import * as ts from "typescript";

export function useProgram(currentDir: string) {
  const configFile = ts.findConfigFile(
    currentDir,
    ts.sys.fileExists,
    "tsconfig.json"
  );
  if (!configFile) throw Error("tsconfig.json not found");
  const { config } = ts.readConfigFile(configFile, ts.sys.readFile);

  config.compilerOptions = Object.assign({}, config.compilerOptions);

  const { options, fileNames, errors } = ts.parseJsonConfigFileContent(
    config,
    ts.sys,
    currentDir
  );

  const program = ts.createProgram({
    options,
    rootNames: fileNames,
    configFileParsingDiagnostics: errors,
  });

  return program;
}

export function searchForSymbol(
  checker: ts.TypeChecker,
  node: ts.Node,
  targetSymbol: ts.Symbol
): ts.Node | undefined {
  const symbol = checker.getSymbolAtLocation(node);
  if (symbol && symbol.escapedName == targetSymbol.escapedName) return node;

  const children = node.getChildren();
  for (const child of children) {
    const recursiveSearch = searchForSymbol(checker, child, targetSymbol);
    if (recursiveSearch) return recursiveSearch;
  }

  return undefined;
}