const estreePlugin = require('prettier/plugins/estree');

function hasSpecifierComments(node) {
  return node.specifiers?.some((specifier) => specifier.comments?.length > 0) ?? false;
}

function flattenImportLines(doc) {
  if (typeof doc === 'string') {
    return doc;
  }

  if (Array.isArray(doc)) {
    return doc.map(flattenImportLines);
  }

  if (!doc || typeof doc !== 'object') {
    return doc;
  }

  if (doc.type === 'line') {
    return ' ';
  }

  if ('contents' in doc) {
    return {
      ...doc,
      contents: flattenImportLines(doc.contents)
    };
  }

  if (doc.type === 'fill' && 'parts' in doc) {
    return {
      ...doc,
      parts: flattenImportLines(doc.parts)
    };
  }

  if (doc.type === 'if-break') {
    return {
      ...doc,
      breakContents: flattenImportLines(doc.breakContents),
      flatContents: flattenImportLines(doc.flatContents)
    };
  }

  if (doc.type === 'group' && 'expandedStates' in doc) {
    return {
      ...doc,
      expandedStates: flattenImportLines(doc.expandedStates)
    };
  }

  return doc;
}

const estreePrinter = estreePlugin.printers.estree;

module.exports = {
  printers: {
    estree: {
      ...estreePrinter,
      print(path, options, print, args) {
        const printed = estreePrinter.print(path, options, print, args);
        const node = path.getNode();

        if (node?.type === 'ImportDeclaration' && !hasSpecifierComments(node)) {
          return flattenImportLines(printed);
        }

        return printed;
      }
    }
  }
};