/**
 * ESC/POS Driver Implementation
 * Converts high-level print commands to ESC/POS byte sequences
 */

import { IPrinterDriver, IQrOptions } from '@/types';
import { EncodingService } from '@/encoding';
import { Encoding } from '@/utils/encoding';
import { ImageProcessing } from '@/utils/image';
import { Logger } from '@/utils/logger';

/**
 * ESC/POS driver options
 */
export interface EscPosOptions {
  /** Use the new EncodingService for better GBK support (default: true) */
  useEncodingService?: boolean;
  /** Show warnings for unsupported characters (default: true) */
  showEncodingWarnings?: boolean;
  /** Fallback character for unsupported characters (default: '?') */
  fallbackChar?: string;
}

/**
 * ESC/POS thermal printer driver
 *
 * Implements the standard ESC/POS command set used by most thermal receipt printers.
 * Supports text, images, QR codes, and paper control commands.
 *
 * @example
 * ```typescript
 * const driver = new EscPos();
 * const commands = [
 *   ...driver.init(),
 *   ...driver.text('Hello World!'),
 *   ...driver.feed(2),
 *   ...driver.cut()
 * ];
 * ```
 */
export class EscPos implements IPrinterDriver {
  private readonly logger = Logger.scope('EscPos');
  private readonly encodingService: EncodingService;
  private readonly useEncodingService: boolean;

  /**
   * Creates a new EscPos driver instance
   * @param options - Driver options
   */
  constructor(options?: EscPosOptions) {
    this.useEncodingService = options?.useEncodingService ?? true;
    this.encodingService = new EncodingService({
      showWarnings: options?.showEncodingWarnings ?? true,
      fallbackChar: options?.fallbackChar ?? '?',
    });
  }

  /**
   * Initializes the printer
   * Sends ESC @ command to reset printer to default state
   *
   * @returns Array of command buffers
   */
  init(): Uint8Array[] {
    return [new Uint8Array([0x1b, 0x40])]; // ESC @
  }

  /**
   * Generates text print command
   *
   * @param content - Text content to print
   * @param encoding - Text encoding (default: 'GBK')
   * @returns Array of command buffers
   *
   * @example
   * ```typescript
   * driver.text('你好世界', 'GBK');
   * ```
   */
  text(content: string, encoding = 'GBK'): Uint8Array[] {
    if (!content || typeof content !== 'string') {
      return [];
    }

    // Use new EncodingService for better GBK/GB2312/Big5 support
    if (this.useEncodingService && this.encodingService.isSupported(encoding)) {
      const encoded = this.encodingService.encode(content, encoding);
      return [encoded];
    }

    // Fall back to legacy encoding for backward compatibility
    const encoded = Encoding.encode(content, encoding);
    return [encoded];
  }

  /**
   * Generates line feed command
   *
   * @param lines - Number of lines to feed (default: 1)
   * @returns Array of command buffers
   *
   * @example
   * ```typescript
   * driver.feed(3); // Feed 3 lines
   * ```
   */
  feed(lines = 1): Uint8Array[] {
    // 限制行数范围 1-255
    const safeLines = Math.max(1, Math.min(255, Math.floor(lines)));
    return [new Uint8Array([0x1b, 0x64, safeLines])]; // ESC d n
  }

  /**
   * Generates paper cut command
   *
   * @returns Array of command buffers
   *
   * @example
   * ```typescript
   * driver.cut();
   * ```
   */
  cut(): Uint8Array[] {
    return [new Uint8Array([0x1d, 0x56, 0x00])]; // GS V 0
  }

  /**
   * Generates image print command
   * Uses Floyd-Steinberg dithering for better quality
   *
   * @param data - RGBA pixel data
   * @param width - Image width in pixels
   * @param height - Image height in pixels
   * @returns Array of command buffers
   *
   * @example
   * ```typescript
   * const imageData = new Uint8Array(width * height * 4); // RGBA
   * driver.image(imageData, 200, 100);
   * ```
   */
  image(data: Uint8Array, width: number, height: number): Uint8Array[] {
    // 参数验证
    if (!data || !(data instanceof Uint8Array) || width <= 0 || height <= 0) {
      return [];
    }

    // 确保数据长度正确
    if (data.length !== width * height * 4) {
      this.logger.warn(
        `Invalid image data length: expected ${width * height * 4}, got ${data.length}`
      );
      return [];
    }

    const bitmap = ImageProcessing.toBitmap(data, width, height);
    const bytesPerLine = Math.ceil(width / 8);
    const xL = bytesPerLine % 256;
    const xH = Math.floor(bytesPerLine / 256);
    const yL = height % 256;
    const yH = Math.floor(height / 256);

    // GS v 0 m xL xH yL yH d1...dk
    const header = new Uint8Array([0x1d, 0x76, 0x30, 0x00, xL, xH, yL, yH]);
    return [header, bitmap];
  }

