feat: 复刻小程序四大主页面与底部导航（UI 优先，本地 mock）

feature/checkin/build.gradle.kts

@@ -5,3 +5,7 @@ plugins {
 android {
     namespace = "com.mingyuan.android_client.feature.checkin"
 }
+
+dependencies {
+    implementation(libs.kotlinx.coroutines.core)
+}

feature/checkin/src/main/kotlin/com/mingyuan/android_client/feature/checkin/CheckinScreen.kt

@@ -1,18 +1,301 @@
 package com.mingyuan.android_client.feature.checkin
 
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.mingyuan.android_client.core.designsystem.component.Avatar
+import com.mingyuan.android_client.core.designsystem.component.EmptyState
+import com.mingyuan.android_client.core.designsystem.component.ErrorState
+import com.mingyuan.android_client.core.designsystem.component.SectionCard
+import com.mingyuan.android_client.core.designsystem.component.SkeletonBox
+import com.mingyuan.android_client.core.designsystem.theme.BrandAmber
+import com.mingyuan.android_client.core.designsystem.theme.FaintText
+import com.mingyuan.android_client.core.designsystem.theme.MutedText
+import com.mingyuan.android_client.core.designsystem.theme.NeutralChip
+import com.mingyuan.android_client.core.designsystem.theme.PageBackground
+import com.mingyuan.android_client.core.designsystem.theme.PrimaryText
+import com.mingyuan.android_client.core.designsystem.theme.SecondaryText
+import com.mingyuan.android_client.core.designsystem.theme.StatusNormal
+import com.mingyuan.android_client.core.designsystem.theme.SuccessBackground
+import com.mingyuan.android_client.core.model.CheckinRecord
+import com.mingyuan.android_client.core.model.CheckinStatus
+import com.mingyuan.android_client.core.model.GroupMember
+import com.mingyuan.android_client.core.model.PersonalCheckinRecord
+import com.mingyuan.android_client.core.ui.status.StatusBadge
+import com.mingyuan.android_client.core.ui.status.StatusPill
 
 /** Navigation route for this feature, referenced by the app-level NavHost. */
 const val CHECKIN_ROUTE = "checkin"
 
