feat: Implement functionality of the photolibrary module

Author: azrael8576

build-logic/convention/src/main/kotlin/AndroidLibraryConventionPlugin.kt

@@ -36,6 +36,11 @@ class AndroidLibraryConventionPlugin : Plugin<Project> {
                 add("androidTestImplementation", kotlin("test"))
                 add("androidTestImplementation", project(":core:testing"))
 
+                // Paging 3
+                add("implementation", libs.findLibrary("paging-runtime").get())
+                add("implementation", libs.findLibrary("paging-compose").get())
+                add("testImplementation", libs.findLibrary("paging-common").get())
+
                 // Timber
                 add("implementation", libs.findLibrary("timber").get())
             }

core/data/src/main/java/com/wei/picquest/core/data/model/ImageDetail.kt

@@ -0,0 +1,53 @@
+package com.wei.picquest.core.data.model
+
+import com.wei.picquest.core.network.model.NetworkImageDetail
+
+data class ImageDetail(
+    val id: Int,
+    val pageURL: String,
+    val type: String,
+    val tags: String,
+    val previewURL: String,
+    val previewWidth: Int,
+    val previewHeight: Int,
+    val webformatURL: String,
+    val webformatWidth: Int,
+    val webformatHeight: Int,
+    val largeImageURL: String,
+    val imageWidth: Int,
+    val imageHeight: Int,
+    val imageSize: Long,
+    val views: Int,
+    val downloads: Int,
+    val likes: Int,
+    val comments: Int,
+    val userId: Int,
+    val user: String,
+    val userImageURL: String,
+) {
+    val aspectRatio get() = imageWidth.toFloat() / imageHeight.toFloat()
+}
+
+fun NetworkImageDetail.asExternalModel() = ImageDetail(
+    id = this.id,
+    pageURL = this.pageURL,
+    type = this.type,
+    tags = this.tags,
+    previewURL = this.previewURL,
+    previewWidth = this.previewWidth,
+    previewHeight = this.previewHeight,
+    webformatURL = this.webformatURL,
+    webformatWidth = this.webformatWidth,
+    webformatHeight = this.webformatHeight,
+    largeImageURL = this.largeImageURL,
+    imageWidth = this.imageWidth,
+    imageHeight = this.imageHeight,
+    imageSize = this.imageSize,
+    views = this.views,
+    downloads = this.downloads,
+    likes = this.likes,
+    comments = this.comments,
+    userId = this.userId,
+    user = this.user,
+    userImageURL = this.userImageURL,
+)

core/data/src/main/java/com/wei/picquest/core/data/model/SearchImages.kt

@@ -1,35 +1,31 @@
 package com.wei.picquest.core.data.repository
 
-import com.wei.picquest.core.network.Dispatcher
-import com.wei.picquest.core.network.PqDispatchers
+import androidx.paging.Pager
+import androidx.paging.PagingConfig
+import androidx.paging.PagingData
+import androidx.paging.map
+import com.wei.picquest.core.data.model.ImageDetail
+import com.wei.picquest.core.data.model.asExternalModel
 import com.wei.picquest.core.network.PqNetworkDataSource
-import com.wei.picquest.core.network.model.NetworkSearchImages
-import kotlinx.coroutines.CoroutineDispatcher
+import com.wei.picquest.core.network.pagingsource.PixabayPagingSource
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.flow
-import kotlinx.coroutines.withContext
+import kotlinx.coroutines.flow.map
 import javax.inject.Inject
 
-/**
- * Implementation of the [SearchImagesRepository].
- * @param ioDispatcher 用於執行 IO 相關操作的 CoroutineDispatcher。
- * @param network 數據源的網路接口。
- */
 class DefaultSearchImagesRepository @Inject constructor(
-    @Dispatcher(PqDispatchers.IO) private val ioDispatcher: CoroutineDispatcher,
-    private val network: PqNetworkDataSource,
+    private val pqNetworkDataSource: PqNetworkDataSource,
 ) : SearchImagesRepository {
 
-    /**
-     * @param query。A URL encoded search term. If omitted, all images are returned. This value may not exceed 100 characters.
-     * Example: "yellow+flower"
-     * @return 一個 Flow，內容為 Search Images 的數據。
-     */
-    override suspend fun getSearchImages(
-        query: String,
-    ): Flow<NetworkSearchImages> = withContext(ioDispatcher) {
-        flow {
-            emit(network.searchImages(query))
+    override suspend fun getSearchImages(query: String): Flow<PagingData<ImageDetail>> {
+        return Pager(
+            config = PagingConfig(
+                pageSize = 20,
+                prefetchDistance = 5,
+                enablePlaceholders = false,
+            ),
+            pagingSourceFactory = { PixabayPagingSource(pqNetworkDataSource, query) },
+        ).flow.map { pagingData ->
+            pagingData.map { it.asExternalModel() }
         }
     }
 }

core/data/src/main/java/com/wei/picquest/core/data/repository/DefaultSearchImagesRepository.kt

