refactor/#9 : LoginViewModel에 코루틴 및 UiState 적용

app/src/main/java/com/sopt/now/test/data/ApiFactory.kt

@@ -13,7 +13,7 @@ import java.io.IOException
 object ApiFactory {
     private const val AUTH_BASE_URL: String = BuildConfig.AUTH_BASE_URL
     private const val FRIEND_BASE_URL: String = BuildConfig.FRIEND_BASE_URL
-    private lateinit var userPreference: UserPreference // UserPreference 추가
+    lateinit var userPreference: UserPreference // UserPreference 추가
 
     // UserPreference 초기화
     fun initializeUserPreference(userPreference: UserPreference) {

app/src/main/java/com/sopt/now/test/presentation/login/LoginViewModel.kt

@@ -0,0 +1,39 @@
+package com.sopt.now.test.presentation.login
+
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.sopt.now.test.core.view.UiState
+import com.sopt.now.test.data.ApiFactory
+import com.sopt.now.test.data.ServicePool
+import com.sopt.now.test.data.dto.request.RequestLoginDto
+import com.sopt.now.test.data.dto.response.ResponseAuthDto
+import kotlinx.coroutines.launch
+
+class LoginViewModel : ViewModel() {
+    private val _postLoginLiveData: MutableLiveData<UiState<ResponseAuthDto>> = MutableLiveData()
+    val postLoginLiveData: MutableLiveData<UiState<ResponseAuthDto>> = _postLoginLiveData
+
+    fun postLogin(request: RequestLoginDto) {
+        viewModelScope.launch {
+            runCatching {
+                ServicePool.authService.postLogin(request)
+            }.fold(
+                {
+                    val response = ServicePool.authService.postLogin(request)
+                    val userId = response.headers()["location"]
+                    if (userId != null) {
+                        ApiFactory.userPreference.saveUserId(userId)
+                    }
+                    _postLoginLiveData.value = UiState.Success(
+                        response.body() ?: ResponseAuthDto(
+                            -1,
+                            "Empty response body"
+                        )
+                    )
+                },
+                { _postLoginLiveData.value = UiState.Failure(it.message.toString()) }
+            )
+        }
+    }
+}