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

const VAULT_ROOT = resolve(__dirname, '..', '..');
const JOUR_FIXE_DIR = resolve(VAULT_ROOT, '03 Bereiche/Jour Fixe');

function getJourFixeFolders() {
  if (!existsSync(JOUR_FIXE_DIR)) return [];
  return readdirSync(JOUR_FIXE_DIR, { withFileTypes: true })
    .filter(d => d.isDirectory())
    .map(d => d.name);
}

function detectSeries(eventTitle, jourFixeFolders) {
  const titleLower = eventTitle.toLowerCase();

  const exact = jourFixeFolders.find(f => f.toLowerCase() === titleLower);
  if (exact) return exact;

  const contained = jourFixeFolders.find(f => titleLower.includes(f.toLowerCase()));
  if (contained) return contained;

  return '';
}

function loadJourFixeAgenda(serie) {
  const agendaPath = resolve(JOUR_FIXE_DIR, serie, 'Agenda.md');
  if (!existsSync(agendaPath)) return '';

  const content = readFileSync(agendaPath, 'utf-8');

  const openMatch = content.match(/## 🔴 Offen\n([\s\S]*?)(?=\n## |$)/);
  if (!openMatch) return '';

  const items = openMatch[1].trim();
  return items || '';
}

function buildFileName(date, title) {
  const sanitized = title
    .replace(/:/g, ' -')
    .replace(/[\/\\]/g, '-')
    .replace(/[<>"|?*]/g, '')
    .trim();
  return `${date} ${sanitized}.md`;
}

function buildMeetingNote(data) {
  const teilnehmerYaml = data.teilnehmer
    .map(t => `  - "${t.wikilink}"`)
    .join('\n');

  const teilnehmerList = data.teilnehmer
    .map(t => `- ${t.wikilink}${t.isNew ? ' *(neu angelegt)*' : ''}`)
    .join('\n');

  const agenda = data.agenda || '';

  return `---
tags: [meeting]
date: ${data.date}
start: "${data.start}"
end: "${data.end}"
serie: "${data.serie}"
projekt:
teilnehmer:
${teilnehmerYaml}
status: offen
o365_id: "${data.o365_id}"
---

# ${data.title}

## Teilnehmer
${teilnehmerList}

## Agenda
${agenda}

## Notizen


## Entscheidungen


## Aufgaben

`;
}

function buildMeetingFromEvent(meeting, resolvedAttendees) {
  const jourFixeFolders = getJourFixeFolders();
  const serie = meeting.isRecurring ? detectSeries(meeting.title, jourFixeFolders) : '';

  let agenda = '';
  if (serie) {
    agenda = loadJourFixeAgenda(serie);
  }
  if (!agenda && meeting.bodyText) {
    agenda = meeting.bodyText;
  }

  return {
    title: meeting.title,
    date: meeting.date,
    start: meeting.start,
    end: meeting.end,
    serie,
    o365_id: meeting.id,
    teilnehmer: resolvedAttendees,
    agenda
  };
}

module.exports = {
  getJourFixeFolders, detectSeries, loadJourFixeAgenda,
  buildFileName, buildMeetingNote, buildMeetingFromEvent
};