/****************************************************
 * Aplikasi Form Guru Bertugas + Automasi Google Sheets
 * Disalin/ditiru sebagai replika fungsi umum.
 * Oleh: (isi nama anda jika perlu)
 ****************************************************/

const SHEET = {
  TEACHERS: 'SenaraiGuru',
  DUTIES: 'Tugas',
  HOLIDAYS: 'Cuti',
  SCHEDULE: 'Jadual',
  RESPONSES: 'Form Responses 1'
};

const Q = { // Tajuk soalan pada Google Form (juga jadi header di Responses)
  NAME: 'Nama Guru',
  DATE: 'Tarikh Bertugas',
  SESSION: 'Sesi',
  DUTY: 'Tugas',
  NOTE: 'Catatan'
};

const MENU = 'Guru Bertugas';
const PROP = PropertiesService.getScriptProperties();
const KEYS = {
  FORM_ID: 'FORM_ID',
  LAST_ROTATION_OFFSET: 'LAST_ROTATION_OFFSET' // untuk penjanaan giliran
};

/** Menu utama */
function onOpen() {
  const ui = SpreadsheetApp.getUi();
  ui.createMenu(MENU)
    .addItem('1) Bina / Kemas Kini Google Form', 'createOrUpdateForm')
    .addItem('2) Jana Jadual Mingguan (Isnin–Jumaat)', 'generateWeeklyRosterPrompt')
    .addItem('3) Hantar Emel Notifikasi Mingguan', 'sendWeeklyEmailsPrompt')
    .addToUi();

ensureBaseSheets();
}

/** Pastikan helaian asas wujud & setup header Jadual */
function ensureBaseSheets() {
  const ss = SpreadsheetApp.getActive();

// Cipta helaian jika tiada
  [SHEET.TEACHERS, SHEET.DUTIES, SHEET.HOLIDAYS, SHEET.SCHEDULE].forEach(name => {
    if (!ss.getSheetByName(name)) ss.insertSheet(name);
  });

// Header Jadual
  const jad = ss.getSheetByName(SHEET.SCHEDULE);
  const headers = ['Tarikh', 'Hari', 'Sesi', 'Nama', 'Tugas', 'Catatan', 'Status'];
  const firstRow = jad.getRange(1,1,1,headers.length).getValues()[0];
  const needHeader = headers.some((h,i)=> firstRow[i] !== h);
  if (needHeader) {
    jad.clear();
    jad.getRange(1,1,1,headers.length).setValues([headers]);
    jad.setFrozenRows(1);
  }
}

/** Baca senarai nilai dari satu kolum (unik, tak kosong) */
function getList(sheetName, colIndex=1) {
  const sh = SpreadsheetApp.getActive().getSheetByName(sheetName);
  if (!sh) return [];
  const last = sh.getLastRow();
  if (last < 2) return [];
  const vals = sh.getRange(2, colIndex, last-2+1, 1).getValues().flat()
    .map(v => (v||'').toString().trim())
    .filter(v => v);
  return Array.from(new Set(vals));
}

/** CIPTA atau KEMAS KINI Google Form & link ke spreadsheet ini */
function createOrUpdateForm() {
  ensureBaseSheets();
  const ss = SpreadsheetApp.getActive();
  const teachers = getList(SHEET.TEACHERS, 1);
  const duties = getList(SHEET.DUTIES, 1);

if (teachers.length === 0) throw new Error('SenaraiGuru kosong. Isi Nama (kolum A) dan Emel (kolum B).');
  if (duties.length === 0) throw new Error('Helaian Tugas kosong. Isi senarai tugasan.');

let form;
  const formId = PROP.getProperty(KEYS.FORM_ID);
  if (formId) {
    try {
      form = FormApp.openById(formId);
      // Bersih & bina semula item untuk sinkron
      form.getItems().forEach(it => form.deleteItem(it));
    } catch (e) {
      // Jika gagal buka, cipta baharu
      form = FormApp.create('Borang Guru Bertugas');
      PROP.setProperty(KEYS.FORM_ID, form.getId());
    }
  } else {
    form = FormApp.create('Borang Guru Bertugas');
    PROP.setProperty(KEYS.FORM_ID, form.getId());
  }

// Item: Nama Guru (dropdown)
  form.addListItem()
      .setTitle(Q.NAME)
      .setChoiceValues(teachers)
      .setRequired(true);

// Item: Tarikh Bertugas
  form.addDateItem()
      .setTitle(Q.DATE)
      .setRequired(true);

// Item: Sesi
  form.addMultipleChoiceItem()
      .setTitle(Q.SESSION)
      .setChoiceValues(['Pagi','Petang'])
      .setRequired(true);

// Item: Tugas
  form.addListItem()
      .setTitle(Q.DUTY)
      .setChoiceValues(duties)
      .setRequired(true);

