import { parse } from "@retorquere/bibtex-parser";
import fs from "fs";
import path from "path";

const bibliographyPath = path.join(process.cwd(), "content", "_bibliography.bib");

export interface Publication {
  key: string;
  title: string;
  authors: string[];
  journal: string;
  year: string;
  bibtex: string;
  pdfUrl: string;
  url?: string;
  pdfAvailable?: boolean;
}

export function getPublicationsData(): Publication[] {
  const bibtexString = fs.readFileSync(bibliographyPath, "utf8");
  const bibtexJson = parse(bibtexString);

  return bibtexJson.entries.map((entry) => {
    const authorNames = entry.fields.author
      ? entry.fields.author.map(
          (author) => `${author.firstName} ${author.lastName}`
        )
      : [];

    let bibtexEntryString = `@${entry.type}{${entry.key},\n`;
    for (const [key, value] of Object.entries(entry.fields)) {
      if (key === 'author') {
        bibtexEntryString += `  author = {${entry.fields.author
          ? entry.fields.author.map(a => `${a.lastName}, ${a.firstName}`).join(' and ')
          : ''}},
`;
      } else {
        if (Array.isArray(value)) {
          bibtexEntryString += `  ${key} = {${value.join(" ")}},
`;
        }
      }
    }
    bibtexEntryString += `}`

    const journalField = entry.fields.booktitle || entry.fields.journal;
    
    const pdfPath = path.join(process.cwd(), "public", "publications", `${entry.key}.pdf`);
    const pdfExists = fs.existsSync(pdfPath);

    return {
      key: entry.key,
      title: Array.isArray(entry.fields.title) ? entry.fields.title.join(" ") : entry.fields.title,
      authors: authorNames,
      journal: Array.isArray(journalField) ? journalField.join(" ") : journalField,
      year: Array.isArray(entry.fields.year) ? entry.fields.year.join(" ") : entry.fields.year,
      url: Array.isArray(entry.fields.url) ? entry.fields.url.join(" ") : entry.fields.url,
      bibtex: bibtexEntryString,
      pdfUrl: `/publications/${entry.key}.pdf`,
      pdfAvailable: pdfExists,
    };
  });
}