// server/notifications.js — Bilingual email notification system
const { sendMail } = require('./mail');
const nocodb = require('./nocodb');
const { parseApproverIds } = require('./helpers');

const APP_URL = process.env.APP_URL || process.env.CORS_ORIGIN || 'http://localhost:3001';
const APP_NAME_EN = "Samaya's Digital Hub";
const APP_NAME_AR = 'المركز الرقمي لسمايا';

// ─── TRANSLATIONS ───────────────────────────────────────────────

const t = {
  appName:          { en: APP_NAME_EN, ar: APP_NAME_AR },
  automatedNotice:  { en: `This is an automated notification from ${APP_NAME_EN}`, ar: `هذا إشعار تلقائي من ${APP_NAME_AR}` },

  // Review
  reviewRequested:      { en: 'Review Requested',             ar: 'طلب مراجعة' },
  reviewRequestedBody:  { en: (type, title) => `You've been asked to review the ${type} <strong>"${title}"</strong>.`,
                          ar: (type, title) => `تمت دعوتك لمراجعة ${type} <strong>"${title}"</strong>.` },
  reviewFeedbackPrompt: { en: 'Please click the button below to review and provide your feedback.',
                          ar: 'يرجى الضغط على الزر أدناه للمراجعة وتقديم ملاحظاتك.' },
  reviewNow:            { en: 'Review Now', ar: 'مراجعة الآن' },

  // Approved
  approved:          { en: 'Approved',                    ar: 'تمت الموافقة' },
  approvedHeading:   { en: (type) => `Your ${type} Has Been Approved`,
                       ar: (type) => `تمت الموافقة على ${type}` },
  approvedBody:      { en: (title, name) => `Great news! <strong>"${title}"</strong> has been approved by <strong>${name}</strong>.`,
                       ar: (title, name) => `أخبار رائعة! تمت الموافقة على <strong>"${title}"</strong> من قبل <strong>${name}</strong>.` },

  // Rejected
  needsChanges:      { en: 'Needs Changes',               ar: 'يحتاج تعديلات' },
  rejectedHeading:   { en: (type) => `Your ${type} Needs Changes`,
                       ar: (type) => `${type} يحتاج تعديلات` },
  rejectedBody:      { en: (title, name) => `<strong>"${title}"</strong> was reviewed by <strong>${name}</strong> and requires changes.`,
                       ar: (title, name) => `تمت مراجعة <strong>"${title}"</strong> من قبل <strong>${name}</strong> ويحتاج إلى تعديلات.` },

  // Revision
  revisionRequested:     { en: 'Revision Requested',       ar: 'طلب تعديل' },
  revisionRequestedBody: { en: (title, name) => `<strong>"${title}"</strong> was reviewed by <strong>${name}</strong> and a revision has been requested.`,
                           ar: (title, name) => `تمت مراجعة <strong>"${title}"</strong> من قبل <strong>${name}</strong> وتم طلب تعديل.` },

  // Task
  taskAssigned:        { en: 'Task Assigned',              ar: 'تم تعيين مهمة' },
  taskAssignedHeading: { en: 'New Task Assigned to You',   ar: 'مهمة جديدة مُسندة إليك' },
  taskAssignedBody:    { en: (name) => `<strong>${name}</strong> assigned you a task:`,
                         ar: (name) => `قام <strong>${name}</strong> بتعيين مهمة لك:` },
  taskCompleted:        { en: 'Task Completed',            ar: 'تم إنجاز المهمة' },
  taskCompletedHeading: { en: 'A Task You Created Has Been Completed', ar: 'تم إنجاز مهمة قمت بإنشائها' },
  taskCompletedBody:    { en: (title) => `The task <strong>"${title}"</strong> has been marked as done.`,
                          ar: (title) => `تم وضع علامة "منجز" على المهمة <strong>"${title}"</strong>.` },
  priority:  { en: 'Priority', ar: 'الأولوية' },
  dueDate:   { en: 'Due',      ar: 'الاستحقاق' },
  category:  { en: 'Category', ar: 'الفئة' },

