/**
 * Élevé Content Hub — Google Sheets Backend
 *
 * This script lets the HTML hub read and write data to a Google Sheet.
 * Paste this into the Apps Script editor of your Google Sheet.
 *
 * Setup:
 *  1. In your Google Sheet, go to Extensions → Apps Script
 *  2. Delete any existing code in the editor
 *  3. Paste this entire file in
 *  4. Click "Save" (the disk icon)
 *  5. Click "Deploy" → "New deployment"
 *  6. Click the gear icon next to "Select type" → choose "Web app"
 *  7. Settings:
 *       - Description: "Eleve Content Hub Backend" (or anything)
 *       - Execute as: "Me"
 *       - Who has access: "Anyone"
 *  8. Click "Deploy"
 *  9. Authorize when Google asks (it will warn — click "Advanced" → "Go to..." → "Allow")
 * 10. Copy the Web app URL it gives you
 * 11. Paste that URL into the HTML file where it says PASTE_YOUR_APPS_SCRIPT_URL_HERE
 */

const SHEET_NAME = 'HubData';
const DATA_CELL = 'A1';

function doGet(e) {
  try {
    const action = e.parameter.action;
    if (action === 'load') {
      return jsonResponse({ success: true, data: loadData() });
    }
    return jsonResponse({ success: false, error: 'Unknown action' });
  } catch (err) {
    return jsonResponse({ success: false, error: err.toString() });
  }
}

function doPost(e) {
  try {
    const body = JSON.parse(e.postData.contents);
    if (body.action === 'save') {
      saveData(body.data);
      return jsonResponse({ success: true });
    }
    return jsonResponse({ success: false, error: 'Unknown action' });
  } catch (err) {
    return jsonResponse({ success: false, error: err.toString() });
  }
}

function getOrCreateSheet() {
  const ss = SpreadsheetApp.getActiveSpreadsheet();
  let sheet = ss.getSheetByName(SHEET_NAME);
  if (!sheet) {
    sheet = ss.insertSheet(SHEET_NAME);
    sheet.getRange('A1').setNote('This cell stores all hub data as JSON. Do not edit directly — edit through the hub.');
  }
  return sheet;
}

function loadData() {
  const sheet = getOrCreateSheet();
  const a1 = sheet.getRange('A1').getValue() || '';
  const a2 = sheet.getRange('A2').getValue() || '';
  const a3 = sheet.getRange('A3').getValue() || '';
  const combined = String(a1) + String(a2) + String(a3);
  if (!combined) return null;
  try {
    return JSON.parse(combined);
  } catch (e) {
    return null;
  }
}

function saveData(data) {
  const sheet = getOrCreateSheet();
  const json = JSON.stringify(data);
  // Google Sheets has a 50,000 char limit per cell — split if needed
  if (json.length > 49000) {
    // Split across multiple cells
    sheet.getRange('A1').setValue(json.slice(0, 49000));
    sheet.getRange('A2').setValue(json.slice(49000, 98000));
    sheet.getRange('A3').setValue(json.slice(98000, 147000));
  } else {
    sheet.getRange('A1').setValue(json);
    // Clear backup cells
    sheet.getRange('A2:A3').clearContent();
  }
  // Also save a timestamp for reference
  sheet.getRange('B1').setValue('Last updated: ' + new Date().toLocaleString());
}

function jsonResponse(obj) {
  return ContentService
    .createTextOutput(JSON.stringify(obj))
    .setMimeType(ContentService.MimeType.JSON);
}

/**
 * Test function — run this manually from the Apps Script editor
 * to confirm everything is set up correctly.
 */
function testSetup() {
  const sheet = getOrCreateSheet();
  Logger.log('Sheet ready: ' + sheet.getName());
  saveData({ test: 'hello world', timestamp: new Date().toISOString() });
  Logger.log('Wrote test data');
  const loaded = loadData();
  Logger.log('Read back: ' + JSON.stringify(loaded));
}