[User Availability] Implement user availability UI and networking stubs.

.gitignore

@@ -7,6 +7,7 @@ local.properties
 
 # Log/OS Files
 *.log
+.DS_Store
 
 # Android Studio generated files and folders
 captures/
@@ -28,11 +29,11 @@ render.experimental.xml
 *.keystore
 
 # Google Services (e.g. APIs or Firebase)
-app/google-services.json
+google-services.json
 
 # Android Profiling
 *.hprof
 
 # Secrets
 secrets.properties
-app/src/main/assets/resell-service.json
+resell-service.json

app/src/main/java/com/cornellappdev/resell/android/model/api/AvailabilityApiService.kt

@@ -0,0 +1,36 @@
+package com.cornellappdev.resell.android.model.api
+
+import retrofit2.http.Body
+import retrofit2.http.GET
+import retrofit2.http.POST
+
+interface AvailabilityApiService {
+
+    @GET("availability/")
+    suspend fun getMyAvailability(): AvailabilityResponse
+
+    @POST("availability/update/")
+    suspend fun updateAvailability(
+        @Body request: UpdateAvailabilityRequest
+    ): AvailabilityResponse
+}
+
+data class AvailabilityResponse(
+    val availability: UserAvailability
+)
+
+data class UserAvailability(
+    val id: String,
+    val userId: String,
+    val schedule: Map<String, List<AvailabilitySlot>>,
+    val updatedAt: String
+)
+
+data class AvailabilitySlot(
+    val startDate: String,
+    val endDate: String
+)
+
+data class UpdateAvailabilityRequest(
+    val schedule: Map<String, List<AvailabilitySlot>>
+)

app/src/main/java/com/cornellappdev/resell/android/model/api/RetrofitInstance.kt

@@ -158,6 +158,15 @@ class RetrofitInstance @Inject constructor(
             .create(SettingsApiService::class.java)
     }
 
+    val availabilityApi: AvailabilityApiService by lazy {
+        Retrofit.Builder()
+            .baseUrl(BuildConfig.BASE_API_URL)
+            .client(okHttpClient)
+            .addConverterFactory(GsonConverterFactory.create())
+            .build()
+            .create(AvailabilityApiService::class.java)
+    }
+
     val transactionApi: TransactionApiService by lazy {
         Retrofit.Builder()
             .baseUrl(BuildConfig.BASE_API_URL)

app/src/main/java/com/cornellappdev/resell/android/model/profile/AvailabilityRepository.kt

@@ -0,0 +1,43 @@
+package com.cornellappdev.resell.android.model.profile
+
+import com.cornellappdev.resell.android.model.api.AvailabilitySlot
+import com.cornellappdev.resell.android.model.api.RetrofitInstance
+import com.cornellappdev.resell.android.model.api.UpdateAvailabilityRequest
+import com.cornellappdev.resell.android.model.api.UserAvailability
+import com.cornellappdev.resell.android.ui.components.availability.helper.SLOT_DURATION_MINUTES
+import java.time.LocalDateTime
+import java.time.ZoneId
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class AvailabilityRepository @Inject constructor(
+    private val retrofitInstance: RetrofitInstance
+) {
+    suspend fun getMyAvailability(): UserAvailability {
+        return retrofitInstance.availabilityApi.getMyAvailability().availability
+    }
+
+    suspend fun updateAvailability(slots: List<LocalDateTime>): UserAvailability {
+        // Convert List<LocalDateTime> to Map<"yyyy-MM-dd", List<AvailabilitySlot>>
+        val schedule = slots
+            .groupBy { it.toLocalDate().toString() }
+            .mapValues { (_, daySlots) ->
+                daySlots.sorted().map { start ->
+                    AvailabilitySlot(
+                        startDate = start.toUtcInstantString(),
+                        endDate = start.plusMinutes(SLOT_DURATION_MINUTES.toLong()).toUtcInstantString()
+                    )
+                }
+            }
+
+        return retrofitInstance.availabilityApi.updateAvailability(
+            UpdateAvailabilityRequest(schedule = schedule)
+        ).availability
+    }
+}
+
+// The backend stores/returns dates as UTC instants (e.g. "2026-01-23T16:00:00.000Z"), so
+// device-local wall-clock times must be converted to an instant before sending.
+private fun LocalDateTime.toUtcInstantString(): String =
+    atZone(ZoneId.systemDefault()).toInstant().toString()

app/src/main/java/com/cornellappdev/resell/android/ui/components/availability/helper/AvailabilityFilters.kt