  // Issue
  issueAssigned:        { en: 'Issue Assigned',            ar: 'تم تعيين مشكلة' },
  issueAssignedHeading: { en: 'Issue Assigned to You',     ar: 'مشكلة مُسندة إليك' },
  issueAssignedBody:    { en: (name) => `<strong>${name}</strong> assigned you an issue:`,
                          ar: (name) => `قام <strong>${name}</strong> بتعيين مشكلة لك:` },
  issueUpdate:          { en: 'Issue Update',              ar: 'تحديث المشكلة' },
  issueUpdateHeading:   { en: 'Your Issue Has Been Updated', ar: 'تم تحديث مشكلتك' },
  issueUpdateBody:      { en: (title) => `The status of your issue <strong>"${title}"</strong> has changed:`,
                          ar: (title) => `تم تغيير حالة مشكلتك <strong>"${title}"</strong>:` },
  resolution:           { en: 'Resolution', ar: 'الحل' },
  trackIssue:           { en: 'Track Your Issue', ar: 'تتبع مشكلتك' },

  // Campaign
  newCampaign:        { en: 'New Campaign',                ar: 'حملة جديدة' },
  campaignHeading:    { en: 'A New Campaign Has Been Created', ar: 'تم إنشاء حملة جديدة' },
  campaignBody:       { en: (name) => `A new campaign <strong>"${name}"</strong> has been created in your team.`,
                        ar: (name) => `تم إنشاء حملة جديدة <strong>"${name}"</strong> في فريقك.` },
  viewCampaign:       { en: 'View Campaign', ar: 'عرض الحملة' },

  // Welcome
  welcome:         { en: (name) => `Welcome, ${name}!`,           ar: (name) => `!أهلاً بك، ${name}` },
  welcomeBody:     { en: (inviter) => `<strong>${inviter}</strong> has invited you to ${APP_NAME_EN}.`,
                     ar: (inviter) => `قام <strong>${inviter}</strong> بدعوتك إلى ${APP_NAME_AR}.` },
  emailLabel:      { en: 'Email',    ar: 'البريد الإلكتروني' },
  passwordLabel:   { en: 'Password', ar: 'كلمة المرور' },
  changePassword:  { en: 'Please change your password after your first login.',
                     ar: 'يرجى تغيير كلمة المرور بعد أول تسجيل دخول.' },
  signIn:          { en: 'Sign In',  ar: 'تسجيل الدخول' },

  // Types
  post:     { en: 'post',     ar: 'منشور' },
  artefact: { en: 'artefact', ar: 'قطعة إبداعية' },
  Post:        { en: 'Post',        ar: 'المنشور' },
  Artefact:    { en: 'Artefact',    ar: 'القطعة الإبداعية' },
  translation: { en: 'translation', ar: 'ترجمة' },
  Translation: { en: 'Translation', ar: 'الترجمة' },

  // Generic
  view:     { en: 'View',     ar: 'عرض' },
  viewTask: { en: 'View Task', ar: 'عرض المهمة' },
  viewIssue:{ en: 'View Issue', ar: 'عرض المشكلة' },
};

function tr(key, lang) { return t[key]?.[lang] || t[key]?.en || key; }

// ─── HTML EMAIL TEMPLATE ────────────────────────────────────────

function renderEmail({ heading, bodyHtml, ctaText, ctaUrl, lang = 'en' }) {
  const isRtl = lang === 'ar';
  const dir = isRtl ? 'rtl' : 'ltr';
  const align = isRtl ? 'right' : 'left';
  const appName = isRtl ? APP_NAME_AR : APP_NAME_EN;

  const html = `
<!DOCTYPE html>
<html dir="${dir}" lang="${lang}"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1"></head>
<body style="margin:0;padding:0;background:#f4f5f7;font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif">
<div style="max-width:600px;margin:0 auto;padding:20px;direction:${dir};text-align:${align}">
  <div style="background:#1e293b;color:#fff;padding:16px 24px;border-radius:12px 12px 0 0;font-size:16px;font-weight:600;text-align:${align}">
    ${appName}
  </div>
  <div style="background:#fff;padding:32px 24px;border-radius:0 0 12px 12px;border:1px solid #e2e8f0;border-top:none">
    <h2 style="margin:0 0 16px;color:#1e293b;font-size:20px">${heading}</h2>
    <div style="color:#475569;font-size:15px;line-height:1.6">
      ${bodyHtml}
    </div>
    ${ctaText && ctaUrl ? `
    <div style="margin:24px 0 8px">
      <a href="${ctaUrl}" style="display:inline-block;background:#3b82f6;color:#fff;padding:12px 24px;border-radius:8px;text-decoration:none;font-weight:600;font-size:14px">${ctaText}</a>
    </div>` : ''}
  </div>
  <div style="text-align:center;padding:16px;color:#94a3b8;font-size:12px">
    ${tr('automatedNotice', lang)}
  </div>
</div>
</body></html>`;

