/**
 * TinyFlowLab — Lead Capture Mini  v1.1  (changelog: CHANGELOG.md)
 * Google Form → check required fields → "Leads" sheet → a manual next step with an owner and due date.
 *
 * Paste this whole file into Extensions → Apps Script of the Google Sheet that collects your form responses.
 * Full guide: GUIDE.md (https://tinyflowlab.com/free)
 *
 * What it does on every form submission:
 *   1. Reads the answer row.
 *   2. Checks required fields (name, a valid email, a message).
 *   3. Skips it if this exact submission was already processed (same Submission ID).
 *   4. Adds one row to the "Leads" tab: status "New" (ready to reply) or "Needs review" (with the reason).
 *   5. Writes a next step, owner and due date. It never sends an email or a message.
 *
 * No API keys, no external services, no data leaves your Google account.
 * License: free for personal and commercial use in your own business; please don't resell the template.
 *
 * @OnlyCurrentDoc  — limits the script's access to this one spreadsheet.
 */

// ----------------------------------------------------------------------------------------------------
// Settings — change these to match your form. Question titles must match your form exactly.
// ----------------------------------------------------------------------------------------------------
var CONFIG = {
  responsesSheet: 'Form Responses 1',
  leadsSheet: 'Leads',
  fields: {
    timestamp: 'Timestamp',
    name: 'Your name',
    email: 'Email address',
    company: 'Company or website',
    need: 'What do you need help with?',
  },
  required: ['name', 'email', 'need'],
  minNeedLength: 10,
  owner: 'Me', // who handles new leads — a name or an email
  replyWithinBusinessDays: 1,
  // Flag a lead for review when the same email has already sent a request (it is still added).
  flagRepeatEmails: true,
};

var VERSION = '1.1.0';

var LEADS_HEADER = [
  'Submission ID', 'Received', 'Name', 'Email', 'Company', 'Need',
  'Status', 'Issues', 'Next step', 'Owner', 'Due', 'Done',
];

// ----------------------------------------------------------------------------------------------------
// Pure logic (no Google services) — tested in test/code.test.mjs
// ----------------------------------------------------------------------------------------------------

/** Trim, collapse inner whitespace. */
function clean_(v) {
  if (v === null || v === undefined) return '';
  return String(v).replace(/\s+/g, ' ').trim();
}

/** Practical email check: something@something.tld, no spaces. Not a deliverability check. */
function isValidEmail_(email) {
  return /^[^\s@]+@[^\s@]+\.[^\s@]{2,}$/.test(email);
}

/**
 * Stable ID for one submission, hashed (FNV-1a, 32-bit, hex).
 * With a timestamp: timestamp + email + name. Without one (pasted/imported rows): email + name + message,
 * so the same row still gets the same ID on every run and is never added twice.
 */
function submissionId_(timestampIso, email, name, need) {
  var parts = timestampIso
    ? [timestampIso, email.toLowerCase(), name.toLowerCase()]
    : ['no-ts', email.toLowerCase(), name.toLowerCase(), (need || '').toLowerCase()];
  var s = parts.join('|');
  var h = 0x811c9dc5;
  for (var i = 0; i < s.length; i++) {
    h ^= s.charCodeAt(i);
    h = (h + ((h << 1) + (h << 4) + (h << 7) + (h << 8) + (h << 24))) >>> 0;
  }
  return 'L-' + ('0000000' + h.toString(16)).slice(-8);
}

/**
 * Makes a value safe to write into a cell: text starting with = + - @ (or a tab/CR) would be run as a formula
 * by Google Sheets ("formula injection"), so it is prefixed with an apostrophe and shown as plain text.
 */
function safeCell_(v) {
  if (typeof v !== 'string') return v;
  return /^[=+\-@\t\r]/.test(v) ? "'" + v : v;
}

/** Adds business days (Mon–Fri) to a date. */
function addBusinessDays_(date, days) {
  var d = new Date(date.getTime());
  var added = 0;
  while (added < days) {
    d.setDate(d.getDate() + 1);
    var wd = d.getDay();
    if (wd !== 0 && wd !== 6) added++;
  }
  return d;
}

