/*
 * Copyright KG Soft
 *
 * 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.kgurgul.cpuinfo.features.information.sensors

import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import com.kgurgul.cpuinfo.domain.model.SensorData
import com.kgurgul.cpuinfo.domain.observable.SensorsDataObservable
import com.kgurgul.cpuinfo.domain.observe
import kotlinx.collections.immutable.ImmutableList
import kotlinx.collections.immutable.persistentListOf
import kotlinx.collections.immutable.toImmutableList
import kotlinx.coroutines.flow.SharingStarted
import kotlinx.coroutines.flow.map
import kotlinx.coroutines.flow.scan
import kotlinx.coroutines.flow.stateIn

class SensorsInfoViewModel(sensorsDataObservable: SensorsDataObservable) : ViewModel() {

    val uiStateFlow =
        sensorsDataObservable
            .observe()
            .scan(emptyList<SensorData>()) { previous, new ->
                buildList {
                    addAll(previous)
                    new.forEach { newSensorData ->
                        val updatedRowId = indexOfFirst { it.id == newSensorData.id }
                        if (updatedRowId != -1) {
                            set(
                                updatedRowId,
                                SensorData(
                                    id = newSensorData.id,
                                    name = newSensorData.name,
                                    value = newSensorData.value,
                                ),
                            )
                        } else {
                            add(newSensorData)
                        }
                    }
                }
            }
            .map { UiState(isInitializing = false, sensors = it.toImmutableList()) }
            .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5_000), UiState())

    data class UiState(
        val isInitializing: Boolean = true,
        val sensors: ImmutableList<SensorData> = persistentListOf(),
    )
}
