import assert from 'node:assert/strict';
import fs from 'node:fs';
import os from 'node:os';
import path from 'node:path';
import test from 'node:test';

import {
  atomicWriteJson,
  createStateStore,
  STATE_SCHEMA_VERSION,
} from '../../dist/server/services/stateStore.js';
import { createServerId } from '../../dist/shared/serverIdentity.js';

const fixture = (t) => {
  const directory = fs.mkdtempSync(path.join(os.tmpdir(), 'harbor-state-store-'));
  t.after(() => fs.rmSync(directory, { recursive: true, force: true }));
  return path.join(directory, 'state.json');
};

test('raw JSON stores stay typed unknown until a migrator validates them', () => {
  const source = fs.readFileSync(
    new URL('../../src/server/services/stateStore.ts', import.meta.url),
    'utf8',
  );
  assert.match(source, /createJsonStore\(options: RawJsonStoreOptions\): JsonStore<unknown>/);
  assert.match(source, /const migrate = options\.migrate \|\| \(\(value: unknown\) => value\)/);
  assert.doesNotMatch(source, /value as T|migrate = \(value\) => value as/);
});

test('data invariant: failure before rename preserves the last successful file', (t) => {
  const filePath = fixture(t);
  atomicWriteJson(filePath, { revision: 1 });

  assert.throws(
    () => atomicWriteJson(filePath, { revision: 2 }, {
      beforeRename: () => { throw new Error('injected failure'); },
    }),
    /injected failure/,
  );
  assert.deepEqual(JSON.parse(fs.readFileSync(filePath, 'utf8')), { revision: 1 });
  assert.equal(
    fs.readdirSync(path.dirname(filePath)).some((name) => name.endsWith('.tmp')),
    false,
  );
});

test('schema v2 state migrates built-in .ru into a normal enabled rule', (t) => {
  const filePath = fixture(t);
  const legacy = {
    schemaVersion: 2,
    revision: 7,
    selectedTag: 'nl',
    servers: [{ tag: 'nl', type: 'vless', server: 'nl.example', server_port: 443 }],
  };
  fs.writeFileSync(filePath, JSON.stringify(legacy));

  const store = createStateStore(filePath, {
    now: () => new Date('2026-07-11T12:00:00.000Z'),
  });
  const migrated = store.read();

  assert.equal(migrated.schemaVersion, STATE_SCHEMA_VERSION);
  assert.deepEqual(migrated.routeRules, [
    { type: 'domain_suffix', value: 'ru', enabled: true },
  ]);
  const primary = migrated.profiles[0];
  assert.equal(primary.label, 'Основной');
  assert.equal(primary.desiredServerId, createServerId(legacy.servers[0]));
  assert.equal(migrated.appliedProfileId, primary.id);
  assert.equal(migrated.appliedServerId, primary.desiredServerId);
  assert.equal(Object.hasOwn(migrated, 'selectedServerId'), false);
  assert.equal(store.migration.fromVersion, 2);
  assert.deepEqual(JSON.parse(fs.readFileSync(store.migration.backupPath, 'utf8')), legacy);
  assert.equal(JSON.parse(fs.readFileSync(filePath, 'utf8')).schemaVersion, STATE_SCHEMA_VERSION);
});

test('ambiguous legacy selectedTag explicitly requires a new choice', (t) => {
  const filePath = fixture(t);
  fs.writeFileSync(filePath, JSON.stringify({
    schemaVersion: 3,
    selectedTag: 'Amsterdam',
    servers: [
      { tag: 'Amsterdam', type: 'vless', server: 'nl-1.example', server_port: 443 },
      { tag: 'Amsterdam', type: 'vless', server: 'nl-2.example', server_port: 443 },
    ],
  }));

  const migrated = createStateStore(filePath).read();

  assert.equal(migrated.profiles[0].desiredServerId, '');
  assert.equal(migrated.appliedServerId, '');
  assert.equal(migrated.profiles[0].servers.length, 2);
});

test('schema v4 migration never combines canonical state with a different cache owner', (t) => {
  const filePath = fixture(t);
  const stateServer = {
    tag: 'State server',
    type: 'vless',
    server: 'state.example',
    server_port: 443,
  };
  const cacheServer = {
    tag: 'Cache server',
    type: 'vless',
    server: 'cache.example',
    server_port: 8443,
  };
  const stateServerId = createServerId(stateServer);
  fs.writeFileSync(filePath, JSON.stringify({
    schemaVersion: 4,
    revision: 9,
    subscriptionUrl: 'https://state.example/subscription-a',
    servers: [stateServer],
    selectedServerId: stateServerId,
    appliedServerId: stateServerId,
    connectionDesired: 'running',
  }));

  const migrated = createStateStore(filePath, {
    legacySubscriptionCache: {
      url: 'https://cache.example/subscription-b',
      config: { outbounds: [cacheServer] },
      servers: [cacheServer],
      userInfo: { total: 123 },
      fetchedAt: '2026-08-11T12:00:00.000Z',
    },
  }).read();

  assert.equal(migrated.profiles.length, 1);
  assert.equal(migrated.profiles[0].subscriptionUrl, 'https://state.example/subscription-a');
  assert.equal(migrated.profiles[0].subscriptionConfig, null);
  assert.deepEqual(migrated.profiles[0].servers.map(({ id }) => id), [stateServerId]);
  assert.equal(migrated.profiles[0].desiredServerId, stateServerId);
  assert.equal(migrated.appliedServerId, stateServerId);
  assert.equal(migrated.appliedServerSnapshot.id, stateServerId);
  assert.equal(JSON.stringify(migrated).includes('cache.example'), false);
});

test('data invariant: corrupt JSON preserves original bytes and returns explicit recovery state', (t) => {
  const filePath = fixture(t);
  fs.writeFileSync(filePath, '{broken');

  const store = createStateStore(filePath, {
    now: () => new Date('2026-07-11T12:00:00.000Z'),
  });
  const recovered = store.read();

  assert.equal(recovered.schemaVersion, STATE_SCHEMA_VERSION);
  assert.equal(recovered.revision, 0);
  assert.equal(store.recovery.kind, 'corrupt-json');
  assert.equal(fs.readFileSync(store.recovery.backupPath, 'utf8'), '{broken');
  assert.equal(JSON.parse(fs.readFileSync(filePath, 'utf8')).schemaVersion, STATE_SCHEMA_VERSION);
});

test('concurrent updates are serialized without lost values', async (t) => {
  const store = createStateStore(fixture(t));
  store.read();

  await Promise.all(Array.from({ length: 50 }, () => Promise.resolve().then(() => (
    store.update((state) => ({ ...state, counter: (state.counter || 0) + 1 }))
  ))));

  assert.equal(store.read().counter, 50);
  assert.throws(() => store.update(async (state) => state), /must be synchronous/);
});