@@ -0,0 +1,115 @@
+package com.cornellappdev.resell.android.ui.components.availability.helper
+import androidx.compose.foundation.background
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.mutableStateMapOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.cornellappdev.resell.android.ui.components.global.ResellCheckboxRow
+import com.cornellappdev.resell.android.ui.components.global.ResellSwitchRow
+import com.cornellappdev.resell.android.ui.theme.AvailabilityPanelBackground
+import com.cornellappdev.resell.android.ui.theme.Style
+
+// TODO: very hard coded right now, should integrate networking here + implement viewmodel
+// TODO: Figure out if we are still implementing this functionality
+@Composable
+fun AvailabilityFilters(
+    modifier: Modifier = Modifier
+) {
+    Column(
+        modifier = modifier
+            .fillMaxWidth()
+            .background(color = AvailabilityPanelBackground)
+            .verticalScroll(rememberScrollState()),
+        verticalArrangement = Arrangement.spacedBy(12.dp),
+        horizontalAlignment = Alignment.Start
+    ) {
+
+        HorizontalDivider()
+
+        ResellSwitchRow(
+            title = "Google Calendar Access",
+            checked = true,
+            enabled = true,
+            onCheckedChange = {
+                // TODO
+            }
+        )
+
+        HorizontalDivider()
+
+        ResellSwitchRow(
+            title = "Availability Sharing",
+            checked = true,
+            enabled = true,
+            onCheckedChange = {
+                // TODO
+            }
+        )
+
+        HorizontalDivider()
+
+        Column(
+            modifier = Modifier.padding(22.dp),
+            verticalArrangement = Arrangement.spacedBy(20.dp)
+        ) {
+            Text(
+                text = "Sub-Calendars",
+                style = Style.body1,
+                fontWeight = FontWeight.SemiBold
+            )
+
+            // TODO: replace dummy here with actual sub-calendars from the user
+            val subCalendars = listOf("Personal", "Leetcode", "Youtube", "Capra")
+            // TODO: this is just hard coded, make it not hard coded
+            val checkedStates = remember { mutableStateMapOf<String, Boolean>().apply {
+                subCalendars.forEach { put(it, it != "Personal" && it != "Capra") }
+            }}
+
+            Column(
+                verticalArrangement = Arrangement.spacedBy(8.dp)
+            ) {
+                subCalendars.chunked(2).forEach { pair ->
+                    Row(
+                        modifier = Modifier.fillMaxWidth(),
+                        horizontalArrangement = Arrangement.spacedBy(12.dp),
+                        verticalAlignment = Alignment.CenterVertically
+                    ) {
+                        pair.forEach { name ->
+                            ResellCheckboxRow(
+                                title = name,
+                                checked = checkedStates[name] ?: false,
+                                enabled = true,
+                                onCheckedChange = { checkedStates[name] = it },
+                                modifier = Modifier.weight(1f)
+                            )
+                        }
+                        if (pair.size == 1) {
+                            Spacer(modifier = Modifier.weight(1f))
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Preview
+@Composable
+fun AvailabilityFiltersPreview() {
+    AvailabilityFilters()
+}

app/src/main/java/com/cornellappdev/resell/android/ui/components/availability/helper/AvailabilityUtil.kt

@@ -5,19 +5,42 @@ import androidx.compose.ui.geometry.Size
 import androidx.compose.ui.graphics.drawscope.DrawScope
 import androidx.compose.ui.graphics.drawscope.Fill
 import androidx.compose.ui.graphics.drawscope.Stroke
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
 import com.cornellappdev.resell.android.ui.theme.ResellPurple
 import com.cornellappdev.resell.android.ui.theme.Stroke
 import com.cornellappdev.resell.android.util.day
 import java.time.LocalDate
 import java.time.LocalDateTime
 import java.time.LocalTime
+import java.time.YearMonth
 import kotlin.math.floor
 
 const val GRID_HEIGHT = 24
+const val SLOT_DURATION_MINUTES = 30
 val gridStartTime: LocalTime = LocalTime.of(9, 0)
 val gridStroke = Stroke
 val fillColor = ResellPurple
 
+/** Minimum horizontal drag distance before a swipe on [MonthCalendar] changes the month. */
+val MonthSwipeThreshold: Dp = 56.dp
+
+/**
+ * Caps [MonthCalendar]'s day-grid at the height of 5 rows (most common case).
+ * A 6-row month only occurs when the 1st falls on a Fri/Sat in a 30/31-day month,
+ * so in this case it scrolls internally instead of growing past this, so the
+ * header stays pinned and the surrounding panel never has to resize.
+ */
+val MonthCalendarGridMaxHeight: Dp = 248.dp
+
+/** Returns a fixed 3-day group containing [date] (1-3, 4-6, ...), rolling into next month if needed. */
+fun dayGroupContaining(date: LocalDate): List<LocalDate> {
+    val month = YearMonth.from(date)
+    val groupIndex = (date.dayOfMonth - 1) / 3
+    val groupStart = month.atDay(groupIndex * 3 + 1)
+    return (0..2).map { groupStart.plusDays(it.toLong()) }
+}
+
 
 fun getGridCell(offset: Offset, canvasSize: Size, width: Int, height: Int): Pair<Int, Int> {
     val gridCol = floor(offset.x / (canvasSize.width / width)).toInt().coerceIn(0, width - 1)
@@ -43,7 +66,7 @@ fun rowColToLocalDateTime(row: Int, col: Int, dates: List<LocalDate>): LocalDate
         .withMinute(gridStartTime.minute)
         .withSecond(gridStartTime.second)
         .withNano(gridStartTime.nano)
-        .plusMinutes(30L * row)
+        .plusMinutes(SLOT_DURATION_MINUTES.toLong() * row)
 }
 
 fun getTimeForRow(row: Int): LocalTime {
@@ -59,7 +82,7 @@ fun List<LocalDateTime>.mapToGrid(dates: List<LocalDate>): List<BooleanArray> {
     forEach { date ->
         val column = dates.indexOfFirst { it.day == date.day }
         if (column == -1) return@forEach
-        val row = (date.hour * 60 + date.minute - gridStartTime.hour * 60) / 30
+        val row = (date.hour * 60 + date.minute - gridStartTime.hour * 60) / SLOT_DURATION_MINUTES
         if (row !in 0 until GRID_HEIGHT) return@forEach
         grid[row][column] = true
     }

app/src/main/java/com/cornellappdev/resell/android/ui/components/availability/helper/AvailibilityTestData.kt

@@ -16,7 +16,7 @@ fun testAvailabilities(dates: List<LocalDate>): List<LocalDateTime> = dates.flat
         val startDate = LocalDateTime.of(date, gridStartTime)
         repeat(GRID_HEIGHT - 1) { i ->
             if (Math.random() < 0.25) {
-                add(startDate.plusMinutes(i * 30L))
+                add(startDate.plusMinutes(i * SLOT_DURATION_MINUTES.toLong()))
             }
         }
     }