/**
 * Turns one answer record into a lead row.
 * @param {Object} answers  map of question title → answer
 * @param {Object} ctx      { knownIds: Set-like {has}, knownEmails: Set-like {has}, now: Date }
 * @return {{skip: boolean, reason?: string, lead?: Object}}
 */
function buildLead_(answers, ctx) {
  var f = CONFIG.fields;
  var rawTs = answers[f.timestamp];
  var ts = rawTs instanceof Date ? rawTs : (rawTs ? new Date(rawTs) : null);
  if (ts && isNaN(ts.getTime())) ts = null;
  var received = ts || ctx.now;

  var lead = {
    name: clean_(answers[f.name]),
    email: clean_(answers[f.email]).toLowerCase(),
    company: clean_(answers[f.company]),
    need: clean_(answers[f.need]),
    received: received,
  };
  lead.id = submissionId_(ts ? ts.toISOString() : '', lead.email, lead.name, lead.need);

  if (ctx.knownIds.has(lead.id)) return { skip: true, reason: 'already processed' };

  var issues = [];
  CONFIG.required.forEach(function (key) {
    if (!lead[key]) issues.push('Missing ' + key);
  });
  if (lead.email && !isValidEmail_(lead.email)) issues.push('Email looks invalid');
  if (lead.need && lead.need.length < CONFIG.minNeedLength) issues.push('Message is very short');
  if (CONFIG.flagRepeatEmails && lead.email && ctx.knownEmails.has(lead.email)) {
    issues.push('Email already sent a request');
  }

  var ok = issues.length === 0;
  lead.status = ok ? 'New' : 'Needs review';
  lead.issues = issues.join('; ');
  lead.nextStep = ok
    ? 'Reply to ' + lead.name + ' about: ' + lead.need.slice(0, 80)
    : 'Check this request and decide whether to reply';
  lead.owner = CONFIG.owner;
  lead.due = addBusinessDays_(ctx.now, CONFIG.replyWithinBusinessDays);
  return { skip: false, lead: lead };
}

function leadToRow_(lead) {
  return [
    lead.id, lead.received, lead.name, lead.email, lead.company, lead.need,
    lead.status, lead.issues, lead.nextStep, lead.owner, lead.due, false,
  ].map(safeCell_);
}

/** Map a header row + value row into {title: value}. */
function rowToAnswers_(header, row) {
  var out = {};
  for (var i = 0; i < header.length; i++) out[clean_(header[i])] = row[i];
  return out;
}

// ----------------------------------------------------------------------------------------------------
// Google Sheets glue
// ----------------------------------------------------------------------------------------------------

/** Adds the "Lead Capture" menu when the sheet opens. */
function onOpen() {
  SpreadsheetApp.getUi()
    .createMenu('Lead Capture')
    .addItem('1. Set up (create Leads tab + trigger)', 'setup')
    .addItem('Process all responses now', 'processAllResponses')
    .addItem('Check setup', 'checkSetup')
    .addItem('About (version ' + VERSION + ')', 'about')
    .addToUi();
}

/** One-time setup: creates the Leads tab and the on-form-submit trigger. Safe to run twice. */
function setup() {
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  getLeadsSheet_(ss);
  var exists = ScriptApp.getProjectTriggers().some(function (t) {
    return t.getHandlerFunction() === 'onFormSubmit';
  });
  if (!exists) ScriptApp.newTrigger('onFormSubmit').forSpreadsheet(ss).onFormSubmit().create();
  notify_('Setup done. New form responses will appear in the "' + CONFIG.leadsSheet + '" tab.');
}

/** Installed trigger: runs on every new form response. */
function onFormSubmit(e) {
  var lock = LockService.getDocumentLock();
  lock.waitLock(30000);
  try {
    var ss = SpreadsheetApp.getActiveSpreadsheet();
    var sheet = e && e.range ? e.range.getSheet() : ss.getSheetByName(CONFIG.responsesSheet);
    var header = sheet.getRange(1, 1, 1, sheet.getLastColumn()).getValues()[0];
    var row = e && e.range ? e.range.getValues()[0] : sheet.getRange(sheet.getLastRow(), 1, 1, header.length).getValues()[0];
    processRows_(ss, header, [row]);
  } finally {
    lock.releaseLock();
  }
}

/** Menu action: (re)process every response row. Already-processed rows are skipped. */
function processAllResponses() {
  var lock = LockService.getDocumentLock();
  lock.waitLock(30000);
  try {
    var ss = SpreadsheetApp.getActiveSpreadsheet();
    var sheet = ss.getSheetByName(CONFIG.responsesSheet);
    if (!sheet) throw new Error('No tab named "' + CONFIG.responsesSheet + '". Check CONFIG.responsesSheet.');
    var values = sheet.getDataRange().getValues();
    if (values.length < 2) return notify_('No responses yet.');
    var res = processRows_(ss, values[0], values.slice(1));
    notify_('Added ' + res.added + ' lead(s), skipped ' + res.skipped + ' already processed.');
  } finally {
    lock.releaseLock();
  }
}

function about() {
  notify_('Lead Capture Mini ' + VERSION + ' by TinyFlowLab — guide: https://tinyflowlab.com/free/guide');
}