 @Composable
-fun CheckinScreen(modifier: Modifier = Modifier) {
-    Box(modifier = modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
-        Text(text = "Check-in")
+fun CheckinScreen(
+    modifier: Modifier = Modifier,
+    viewModel: CheckinViewModel = hiltViewModel(),
+) {
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    val selectedStatus by viewModel.selectedStatus.collectAsStateWithLifecycle()
+    val submitting by viewModel.submitting.collectAsStateWithLifecycle()
+
+    when (val state = uiState) {
+        is CheckinUiState.Loading -> CheckinSkeleton(modifier)
+        is CheckinUiState.Error -> ErrorState(
+            message = state.message,
+            onRetry = {},
+            modifier = modifier.padding(16.dp),
+        )
+
+        is CheckinUiState.Success -> CheckinContent(
+            record = state.record,
+            selectedStatus = selectedStatus,
+            submitting = submitting,
+            onSubmit = viewModel::submit,
+            modifier = modifier,
+        )
+    }
+}
+
+@Composable
+private fun CheckinContent(
+    record: CheckinRecord,
+    selectedStatus: CheckinStatus,
+    submitting: Boolean,
+    onSubmit: (CheckinStatus) -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    var tab by remember { mutableStateOf(CheckinTab.GROUP) }
+
+    LazyColumn(
+        modifier = modifier.fillMaxSize().background(PageBackground),
+        contentPadding = PaddingValues(16.dp),
+        verticalArrangement = Arrangement.spacedBy(16.dp),
+    ) {
+        item { StatusTitleCard(record) }
+        item { StatusSelector(selectedStatus, submitting, onSubmit) }
+        item { RecordPanel(record, tab) { tab = it } }
+    }
+}
+
+@Composable
+private fun StatusTitleCard(record: CheckinRecord) {
+    SectionCard(cornerRadius = 20) {
+        Row(verticalAlignment = Alignment.CenterVertically) {
+            Column(
+                modifier = Modifier
+                    .width(62.dp)
+                    .background(PrimaryText, RoundedCornerShape(14.dp))
+                    .padding(vertical = 12.dp),
+                horizontalAlignment = Alignment.CenterHorizontally,
+            ) {
+                Text(record.weekday, color = Color(0xFFE8DCCB), fontSize = 12.sp)
+                Text(
+                    text = record.dayNum.toString(),
+                    color = Color.White,
+                    fontSize = 20.sp,
+                    fontWeight = FontWeight.Bold,
+                )
+            }
+            Spacer(Modifier.width(16.dp))
+            Column(Modifier.weight(1f)) {
+                Text(
+                    text = if (record.checked) "已打卡" else "未打卡",
+                    color = if (record.checked) StatusNormal else BrandAmber,
+                    fontSize = 20.sp,
+                    fontWeight = FontWeight.Bold,
+                )
+                Spacer(Modifier.height(6.dp))
+                val status = record.status
+                if (record.checked && status != null) {
+                    StatusBadge(status)
+                } else {
+                    Text("请选择状态完成打卡", color = MutedText, fontSize = 12.sp)
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun StatusSelector(
+    selectedStatus: CheckinStatus,
+    submitting: Boolean,
+    onSubmit: (CheckinStatus) -> Unit,
+) {
+    SectionCard {
+        Column(verticalArrangement = Arrangement.spacedBy(12.dp)) {
+            CheckinStatus.entries.chunked(3).forEach { row ->
+                Row(horizontalArrangement = Arrangement.spacedBy(10.dp)) {
+                    row.forEach { status ->
+                        StatusPill(
+                            status = status,
+                            selected = status == selectedStatus,
+                            onClick = { onSubmit(status) },
+                            modifier = Modifier.weight(1f),
+                        )
+                    }
+                    repeat(3 - row.size) { Spacer(Modifier.weight(1f)) }
+                }
+            }
+            if (submitting) {
+                Text("提交中…", color = MutedText, fontSize = 12.sp)
+            }
+        }
+    }
+}
+
+private enum class CheckinTab { GROUP, PERSONAL }
+
+@Composable
+private fun RecordPanel(
+    record: CheckinRecord,
+    tab: CheckinTab,
+    onTabChange: (CheckinTab) -> Unit,
+) {
+    SectionCard {
+        Row(horizontalArrangement = Arrangement.spacedBy(24.dp)) {
+            TabItem("小组", tab == CheckinTab.GROUP) { onTabChange(CheckinTab.GROUP) }
+            TabItem("个人", tab == CheckinTab.PERSONAL) { onTabChange(CheckinTab.PERSONAL) }
+        }
+        Spacer(Modifier.height(16.dp))
+        when (tab) {
+            CheckinTab.GROUP -> GroupList(record)
+            CheckinTab.PERSONAL -> PersonalList(record.personalHistory)
+        }
+    }
+}
+
+@Composable
+private fun TabItem(label: String, selected: Boolean, onClick: () -> Unit) {
+    Column(Modifier.clickable(onClick = onClick)) {
+        Text(
+            text = label,
+            color = if (selected) BrandAmber else SecondaryText,
+            fontSize = 15.sp,
+            fontWeight = if (selected) FontWeight.Bold else FontWeight.Normal,
+        )
+        Spacer(Modifier.height(6.dp))
+        Box(
+            Modifier
+                .width(40.dp)
+                .height(2.dp)
+                .background(if (selected) BrandAmber else Color.Transparent),
+        )
+    }
+}
+
+@Composable
+private fun GroupList(record: CheckinRecord) {
+    val checkedCount = record.groupMembers.count { it.checkedIn }
+    Column {
+        Row(Modifier.fillMaxWidth(), verticalAlignment = Alignment.CenterVertically) {
+            Text(
+                text = "${record.groupName} · ${record.classDate}",
+                color = PrimaryText,
+                fontSize = 13.sp,
+                fontWeight = FontWeight.SemiBold,
+            )
+            Spacer(Modifier.weight(1f))
+            Text(
+                text = "$checkedCount/${record.groupMembers.size} 已打卡",
+                color = MutedText,
+                fontSize = 12.sp,
+            )
+        }
+        Spacer(Modifier.height(12.dp))
+        record.groupMembers.forEach { member ->
+            GroupMemberRow(member)
+        }
+    }
+}
+
+@Composable
+private fun GroupMemberRow(member: GroupMember) {
+    Row(
+        Modifier.fillMaxWidth().padding(vertical = 8.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        Avatar(
+            initial = member.name,
+            size = 30.dp,
+            backgroundColor = if (member.checkedIn) SuccessBackground else NeutralChip,
+            textColor = if (member.checkedIn) StatusNormal else BrandAmber,
+        )
+        Spacer(Modifier.width(12.dp))
+        Text(member.name, color = PrimaryText, fontSize = 14.sp, modifier = Modifier.weight(1f))
+        val status = member.status
+        if (member.checkedIn && status != null) {
+            Text("打卡 ${member.checkinTime}", color = MutedText, fontSize = 12.sp)
+            Spacer(Modifier.width(8.dp))
+            StatusBadge(status)
+        } else {
+            Text("未打卡", color = FaintText, fontSize = 12.sp)
+        }
+    }
+}
+
+@Composable
+private fun PersonalList(history: List<PersonalCheckinRecord>) {
+    if (history.isEmpty()) {
+        EmptyState("📒", "暂无个人打卡记录")
+    } else {
+        Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+            history.forEach { item ->
+                Row(
+                    Modifier.fillMaxWidth().padding(vertical = 8.dp),
+                    verticalAlignment = Alignment.CenterVertically,
+                ) {
+                    Text(
+                        text = item.date,
+                        color = PrimaryText,
+                        fontSize = 14.sp,
+                        fontWeight = FontWeight.SemiBold,
+                        modifier = Modifier.weight(1f),
+                    )
+                    StatusBadge(item.status)
+                    Spacer(Modifier.width(8.dp))
+                    Text(item.time, color = MutedText, fontSize = 12.sp)
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun CheckinSkeleton(modifier: Modifier = Modifier) {
+    Column(
+        modifier = modifier.fillMaxSize().background(PageBackground).padding(16.dp),
+        verticalArrangement = Arrangement.spacedBy(16.dp),
+    ) {
+        SkeletonBox(Modifier.fillMaxWidth().height(120.dp), cornerRadius = 20)
+        SkeletonBox(Modifier.fillMaxWidth().height(140.dp), cornerRadius = 16)
+        repeat(4) {
+            SkeletonBox(Modifier.fillMaxWidth().height(48.dp), cornerRadius = 12)
+        }
     }
 }

