/*
 * This script extracts event data from a table on a webpage and generates an iCalendar (.ics) file for download.
 * It looks for a table with specific headers ('event', 'date', 'venue', 'address'), parses the event details,
 * and then creates an iCalendar file with the extracted event information. The file is then automatically
 * downloaded to the user's device.
 */
javascript: (() => {
  function extractEventData() {
    let tables = document.querySelectorAll('table');
    if (tables.length > 1) {
      tables = [tables[0]];
    }
    const data = [];

    tables.forEach(table => {
      const headers = [];
      const rows = table.querySelectorAll('tr');

      const firstRow = rows[0];
      firstRow.querySelectorAll('td').forEach(td => {
        headers.push(td.textContent.trim().toLowerCase());
      });

      if (
        headers.includes('event') &&
        headers.includes('date') &&
        headers.includes('venue') &&
        headers.includes('address')
      ) {
        Array.from(rows)
          .slice(1)
          .forEach(row => {
            const cells = row.querySelectorAll('td');
            const rowData = {};

            cells.forEach((cell, j) => {
              const header = headers[j];
              let cellText = cell.innerHTML
                .replace(/<br\s*\/?>/gi, ', ')
                .trim();
              cellText = cellText.replace(/<\/?[^>]+(>|$)/g, '').trim();

              if (header === 'event') {
                rowData.event = cellText;
              } else if (header === 'date') {
                const month = cellText.split(' ')[0];
                const year = cellText.split(',')[1].trim();
                const startDay = cellText
                  .split(' ')[1]
                  .split(cellText.includes(' – ') ? ' – ' : '–')[0]
                  .trim();
                const endDay = cellText
                  .split(cellText.includes(' – ') ? ' – ' : '–')[1]
                  .split(',')[0]
                  .trim();
                rowData.startDate = `${month} ${startDay}, ${year}`;
                rowData.endDate = `${month} ${endDay}, ${year}`;
              } else if (header === 'venue') {
                rowData.venue = cellText;
              } else if (header === 'location') {
                rowData.address = cellText;
              }
            });

            data.push(rowData);
          });
      }
    });
    console.log(data);
    return data;
  }

  const data = extractEventData();

  function createICal(events) {
    let icalContent =
      'BEGIN:VCALENDAR\nVERSION:2.0\nPRODID:-//FragginWagon//International-Championships\n';

    events.forEach(event => {
      icalContent += 'BEGIN:VEVENT\n';
      icalContent += `DTSTART:${new Date(event.startDate).toISOString().replace(/[-:]/g, '').split('.')[0]}Z\n`;
      icalContent += `DTEND:${new Date(event.endDate).toISOString().replace(/[-:]/g, '').split('.')[0]}Z\n`;
      icalContent += `SUMMARY:${event.event} \n`;
      icalContent += `LOCATION:${event.location}\n`;
      icalContent += 'END:VEVENT\n';
    });

    icalContent += 'END:VCALENDAR';

    return icalContent;
  }

  function downloadICal(content, filename) {
    const blob = new Blob([content], { type: 'text/calendar' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = filename;
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
    URL.revokeObjectURL(url);
  }

  const newIcalContent = createICal(data);
  downloadICal(
    newIcalContent,
    'play_pokemon_international_championships_events.ics'
  );
})();