feat: Add Jetpack Compose previews for UI components

This commit adds Jetpack Compose `@Preview` annotations to several UI components in the `ui:home` module. This allows developers to visualize these components in Android Studio without needing to run the full application.

Key changes:
- Added `@PreviewDevices` and `FlightsTheme` to `PassengersOptions.kt` and created a `PassengersOptionsPreview` composable function with sample data.
- Added `@PreviewDevices` and `FlightsTheme` to `DatePicker.kt` and created a `DatePickerPreview` composable function with sample data.
- Added `@PreviewDevices` and `FlightsTheme` to `SearchForm.kt` and created a `SearchFormPreview` composable function with sample airport and passenger data.
- Added `@PreviewDevices` and `FlightsTheme` to `AirportDropdown.kt` and created an `AirportDropdownPreview` composable function with sample airport data.

ui/home/src/main/kotlin/dev/adriankuta/flights/ui/home/components/AirportDropdown.kt

@@ -15,6 +15,13 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import dev.adriankuta.flights.domain.types.AirportInfo
+import dev.adriankuta.flights.domain.types.City
+import dev.adriankuta.flights.domain.types.Coordinates
+import dev.adriankuta.flights.domain.types.Country
+import dev.adriankuta.flights.domain.types.MacCity
+import dev.adriankuta.flights.domain.types.Region
+import dev.adriankuta.flights.ui.designsystem.theme.FlightsTheme
+import dev.adriankuta.flights.ui.designsystem.theme.PreviewDevices
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -64,3 +71,75 @@ fun AirportDropdown(
         }
     }
 }
+
+@OptIn(ExperimentalMaterial3Api::class)
+@PreviewDevices
+@Composable
+@Suppress("LongMethod")
+private fun AirportDropdownPreview() {
+    val sampleAirports = listOf(
+        AirportInfo(
+            code = "WAW",
+            name = "Warsaw Chopin",
+            seoName = "warsaw",
+            isBase = true,
+            timeZone = "Europe/Warsaw",
+            city = City(
+                code = "WAW",
+                name = "Warsaw",
+            ),
+            macCity = MacCity(
+                macCode = "WAW",
+            ),
+            region = Region(
+                code = "PL",
+                name = "Poland",
+            ),
+            country = Country(
+                code = "PL",
+                name = "Poland",
+                currencyCode = "PLN",
+            ),
+            coordinates = Coordinates(
+                latitude = 52.1657,
+                longitude = 20.9671,
+            ),
+        ),
+        AirportInfo(
+            code = "LHR",
+            name = "London Heathrow",
+            seoName = "london",
+            isBase = false,
+            timeZone = "Europe/London",
+            city = City(
+                code = "LON",
+                name = "London",
+            ),
+            macCity = MacCity(
+                macCode = "LON",
+            ),
+            region = Region(
+                code = "UK",
+                name = "United Kingdom",
+            ),
+            country = Country(
+                code = "UK",
+                name = "United Kingdom",
+                currencyCode = "GBP",
+            ),
+            coordinates = Coordinates(
+                latitude = 51.4700,
+                longitude = -0.4543,
+            ),
+        ),
+    )
+
+    FlightsTheme {
+        AirportDropdown(
+            label = "Departure Airport",
+            airports = sampleAirports,
+            selectedAirport = sampleAirports.first(),
+            onAirportSelect = {},
+        )
+    }
+}

ui/home/src/main/kotlin/dev/adriankuta/flights/ui/home/components/DatePicker.kt

@@ -20,6 +20,8 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalFocusManager
+import dev.adriankuta.flights.ui.designsystem.theme.FlightsTheme
+import dev.adriankuta.flights.ui.designsystem.theme.PreviewDevices
 import kotlinx.coroutines.channels.BufferOverflow
 import kotlinx.coroutines.flow.MutableSharedFlow
 import java.time.Instant
@@ -152,3 +154,19 @@ class FutureSelectableDates : SelectableDates {
         return year >= now.year
     }
 }
+
+@OptIn(ExperimentalMaterial3Api::class)
+@PreviewDevices
+@Composable
+private fun DatePickerPreview() {
+    val today = LocalDate.now()
+    val futureDate = today.plusDays(7) // A week from today
+
+    FlightsTheme {
+        DatePicker(
+            label = "Departure Date",
+            selectedDate = futureDate,
+            onDateSelect = {},
+        )
+    }
+}

ui/home/src/main/kotlin/dev/adriankuta/flights/ui/home/components/PassengersOptions.kt

