import { afterEach, test } from 'node:test';
import assert from 'node:assert/strict';
import { existsSync, readFileSync } from 'node:fs';
import { mkdtemp, mkdir, rm, writeFile } from 'node:fs/promises';
import { tmpdir } from 'node:os';
import { dirname, join, resolve } from 'node:path';
import { fileURLToPath } from 'node:url';
import ts from 'typescript';
import { scanImportBoundaries } from '../../scripts/lib/import-boundaries.mjs';

const roots = [];

afterEach(async () => {
  await Promise.all(roots.splice(0).map((root) => rm(root, { recursive: true, force: true })));
});

async function createFixtureRoot() {
  const root = await mkdtemp(join(tmpdir(), 'youle-import-boundaries-'));
  roots.push(root);
  return root;
}

async function writeFixture(root, relativePath, source) {
  const file = join(root, relativePath);
  await mkdir(dirname(file), { recursive: true });
  await writeFile(file, source, 'utf8');
}

function scan(root) {
  return scanImportBoundaries({
    frameworkDir: join(root, 'framework'),
    gamesDir: join(root, 'games'),
  });
}

const frameworkRoot = fileURLToPath(new URL('../../YouleNexus/assets/framework/', import.meta.url));
const modernRuntimeEntries = [
  'net/wire-client.ts',
  'platform/runtime-session.ts',
  'protocol/platform-handlers.ts',
  'protocol/router.ts',
  // Task 10 creates this entry; the same assertion starts covering it as soon as it exists.
  'platform/runtime.ts',
];
const legacyRuntimeFiles = new Set([
  'net/net-client.ts',
  'platform/session.ts',
  'platform/startup.ts',
  'platform/room-rpc-bus.ts',
  'platform/readonly.ts',
  'platform/stores/app-store.ts',
  'platform/stores/player-store.ts',
  'platform/stores/room-store.ts',
  'platform/stores/types.ts',
  'protocol/room-handlers.ts',
].map((file) => resolve(frameworkRoot, file)));

function relativeImports(file) {
  const source = readFileSync(file, 'utf8');
  const sourceFile = ts.createSourceFile(file, source, ts.ScriptTarget.Latest, false, ts.ScriptKind.TS);
  const imports = [];
  const visit = (node) => {
    let specifier;
    if ((ts.isImportDeclaration(node) || ts.isExportDeclaration(node))
      && node.moduleSpecifier && ts.isStringLiteral(node.moduleSpecifier)) {
      specifier = node.moduleSpecifier.text;
    } else if (ts.isImportTypeNode(node)
      && ts.isLiteralTypeNode(node.argument)
      && ts.isStringLiteral(node.argument.literal)) {
      specifier = node.argument.literal.text;
    } else if (ts.isCallExpression(node)
      && node.expression.kind === ts.SyntaxKind.ImportKeyword
      && node.arguments.length === 1 && ts.isStringLiteral(node.arguments[0])) {
      specifier = node.arguments[0].text;
    }
    if (specifier?.startsWith('.')) {
      const imported = resolve(dirname(file), specifier);
      const candidates = [imported, `${imported}.ts`, join(imported, 'index.ts')];
      const resolvedImport = candidates.find((candidate) => existsSync(candidate));
      if (resolvedImport) imports.push(resolvedImport);
    }
    ts.forEachChild(node, visit);
  };
  ts.forEachChild(sourceFile, visit);
  return imports;
}

function findLegacyDependency(entry, path = [], visited = new Set()) {
  if (legacyRuntimeFiles.has(entry)) return [...path, entry];
  if (visited.has(entry)) return null;
  visited.add(entry);
  for (const imported of relativeImports(entry)) {
    const found = findLegacyDependency(imported, [...path, entry], visited);
    if (found) return found;
  }
  return null;
}

test('every existing modern runtime entry is transitively isolated from the legacy compatibility island', () => {
  const entries = modernRuntimeEntries
    .map((file) => resolve(frameworkRoot, file))
    .filter((file) => existsSync(file));
  assert.ok(entries.some((file) => file.endsWith(`${join('protocol', 'router.ts')}`)));

  for (const entry of entries) {
    const dependencyPath = findLegacyDependency(entry);
    assert.equal(
      dependencyPath,
      null,
      dependencyPath?.map((file) => file.slice(frameworkRoot.length)).join(' -> '),
    );
  }
});

test('scanner rejects sdk contracts importing a framework platform path', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'framework/sdk/contracts/bad.ts', "import '../platform/session.ts'\n");
  assert.match(scan(root)[0].message, /sdk.*platform/);
});