  const text = `${heading}\n\n${bodyHtml.replace(/<blockquote[^>]*>(.*?)<\/blockquote>/gs, '> $1').replace(/<[^>]+>/g, '').replace(/&nbsp;/g, ' ').trim()}${ctaUrl ? `\n\n${ctaText}: ${ctaUrl}` : ''}`;

  return { html, text };
}

// ─── HELPERS ────────────────────────────────────────────────────

async function getUser(userId) {
  if (!userId) return null;
  try {
    const user = await nocodb.get('Users', userId);
    return user?.email ? { email: user.email, name: user.name || 'User', lang: user.preferred_language || 'en' } : null;
  } catch { return null; }
}

async function getMultipleUsers(userIds) {
  const results = await Promise.all(userIds.map(id => getUser(id)));
  return results.filter(Boolean);
}

function send({ to, subject, heading, bodyHtml, ctaText, ctaUrl, lang }) {
  const { html, text } = renderEmail({ heading, bodyHtml, ctaText, ctaUrl, lang });
  sendMail({ to, subject, html, text })
    .then(() => console.log(`[notifications] Sent "${subject}" to ${to}`))
    .catch(err => console.error(`[notifications] FAILED "${subject}" to ${to}:`, err.message));
}

const BLOCKQUOTE = 'style="margin:16px 0;padding:12px 16px;background:#fef3c7;border-left:4px solid #f59e0b;border-radius:4px;color:#92400e"';

// ─── NOTIFICATION EVENTS ────────────────────────────────────────

// 1. Review submitted → notify approvers
function notifyReviewSubmitted({ type, record, reviewUrl }) {
  const ids = parseApproverIds(record.approver_ids);
  if (ids.length === 0) return;
  const title = record.title || 'Untitled';

  getMultipleUsers(ids).then(users => {
    for (const user of users) {
      const l = user.lang;
      const typeLabel = tr(type, l);
      send({
        to: user.email, lang: l,
        subject: `${tr('reviewRequested', l)}: ${title}`,
        heading: tr('reviewRequested', l),
        bodyHtml: `
          <p>${tr('reviewRequestedBody', l)(typeLabel, title)}</p>
          <p>${tr('reviewFeedbackPrompt', l)}</p>`,
        ctaText: tr('reviewNow', l),
        ctaUrl: reviewUrl,
      });
    }
  });
}

// 2. Post/Artefact approved → notify creator
function notifyApproved({ type, record, approverName }) {
  const creatorId = record.created_by_user_id;
  if (!creatorId) return;
  const title = record.title || 'Untitled';

  getUser(creatorId).then(user => {
    if (!user) return;
    const l = user.lang;
    const typeLabel = tr(type === 'post' ? 'Post' : type === 'translation' ? 'Translation' : 'Artefact', l);
    send({
      to: user.email, lang: l,
      subject: `${tr('approved', l)}: ${title}`,
      heading: tr('approvedHeading', l)(typeLabel),
      bodyHtml: `<p>${tr('approvedBody', l)(title, approverName || (l === 'ar' ? 'مراجع' : 'a reviewer'))}</p>`,
      ctaText: `${tr('view', l)} ${typeLabel}`,
      ctaUrl: `${APP_URL}/${type === 'post' ? 'posts' : type === 'translation' ? 'translations' : 'artefacts'}`,
    });
  });
}

