const { readFileSync, writeFileSync, readdirSync, existsSync } = require('node:fs');
const { resolve } = require('node:path');

const VAULT_ROOT = resolve(__dirname, '..', '..');
const PERSONS_DIR = resolve(VAULT_ROOT, '00 Kontext/Personen');
const COMPANIES_DIR = resolve(VAULT_ROOT, '00 Kontext/Firmen');

function parseFrontmatter(content) {
  const match = content.match(/^---\n([\s\S]*?)\n---/);
  if (!match) return {};

  const fm = {};
  for (const line of match[1].split('\n')) {
    const colonIdx = line.indexOf(':');
    if (colonIdx === -1) continue;
    const key = line.substring(0, colonIdx).trim();
    let value = line.substring(colonIdx + 1).trim();
    if ((value.startsWith('"') && value.endsWith('"')) ||
        (value.startsWith("'") && value.endsWith("'"))) {
      value = value.slice(1, -1);
    }
    if (value.startsWith('[') || value.startsWith('{')) continue;
    fm[key] = value;
  }
  return fm;
}

function loadPersons() {
  if (!existsSync(PERSONS_DIR)) return [];
  return readdirSync(PERSONS_DIR)
    .filter(f => f.endsWith('.md'))
    .map(file => {
      const content = readFileSync(resolve(PERSONS_DIR, file), 'utf-8');
      return { file, fm: parseFrontmatter(content) };
    });
}

function loadCompanies() {
  if (!existsSync(COMPANIES_DIR)) return [];
  return readdirSync(COMPANIES_DIR)
    .filter(f => f.endsWith('.md'))
    .map(file => {
      const content = readFileSync(resolve(COMPANIES_DIR, file), 'utf-8');
      return { file, fm: parseFrontmatter(content) };
    });
}

function matchAttendeeToPersons(attendee, persons) {
  const emailMatch = persons.find(p =>
    p.fm.email && p.fm.email.toLowerCase() === attendee.email.toLowerCase()
  );
  if (emailMatch) {
    return { matched: true, file: emailMatch.file, matchType: 'email' };
  }

  const nameMatch = persons.find(p => {
    const fullName = `${p.fm.vorname || ''} ${p.fm.nachname || ''}`.trim().toLowerCase();
    return fullName && fullName === attendee.name.toLowerCase();
  });
  if (nameMatch) {
    return { matched: true, file: nameMatch.file, matchType: 'name' };
  }

  return { matched: false };
}

function resolveCompanyFromDomain(email, companies) {
  const domain = email.split('@')[1]?.toLowerCase();
  if (!domain) return '';

  const match = companies.find(c =>
    c.fm.domain && c.fm.domain.toLowerCase() === domain
  );
  if (match) {
    const name = match.file.replace('.md', '');
    return `[[00 Kontext/Firmen/${name}]]`;
  }

  return domain;
}

function splitName(displayName) {
  const parts = displayName.trim().split(/\s+/);
  if (parts.length === 1) {
    return { vorname: parts[0], nachname: '' };
  }
  const nachname = parts.pop();
  return { vorname: parts.join(' '), nachname };
}

function buildNewPersonNote({ name, email, firma }) {
  const { vorname, nachname } = splitName(name);

  return `---
tags: [person]
vorname: ${vorname}
nachname: ${nachname ? nachname : '""'}
email: ${email}
kategorie: Extern
firma: "${firma}"
status: ungeprüft
---

# ${name}

## Zur Person

- **E-Mail:** ${email}
- **Firma:** ${firma}

## Notizen

`;
}

function createPersonNote({ name, email }, companies) {
  const firma = resolveCompanyFromDomain(email, companies);
  const content = buildNewPersonNote({ name, email, firma });
  const { vorname, nachname } = splitName(name);
  const fileName = nachname ? `${vorname} ${nachname}.md` : `${vorname}.md`;
  const filePath = resolve(PERSONS_DIR, fileName);

  if (!existsSync(filePath)) {
    writeFileSync(filePath, content, 'utf-8');
  }

  return fileName;
}

function resolveAttendees(attendees) {
  const persons = loadPersons();
  const companies = loadCompanies();

  return attendees.map(attendee => {
    const match = matchAttendeeToPersons(attendee, persons);

    if (match.matched) {
      const personName = match.file.replace('.md', '');
      return { wikilink: `[[${personName}]]`, name: attendee.name, isNew: false };
    }

    const fileName = createPersonNote(attendee, companies);
    const personName = fileName.replace('.md', '');
    return { wikilink: `[[${personName}]]`, name: attendee.name, isNew: true };
  });
}

module.exports = {
  parseFrontmatter, loadPersons, loadCompanies,
  matchAttendeeToPersons, resolveCompanyFromDomain,
  buildNewPersonNote, createPersonNote, resolveAttendees
};