/*
 * 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.ui.desktop

import android.graphics.Bitmap
import androidx.compose.ui.geometry.Offset
import androidx.lifecycle.SavedStateHandle
import com.android.eyedropper.ui.BaseEyeDropperViewModel
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.asStateFlow

// TODO: b/353144000 - Implement with Hilt
/**
 * [BaseEyeDropperViewModel] subclass that manages additional desktop UX specific state:
 *
 * On initialization, we initialize the reticle to the current cursor position to provide a
 * seamless launch.
 *
 * This ViewModel supports multi-display, and is instantiated per display,
 */
class DesktopViewModel(
    savedStateHandle: SavedStateHandle,
) : BaseEyeDropperViewModel(savedStateHandle) {
    /**
     * The display with the cursor will display its reticle. Correctness is guaranteed by the fact
     * that there can only be one pointer.
     */
    private var _hasCursor = MutableStateFlow(false)
    val hasCursor = _hasCursor.asStateFlow()

    /**
     * Initialize at current cursor position, or center of screen (hypothetically impossible)
     */
    fun initialize(
        bitmap: Bitmap,
        cursorPosition: Offset?, // If null, then this display doesn't have the cursor
        onColorSelected: (Int) -> Unit,
        onSelectionCanceled: () -> Unit,
    ) {
        super.initialize(bitmap, onColorSelected, onSelectionCanceled)

        val initialPosition = cursorPosition ?: Offset.Zero
        updateBitmapPointerPosition(
            Offset(initialPosition.x, initialPosition.y)
        )
        updateHasCursor(cursorPosition != null)
    }

    fun updateHasCursor(hasCursor: Boolean) {
        _hasCursor.value = hasCursor
    }
}