// 3. Post/Artefact rejected → notify creator
function notifyRejected({ type, record, approverName, feedback }) {
  const creatorId = record.created_by_user_id;
  if (!creatorId) return;
  const title = record.title || 'Untitled';

  getUser(creatorId).then(user => {
    if (!user) return;
    const l = user.lang;
    const typeLabel = tr(type === 'post' ? 'Post' : type === 'translation' ? 'Translation' : 'Artefact', l);
    send({
      to: user.email, lang: l,
      subject: `${tr('needsChanges', l)}: ${title}`,
      heading: tr('rejectedHeading', l)(typeLabel),
      bodyHtml: `
        <p>${tr('rejectedBody', l)(title, approverName || (l === 'ar' ? 'مراجع' : 'a reviewer'))}</p>
        ${feedback ? `<blockquote ${BLOCKQUOTE}>${feedback}</blockquote>` : ''}`,
      ctaText: `${tr('view', l)} ${typeLabel}`,
      ctaUrl: `${APP_URL}/${type === 'post' ? 'posts' : type === 'translation' ? 'translations' : 'artefacts'}`,
    });
  });
}

// 4. Revision requested (artefact) → notify creator
function notifyRevisionRequested({ type, record, approverName, feedback }) {
  const creatorId = record.created_by_user_id;
  if (!creatorId) return;
  const title = record.title || 'Untitled';
  const entityType = type === 'translation' ? 'Translation' : 'Artefact';
  const entityPath = type === 'translation' ? 'translations' : 'artefacts';

  getUser(creatorId).then(user => {
    if (!user) return;
    const l = user.lang;
    send({
      to: user.email, lang: l,
      subject: `${tr('revisionRequested', l)}: ${title}`,
      heading: tr('revisionRequested', l),
      bodyHtml: `
        <p>${tr('revisionRequestedBody', l)(title, approverName || (l === 'ar' ? 'مراجع' : 'a reviewer'))}</p>
        ${feedback ? `<blockquote ${BLOCKQUOTE}>${feedback}</blockquote>` : ''}`,
      ctaText: `${tr('view', l)} ${tr(entityType, l)}`,
      ctaUrl: `${APP_URL}/${entityPath}`,
    });
  });
}

// 5. Task assigned → notify assignee
function notifyTaskAssigned({ task, assignerName }) {
  const assigneeId = task.assigned_to_id;
  if (!assigneeId) return;
  const title = task.title || 'Untitled';

  getUser(assigneeId).then(user => {
    if (!user) return;
    const l = user.lang;
    send({
      to: user.email, lang: l,
      subject: `${tr('taskAssigned', l)}: ${title}`,
      heading: tr('taskAssignedHeading', l),
      bodyHtml: `
        <p>${tr('taskAssignedBody', l)(assignerName || (l === 'ar' ? 'أحدهم' : 'Someone'))}</p>
        <p style="font-size:16px;font-weight:600;color:#1e293b">${title}</p>
        ${task.description ? `<p style="color:#64748b">${task.description.substring(0, 200)}</p>` : ''}
        ${task.priority ? `<p>${tr('priority', l)}: <strong>${task.priority}</strong></p>` : ''}
        ${task.due_date ? `<p>${tr('dueDate', l)}: <strong>${task.due_date}</strong></p>` : ''}`,
      ctaText: tr('viewTask', l),
      ctaUrl: `${APP_URL}/tasks`,
    });
  });
}

// 6. Task completed → notify creator
function notifyTaskCompleted({ task }) {
  const creatorId = task.created_by_user_id;
  if (!creatorId || creatorId === task.assigned_to_id) return;
  const title = task.title || 'Untitled';

  getUser(creatorId).then(user => {
    if (!user) return;
    const l = user.lang;
    send({
      to: user.email, lang: l,
      subject: `${tr('taskCompleted', l)}: ${title}`,
      heading: tr('taskCompletedHeading', l),
      bodyHtml: `<p>${tr('taskCompletedBody', l)(title)}</p>`,
      ctaText: tr('viewTask', l),
      ctaUrl: `${APP_URL}/tasks`,
    });
  });
}

