import { Injectable } from "@nestjs/common";
import { XMLParser } from "fast-xml-parser";
import { MetadataLookup, MetadataMatch, MetadataProvider, MetadataProviderConfig } from "../metadata.types.js";

const parser = new XMLParser({ ignoreAttributes: false, attributeNamePrefix: "@_" });

@Injectable()
export class BnfProvider implements MetadataProvider {
  readonly id = "bnf" as const;

  async lookup(lookup: MetadataLookup, _config: MetadataProviderConfig): Promise<MetadataMatch | null> {
    const query = lookup.identifiers.isbn13
      ? `bib.isbn all "${lookup.identifiers.isbn13}"`
      : `bib.title all "${lookup.title.replace(/"/g, " ")}"`;
    const url = new URL("https://catalogue.bnf.fr/api/SRU");
    url.searchParams.set("version", "1.2");
    url.searchParams.set("operation", "searchRetrieve");
    url.searchParams.set("query", query);
    url.searchParams.set("maximumRecords", "1");

    const response = await fetch(url, { signal: AbortSignal.timeout(5000) });
    if (!response.ok) return null;
    const parsed = parser.parse(await response.text());
    const record = parsed?.searchRetrieveResponse?.records?.record?.recordData;
    if (!record) return null;
    const text = JSON.stringify(record);
    return {
      title: match(text, /"titleInfo"[^}]*"title":"([^"]+)"/),
      author: match(text, /"namePart":"([^"]+)"/),
      publisher: match(text, /"publisher":"([^"]+)"/),
      publishedDate: match(text, /"dateIssued":"([^"]+)"/)
    };
  }
}

function match(value: string, pattern: RegExp): string | undefined {
  return value.match(pattern)?.[1];
}