//
//  UsbCameraAndroidPlugin.swift
//  usb_camera_android
//
//  Flutter iOS 插件入口：注册 MethodChannel / EventChannel / PlatformView，
//  通道名与 Android 端完全一致，上层 Dart 无需区分平台。
//

import Flutter
import UIKit

public class UsbCameraAndroidPlugin: NSObject, FlutterPlugin, FlutterStreamHandler {

    private static let METHOD_CHANNEL = "com.maibu.usb_camera_android/methods"
    private static let EVENT_CHANNEL = "com.maibu.usb_camera_android/events"
    private static let VIEW_TYPE = "com.maibu.usb_camera_android/preview"

    private let engine = UsbCameraEngine()

    public static func register(with registrar: FlutterPluginRegistrar) {
        let instance = UsbCameraAndroidPlugin()

        let methodChannel = FlutterMethodChannel(
            name: METHOD_CHANNEL, binaryMessenger: registrar.messenger())
        registrar.addMethodCallDelegate(instance, channel: methodChannel)

        let eventChannel = FlutterEventChannel(
            name: EVENT_CHANNEL, binaryMessenger: registrar.messenger())
        eventChannel.setStreamHandler(instance)

        registrar.register(UsbCameraViewFactory(engine: instance.engine),
                           withId: VIEW_TYPE)

        instance.engine.startMonitoring()
    }

    // MARK: - FlutterStreamHandler（转发给 engine）

    public func onListen(withArguments arguments: Any?,
                         eventSink events: @escaping FlutterEventSink) -> FlutterError? {
        return engine.onListen(withArguments: arguments, eventSink: events)
    }

    public func onCancel(withArguments arguments: Any?) -> FlutterError? {
        return engine.onCancel(withArguments: arguments)
    }

    // MARK: - MethodCallHandler

    public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
        switch call.method {
        case "isSupported":
            result(engine.isSupported())
        case "getDeviceList":
            result(engine.getDeviceList())
        case "getSupportedResolutions":
            result(engine.getSupportedResolutions())
        case "getPreviewSize":
            result(engine.getPreviewSize())
        case "open":
            let args = call.arguments as? [String: Any]
            engine.open(deviceId: args?["deviceId"] as? String,
                        resolution: args?["resolution"] as? String,
                        result: result)
        case "close":
            engine.close(result: result)
        case "setResolution":
            let args = call.arguments as? [String: Any]
            engine.setResolution(args?["resolution"] as? String, result: result)
        default:
            result(FlutterMethodNotImplemented)
        }
    }
}