[feat] #7 paging source

core/data/build.gradle.kts

@@ -12,5 +12,8 @@ dependencies {
     implementation(projects.core.datastore)
     implementation(projects.core.database)
     implementation(projects.core.common)
+    implementation(projects.core.network)
     implementation(libs.retrofit.kotlin.serialization)
+    implementation(libs.kotlinx.serialization.json)
+    implementation(libs.androidx.paging)
 }

core/data/src/main/java/org/sopt/data/paging/UserPagingSource.kt

@@ -0,0 +1,39 @@
+package org.sopt.data.paging
+
+import androidx.paging.PagingSource
+import androidx.paging.PagingState
+import org.sopt.model.ReqresUser
+import org.sopt.network.api.ReqresApi
+import org.sopt.network.model.response.toReqresUser
+import retrofit2.HttpException
+import java.io.IOException
+import javax.inject.Inject
+
+class UserPagingSource @Inject constructor(
+    private val reqresApi: ReqresApi,
+) : PagingSource<Int, ReqresUser>() {
+    override fun getRefreshKey(state: PagingState<Int, ReqresUser>): Int? {
+        return state.anchorPosition
+    }
+
+    override suspend fun load(params: LoadParams<Int>): LoadResult<Int, ReqresUser> {
+        return try {
+            val currentPage = params.key ?: 1
+            val users = toReqresUser(
+                reqresApi.getUsers(
+                    currentPage
+                ).data
+            )
+
+            LoadResult.Page(
+                data = users,
+                prevKey = if (currentPage == 1) null else currentPage - 1,
+                nextKey = if (users.isEmpty()) null else currentPage + 1
+            )
+        } catch (exception: IOException) {
+            return LoadResult.Error(exception)
+        } catch (exception: HttpException) {
+            return LoadResult.Error(exception)
+        }
+    }
+}