/**
 * 契约漂移检查（任务 A1.7）。
 *
 * 三件事：
 *   1. 事件与 HTTP 样例必须符合 contracts/schemas 下的 JSON Schema
 *   2. 事件类型在 schema、TS 镜像、协议文档三处必须完全一致
 *   3. 每种事件类型都要有样例，避免新增类型忘了配样例
 */
import assert from 'node:assert/strict';
import { readFile, readdir } from 'node:fs/promises';
import { join } from 'node:path';
import { test } from 'node:test';
import { fileURLToPath } from 'node:url';

import Ajv2020 from 'ajv/dist/2020.js';

const ROOT = fileURLToPath(new URL('..', import.meta.url));
const SCHEMA_DIR = join(ROOT, 'contracts', 'schemas');
const EVENTS_SCHEMA_ID = 'https://aps.local/contracts/events.schema.json';

const readText = (rel) => readFile(join(ROOT, rel), 'utf8');

async function buildAjv() {
  const ajv = new Ajv2020({ allErrors: true, strict: false });
  for (const name of await readdir(SCHEMA_DIR)) {
    if (!name.endsWith('.json')) continue;
    ajv.addSchema(JSON.parse(await readFile(join(SCHEMA_DIR, name), 'utf8')));
  }
  return ajv;
}

const formatErrors = (errors) => (errors ?? []).map((e) => `${e.instancePath || '/'} ${e.message}`).join('; ');

test('事件样例符合 events.schema.json', async () => {
  const ajv = await buildAjv();
  const validate = ajv.getSchema(EVENTS_SCHEMA_ID);
  assert.ok(validate, '未注册 events.schema.json');
  const lines = (await readText('contracts/fixtures/events.jsonl')).split(/\r?\n/).filter((l) => l.trim());
  assert.ok(lines.length >= 11, `样例太少：${lines.length}`);
  for (const line of lines) {
    const event = JSON.parse(line);
    assert.ok(validate(event), `${event.type} 样例不符合 schema：${formatErrors(validate.errors)}`);
  }
});

test('HTTP 样例符合各自 schema', async () => {
  const ajv = await buildAjv();
  const cases = JSON.parse(await readText('contracts/fixtures/http.json'));
  for (const [name, testCase] of Object.entries(cases)) {
    const schemaId = `https://aps.local/contracts/${testCase.schema}`;
    const validate = ajv.getSchema(schemaId);
    assert.ok(validate, `${name}：未注册 ${testCase.schema}`);
    assert.ok(validate(testCase.value), `${name} 样例不符合 ${testCase.schema}：${formatErrors(validate.errors)}`);
  }
});

test('事件类型在 schema、TS 与协议文档三处一致', async () => {
  const schemaTypes = new Set(
    [...(await readText('contracts/schemas/events.schema.json')).matchAll(/"const":\s*"([a-z][a-z0-9]*(?:\.[a-z][a-z0-9-]*)*)"/g)].map((m) => m[1]),
  );
  const tsTypes = new Set([...(await readText('contracts/events.ts')).matchAll(/EventEnvelope<'([^']+)'/g)].map((m) => m[1]));
  const docTypes = new Set([...(await readText('docs/spec/protocol.md')).matchAll(/^\| `([a-z][a-z0-9]*(?:\.[a-z][a-z0-9-]*)*)` \|/gm)].map((m) => m[1]));

  assert.ok(schemaTypes.size >= 11, `schema 里事件类型太少：${schemaTypes.size}`);
  const diff = (a, b, label) => [...a].filter((t) => !b.has(t)).map((t) => `${label}:${t}`);
  const problems = [
    ...diff(schemaTypes, tsTypes, '只在 schema'),
    ...diff(tsTypes, schemaTypes, '只在 TS'),
    ...diff(schemaTypes, docTypes, '只在 schema（文档缺）'),
    ...diff(docTypes, schemaTypes, '只在文档'),
  ];
  assert.deepEqual(problems, [], `事件类型不一致：\n${problems.join('\n')}`);
});

test('每种事件类型都有样例', async () => {
  const fixtureTypes = new Set(
    (await readText('contracts/fixtures/events.jsonl'))
      .split(/\r?\n/)
      .filter((l) => l.trim())
      .map((l) => JSON.parse(l).type),
  );
  const schemaTypes = new Set(
    [...(await readText('contracts/schemas/events.schema.json')).matchAll(/"const":\s*"([a-z][a-z0-9]*(?:\.[a-z][a-z0-9-]*)*)"/g)].map((m) => m[1]),
  );
  const missing = [...schemaTypes].filter((t) => !fixtureTypes.has(t));
  assert.deepEqual(missing, [], `以下事件类型缺样例：${missing.join('、')}`);
});