/*
 * Copyright (C) 2025 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.eyedropper.util

import android.hardware.input.InputManager
import android.os.Handler
import android.view.InputDevice
import androidx.compose.ui.geometry.Offset
import javax.inject.Inject
import javax.inject.Singleton

@Singleton // Match scope of InputManager
class InputHelper @Inject constructor(
    private val inputManager: InputManager,
    private val mainThreadHandler: Handler,
) {
    fun getInputDeviceIds(): IntArray {
        return inputManager.inputDeviceIds
    }

    fun isDesktopMode(): Boolean {
        return hasMouseConnected() && hasKeyboardConnected()
    }

    fun hasKeyboardConnected(): Boolean {
        return inputManager.inputDeviceIds.any { deviceId -> isFullKeyboard(deviceId) }
    }

    fun hasMouseConnected(): Boolean {
        return inputManager.inputDeviceIds.any { deviceId -> isMouse(deviceId)
        }
    }

    fun isFullKeyboard(deviceId: Int): Boolean {
        val device = inputManager.getInputDevice(deviceId) ?: return false
        return device.isEnabled && device.isFullKeyboard && !device.isVirtual
    }

    fun isMouse(deviceId: Int): Boolean {
        val device = inputManager.getInputDevice(deviceId) ?: return false
        return device.supportsSource(InputDevice.SOURCE_MOUSE) &&
                !device.isVirtual && device.isEnabled
    }

    fun registerInputDeviceListener(listener: InputManager.InputDeviceListener) {
        inputManager.registerInputDeviceListener(listener, mainThreadHandler)
    }

    fun unregisterInputDeviceListener(listener: InputManager.InputDeviceListener) {
        inputManager.unregisterInputDeviceListener(listener)
    }

    /**
     * Returns the coordinates of the cursor alongside its displayId.
     * Exhaustively search all displays until finds one with cursor, else null.
     */
    fun getCursorPosition(displayIds: Set<Int>): Pair<Int, Offset>? {
       displayIds.forEach { displayId ->
            val pos = inputManager.getCursorPosition(displayId)
            if (pos != null) {
                return Pair(displayId, Offset(pos.x, pos.y))
            }
        }
        return null
    }
}