import ts from 'typescript';

export function parseFunctionInfo(sourceCode: string, functionName: string): { arguments: { name: string, type: string }[], returnType: string } | null {
  const sourceFile = ts.createSourceFile('temp.ts', sourceCode, ts.ScriptTarget.ES2015, true);

  let functionInfo: { arguments: { name: string, type: string }[], returnType: string } | null = null;

  for (const node of sourceFile.statements) {
    if (ts.isFunctionDeclaration(node) && node.name && node.name.text === functionName) {
      const argumentTypes: { name: string, type: string }[] = node.parameters.map(parameter => {
        const name = parameter.name.getText();
        const type = parameter.type ? sourceCode.substring(parameter.type.pos, parameter.type.end) : 'any';
        return { name, type };
      });

      const returnType = node.type ? sourceCode.substring(node.type.pos, node.type.end) : 'any';

      functionInfo = { arguments: argumentTypes, returnType };
      break;
    }
  }

  return functionInfo;
}