task_receipts/server/src/printer/serial-printer.ts

import { Printer } from "@node-escpos/core";
import USB from "@node-escpos/usb-adapter";
import { Task, Step, Printer as PrinterInterface } from '@shared/index';
import { steps } from '../db';
import { Knex } from 'knex';
import logger from '../logger';

export class SerialPrinter implements PrinterInterface {
  private device: USB | null = null;
  private printer: Printer<[]> | null = null;

  constructor() {
    this.initializePrinter();
  }

  private async initializePrinter() {
    try {
      this.device = new USB();
      await new Promise<void>((resolve, reject) => {
        this.device?.open((err) => {
          if (err) {
            logger.error('Failed to open printer:', err);
            reject(err);
            return;
          }
          resolve();
        });
      });

      const options = { encoding: "CP437" };
      this.printer = new Printer(this.device, options);
      logger.info('Printer initialized successfully');
    } catch (error) {
      logger.error('Failed to initialize printer:', error);
    }
  }

  async getTaskSteps(db: Knex, task: Task): Promise<Step[]> {
    return await steps(db).where('task_id', task.id).orderBy('order').select('*');
  }

  async printTask(task: Task, db: Knex): Promise<void> {
    if (!this.printer || !this.device) {
      throw new Error('Printer not initialized');
    }

    const taskSteps = await this.getTaskSteps(db, task);

    try {
      // Print header with task ID as barcode
      await this.printer
        .font('a')
        .align('ct')
        .style('b')
        .size(1, 1)  // Normal size (0.08 x 2.13 mm)
        .text(`Task: ${task.name}`)
        .text('='.repeat(32))
        .text('')
        .align('lt');

      // Print task ID as barcode
      await this.printer
        .barcode(task.id.toString(), 'CODE128', { width: 2, height: 50 })
        .text('')
        .text('');

      // Print steps
      for (let i = 0; i < taskSteps.length; i++) {
        const step = taskSteps[i];
        await this.printer
          .size(1, 1)  // Normal size for step header
          .text(`Step ${i + 1}: ${step.name}`)
          .text('-'.repeat(32))
          .size(0, 0)  // Smaller size for instructions (0.08 x 2.13 mm)
          .text(step.instructions)
          .text('');

        // Print step ID as barcode
        await this.printer
          .barcode(step.id.toString(), 'CODE128', { width: 2, height: 50 })
          .text('');
      }

      await this.printer
        .text('')
        .text('')
        .cut()
        .close();

      logger.info(`Printed task ${task.id}`);
    } catch (error) {
      logger.error('Failed to print task:', error);
      throw error;
    }
  }

  async printStep(step: Step, db: Knex): Promise<void> {
    if (!this.printer || !this.device) {
      throw new Error('Printer not initialized');
    }

    try {
      await this.printer
        .font('a')
        .align('ct')
        .style('b')
        .size(1, 1)  // Normal size (0.08 x 2.13 mm)
        .text(`Step: ${step.name}`)
        .text('='.repeat(32))
        .text('')
        .align('lt')
        .size(0, 0)  // Smaller size for instructions
        .text(step.instructions)
        .text('')
        .text('');

      // Print step ID as barcode
      await this.printer
        .barcode(step.id.toString(), 'CODE128', { width: 2, height: 50 })
        .text('')
        .text('')
        .cut()
        .close();

      logger.info(`Printed step ${step.id}`);
    } catch (error) {
      logger.error('Failed to print step:', error);
      throw error;
    }
  }
}