// Item: Catatan
  form.addParagraphTextItem()
      .setTitle(Q.NOTE)
      .setRequired(false);

// Linkkan respon ke Spreadsheet ini
  form.setDestination(FormApp.DestinationType.SPREADSHEET, ss.getId());

SpreadsheetApp.getUi().alert('Borang siap! Tajuk: "'+ form.getTitle() + '". Respon ke "'+ SHEET.RESPONSES +'".');
}

/** Trigger spreadsheet "On form submit" -> Process */
function onFormSubmit(e) {
  // Tip: Set up installable trigger: Triggers > Add Trigger > onFormSubmit > From spreadsheet > On form submit
  try {
    processSubmission_();
  } catch (err) {
    console.error(err);
  }
}

/** Proses respon terbaru dan tulis ke Jadual */
function processSubmission_() {
  ensureBaseSheets();
  const ss = SpreadsheetApp.getActive();
  const resp = ss.getSheetByName(SHEET.RESPONSES);
  if (!resp) return;

const lastRow = resp.getLastRow();
  if (lastRow < 2) return;

const header = resp.getRange(1,1,1, resp.getLastColumn()).getValues()[0];
  const row = resp.getRange(lastRow,1,1, resp.getLastColumn()).getValues()[0];

// Dapatkan nilai ikut tajuk soalan
  const getByTitle = (title) => {
    const idx = header.indexOf(title);
    return idx === -1 ? '' : row[idx];
  };

const nama = getByTitle(Q.NAME);
  const tarikh = new Date(getByTitle(Q.DATE));
  const sesi = getByTitle(Q.SESSION);
  const tugas = getByTitle(Q.DUTY);
  const catatan = getByTitle(Q.NOTE);

// Skip jika tarikh cuti
  if (isHoliday_(tarikh)) {
    appendScheduleRow_({tarikh, hari: getDayName_(tarikh), sesi, nama, tugas, catatan, status: 'Cuti - tidak dijadualkan'});
    return;
  }

appendScheduleRow_({tarikh, hari: getDayName_(tarikh), sesi, nama, tugas, catatan, status: 'Dijadualkan'});
}

/** Tambah satu rekod ke helaian Jadual */
function appendScheduleRow_({tarikh, hari, sesi, nama, tugas, catatan, status}) {
  const sh = SpreadsheetApp.getActive().getSheetByName(SHEET.SCHEDULE);
  sh.appendRow([tarikh, hari, sesi, nama, tugas, catatan, status]);
  // Format tarikh & auto-size
  const lastRow = sh.getLastRow();
  sh.getRange(lastRow,1).setNumberFormat('yyyy-mm-dd');
  sh.autoResizeColumns(1, sh.getLastColumn());
}

/** Semak tarikh cuti */
function isHoliday_(dateObj) {
  const sh = SpreadsheetApp.getActive().getSheetByName(SHEET.HOLIDAYS);
  if (!sh) return false;
  const last = sh.getLastRow();
  if (last < 2) return false;
  const vals = sh.getRange(2,1,last-1,1).getValues().flat().filter(v => v);
  const dStr = toYMD_(dateObj);
  return vals.some(v => toYMD_(new Date(v)) === dStr);
}

function toYMD_(d) {
  const y = d.getFullYear();
  const m = ('0'+(d.getMonth()+1)).slice(-2);
  const da = ('0'+d.getDate()).slice(-2);
  return `${y}-${m}-${da}`;
}

function getDayName_(d) {
  const days = ['Ahad','Isnin','Selasa','Rabu','Khamis','Jumaat','Sabtu'];
  return days[d.getDay()];
}

/** Prompt pilih tarikh mula minggu (Isnin) */
function generateWeeklyRosterPrompt() {
  const ui = SpreadsheetApp.getUi();
  const resp = ui.prompt('Tarikh mula minggu','Masukkan tarikh Isnin (yyyy-mm-dd):', ui.ButtonSet.OK_CANCEL);
  if (resp.getSelectedButton() !== ui.Button.OK) return;
  const d = new Date(resp.getResponseText());
  generateWeeklyRoster_(d);
  ui.alert('Jadual mingguan dijana.');
}

/** Jana jadual Isnin–Jumaat ikut senarai guru & tugasan; skip cuti */
function generateWeeklyRoster_(mondayDate) {
  ensureBaseSheets();
  const teachers = getList(SHEET.TEACHERS, 1); // nama
  const duties = getList(SHEET.DUTIES, 1);
  if (teachers.length === 0 || duties.length === 0) throw new Error('SenaraiGuru/Tugas kosong.');

