import { readdir, readFile, stat } from 'node:fs/promises';
import path from 'node:path';
import process from 'node:process';
import ts from 'typescript';

const TYPESCRIPT_EXTENSIONS = new Set(['.ts', '.tsx', '.mts', '.cts']);
const INTERNAL_MESSAGE_MARKERS = ['MessageEnvelope', 'message-contracts'];

async function collectTypeScriptFiles(directory) {
  const entries = await readdir(directory, { withFileTypes: true });
  const nestedFiles = await Promise.all(
    entries.map(async (entry) => {
      const entryPath = path.join(directory, entry.name);
      if (entry.isDirectory()) return collectTypeScriptFiles(entryPath);
      return TYPESCRIPT_EXTENSIONS.has(path.extname(entry.name)) ? [entryPath] : [];
    }),
  );
  return nestedFiles.flat();
}

function collectModuleSpecifiers(sourceFile) {
  const specifiers = [];

  function visit(node) {
    if (
      (ts.isImportDeclaration(node) || ts.isExportDeclaration(node)) &&
      node.moduleSpecifier &&
      ts.isStringLiteralLike(node.moduleSpecifier)
    ) {
      specifiers.push(node.moduleSpecifier.text);
    }
    if (
      ts.isCallExpression(node) &&
      node.expression.kind === ts.SyntaxKind.ImportKeyword &&
      node.arguments.length === 1 &&
      ts.isStringLiteralLike(node.arguments[0])
    ) {
      specifiers.push(node.arguments[0].text);
    }
    ts.forEachChild(node, visit);
  }

  visit(sourceFile);
  return specifiers;
}

function resolvesInsideServer(specifier, sourcePath, repositoryRoot, compilerOptions) {
  const serverRoot = path.join(repositoryRoot, 'server');
  const resolved = ts.resolveModuleName(specifier, sourcePath, compilerOptions, ts.sys)
    .resolvedModule?.resolvedFileName;

  // 模块解析在 fixture 没有目标文件时可能失败，此时仍需按导入者目录规范化相对路径，
  // 避免通过尚未生成的 Server 文件绕过工程边界。
  const candidate =
    resolved ??
    (specifier.startsWith('.') ? path.resolve(path.dirname(sourcePath), specifier) : '');
  return candidate === serverRoot || candidate.startsWith(`${serverRoot}${path.sep}`);
}

export async function verifyProjectBoundaries(repositoryRoot) {
  const webSourceRoot = path.join(repositoryRoot, 'web', 'src');
  const configPath = path.join(repositoryRoot, 'web', 'tsconfig.json');
  const configFile = ts.readConfigFile(configPath, ts.sys.readFile);
  const compilerOptions = configFile.error
    ? { module: ts.ModuleKind.ESNext, moduleResolution: ts.ModuleResolutionKind.Bundler }
    : ts.parseJsonConfigFileContent(configFile.config, ts.sys, path.dirname(configPath)).options;
  const files = await collectTypeScriptFiles(webSourceRoot);
  const violations = [];

  for (const sourcePath of files) {
    const sourceText = await readFile(sourcePath, 'utf8');
    const sourceFile = ts.createSourceFile(
      sourcePath,
      sourceText,
      ts.ScriptTarget.Latest,
      true,
      ts.ScriptKind.TS,
    );
    for (const specifier of collectModuleSpecifiers(sourceFile)) {
      if (resolvesInsideServer(specifier, sourcePath, repositoryRoot, compilerOptions)) {
        violations.push(
          `Web 禁止依赖 Server：${path.relative(repositoryRoot, sourcePath)} -> ${specifier}`,
        );
      }
    }
  }

  const generatedSchemaPath = path.join(webSourceRoot, 'api', 'generated', 'schema.ts');
  try {
    const generatedSchema = await readFile(generatedSchemaPath, 'utf8');
    for (const marker of INTERNAL_MESSAGE_MARKERS) {
      if (generatedSchema.includes(marker)) {
        violations.push(`生成契约包含 Server 内部消息：${marker}`);
      }
    }
  } catch (error) {
    if (error.code !== 'ENOENT') throw error;
  }

  if (violations.length > 0) {
    throw new Error(violations.join('\n'));
  }
}

function parseRepositoryRoot(argv) {
  const rootIndex = argv.indexOf('--root');
  if (rootIndex >= 0 && argv[rootIndex + 1]) return path.resolve(argv[rootIndex + 1]);
  return process.cwd();
}

if (
  process.argv[1] &&
  path.resolve(process.argv[1]) === path.resolve(new URL(import.meta.url).pathname)
) {
  const repositoryRoot = parseRepositoryRoot(process.argv.slice(2));
  try {
    const rootStats = await stat(repositoryRoot);
    if (!rootStats.isDirectory()) throw new Error('仓库根路径不是目录');
    await verifyProjectBoundaries(repositoryRoot);
    process.stdout.write('项目边界验证通过\n');
  } catch (error) {
    process.stderr.write(`${error.message}\n`);
    process.exitCode = 1;
  }
}