/** Checks that question titles in the responses tab match CONFIG.fields. */
function checkSetup() {
  var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName(CONFIG.responsesSheet);
  if (!sheet) return notify_('Missing tab "' + CONFIG.responsesSheet + '". Link your form to this sheet first.');
  var header = sheet.getRange(1, 1, 1, Math.max(1, sheet.getLastColumn())).getValues()[0].map(clean_);
  var missing = [];
  for (var k in CONFIG.fields) if (header.indexOf(CONFIG.fields[k]) === -1) missing.push(CONFIG.fields[k]);
  var hasTrigger = ScriptApp.getProjectTriggers().some(function (t) { return t.getHandlerFunction() === 'onFormSubmit'; });
  notify_(
    (missing.length ? 'Columns not found: ' + missing.join(', ') + '. Rename them in CONFIG.fields. ' : 'All columns found. ') +
    (hasTrigger ? 'Trigger is installed.' : 'Trigger is NOT installed — run "Set up".')
  );
}

function processRows_(ss, header, rows) {
  var leads = getLeadsSheet_(ss);
  var existing = leads.getLastRow() > 1 ? leads.getRange(2, 1, leads.getLastRow() - 1, 4).getValues() : [];
  var ids = {}, emails = {};
  existing.forEach(function (r) { ids[r[0]] = true; if (r[3]) emails[String(r[3]).toLowerCase()] = true; });
  var ctx = {
    knownIds: { has: function (k) { return !!ids[k]; } },
    knownEmails: { has: function (k) { return !!emails[k]; } },
    now: new Date(),
  };
  var out = [], skipped = 0;
  rows.forEach(function (row) {
    if (row.every(function (c) { return c === '' || c === null; })) return;
    // A pasted/imported copy of the header row is not a lead.
    if (row.every(function (c, i) { return clean_(c) === clean_(header[i]); })) return;
    var res = buildLead_(rowToAnswers_(header, row), ctx);
    if (res.skip) { skipped++; return; }
    ids[res.lead.id] = true;
    if (res.lead.email) emails[res.lead.email] = true;
    out.push(leadToRow_(res.lead));
  });
  if (out.length) {
    var start = leads.getLastRow() + 1;
    leads.getRange(start, 1, out.length, LEADS_HEADER.length).setValues(out);
    leads.getRange(start, 12, out.length, 1).insertCheckboxes();
  }
  return { added: out.length, skipped: skipped };
}

function getLeadsSheet_(ss) {
  var sheet = ss.getSheetByName(CONFIG.leadsSheet);
  if (!sheet) {
    sheet = ss.insertSheet(CONFIG.leadsSheet);
    sheet.getRange(1, 1, 1, LEADS_HEADER.length).setValues([LEADS_HEADER]).setFontWeight('bold');
    sheet.setFrozenRows(1);
    sheet.getRange('B:B').setNumberFormat('yyyy-mm-dd hh:mm');
    sheet.getRange('K:K').setNumberFormat('yyyy-mm-dd');
    var rules = [
      SpreadsheetApp.newConditionalFormatRule().whenTextEqualTo('Needs review')
        .setBackground('#FFF1D6').setRanges([sheet.getRange('G2:G')]).build(),
      SpreadsheetApp.newConditionalFormatRule().whenTextEqualTo('New')
        .setBackground('#E3EAFE').setRanges([sheet.getRange('G2:G')]).build(),
    ];
    sheet.setConditionalFormatRules(rules);
  }
  return sheet;
}

function notify_(msg) {
  try { SpreadsheetApp.getActiveSpreadsheet().toast(msg, 'Lead Capture', 8); } catch (err) { /* no UI in trigger context */ }
  console.log(msg);
}

// Node test hook (ignored by Apps Script).
if (typeof module !== 'undefined') {
  module.exports = { CONFIG: CONFIG, clean_: clean_, isValidEmail_: isValidEmail_, submissionId_: submissionId_,
    addBusinessDays_: addBusinessDays_, buildLead_: buildLead_, rowToAnswers_: rowToAnswers_, leadToRow_: leadToRow_,
    processRows_: processRows_, LEADS_HEADER: LEADS_HEADER, safeCell_: safeCell_, VERSION: VERSION };
}