// "Giliran" ringkas: offset bertambah setiap kali jana
  let offset = parseInt(PROP.getProperty(KEYS.LAST_ROTATION_OFFSET) || '0', 10);
  const jad = SpreadsheetApp.getActive().getSheetByName(SHEET.SCHEDULE);

for (let i=0; i<5; i++) { // Isnin–Jumaat
    const d = new Date(mondayDate);
    d.setDate(d.getDate() + i);
    if (isHoliday_(d)) {
      appendScheduleRow_({tarikh:d, hari:getDayName_(d), sesi:'-', nama:'-', tugas:'-', catatan:'Cuti', status:'Cuti - tidak dijadualkan'});
      continue;
    }

// Tugaskan seorang guru untuk setiap tugas (atau satu tugas sahaja — ubah ikut keperluan)
    duties.forEach((tugas, di) => {
      const guru = teachers[(offset + i + di) % teachers.length];
      appendScheduleRow_({tarikh:d, hari:getDayName_(d), sesi:'Pagi', nama:guru, tugas, catatan:'', status:'Dijadualkan (Auto)'});
    });
  }

PROP.setProperty(KEYS.LAST_ROTATION_OFFSET, (offset + 1).toString());
}

/** Prompt emel minggu bermula pada tarikh */
function sendWeeklyEmailsPrompt() {
  const ui = SpreadsheetApp.getUi();
  const resp = ui.prompt('Tarikh mula minggu','Masukkan tarikh Isnin (yyyy-mm-dd):', ui.ButtonSet.OK_CANCEL);
  if (resp.getSelectedButton() !== ui.Button.OK) return;
  const monday = new Date(resp.getResponseText());
  const count = sendWeeklyEmails_(monday);
  ui.alert(`Emel dihantar kepada ${count} penerima.`);
}

/** Hantar emel notifikasi untuk jadual minggu tersebut */
function sendWeeklyEmails_(mondayDate) {
  const mapEmail = buildEmailMap_(); // {Nama: Emel}
  const sh = SpreadsheetApp.getActive().getSheetByName(SHEET.SCHEDULE);
  const last = sh.getLastRow();
  if (last < 2) return 0;

const rows = sh.getRange(2,1,last-1, sh.getLastColumn()).getValues();
  const start = new Date(mondayDate);
  const end = new Date(mondayDate); end.setDate(end.getDate()+6);

let sent = 0;
  rows.forEach(r => {
    const [tarikh, , sesi, nama, tugas, catatan, status] = r;
    if (!tarikh) return;
    const d = new Date(tarikh);
    if (d < start || d > end) return;
    if (!nama || nama === '-' || String(status).match(/cuti/i)) return;

const email = mapEmail[nama];
    if (!email) return;

const subj = `Notifikasi Guru Bertugas: ${toYMD_(d)} (${sesi})`;
    const body =
`Assalamualaikum / Salam sejahtera ${nama},

Anda telah dijadualkan sebagai GURU BERTUGAS.

Butiran:
- Tarikh: ${toYMD_(d)} (${getDayName_(d)})
- Sesi: ${sesi}
- Tugasan: ${tugas}
- Catatan: ${catatan || '-'}

Pautan WhatsApp (pra-isi, jika perlu):
${makeWhatsAppLink_(nama, d, sesi, tugas)}

Terima kasih.`;

MailApp.sendEmail(email, subj, body);
    sent++;
  });
  return sent;
}

function buildEmailMap_() {
  const sh = SpreadsheetApp.getActive().getSheetByName(SHEET.TEACHERS);
  const last = sh.getLastRow();
  const map = {};
  if (last >= 2) {
    const vals = sh.getRange(2,1,last-1,2).getValues(); // Nama, Emel
    vals.forEach(([nama, emel]) => {
      nama = (nama||'').toString().trim();
      emel = (emel||'').toString().trim();
      if (nama && emel) map[nama] = emel;
    });
  }
  return map;
}

/** Pautan WhatsApp pra-isi mesej (optional) */
function makeWhatsAppLink_(nama, d, sesi, tugas) {
  const msg = `Assalamualaikum ${nama}. Anda bertugas pada ${toYMD_(d)} (${getDayName_(d)}), sesi ${sesi}, tugasan: ${tugas}.`;
  return 'https://wa.me/?text=' + encodeURIComponent(msg);
}

/** (Pilihan) Trigger mingguan automatik – set manual dalam Triggers:
 *  Time-driven → Weekly → pilih hari & masa → jalankan fungsi ini
 */
function weeklyAuto_() {
  // Contoh: ambil Isnin minggu semasa
  const today = new Date();
  const monday = new Date(today);
  const day = monday.getDay(); // 0 Ahad, 1 Isnin
  const diffToMonday = (day === 0 ? -6 : 1 - day);
  monday.setDate(monday.getDate() + diffToMonday);

generateWeeklyRoster_(monday);
  sendWeeklyEmails_(monday);
}