farmcontrol-ws/src/templates/templatemanager.js

import ejs from 'ejs';
import log4js from 'log4js';
import posthtml from 'posthtml';

import { documentTemplateModel } from '../database/schemas/management/documenttemplate.schema.js';
import '../database/schemas/management/documentsize.schema.js';
// Load configuration
import { loadConfig } from '../config.js';
import fs from 'fs';
import dayjs from 'dayjs';
import utc from 'dayjs/plugin/utc.js';
import timezone from 'dayjs/plugin/timezone.js';
import { fileURLToPath } from 'url';
import { dirname, join } from 'path';
import { getObject } from '../database/database.js';
const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);

// Extend plugins
dayjs.extend(utc);
dayjs.extend(timezone);

const config = loadConfig();

const logger = log4js.getLogger('Template Manager');
logger.level = config.server.logLevel;

let baseTemplate;
let baseCSS;
let previewTemplate;
let contentPlaceholder;

async function loadTemplates() {
  // Synchronously load files
  baseTemplate = fs.readFileSync(
    join(__dirname, '/assets/basetemplate.ejs'),
    'utf8'
  );
  baseCSS = fs.readFileSync(join(__dirname, '/assets/styles.css'), 'utf8');
  previewTemplate = fs.readFileSync(
    join(__dirname, '/assets/previewtemplate.ejs'),
    'utf8'
  );
  contentPlaceholder = fs.readFileSync(
    join(__dirname, '/assets/contentplaceholder.ejs'),
    'utf8'
  );
}

loadTemplates();

function getNodeStyles(attributes) {
  var styles = '';
  if (attributes?.padding) {
    styles += `padding: ${attributes.padding};`;
  }
  if (attributes?.width) {
    styles += `width: ${attributes.width};`;
  }
  if (attributes?.height) {
    styles += `height: ${attributes.height};`;
  }
  if (attributes?.gap && attributes?.vertical != 'true') {
    styles += `column-gap: ${attributes.gap};`;
  }
  if (attributes?.gap && attributes?.vertical == 'true') {
    styles += `row-gap: ${attributes.gap};`;
  }
  if (attributes?.justify) {
    styles += `justify-content: ${attributes.justify};`;
  }
  if (attributes?.align) {
    styles += `align-items: ${attributes.align};`;
  }
  if (attributes?.border) {
    styles += `border: ${attributes.border};`;
  }
  if (attributes?.borderRadius) {
    styles += `border-radius: ${attributes.borderRadius};`;
  }
  if (attributes?.vertical == 'true') {
    styles += `flex-direction: column;`;
  }
  if (attributes?.grow) {
    styles += `flex-grow: ${attributes.grow};`;
  }
  if (attributes?.shrink) {
    styles += `flex-shrink: ${attributes.shrink};`;
  }
  return styles;
}

async function transformCustomElements(content) {
  const result = await posthtml([
    tree =>
      tree.match({ tag: 'Title1' }, node => ({
        ...node,
        tag: 'h1',
        attrs: { class: 'documentTitle' }
      })),
    tree =>
      tree.match({ tag: 'Title2' }, node => ({
        ...node,
        tag: 'h2',
        attrs: { class: 'documentTitle' }
      })),
    tree =>
      tree.match({ tag: 'Title3' }, node => ({
        ...node,
        tag: 'h3',
        attrs: { class: 'documentText' }
      })),
    tree =>
      tree.match({ tag: 'Title4' }, node => ({
        ...node,
        tag: 'h4',
        attrs: { class: 'documentText' }
      })),
    tree =>
      tree.match({ tag: 'Text' }, node => ({
        ...node,
        tag: 'p',
        attrs: { class: 'documentText' }
      })),
    tree =>
      tree.match({ tag: 'Bold' }, node => ({
        ...node,
        tag: 'strong',
        attrs: { style: 'font-weight: bold;', class: 'documentBoldText' }
      })),
    tree =>
      tree.match({ tag: 'Barcode' }, node => {
        return {
          tag: 'svg',
          attrs: {
            class: 'documentBarcode',
            'jsbarcode-width': node.attrs?.width,
            'jsbarcode-height': node.attrs?.height,
            'jsbarcode-value': node.content[0],
            'jsbarcode-format': node.attrs.format
          }
        };
      }),
    tree =>
      tree.match({ tag: 'Container' }, node => ({
        ...node,
        tag: 'div',
        attrs: {
          class: 'documentContainer',
          style: getNodeStyles(node.attrs)
        }
      })),
    tree =>
      tree.match({ tag: 'Flex' }, node => {
        return {
          ...node,
          tag: 'div',
          attrs: {
            class: 'documentFlex',
            style: getNodeStyles(node.attrs)
          }
        };
      }),
    tree =>
      tree.match({ tag: 'Divider' }, node => {
        return {
          ...node,
          tag: 'hr',
          attrs: {
            class: 'documentDivider',
            style: getNodeStyles(node.attrs)
          }
        };
      }),
    tree =>
      tree.match({ tag: 'DateTime' }, node => {
        const dateTime = dayjs.utc(node.content[0]);
        return {
          content: [dateTime.format('YYYY-MM-DD hh:mm:ss')],
          tag: 'span',
          attrs: {
            class: 'documentDateTime',
            style: getNodeStyles(node.attrs)
          }
        };
      })
  ]).process(content);

  return result.html;
}

export class TemplateManager {
  /**
   * Previews an EJS template by rendering it with provided data
   * @param {string} templateString - The EJS template as a string
   * @param {Object} data - Data object to pass to the template
   * @param {Object} options - EJS rendering options
   * @returns {Promise<string>} The rendered HTML string
   */
  async renderTemplate(id, content, data = {}, scale, options = {}) {
    try {
      // Set default options for EJS rendering
      const defaultOptions = {
        async: true,
        ...options
      };

      const documentTemplate = await getObject({
        model: documentTemplateModel,
        id,
        populate: [
          { path: 'documentSize' },
          { path: 'parent', strictPopulate: false }
        ],
        cached: true
      });

      if (documentTemplate == null) {
        return { error: 'Document template not found.' };
      }

      const documentSize = documentTemplate.documentSize;

      var templateData = data;

      if (documentTemplate.global == true) {
        templateData = { content: contentPlaceholder };
      }

      // Render the template
      const templateContent = await ejs.render(
        content,
        templateData,
        defaultOptions
      );

      var templateWithParentContent;

      if (documentTemplate.parent != undefined) {
        templateWithParentContent = await ejs.render(
          documentTemplate.parent.content,
          { content: templateContent },
          defaultOptions
        );
      } else {
        templateWithParentContent = templateContent;
      }

      const templateHtml = await transformCustomElements(
        templateWithParentContent
      );

      const previewHtml = await ejs.render(
        previewTemplate,
        { content: templateHtml },
        defaultOptions
      );

      const baseHtml = await ejs.render(
        baseTemplate,
        {
          content: previewHtml,
          width: `${documentSize.width}mm`,
          height: `${documentSize.height}mm`,
          scale: `${scale}`,
          baseCSS: baseCSS
        },
        defaultOptions
      );

      const previewObject = {
        html: baseHtml
      };

      return previewObject;
    } catch (error) {
      logger.warn('Error whilst previewing template:', error.message);
      return { error: error.message };
    }
  }

  /**
   * Validates if a template string is valid EJS syntax
   * @param {string} templateString - The EJS template as a string
   * @returns {boolean} True if template is valid, false otherwise
   */
  validateTemplate(templateString) {
    try {
      // Try to compile the template to check for syntax errors
      ejs.compile(templateString);
      return true;
    } catch (error) {
      return false;
    }
  }
}