  /**
   * Generates QR code print command
   *
   * @param content - QR code content (URL, text, etc.)
   * @param options - QR code options
   * @returns Array of command buffers
   *
   * @example
   * ```typescript
   * driver.qr('https://example.com', {
   *   model: 2,
   *   size: 8,
   *   errorCorrection: 'M'
   * });
   * ```
   */
  qr(content: string, options?: IQrOptions): Uint8Array[] {
    // 参数验证
    if (!content || typeof content !== 'string') {
      return [];
    }

    const model = options?.model ?? 2;
    // 限制模块大小 1-16
    const size = Math.max(1, Math.min(16, options?.size ?? 6));
    const errorCorrection = options?.errorCorrection ?? 'M';

    const commands: Uint8Array[] = [];

    // 1. Set Model (Function 165)
    // GS ( k 04 00 31 41 n1 n2
    commands.push(
      new Uint8Array([0x1d, 0x28, 0x6b, 0x04, 0x00, 0x31, 0x41, model === 1 ? 49 : 50, 0])
    );

    // 2. Set Module Size (Function 167)
    // GS ( k 03 00 31 43 n (n = 1-16)
    commands.push(new Uint8Array([0x1d, 0x28, 0x6b, 0x03, 0x00, 0x31, 0x43, size]));

    // 3. Set Error Correction (Function 169)
    // GS ( k 03 00 31 45 n
    // n: 48 (L=7%), 49 (M=15%), 50 (Q=25%), 51 (H=30%)
    const ecMap: Record<string, number> = { L: 48, M: 49, Q: 50, H: 51 };
    const ecValue = ecMap[errorCorrection] ?? 49; // Default to M (15%)
    commands.push(new Uint8Array([0x1d, 0x28, 0x6b, 0x03, 0x00, 0x31, 0x45, ecValue]));

    // 4. Store Data (Function 180)
    // GS ( k pL pH 31 50 30 d1...dk
    // pL, pH: length of data + 3
    // Use new EncodingService for better GBK support
    const data =
      this.useEncodingService && this.encodingService.isSupported('GBK')
        ? this.encodingService.encode(content, 'GBK')
        : Encoding.encode(content, 'GBK');
    const len = data.length + 3;
    const pL = len % 256;
    const pH = Math.floor(len / 256);

    commands.push(new Uint8Array([0x1d, 0x28, 0x6b, pL, pH, 0x31, 0x50, 0x30]));
    commands.push(data);

    // 5. Print Symbol (Function 181)
    // GS ( k 03 00 31 51 30
    commands.push(new Uint8Array([0x1d, 0x28, 0x6b, 0x03, 0x00, 0x31, 0x51, 0x30]));

    return commands;
  }

  /**
   * ESC/POS: Open cash drawer (钱箱控制)
   * Sends ESC p command to trigger cash drawer kick-out
   *
   * @param pin - Cash drawer pin (0 or 1, default: 0)
   * @returns Array of command buffers
   */
  openCashDrawer(pin = 0): Uint8Array[] {
    return [new Uint8Array([0x1b, 0x70, pin, 50, 200])];
  }

  /**
   * ESC/POS: Sound buzzer (蜂鸣器)
   * Sends ESC B command to activate the printer's built-in buzzer
   *
   * @param times - Number of beeps (1-9, default: 3)
   * @param duration - Duration in ms (default: 50)
   * @returns Array of command buffers
   */
  beep(times = 3, duration = 50): Uint8Array[] {
    return [new Uint8Array([0x1b, 0x42, times, duration])];
  }

  /**
   * ESC/POS: Self test (自检)
   * Sends ESC i command to print a self-test page and return status
   *
   * @returns Array of command buffers
   */
  selfTest(): Uint8Array[] {
    return [new Uint8Array([0x1b, 0x69])];
  }

  /**
   * ESC/POS: Get printer status (状态查询)
   * Sends DLE EOT n commands to query printer, offline, error, and paper status
   *
   * @returns Array of command buffers (4 status queries)
   */
  getStatus(): Uint8Array[] {
    const buffers: Uint8Array[] = [];
    for (let i = 1; i <= 4; i++) {
      buffers.push(new Uint8Array([0x10, 0x04, i]));
    }
    return buffers;
  }

  /**
   * ESC/POS: Set character code page (代码页设置)
   * Sends ESC t command to select character code page
   *
   * @param codePage - Code page number (0-255)
   * @returns Array of command buffers
   */
  setCodePage(codePage: number): Uint8Array[] {
    return [new Uint8Array([0x1b, 0x74, codePage])];
  }

  /**
   * ESC/POS: Set left margin (左边界设置)
   * Sends ESC l command to set left margin in characters
   *
   * @param n - Number of characters from left edge
   * @returns Array of command buffers
   */
  setLeftMargin(n: number): Uint8Array[] {
    return [new Uint8Array([0x1b, 0x6c, n])];
  }

  /**
   * ESC/POS: Set print area width (打印区域宽度)
   * Sends ESC W command to set print width in characters
   *
   * @param n - Width in characters
   * @returns Array of command buffers
   */
  setPrintWidth(n: number): Uint8Array[] {
    return [new Uint8Array([0x1b, 0x57, n])];
  }
}