feat: 新建记录标题预填拍摄日期并支持联动

core/src/main/kotlin/plus/rua/project/RecordEditViewModel.kt

@@ -10,6 +10,7 @@ import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
+import kotlinx.datetime.number
 import kotlinx.datetime.todayIn
 import java.io.File
 import kotlin.time.Clock
@@ -58,6 +59,9 @@ class RecordEditViewModel(
     private val _uiState = MutableStateFlow(RecordEditUiState())
     val uiState: StateFlow<RecordEditUiState> = _uiState.asStateFlow()
 
+    /** 用户是否手动编辑过标题；为 false 时标题随拍摄日期联动 */
+    private var titleManuallyEdited = false
+
     init {
         if (recordId != null) {
             loadExistingRecord(recordId)
@@ -69,11 +73,14 @@ class RecordEditViewModel(
     private fun initNewRecord() {
         requireNotNull(photoPath) { "新建模式必须提供 photoPath" }
         val file = File(photoPath)
+        val today = Clock.System.todayIn(TimeZone.currentSystemDefault())
         _uiState.value = RecordEditUiState(
             loading = false,
+            title = formatLocalDate(today),
+            shootDate = today,
             photoUri = "file://${file.absolutePath}",
             photoAbsolutePath = file.absolutePath,
-            canSave = false,
+            canSave = true,
             isExistingRecord = false
         )
     }
@@ -83,6 +90,7 @@ class RecordEditViewModel(
             val record = repository.observeById(id).first()
             if (record != null) {
                 val absFile = repository.absoluteFileOf(record.photoPath)
+                titleManuallyEdited = true
                 _uiState.value = RecordEditUiState(
                     loading = false,
                     title = record.title,
@@ -102,6 +110,7 @@ class RecordEditViewModel(
     }
 
     fun onTitleChange(value: String) {
+        titleManuallyEdited = true
         _uiState.update { it.copy(title = value, canSave = value.isNotBlank() && it.photoAbsolutePath != null) }
     }
 
@@ -110,7 +119,13 @@ class RecordEditViewModel(
     }
 
     fun onShootDateChange(date: LocalDate) {
-        _uiState.update { it.copy(shootDate = date) }
+        _uiState.update {
+            if (titleManuallyEdited) {
+                it.copy(shootDate = date)
+            } else {
+                it.copy(shootDate = date, title = formatLocalDate(date))
+            }
+        }
     }
 
     fun onLinkedDateChange(date: LocalDate) {
@@ -155,3 +170,12 @@ class RecordEditViewModel(
         }
     }
 }
+
+/**
+ * 将日期格式化为 `yyyy-MM-dd`，用于新建记录的默认标题和编辑页的日期显示。
+ *
+ * @param date 待格式化的日期
+ */
+internal fun formatLocalDate(date: LocalDate): String {
+    return "${date.year}-${date.month.number.toString().padStart(2, '0')}-${date.day.toString().padStart(2, '0')}"
+}

core/src/test/kotlin/plus/rua/project/RecordEditViewModelTest.kt

@@ -0,0 +1,62 @@
+package plus.rua.project
+
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flowOf
+import kotlinx.datetime.LocalDate
+import java.io.File
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+/**
+ * 新建记录标题预填与拍摄日期联动的单元测试。
+ *
+ * 新建模式的被测路径不会触发 DAO 调用，[FakeDateRecordDao] 返回空数据即可。
+ */
+class RecordEditViewModelTest {
+
+    private fun newViewModel(): RecordEditViewModel {
+        val repository = DateRecorderRepository(FakeDateRecordDao(), File("build/tmp/record_edit_test"))
+        return RecordEditViewModel(repository, photoPath = "/tmp/fake_photo.jpg", recordId = null)
+    }
+
+    @Test
+    fun newRecord_prefillsTitleWithShootDate_andCanSave() {
+        val vm = newViewModel()
+        val state = vm.uiState.value
+        assertEquals(formatLocalDate(state.shootDate), state.title)
+        assertTrue(state.canSave)
+    }
+
+    @Test
+    fun shootDateChange_updatesTitle_whenTitleNotManuallyEdited() {
+        val vm = newViewModel()
+        vm.onShootDateChange(LocalDate(2026, 3, 5))
+        assertEquals("2026-03-05", vm.uiState.value.title)
+        assertTrue(vm.uiState.value.canSave)
+    }
+
+    @Test
+    fun shootDateChange_keepsTitle_whenTitleManuallyEdited() {
+        val vm = newViewModel()
+        vm.onTitleChange("我的记录")
+        vm.onShootDateChange(LocalDate(2026, 3, 5))
+        assertEquals("我的记录", vm.uiState.value.title)
+    }
+
+    @Test
+    fun titleCleared_disablesSave() {
+        val vm = newViewModel()
+        vm.onTitleChange("")
+        assertFalse(vm.uiState.value.canSave)
+    }
+}
+
+private class FakeDateRecordDao : DateRecordDao {
+    override fun getByIdFlow(id: Long): Flow<DateRecord?> = flowOf(null)
+    override fun getAllFlow(): Flow<List<DateRecord>> = flowOf(emptyList())
+    override suspend fun insert(record: DateRecord): Long = 0
+    override suspend fun update(record: DateRecord) = Unit
+    override suspend fun deleteByIds(ids: List<Long>): Int = 0
+}