feat: add ESC/POS renderer

src/engine/escpos.ts

@@ -0,0 +1,84 @@
+// ESC/POS 指令常量
+export const ESC = 0x1B;
+export const GS = 0x1D;
+export const LF = 0x0A;
+export const CR = 0x0D;
+
+// 初始化打印机
+export function initialize(): Uint8Array {
+  return new Uint8Array([ESC, 0x40]);
+}
+
+// 切纸
+export function cut(): Uint8Array {
+  return new Uint8Array([GS, 0x56, 0x00]);
+}
+
+// 文本编码
+export function text(str: string): Uint8Array {
+  const encoder = new TextEncoder();
+  return encoder.encode(str);
+}
+
+// 换行
+export function newline(): Uint8Array {
+  return new Uint8Array([LF]);
+}
+
+// 加粗
+export function bold(on: boolean): Uint8Array {
+  return new Uint8Array([ESC, 0x45, on ? 1 : 0]);
+}
+
+// 下划线
+export function underline(on: boolean): Uint8Array {
+  return new Uint8Array([ESC, 0x2D, on ? 1 : 0]);
+}
+
+// 对齐
+export function align(align: 'left' | 'center' | 'right'): Uint8Array {
+  const n = align === 'left' ? 0 : align === 'center' ? 1 : 2;
+  return new Uint8Array([ESC, 0x61, n]);
+}
+
+// 字体大小
+export function fontSize(size: 'small' | 'normal' | 'large' | 'xlarge'): Uint8Array {
+  let n = 0;
+  switch (size) {
+    case 'small': n = 0; break;
+    case 'normal': n = 0; break;
+    case 'large': n = 0x11; break;
+    case 'xlarge': n = 0x22; break;
+  }
+  return new Uint8Array([GS, 0x21, n]);
+}
+
+// 恢复默认字体大小
+export function resetFontSize(): Uint8Array {
+  return new Uint8Array([GS, 0x21, 0]);
+}
+
+// 打印条码 (CODE128)
+export function barcodeCode128(data: string, height: number = 64): Uint8Array {
+  const encoder = new TextEncoder();
+  const dataBytes = encoder.encode(data);
+  return new Uint8Array([
+    GS, 0x68, height,
+    GS, 0x6B, 0x49, dataBytes.length,
+    ...dataBytes,
+    0
+  ]);
+}
+
+// 打印 QR 码
+export function qrCode(data: string, size: number = 3): Uint8Array {
+  const encoder = new TextEncoder();
+  const dataBytes = encoder.encode(data);
+  const len = dataBytes.length + 3;
+  return new Uint8Array([
+    GS, 0x28, 0x6B, 0x03, 0x00, 0x31, 0x43, size,
+    GS, 0x28, 0x6B, len & 0xFF, (len >> 8) & 0xFF, 0x31, 0x50, 0x30,
+    ...dataBytes,
+    GS, 0x28, 0x6B, 0x03, 0x00, 0x31, 0x51, 0x30
+  ]);
+}

src/engine/render.ts

@@ -0,0 +1,73 @@
+import Mustache from 'mustache';
+import type { Template, Block } from '../types/template';
+import * as escpos from './escpos';
+
+export function renderTemplate(template: Template, data: any): Uint8Array {
+  const buffers: Uint8Array[] = [];
+  
+  // 初始化打印机
+  buffers.push(escpos.initialize());
+  
+  // 渲染每个 block
+  for (const block of template.blocks) {
+    buffers.push(renderBlock(block, data, template.defaults));
+  }
+  
+  // 切纸
+  buffers.push(escpos.cut());
+  
+  return mergeBuffers(buffers);
+}
+
+function renderBlock(block: Block, data: any, defaults: any = {}): Uint8Array {
+  // 根据 block 类型渲染
+  switch (block.type) {
+    case 'text':
+      return renderTextBlock(block, data);
+    case 'divider':
+      return renderDividerBlock(block);
+    case 'space':
+      return renderSpaceBlock(block);
+    default:
+      console.warn(`Unknown block type: ${(block as any).type}`);
+      return new Uint8Array(0);
+  }
+}
+
+function renderTextBlock(block: any, data: any): Uint8Array {
+  const buffers: Uint8Array[] = [];
+  buffers.push(escpos.align(block.align || 'left'));
+  buffers.push(escpos.bold(block.bold || false));
+  const content = Mustache.render(block.content, data);
+  buffers.push(escpos.text(content));
+  buffers.push(escpos.newline());
+  buffers.push(escpos.bold(false));
+  buffers.push(escpos.align('left'));
+  return mergeBuffers(buffers);
+}
+
+function renderDividerBlock(block: any): Uint8Array {
+  const char = block.char || '-';
+  const line = char.repeat(48);
+  return mergeBuffers([escpos.text(line), escpos.newline()]);
+}
+
+function renderSpaceBlock(block: any): Uint8Array {
+  const lines = block.lines || 1;
+  const buffers: Uint8Array[] = [];
+  for (let i = 0; i < lines; i++) {
+    buffers.push(escpos.newline());
+  }
+  return mergeBuffers(buffers);
+}
+
+function mergeBuffers(buffers: Uint8Array[]): Uint8Array {
+  const totalLength = buffers.reduce((sum, buf) => sum + buf.length, 0);
+  const result = new Uint8Array(totalLength);
+  let offset = 0;
+  for (const buf of buffers) {
+    result.set(buf, offset);
+    offset += buf.length;
+  }
+  return result;
+}

tests/render.test.ts

@@ -0,0 +1,52 @@
+import { describe, it, expect } from 'bun:test';
+import { renderTemplate } from '../src/engine/render';
+import type { Template } from '../src/types/template';
+
+describe('Template Renderer', () => {
+  it('should render text block', () => {
+    const template: Template = {
+      id: 'test',
+      name: 'Test',
+      width: '80mm',
+      blocks: [
+        { type: 'text', content: 'Hello World', align: 'center' }
+      ]
+    };
+    
+    const data = {};
+    const result = renderTemplate(template, data);
+    expect(result).toBeInstanceOf(Uint8Array);
+    expect(result.length).toBeGreaterThan(0);
+  });
+
+  it('should substitute mustache variables', () => {
+    const template: Template = {
+      id: 'test',
+      name: 'Test',
+      width: '80mm',
+      blocks: [
+        { type: 'text', content: 'Hello {{name}}' }
+      ]
+    };
+    
+    const data = { name: 'Alice' };
+    const result = renderTemplate(template, data);
+    const text = new TextDecoder().decode(result);
+    expect(text).toContain('Hello Alice');
+  });
+
+  it('should render divider', () => {
+    const template: Template = {
+      id: 'test',
+      name: 'Test',
+      width: '80mm',
+      blocks: [
+        { type: 'divider', char: '=' }
+      ]
+    };
+    
+    const result = renderTemplate(template, {});
+    const text = new TextDecoder().decode(result);
+    expect(text).toContain('========');
+  });
+});