@@ -9,7 +9,10 @@ import androidx.compose.material3.VerticalDivider
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
+import dev.adriankuta.flights.ui.designsystem.theme.FlightsTheme
+import dev.adriankuta.flights.ui.designsystem.theme.PreviewDevices
 import dev.adriankuta.flights.ui.home.HomeUiState
+import dev.adriankuta.flights.ui.home.PassengersState
 import dev.adriankuta.flights.ui.sharedui.Counter
 
 @Composable
@@ -53,3 +56,31 @@ internal fun PassengersOptions(
         )
     }
 }
+
+@PreviewDevices
+@Composable
+private fun PassengersOptionsPreview() {
+    val samplePassengersState = PassengersState(
+        adultCount = 2,
+        teenCount = 1,
+        childCount = 1,
+    )
+
+    val sampleUiState = HomeUiState.Success(
+        originAirports = emptyList(),
+        destinationAirports = emptyList(),
+        selectedOriginAirport = null,
+        selectedDestinationAirport = null,
+        selectedDate = java.time.LocalDate.now(),
+        passengers = samplePassengersState,
+    )
+
+    FlightsTheme {
+        PassengersOptions(
+            uiState = sampleUiState,
+            onAdultCountChange = {},
+            onTeenCountChange = {},
+            onChildCountChange = {},
+        )
+    }
+}

ui/home/src/main/kotlin/dev/adriankuta/flights/ui/home/components/SearchForm.kt

@@ -10,7 +10,15 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
 import dev.adriankuta.flights.domain.types.AirportInfo
+import dev.adriankuta.flights.domain.types.City
+import dev.adriankuta.flights.domain.types.Coordinates
+import dev.adriankuta.flights.domain.types.Country
+import dev.adriankuta.flights.domain.types.MacCity
+import dev.adriankuta.flights.domain.types.Region
+import dev.adriankuta.flights.ui.designsystem.theme.FlightsTheme
+import dev.adriankuta.flights.ui.designsystem.theme.PreviewDevices
 import dev.adriankuta.flights.ui.home.HomeUiState
+import dev.adriankuta.flights.ui.home.PassengersState
 import java.time.LocalDate
 
 @Composable
@@ -74,3 +82,93 @@ internal fun SearchForm(
         }
     }
 }
+
+@PreviewDevices
+@Composable
+@Suppress("LongMethod")
+private fun SearchFormPreview() {
+    val sampleAirports = listOf(
+        AirportInfo(
+            code = "WAW",
+            name = "Warsaw Chopin",
+            seoName = "warsaw",
+            isBase = true,
+            timeZone = "Europe/Warsaw",
+            city = City(
+                code = "WAW",
+                name = "Warsaw",
+            ),
+            macCity = MacCity(
+                macCode = "WAW",
+            ),
+            region = Region(
+                code = "PL",
+                name = "Poland",
+            ),
+            country = Country(
+                code = "PL",
+                name = "Poland",
+                currencyCode = "PLN",
+            ),
+            coordinates = Coordinates(
+                latitude = 52.1657,
+                longitude = 20.9671,
+            ),
+        ),
+        AirportInfo(
+            code = "LHR",
+            name = "London Heathrow",
+            seoName = "london",
+            isBase = false,
+            timeZone = "Europe/London",
+            city = City(
+                code = "LON",
+                name = "London",
+            ),
+            macCity = MacCity(
+                macCode = "LON",
+            ),
+            region = Region(
+                code = "UK",
+                name = "United Kingdom",
+            ),
+            country = Country(
+                code = "UK",
+                name = "United Kingdom",
+                currencyCode = "GBP",
+            ),
+            coordinates = Coordinates(
+                latitude = 51.4700,
+                longitude = -0.4543,
+            ),
+        ),
+    )
+
+    val samplePassengersState = PassengersState(
+        adultCount = 2,
+        teenCount = 1,
+        childCount = 1,
+    )
+
+    val sampleUiState = HomeUiState.Success(
+        originAirports = sampleAirports,
+        destinationAirports = sampleAirports.drop(1),
+        selectedOriginAirport = sampleAirports.first(),
+        selectedDestinationAirport = sampleAirports.last(),
+        selectedDate = LocalDate.now().plusDays(7),
+        passengers = samplePassengersState,
+    )
+
+    FlightsTheme {
+        SearchForm(
+            uiState = sampleUiState,
+            onOriginAirportSelect = {},
+            onDestinationAirportSelect = {},
+            onDateSelect = {},
+            onAdultCountChange = {},
+            onTeenCountChange = {},
+            onChildCountChange = {},
+            onSearch = {},
+        )
+    }
+}