chore: improve data layer abstraction for search suggestions

/*

 * Copyright (C) 2026 e Foundation

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>.

 *

 */

package foundation.e.apps.data.playstore.search

import foundation.e.apps.data.playstore.PlayStoreSearchHelper

import foundation.e.apps.data.search.SuggestionSource

import java.util.Locale

import javax.inject.Inject

private const val MAX_SUGGESTIONS = 10

class PlayStoreSuggestionSource @Inject constructor(

    private val playStoreSearchHelper: PlayStoreSearchHelper,

) : SuggestionSource {

    override suspend fun suggest(query: String): List<String> {

        val trimmed = query.trim()

        if (trimmed.isEmpty()) {

            return emptyList()

        }

        return runCatching {

            playStoreSearchHelper.getSearchSuggestions(trimmed)

                .asSequence()

                .map { it.suggestion }

                .map { it.trim() }

                .filter { it.isNotEmpty() }

                .distinctBy { it.lowercase(Locale.getDefault()) }

                .take(MAX_SUGGESTIONS)

                .toList()

        }.getOrElse { emptyList() }

    }

}

/*

 * Copyright (C) 2025 e Foundation

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>.

 *

 */

package foundation.e.apps.data.search

interface SuggestionSource {

    suspend fun suggest(query: String): List<String>

}

/*

 * Copyright (C) 2025 e Foundation

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>.

 *

 */

package foundation.e.apps.di

import dagger.Binds

import dagger.Module

import dagger.hilt.InstallIn

import dagger.hilt.components.SingletonComponent

import foundation.e.apps.data.playstore.search.PlayStoreSuggestionSource

import foundation.e.apps.data.search.SuggestionSource

import javax.inject.Singleton

@Module

@InstallIn(SingletonComponent::class)

abstract class SearchSuggestionModule {

    @Binds

    @Singleton

    abstract fun bindSuggestionSource(impl: PlayStoreSuggestionSource): SuggestionSource

}

package foundation.e.apps.ui.search.v2

import androidx.lifecycle.ViewModel

import androidx.lifecycle.viewModelScope

import dagger.hilt.android.lifecycle.HiltViewModel

import foundation.e.apps.data.search.SuggestionSource

import kotlinx.coroutines.Job

import kotlinx.coroutines.delay

import kotlinx.coroutines.flow.MutableStateFlow

import kotlinx.coroutines.flow.StateFlow

import kotlinx.coroutines.flow.asStateFlow

import kotlinx.coroutines.flow.update

import kotlinx.coroutines.launch

import javax.inject.Inject

private const val SUGGESTION_DEBOUNCE_MS = 200L

data class SearchUiState(

    val query: String = "",

    val suggestions: List<String> = emptyList(),

    val isSuggestionVisible: Boolean = false,

)

@HiltViewModel

class SearchViewModelV2 @Inject constructor() : ViewModel()

class SearchViewModelV2 @Inject constructor(

    private val suggestionSource: SuggestionSource,

) : ViewModel() {

    private val _uiState = MutableStateFlow(SearchUiState())

    val uiState: StateFlow<SearchUiState> = _uiState.asStateFlow()

    private var suggestionJob: Job? = null

    fun onQueryChanged(newQuery: String) {

        _uiState.update { current ->

            current.copy(query = newQuery)

        }

        suggestionJob?.cancel()

        if (newQuery.isBlank()) {

            _uiState.update { current ->

                current.copy(

                    suggestions = emptyList(),

                    isSuggestionVisible = false,

                )

            }

            return

        }

        suggestionJob = viewModelScope.launch {

            delay(SUGGESTION_DEBOUNCE_MS)

            val suggestions = suggestionSource.suggest(newQuery)

            _uiState.update { current ->

                current.copy(

                    suggestions = suggestions,

                    isSuggestionVisible = suggestions.isNotEmpty(),

                )

            }

        }

    }

    fun onSuggestionSelected(suggestion: String) {

        _uiState.update { current ->

            current.copy(

                query = suggestion,

                suggestions = emptyList(),

                isSuggestionVisible = false,

            )

        }

    }

    fun onQueryCleared() {

        suggestionJob?.cancel()

        _uiState.value = SearchUiState()

    }

    fun onSearchSubmitted(submitted: String) {

        _uiState.update { current ->

            current.copy(

                query = submitted,

                suggestions = emptyList(),

                isSuggestionVisible = false,

            )

        }

    }

}