wfh/src/lib/google-drive.ts

import { google, Auth } from 'googleapis';
import { Readable } from 'stream';
import { readFileSync } from 'fs';
import path from 'path';
import { prisma } from './prisma';
import type { Prisma } from '@prisma/client';

// The MPM logo is embedded directly into the report HTML as a base64 data URI
// so it renders regardless of network reachability (e.g. a LAN-only deployment
// where Google's importer can't fetch an external URL). Read from disk once and
// cache; `null` means the asset was missing and the report renders without it.
let cachedLogoDataUri: string | null | undefined;
function getLogoDataUri(): string | null {
  if (cachedLogoDataUri !== undefined) return cachedLogoDataUri;
  try {
    const logoPath = path.join(process.cwd(), 'public', 'mpm-logo-doc.png');
    const b64 = readFileSync(logoPath).toString('base64');
    cachedLogoDataUri = `data:image/png;base64,${b64}`;
  } catch (error) {
    console.error('MPM report logo could not be loaded; rendering without it:', error);
    cachedLogoDataUri = null;
  }
  return cachedLogoDataUri;
}

type ReportWithRelations = Prisma.ReportGetPayload<{
  include: { tasks: true; user: true };
}>;

export async function getGoogleAuth(userId: string) {
  const account = await prisma.account.findFirst({
    where: { userId, provider: 'google' },
  });

  if (!account) {
    throw new Error('Google account not found');
  }

  const auth = new google.auth.OAuth2(
    process.env.GOOGLE_CLIENT_ID,
    process.env.GOOGLE_CLIENT_SECRET
  );

  auth.setCredentials({
    access_token: account.access_token,
    refresh_token: account.refresh_token,
    expiry_date: account.expires_at ? account.expires_at * 1000 : null,
  });

  // Check if the token is expired or will expire in the next 1 minute
  // NextAuth stores expires_at in seconds
  const isExpired = account.expires_at ? (account.expires_at * 1000) < (Date.now() + 60000) : true;

  if (isExpired && account.refresh_token) {
    try {
      const { credentials } = await auth.refreshAccessToken();
      auth.setCredentials(credentials);

      // Update database with new tokens
      await prisma.account.update({
        where: { id: account.id },
        data: {
          access_token: credentials.access_token,
          refresh_token: credentials.refresh_token || account.refresh_token,
          expires_at: credentials.expiry_date ? Math.floor(credentials.expiry_date / 1000) : null,
        },
      });
      console.log('Successfully refreshed Google access token for user:', userId);
    } catch (error) {
      console.error('Error refreshing access token:', error);
      // If refresh fails, we still return the auth object, but requests will fail with 401
    }
  }

  return auth;
}

export async function uploadToDrive(auth: Auth.OAuth2Client, fileName: string, content: string, folderId?: string) {
  const drive = google.drive({ version: 'v3', auth });

  const fileMetadata: { name: string; mimeType: string; parents?: string[] } = {
    name: fileName,
    mimeType: 'application/vnd.google-apps.document', // Automatically convert to Google Doc
  };

  if (folderId) {
    fileMetadata.parents = [folderId];
  }

  const media = {
    mimeType: 'text/html',
    body: Readable.from([content]),
  };

  try {
    const response = await drive.files.create({
      requestBody: fileMetadata,
      media: media,
      fields: 'id, webViewLink'
    });
    return response.data;
  } catch (error) {
    console.error('Error uploading to Google Drive:', error);
    throw error;
  }
}

export async function updateDriveFile(auth: Auth.OAuth2Client, fileId: string, content: string) {
  const drive = google.drive({ version: 'v3', auth });

  const media = {
    mimeType: 'text/html',
    body: Readable.from([content]),
  };

  try {
    const response = await drive.files.update({
      fileId,
      media,
      fields: 'id, webViewLink',
    });
    return response.data;
  } catch (error) {
    console.error('Error updating Google Drive file:', error);
    throw error;
  }
}

function escapeHtml(value: unknown): string {
  return String(value ?? '')
    .replace(/&/g, '&amp;')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
    .replace(/'/g, '&#39;');
}

// Only allow plain http(s) URLs into href attributes
function safeLink(link: unknown): string | null {
  const url = String(link ?? '').trim();
  return /^https?:\/\//i.test(url) ? url : null;
}

export function generateReportHTML(report: ReportWithRelations) {
  const dateObj = new Date(report.date);
  const dateStr = dateObj.toLocaleDateString('en-US', { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' });
  const plannedTasks = report.tasks.filter((t) => t.type === 'PLANNED');
  const completedTasks = report.tasks.filter((t) => t.type === 'COMPLETED');

  // MPM brand palette
  const GOLD_DARK = '#998643';   // titles on light backgrounds
  const GOLD_MID = '#DCBB4F';    // accent lines, dividers
  const SHADE_DARK = '#232022';  // body text / table header background
  const SHADE_LIGHT = '#F5F1EC'; // section panels / table header text
  const OFF_WHITE = '#FAF7F2';   // alternating table rows
  const ACCENT = '#849698';      // secondary / muted text

  const bodyFont = "'Open Sans', Arial, sans-serif";
  const headingFont = "'Montserrat', 'Open Sans', Arial, sans-serif";

  const cellStyle = `padding: 10px; border-bottom: 1px solid #E7E0D5; font-family: ${bodyFont}; font-size: 11pt; color: ${SHADE_DARK};`;
  const headerStyle = `padding: 12px 10px; background-color: ${SHADE_DARK}; font-family: ${headingFont}; font-size: 11pt; font-weight: 600; text-align: left; color: ${SHADE_LIGHT};`;

