import type { JSONSchema4 } from 'json-schema';
import { compile } from 'json-schema-to-typescript';

/**
 * Remove unnecessary comments that are generated by `json-schema-to-typescript`.
 */
function cleanJsDoc(content: string): string {
  const patterns = [
    /\* This interface was referenced by .+ JSON-Schema definition/,
    /\* via the `.+` "/,
  ];

  return content
    .split('\n')
    .filter(line => !patterns.some(ignoredLine => ignoredLine.test(line)))
    .join('\n');
}

/**
 * Replace some types that are generated by `json-schema-to-typescript`.
 */
export function patchTypes(content: string): string {
  const replacements: [RegExp, string][] = [
    [
      /\(string & \{\s*\[k: string\]: any\s*\} & \{\s*\[k: string\]: any\s*\}\)\[\]/,
      'string[]',
    ],
  ];

  for (const [pattern, replacement] of replacements) {
    content = content.replace(pattern, replacement);
  }

  return content;
}

/**
 * Generate a type from the given JSON schema.
 */
export async function generateTypeFromSchema(
  schema: JSONSchema4,
  typeName: string,
): Promise<string> {
  schema = JSON.parse(
    JSON.stringify(schema).replace(/#\/items\/0\/\$defs\//g, '#/$defs/'),
  );
  const result = await compile(schema, typeName, {
    format: false,
    bannerComment: '',
    style: {
      singleQuote: true,
      trailingComma: 'all',
    },
    unknownAny: false,
  });

  return patchTypes(cleanJsDoc(result));
}