feature/checkin/src/main/kotlin/com/mingyuan/android_client/feature/checkin/CheckinViewModel.kt

@@ -1,8 +1,55 @@
 package com.mingyuan.android_client.feature.checkin
 
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.mingyuan.android_client.core.domain.repository.CheckinRepository
+import com.mingyuan.android_client.core.model.CheckinRecord
+import com.mingyuan.android_client.core.model.CheckinStatus
 import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.onStart
+import kotlinx.coroutines.flow.stateIn
+import kotlinx.coroutines.launch
 import javax.inject.Inject
 
+sealed interface CheckinUiState {
+    data object Loading : CheckinUiState
+    data class Success(val record: CheckinRecord) : CheckinUiState
+    data class Error(val message: String) : CheckinUiState
+}
+
 @HiltViewModel
-class CheckinViewModel @Inject constructor() : ViewModel()
+class CheckinViewModel @Inject constructor(
+    private val checkinRepository: CheckinRepository,
+) : ViewModel() {
+
+    private val _selectedStatus = MutableStateFlow(CheckinStatus.NORMAL)
+    val selectedStatus: StateFlow<CheckinStatus> = _selectedStatus.asStateFlow()
+
+    private val _submitting = MutableStateFlow(false)
+    val submitting: StateFlow<Boolean> = _submitting.asStateFlow()
+
+    val uiState: StateFlow<CheckinUiState> = checkinRepository.observeCheckin()
+        .map<CheckinRecord, CheckinUiState>(CheckinUiState::Success)
+        .onStart { emit(CheckinUiState.Loading) }
+        .catch { emit(CheckinUiState.Error(it.message ?: "加载失败，请稍后再试")) }
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5_000),
+            initialValue = CheckinUiState.Loading,
+        )
+
+    fun submit(status: CheckinStatus) {
+        _selectedStatus.value = status
+        viewModelScope.launch {
+            _submitting.value = true
+            checkinRepository.submitCheckin(status)
+            _submitting.value = false
+        }
+    }
+}