// 7. Issue assigned → notify assignee
function notifyIssueAssigned({ issue, assignerName }) {
  const assigneeId = issue.assigned_to_id;
  if (!assigneeId) return;
  const title = issue.title || 'Untitled';

  getUser(assigneeId).then(user => {
    if (!user) return;
    const l = user.lang;
    send({
      to: user.email, lang: l,
      subject: `${tr('issueAssigned', l)}: ${title}`,
      heading: tr('issueAssignedHeading', l),
      bodyHtml: `
        <p>${tr('issueAssignedBody', l)(assignerName || (l === 'ar' ? 'أحدهم' : 'Someone'))}</p>
        <p style="font-size:16px;font-weight:600;color:#1e293b">${title}</p>
        ${issue.priority ? `<p>${tr('priority', l)}: <strong>${issue.priority}</strong></p>` : ''}
        ${issue.category ? `<p>${tr('category', l)}: <strong>${issue.category}</strong></p>` : ''}`,
      ctaText: tr('viewIssue', l),
      ctaUrl: `${APP_URL}/issues`,
    });
  });
}

// 8. Issue status update → notify submitter (external — always English, no user record)
function notifyIssueStatusUpdate({ issue, oldStatus, newStatus }) {
  if (!issue.submitter_email || oldStatus === newStatus) return;
  const title = issue.title || 'Untitled';

  send({
    to: issue.submitter_email, lang: 'en',
    subject: `${tr('issueUpdate', 'en')}: ${title}`,
    heading: tr('issueUpdateHeading', 'en'),
    bodyHtml: `
      <p>${tr('issueUpdateBody', 'en')(title)}</p>
      <p><span style="color:#94a3b8">${oldStatus || 'new'}</span> → <strong style="color:#3b82f6">${newStatus}</strong></p>
      ${issue.resolution_summary ? `<p style="margin-top:12px"><strong>${tr('resolution', 'en')}:</strong> ${issue.resolution_summary}</p>` : ''}`,
    ctaText: issue.tracking_token ? tr('trackIssue', 'en') : null,
    ctaUrl: issue.tracking_token ? `${APP_URL}/track/${issue.tracking_token}` : null,
  });
}

// 9. Campaign created → notify team members
function notifyCampaignCreated({ campaign, creatorUserId }) {
  if (!campaign.team_id) return;
  const name = campaign.name || 'Untitled';

  nocodb.list('TeamMembers', { where: `(team_id,eq,${campaign.team_id})`, limit: 200 })
    .then(members => {
      const memberIds = members.map(m => m.user_id).filter(id => id !== creatorUserId);
      if (memberIds.length === 0) return;
      return getMultipleUsers(memberIds).then(users => {
        for (const user of users) {
          const l = user.lang;
          send({
            to: user.email, lang: l,
            subject: `${tr('newCampaign', l)}: ${name}`,
            heading: tr('campaignHeading', l),
            bodyHtml: `
              <p>${tr('campaignBody', l)(name)}</p>
              ${campaign.start_date && campaign.end_date ? `<p>${campaign.start_date} — ${campaign.end_date}</p>` : ''}`,
            ctaText: tr('viewCampaign', l),
            ctaUrl: `${APP_URL}/campaigns`,
          });
        }
      });
    })
    .catch(err => console.error('[notifications] Campaign team lookup failed:', err.message));
}

// 10. User invited → send welcome email (default English for new users)
function notifyUserInvited({ email, name, password, inviterName, lang = 'en' }) {
  const l = lang;
  send({
    to: email, lang: l,
    subject: `${tr('welcome', l)(name)} — ${tr('appName', l)}`,
    heading: tr('welcome', l)(name),
    bodyHtml: `
      <p>${tr('welcomeBody', l)(inviterName || (l === 'ar' ? 'فريقك' : 'Your team'))}</p>
      <div style="margin:16px 0;padding:16px;background:#f1f5f9;border-radius:8px">
        <p style="margin:0 0 8px"><strong>${tr('emailLabel', l)}:</strong> ${email}</p>
        <p style="margin:0"><strong>${tr('passwordLabel', l)}:</strong> ${password}</p>
      </div>
      <p style="color:#64748b;font-size:13px">${tr('changePassword', l)}</p>`,
    ctaText: tr('signIn', l),
    ctaUrl: `${APP_URL}/login`,
  });
}

module.exports = {
  notifyReviewSubmitted,
  notifyApproved,
  notifyRejected,
  notifyRevisionRequested,
  notifyTaskAssigned,
  notifyTaskCompleted,
  notifyIssueAssigned,
  notifyIssueStatusUpdate,
  notifyCampaignCreated,
  notifyUserInvited,
};