import assert from 'node:assert/strict';
import { access } from 'node:fs/promises';
import { createHash, webcrypto } from 'node:crypto';
import { test } from 'node:test';
import { loadTypescript } from './support/load-typescript.mjs';

const moduleURL = new URL('../src/analytics/Identity.ts', import.meta.url);
assert.equal(await access(moduleURL).then(() => true, () => false), true, 'private browser identity module must exist');
const { getVisitorId, makeDogId, VISITOR_ID_STORAGE_KEY } = await loadTypescript(moduleURL);
const first = '01234567-89ab-4cde-8f01-23456789abcd';
const second = '12345678-9abc-4def-9012-3456789abcde';
const digest = webcrypto.subtle.digest.bind(webcrypto.subtle);
const hash = (visitor, name) => makeDogId(visitor, name, digest);

test('visitor UUID persists across collector reloads without creating another identifier', () => {
  const values = new Map();
  const storage = { getItem: key => values.get(key) ?? null, setItem: (key, value) => values.set(key, value) };
  assert.equal(getVisitorId({ getStorage: () => storage, randomUUID: () => first }), first);
  assert.equal(values.get(VISITOR_ID_STORAGE_KEY), first);
  assert.equal(VISITOR_ID_STORAGE_KEY, 'behind-glass.visitor-id.v1');
  assert.equal(getVisitorId({ getStorage: () => storage, randomUUID: () => { throw Error('must reuse stored ID'); } }), first);
});

test('malformed stored UUID is replaced by a fresh valid random UUID', () => {
  for (const bad of ['', 'not-a-uuid', first + 'x', '00000000-0000-0000-0000-000000000000', first.replace('-4cde-', '-1cde-'), first.replace('-4cde-', '-7cde-')]) {
    let value = bad;
    assert.equal(getVisitorId({ getStorage: () => ({ getItem: () => value, setItem: (_key, next) => { value = next; } }), randomUUID: () => first }), first);
    assert.equal(value, first);
  }
});

test('blocked storage getter, read, write, and absent storage use one UUID per collector', () => {
  for (const getStorage of [
    () => undefined,
    () => { throw Error('blocked getter'); },
    () => ({ getItem() { throw Error('blocked read'); }, setItem() { throw Error('blocked write'); } }),
    () => ({ getItem: () => null, setItem() { throw Error('full'); } }),
  ]) {
    let created = 0;
    const options = { getStorage, randomUUID: () => (++created === 1 ? first : second) };
    assert.equal(getVisitorId(options), first);
    assert.equal(getVisitorId(options), first);
    assert.equal(created, 1);
    assert.equal(getVisitorId({ getStorage, randomUUID: () => second }), second);
  }
});

test('unavailable, throwing, or invalid random UUID creation leaves telemetry inert', () => {
  for (const randomUUID of [undefined, () => { throw Error('unavailable'); }, () => 'invented-fingerprint', () => first.replace('-4cde-', '-1cde-'), () => first.replace('-4cde-', '-7cde-')]) {
    const options = { getStorage: () => undefined, randomUUID };
    assert.equal(getVisitorId(options), undefined);
    assert.equal(getVisitorId(options), undefined);
  }
});

test('stored uppercase UUID is replaced and noncanonical generated UUID stays inert', () => {
  let stored = first.toUpperCase();
  const storage = { getItem: () => stored, setItem: (_key, value) => { stored = value; } };
  assert.equal(getVisitorId({ getStorage: () => storage, randomUUID: () => second }), second);
  assert.equal(stored, second);
  assert.equal(getVisitorId({ getStorage: () => undefined, randomUUID: () => first.toUpperCase() }), undefined);
});

test('empty and whitespace names use the explicit default name hash', async () => {
  assert.equal(await hash(first, ''), await hash(first, '멍멍이'));
  assert.equal(await hash(first, ' \n\t '), await hash(first, '멍멍이'));
});

test('hash uses NFC, trim and 20 code points without friendly display suffixes', async () => {
  assert.equal(await hash(first, '  호롱  '), await hash(first, '호롱'));
  assert.equal(await hash(first, '🐕'.repeat(21)), await hash(first, '🐕'.repeat(20)));
  assert.notEqual(await hash(first, '호롱'), await hash(first, '호롱이'));
});

test('WebCrypto hashes the exact versioned UTF-8 JSON tuple to lowercase SHA-256', async () => {
  const expected = createHash('sha256').update(JSON.stringify([1, first, '호롱']), 'utf8').digest('hex');
  assert.equal(await hash(first, '호롱'), expected);
  assert.match(expected, /^[0-9a-f]{64}$/);
  assert.notEqual(await hash('a|b', 'c'), await hash('a', 'b|c'), 'tuple framing cannot collide through a delimiter');
});

test('missing, throwing, rejected or malformed digest disables only the affected hash', async () => {
  for (const unavailable of [undefined, () => { throw Error('unavailable'); }, async () => { throw Error('failed'); }, async () => new ArrayBuffer(0)]) {
    assert.equal(await makeDogId(first, '호롱', unavailable), '');
  }
  assert.match(await hash(first, '호롱'), /^[0-9a-f]{64}$/);
});