yes; reject = no; }); return { promise, resolve, reject }; };
const tick = () => new Promise(resolve => setImmediate(resolve));
function fixture() {
  const requests = [], updates = [], errors = [], released = [];
  const view = createResourceView({ resolve(resource, signal) { const gate = deferred(); requests.push({ resource, signal, gate }); return gate.promise; }, onChange(sources, failures) { updates.push({ sources, failures }); }, onError: error => errors.push(error) });
  const finish = (index, url = `blob:${index}`) => { let disposed = false; requests[index].gate.resolve({ url, release() { if (!disposed) { disposed = true; released.push(index); } } }); };
  return { view, requests, updates, errors, released, finish, latest: () => updates.at(-1) };
}
test('ready images display individually; adding a node preserves existing handles and reads', async () => {
  const f = fixture(); f.view.sync([['a', 'r1'], ['b', 'r2']]); await tick(); f.finish(0); await tick();
  assert.deepEqual([...f.latest().sources], [['a', { resourceId: 'r1', url: 'blob:0' }]]);
  f.view.sync([['a', 'r1'], ['b', 'r2'], ['c', 'r3']]); await tick(); assert.deepEqual(f.requests.map(request => request.resource), ['r1', 'r2', 'r3']); assert.deepEqual(f.released, []);
  f.finish(2); await tick(); assert.equal(f.latest().sources.size, 2); f.finish(1); await tick(); assert.equal(f.latest().sources.size, 3); f.view.dispose(); assert.deepEqual(f.released.sort(), [0, 1, 2]);
});
test('a failed reader does not hide other ready images and retry touches only failures', async () => {
  const f = fixture(); f.view.sync([['a', 'r1'], ['b', 'r2']]); await tick(); f.finish(0); f.requests[1].gate.reject(Error('read_failed')); await tick();
  assert.equal(f.latest().sources.get('a').url, 'blob:0'); assert.equal(f.latest().failures, 1); assert.equal(f.errors.length, 1);
  f.view.retry(); await tick(); assert.deepEqual(f.requests.map(request => request.resource), ['r1', 'r2', 'r2']); assert.deepEqual(f.released, []);
  f.finish(2); await tick(); assert.equal(f.latest().failures, 0); assert.equal(f.latest().sources.size, 2); f.view.dispose();
});
test('replacement aborts the old reader and fences a late result that ignored cancellation', async () => {
  const f = fixture(); f.view.sync([['a', 'old']]); await tick(); f.view.sync([['a', 'new']]); await tick(); assert.equal(f.requests[0].signal.aborted, true);
  f.finish(1, 'blob:new'); await tick(); f.finish(0, 'blob:old'); await tick();
  assert.deepEqual(f.latest().sources.get('a'), { resourceId: 'new', url: 'blob:new' }); assert.deepEqual(f.released, [0]); f.view.dispose(); assert.deepEqual(f.released, [0, 1]);
});
test('removing one loaded node retains the other; repeated disposal does not release twice', async () => {
  const f = fixture(); f.view.sync([['a', 'r1'], ['b', 'r2']]); await tick(); f.finish(0); f.finish(1); await tick();
  f.view.sync([['b', 'r2']]); assert.deepEqual(f.released, [0]); assert.equal(f.latest().sources.get('b').url, 'blob:1');
  f.view.dispose(); f.view.dispose(); assert.deepEqual(f.released, [0, 1]); assert.equal(f.latest().sources.size, 0); assert.throws(() => f.view.retry(), { code: 'resource_view_disposed' });
});
test('disposal cleans late handles without publishing into a retired view or reporting cancellation as an error', async () => {
  const f = fixture(); f.view.sync([['a', 'r1']]); await tick(); f.view.dispose(); const count = f.updates.length; f.finish(0); await tick();
  assert.equal(f.updates.length, count); assert.deepEqual(f.released, [0]); assert.deepEqual(f.errors, []);
});
test('invalid target lists reject before changing active subscriptions', async () => {
  const f = fixture(); f.view.sync([['a', 'r1']]); await tick(); f.finish(0); await tick();
  assert.throws(() => f.view.sync([['a', 'r2'], ['a', 'r3']]), { code: 'invalid_resource_view' }); assert.deepEqual(f.released, []);
  f.view.sync([['a', 'r1']]); await tick(); assert.equal(f.requests.length, 1); assert.equal(f.latest().sources.get('a').resourceId, 'r1'); f.view.dispose();
});