printer/lib/printer_method_channel.dart

import 'package:flutter/foundation.dart';
import 'package:flutter/services.dart';

import 'enums/multi_byte_encoding.dart';
import 'enums/printer_alignment.dart';
import 'enums/serial_flow_control.dart';
import 'enums/serial_parity.dart';
import 'enums/serial_stop_bits.dart';
import 'models/printer_exception.dart';
import 'printer_platform_interface.dart';

/// An implementation of [PrinterPlatform] that uses method channels.
class MethodChannelPrinter extends PrinterPlatform {
  /// The method channel used to interact with the native platform.
  @visibleForTesting
  final methodChannel = const MethodChannel('printer');

  @override
  Future<String?> getPlatformVersion() async {
    final version = await methodChannel.invokeMethod<String>(
      'getPlatformVersion',
    );
    return version;
  }

  @override
  Future<int> openComPort({
    required String portName,
    required int baudRate,
    int dataBits = 8,
    SerialParity parity = SerialParity.none,
    SerialStopBits stopBits = SerialStopBits.one,
    SerialFlowControl flowControl = SerialFlowControl.none,
    bool autoReplyMode = true,
  }) async {
    try {
      final result = await methodChannel.invokeMethod<int>('openComPort', {
        'portName': portName,
        'baudRate': baudRate,
        'dataBits': dataBits,
        'parity': parity.value,
        'stopBits': stopBits.value,
        'flowControl': flowControl.value,
        'autoReplyMode': autoReplyMode ? 1 : 0,
      });
      return result!;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to open COM port',
        details: e.details,
      );
    }
  }

  @override
  Future<int> openUsbPort({
    required String portName,
    bool autoReplyMode = true,
  }) async {
    try {
      final result = await methodChannel.invokeMethod<int>('openUsbPort', {
        'portName': portName,
        'autoReplyMode': autoReplyMode ? 1 : 0,
      });
      return result!;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to open USB port',
        details: e.details,
      );
    }
  }

  @override
  Future<bool> closePort(int handle) async {
    try {
      final result = await methodChannel.invokeMethod<bool>(
        'closePort',
        {'handle': handle},
      );
      return result ?? false;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to close port',
        details: e.details,
      );
    }
  }

  @override
  Future<bool> isPortOpened(int handle) async {
    try {
      final result = await methodChannel.invokeMethod<bool>(
        'isPortOpened',
        {'handle': handle},
      );
      return result ?? false;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to check port status',
        details: e.details,
      );
    }
  }

  @override
  Future<List<String>> enumComPorts() async {
    try {
      final result = await methodChannel.invokeMethod<List>('enumComPorts');
      return (result ?? []).map((e) => e.toString()).toList();
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to enumerate COM ports',
        details: e.details,
      );
    }
  }

  @override
  Future<List<String>> enumUsbPorts() async {
    try {
      final result = await methodChannel.invokeMethod<List>('enumUsbPorts');
      return (result ?? []).map((e) => e.toString()).toList();
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to enumerate USB ports',
        details: e.details,
      );
    }
  }

  /// Sets the printer to multi-byte encoding mode.
  @override
  Future<bool> setMultiByteMode(int handle) async {
    try {
      final result = await methodChannel.invokeMethod<bool>(
        'setMultiByteMode',
        {'handle': handle},
      );
      return result ?? false;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to set multi-byte mode',
        details: e.details,
      );
    }
  }

  /// Sets the multi-byte character encoding.
  @override
  Future<bool> setMultiByteEncoding(int handle, MultiByteEncoding encoding) async {
    try {
      final result = await methodChannel.invokeMethod<bool>(
        'setMultiByteEncoding',
        {'handle': handle, 'encoding': encoding.value},
      );
      return result ?? false;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to set multi-byte encoding',
        details: e.details,
      );
    }
  }

  /// Prints text using UTF-8 encoding.
  @override
  Future<bool> printText(int handle, String text) async {
    try {
      final result = await methodChannel.invokeMethod<bool>(
        'printText',
        {'handle': handle, 'text': text},
      );
      return result ?? false;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to print text',
        details: e.details,
      );
    }
  }

  /// Sets text alignment.
  @override
  Future<bool> setAlignment(int handle, PrinterAlignment alignment) async {
    try {
      final result = await methodChannel.invokeMethod<bool>(
        'setAlignment',
        {'handle': handle, 'alignment': alignment.value},
      );
      return result ?? false;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to set alignment',
        details: e.details,
      );
    }
  }

  /// Sets text scale (width and height magnification).
  @override
  Future<bool> setTextScale(int handle, {required int widthScale, required int heightScale}) async {
    try {
      final result = await methodChannel.invokeMethod<bool>(
        'setTextScale',
        {
          'handle': handle,
          'widthScale': widthScale,
          'heightScale': heightScale,
        },
      );
      return result ?? false;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to set text scale',
        details: e.details,
      );
    }
  }

  /// Sets text bold on or off.
  @override
  Future<bool> setTextBold(int handle, bool bold) async {
    try {
      final result = await methodChannel.invokeMethod<bool>(
        'setTextBold',
        {'handle': handle, 'bold': bold ? 1 : 0},
      );
      return result ?? false;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to set text bold',
        details: e.details,
      );
    }
  }

  /// Sets text underline level.
  @override
  Future<bool> setTextUnderline(int handle, int underline) async {
    try {
      final result = await methodChannel.invokeMethod<bool>(
        'setTextUnderline',
        {'handle': handle, 'underline': underline},
      );
      return result ?? false;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to set text underline',
        details: e.details,
      );
    }
  }

  /// Feeds paper by specified number of lines.
  @override
  Future<bool> feedLine(int handle, int numLines) async {
    try {
      final result = await methodChannel.invokeMethod<bool>(
        'feedLine',
        {'handle': handle, 'numLines': numLines},
      );
      return result ?? false;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to feed line',
        details: e.details,
      );
    }
  }

  /// Feeds paper by specified number of dots.
  @override
  Future<bool> feedDot(int handle, int numDots) async {
    try {
      final result = await methodChannel.invokeMethod<bool>(
        'feedDot',
        {'handle': handle, 'numDots': numDots},
      );
      return result ?? false;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to feed dot',
        details: e.details,
      );
    }
  }

  /// Performs a half cut of the paper.
  @override
  Future<bool> halfCutPaper(int handle) async {
    try {
      final result = await methodChannel.invokeMethod<bool>(
        'halfCutPaper',
        {'handle': handle},
      );
      return result ?? false;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to half cut paper',
        details: e.details,
      );
    }
  }

  /// Performs a full cut of the paper.
  @override
  Future<bool> fullCutPaper(int handle) async {
    try {
      final result = await methodChannel.invokeMethod<bool>(
        'fullCutPaper',
        {'handle': handle},
      );
      return result ?? false;
    } on PlatformException catch (e) {
      throw PrinterException(
        code: e.code,
        message: e.message ?? 'Failed to full cut paper',
        details: e.details,
      );
    }
  }
}