@@ -1,9 +1,10 @@
 package com.wei.picquest.core.data.repository
 
-import com.wei.picquest.core.network.model.NetworkSearchImages
+import androidx.paging.PagingData
+import com.wei.picquest.core.data.model.ImageDetail
 import kotlinx.coroutines.flow.Flow
 
 interface SearchImagesRepository {
 
-    suspend fun getSearchImages(query: String): Flow<NetworkSearchImages>
+    suspend fun getSearchImages(query: String): Flow<PagingData<ImageDetail>>
 }

core/data/src/main/java/com/wei/picquest/core/data/repository/SearchImagesRepository.kt

@@ -14,8 +14,10 @@ import androidx.compose.material.icons.rounded.ArrowForward
 import androidx.compose.material.icons.rounded.ArrowForwardIos
 import androidx.compose.material.icons.rounded.CalendarMonth
 import androidx.compose.material.icons.rounded.Close
+import androidx.compose.material.icons.rounded.GridView
 import androidx.compose.material.icons.rounded.Home
 import androidx.compose.material.icons.rounded.Info
+import androidx.compose.material.icons.rounded.List
 import androidx.compose.material.icons.rounded.Menu
 import androidx.compose.material.icons.rounded.Person
 import androidx.compose.material.icons.rounded.Phone
@@ -55,4 +57,6 @@ object PqIcons {
     val Person = Icons.Rounded.Person
     val Menu = Icons.Rounded.Menu
     val Add = Icons.Rounded.Add
+    val ListView = Icons.Rounded.List
+    val GridView = Icons.Rounded.GridView
 }

core/designsystem/src/main/java/com/wei/picquest/core/designsystem/icon/PqIcons.kt

@@ -7,5 +7,5 @@ import com.wei.picquest.core.network.model.NetworkSearchImages
  */
 interface PqNetworkDataSource {
 
-    suspend fun searchImages(query: String): NetworkSearchImages
+    suspend fun searchImages(query: String, page: Int, perPage: Int): NetworkSearchImages
 }

core/network/src/main/java/com/wei/picquest/core/network/PqNetworkDataSource.kt

@@ -0,0 +1,37 @@
+package com.wei.picquest.core.network.pagingsource
+
+import androidx.paging.PagingSource
+import androidx.paging.PagingState
+import com.wei.picquest.core.network.PqNetworkDataSource
+import com.wei.picquest.core.network.model.NetworkImageDetail
+
+class PixabayPagingSource(
+    private val pqNetworkDataSource: PqNetworkDataSource,
+    private val query: String,
+) : PagingSource<Int, NetworkImageDetail>() {
+
+    override suspend fun load(params: LoadParams<Int>): LoadResult<Int, NetworkImageDetail> {
+        try {
+            val currentPage = params.key ?: 1
+            val response = pqNetworkDataSource.searchImages(
+                query = query,
+                page = currentPage,
+                perPage = 20,
+            )
+
+            val endOfPaginationReached = response.hits.isEmpty()
+
+            return LoadResult.Page(
+                data = response.hits,
+                prevKey = if (currentPage == 1) null else currentPage - 1,
+                nextKey = if (endOfPaginationReached) null else currentPage + 1,
+            )
+        } catch (exception: Exception) {
+            return LoadResult.Error(exception)
+        }
+    }
+
+    override fun getRefreshKey(state: PagingState<Int, NetworkImageDetail>): Int? {
+        return state.anchorPosition
+    }
+}

core/network/src/main/java/com/wei/picquest/core/network/pagingsource/PixabayPagingSource.kt

@@ -28,6 +28,8 @@ interface RetrofitPixabayApi {
         @Query("key") apiKey: String = API_KEY,
         @Query("q") query: String,
         @Query("image_type") imageType: String = "photo",
+        @Query("page") page: Int,
+        @Query("perPage") perPage: Int,
         // Add more parameters as needed
     ): NetworkSearchImages
 }
@@ -50,7 +52,7 @@ class RetrofitPqNetwork @Inject constructor(
         .build()
         .create(RetrofitPixabayApi::class.java)
 
-    override suspend fun searchImages(query: String): NetworkSearchImages {
-        return pixabayApi.searchImages(query = query)
+    override suspend fun searchImages(query: String, page: Int, perPage: Int): NetworkSearchImages {
+        return pixabayApi.searchImages(query = query, page = page, perPage = perPage)
     }
 }