test('scanner rejects game imports of framework net internals', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'games/a/assets/game/bad.ts', "import '../../../framework/net/net-client.ts'\n");
  assert.match(scan(root)[0].message, /game.*framework\/net/);
});

test('scanner rejects multiline game imports of framework net internals', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'games/a/assets/game/bad.ts', "import {\n  NetClient,\n} from '../../../../framework/net/net-client.ts'\n");
  const violations = scan(root);
  assert.equal(violations.length, 1);
  assert.match(violations[0].message, /game.*framework\/net/);
});

test('scanner rejects multiline sdk contract imports outside their sibling directory', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'framework/sdk/contracts/bad.ts', "import {\n  PlatformSession,\n} from '../../platform/session.ts'\n");
  const violations = scan(root);
  assert.equal(violations.length, 1);
  assert.match(violations[0].message, /sdk\/contracts.*sibling contracts/);
});

test('scanner permits a game import of the public sdk barrel', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'games/a/assets/game/allowed.ts', "import '../../../../framework/sdk/index.ts'\n");
  assert.deepEqual(scan(root), []);
});

test('scanner rejects games importing migration-only sdk declarations', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'games/a/assets/game/bad.ts', "import type { GameContext } from '../../../../framework/sdk/index.ts'\n");
  assert.match(scan(root)[0].message, /game.*GameContext.*migration-only/);
});

test('scanner rejects cc imports in sdk contracts', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'framework/sdk/contracts/bad.ts', "import { Node } from 'cc'\n");
  assert.match(scan(root)[0].message, /sdk\/contracts.*cc/);
});

test('scanner rejects non-relative imports in sdk contracts', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'framework/sdk/contracts/bad.ts', "import 'node:fs'\n");
  const violations = scan(root);
  assert.equal(violations.length, 1);
  assert.match(violations[0].message, /sdk\/contracts.*non-relative/);
});

test('scanner rejects import-type leaks from sdk contracts', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'framework/sdk/contracts/bad.ts', "type ReadonlyRoom = import('../../platform/readonly.ts').ReadonlyRoomStore\n");
  const violations = scan(root);
  assert.equal(violations.length, 1);
  assert.match(violations[0].message, /sdk\/contracts.*sibling contracts/);
});

test('scanner rejects export-star leaks from sdk contracts', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'framework/sdk/contracts/index.ts', "export * from '../../platform/readonly.ts'\n");
  const violations = scan(root);
  assert.equal(violations.length, 1);
  assert.match(violations[0].message, /sdk\/contracts.*sibling contracts/);
});

test('scanner rejects named re-export leaks from sdk contracts', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'framework/sdk/contracts/index.ts', "export { ReadonlyRoomStore } from '../../platform/readonly.ts'\n");
  const violations = scan(root);
  assert.equal(violations.length, 1);
  assert.match(violations[0].message, /sdk\/contracts.*sibling contracts/);
});

test('scanner permits cc imports in game code', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'games/a/assets/game/allowed.ts', "import { Node } from 'cc'\n");
  assert.deepEqual(scan(root), []);
});

test('scanner rejects framework imports resolving under games', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'framework/ui/bad.ts', "import '../../games/a/assets/game/entry.ts'\n");
  assert.match(scan(root)[0].message, /framework.*games/);
});

test('scanner rejects framework production imports of migration-only sdk declarations', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'framework/application/bad.ts', "import type { GameContext } from '../sdk/index.ts'\n");
  const violations = scan(root);
  assert.equal(violations.length, 1);
  assert.match(violations[0].message, /GameContext.*migration-only/);
});

test('scanner rejects alias imports of migration-only sdk declarations', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'framework/application/bad.ts', "import type { IGameModule } from '@internal/sdk'\n");
  const violations = scan(root);
  assert.equal(violations.length, 1);
  assert.match(violations[0].message, /IGameModule.*migration-only/);
});

test('scanner rejects new production imports of a quarantined legacy runtime', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'framework/application/bad.ts', "import '../net/net-client.ts'\n");
  const violations = scan(root);
  assert.equal(violations.length, 1);
  assert.match(violations[0].message, /new production code.*legacy runtime/);
});

test('scanner rejects string-literal dynamic imports that cross a boundary', async () => {
  const root = await createFixtureRoot();
  await writeFixture(root, 'games/a/assets/game/bad.ts', "await import('../../../framework/net/net-client.ts')\n");
  assert.match(scan(root)[0].message, /game.*framework\/net/);
});