  // Embed the logo inline so it survives conversion without a reachable host.
  const logoDataUri = getLogoDataUri();
  const logoHtml = logoDataUri
    ? `<img src="${logoDataUri}" alt="Message Point Media" style="height: 44px; margin-bottom: 16px;" />`
    : '';

  const rowBg = (i: number) => (i % 2 === 1 ? ` background-color: ${OFF_WHITE};` : '');

  return `
    <html>
      <body style="font-family: ${bodyFont}; color: ${SHADE_DARK}; line-height: 1.6; max-width: 800px; margin: 0 auto; padding: 20px;">
        ${logoHtml}
        <h1 style="color: ${GOLD_DARK}; border-bottom: 3px solid ${GOLD_MID}; padding-bottom: 10px; font-family: ${headingFont}; font-weight: 700; margin-bottom: 20px;">WFH Daily Report</h1>

        <div style="background-color: ${SHADE_LIGHT}; padding: 20px; border-left: 4px solid ${GOLD_MID}; border-radius: 4px; margin-bottom: 30px; font-family: ${bodyFont};">
          <p style="margin: 0 0 8px 0; font-size: 11pt;"><strong>Date:</strong> ${dateStr}</p>
          <p style="margin: 0 0 8px 0; font-size: 11pt;"><strong>Employee:</strong> ${escapeHtml(report.user.name)}</p>
          <p style="margin: 0; font-size: 11pt;"><strong>Manager:</strong> ${escapeHtml(report.managerName || 'N/A')}</p>
        </div>

        <h2 style="color: ${GOLD_DARK}; margin-top: 30px; margin-bottom: 15px; font-family: ${headingFont}; font-weight: 600;">Planned Tasks</h2>
        ${plannedTasks.length > 0 ? `
          <table style="width: 100%; border-collapse: collapse; margin-bottom: 30px;">
            <tr>
              <th style="${headerStyle} width: 45%;">Description</th>
              <th style="${headerStyle} width: 20%;">Estimate</th>
              <th style="${headerStyle} width: 35%;">Notes</th>
            </tr>
            ${plannedTasks.map((t, i) => `
              <tr>
                <td style="${cellStyle}${rowBg(i)}">${escapeHtml(t.description)}</td>
                <td style="${cellStyle}${rowBg(i)} color: ${ACCENT};">${escapeHtml(t.timeEstimate || '-')}</td>
                <td style="${cellStyle}${rowBg(i)} color: ${ACCENT};">${escapeHtml(t.notes || '-')}</td>
              </tr>
            `).join('')}
          </table>
        ` : `<p style="font-style: italic; color: ${ACCENT}; font-family: ${bodyFont}; margin-bottom: 30px;">No planned tasks for today.</p>`}

        <h2 style="color: ${GOLD_DARK}; margin-top: 30px; margin-bottom: 15px; font-family: ${headingFont}; font-weight: 600;">Completed Tasks</h2>
        ${completedTasks.length > 0 ? `
          <table style="width: 100%; border-collapse: collapse; margin-bottom: 30px;">
            <tr>
              <th style="${headerStyle} width: 40%;">Description</th>
              <th style="${headerStyle} width: 20%;">Status</th>
              <th style="${headerStyle} width: 40%;">Work Link</th>
            </tr>
            ${completedTasks.map((t, i) => {
              const link = safeLink(t.link);
              return `
              <tr>
                <td style="${cellStyle}${rowBg(i)}">${escapeHtml(t.description)}</td>
                <td style="${cellStyle}${rowBg(i)} font-weight: bold; color: ${GOLD_DARK};">${escapeHtml(t.status || 'Done')}</td>
                <td style="${cellStyle}${rowBg(i)}">${link ? `<a href="${escapeHtml(link)}" style="color: ${GOLD_DARK}; text-decoration: none;">${escapeHtml(link)}</a>` : '-'}</td>
              </tr>
            `;
            }).join('')}
          </table>
        ` : `<p style="font-style: italic; color: ${ACCENT}; font-family: ${bodyFont}; margin-bottom: 30px;">No completed tasks reported today.</p>`}

        <div style="margin-top: 50px; font-size: 9pt; color: ${ACCENT}; text-align: center; border-top: 1px solid ${GOLD_MID}; padding-top: 20px; font-family: ${bodyFont};">
          <p style="margin: 0 0 4px 0; font-family: ${headingFont}; font-weight: 600; color: ${GOLD_DARK}; letter-spacing: 0.5px;">Born to Innovate. Built to Last.</p>
          <p style="margin: 0;">Message Point Media &middot; Generated automatically by the WFH Daily Report app</p>
        </div>
      </body>
    </html>
  `;
}