1 /*
<lambda>null2  * Copyright (C) 2023 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  *
16  */
17 
18 package com.android.customization.picker.grid.domain.interactor
19 
20 import com.android.customization.model.CustomizationManager
21 import com.android.customization.picker.grid.data.repository.GridRepository
22 import com.android.customization.picker.grid.shared.model.GridOptionItemModel
23 import com.android.customization.picker.grid.shared.model.GridOptionItemsModel
24 import javax.inject.Provider
25 import kotlinx.coroutines.CoroutineScope
26 import kotlinx.coroutines.flow.Flow
27 import kotlinx.coroutines.flow.SharingStarted
28 import kotlinx.coroutines.flow.emptyFlow
29 import kotlinx.coroutines.flow.flatMapLatest
30 import kotlinx.coroutines.flow.flow
31 import kotlinx.coroutines.flow.map
32 import kotlinx.coroutines.flow.onStart
33 import kotlinx.coroutines.flow.shareIn
34 
35 class GridInteractor(
36     private val applicationScope: CoroutineScope,
37     private val repository: GridRepository,
38     private val snapshotRestorer: Provider<GridSnapshotRestorer>,
39 ) {
40     val options: Flow<GridOptionItemsModel> =
41         flow { emit(repository.isAvailable()) }
42             .flatMapLatest { isAvailable ->
43                 if (isAvailable) {
44                     // this upstream flow tells us each time the options are changed.
45                     repository
46                         .getOptionChanges()
47                         // when we start, we pretend the options _just_ changed. This way, we load
48                         // something as soon as possible into the flow so it's ready by the time the
49                         // first observer starts to observe.
50                         .onStart { emit(Unit) }
51                         // each time the options changed, we load them.
52                         .map { reload() }
53                         // we place the loaded options in a SharedFlow so downstream observers all
54                         // share the same flow and don't trigger a new one each time they want to
55                         // start observing.
56                         .shareIn(
57                             scope = applicationScope,
58                             started = SharingStarted.WhileSubscribed(),
59                             replay = 1,
60                         )
61                 } else {
62                     emptyFlow()
63                 }
64             }
65 
66     suspend fun setSelectedOption(model: GridOptionItemModel) {
67         model.onSelected.invoke()
68     }
69 
70     suspend fun getSelectedOption(): GridOptionItemModel? {
71         return (repository.getOptions() as? GridOptionItemsModel.Loaded)?.options?.firstOrNull {
72             optionItem ->
73             optionItem.isSelected.value
74         }
75     }
76 
77     fun getSelectOptionStateFlow() = repository.getSelectedOption()
78 
79     fun clearSelectedOption() = repository.clearSelectedOption()
80 
81     fun isSelectedOptionApplied() = repository.isSelectedOptionApplied()
82 
83     fun applySelectedOption(callback: CustomizationManager.Callback) {
84         repository.applySelectedOption(callback)
85     }
86 
87     private suspend fun reload(): GridOptionItemsModel {
88         val model = repository.getOptions()
89         return if (model is GridOptionItemsModel.Loaded) {
90             GridOptionItemsModel.Loaded(
91                 options =
92                     model.options.map { option ->
93                         GridOptionItemModel(
94                             name = option.name,
95                             cols = option.cols,
96                             rows = option.rows,
97                             isSelected = option.isSelected,
98                             onSelected = {
99                                 option.onSelected()
100                                 snapshotRestorer.get().store(option)
101                             },
102                         )
103                     }
104             )
105         } else {
106             model
107         }
108     }
109 }
110