Add buy flow for paid apps in app details

Resolves #1499

Surface a 'Buy @ price' action on the install error sheet for paid apps
on signed-in accounts, opening the Play Store listing to purchase. For
anonymous accounts, show the price on a disabled install button and
disable manual downloads since paid apps can't be acquired.

app/src/main/java/com/aurora/store/compose/ui/details/AppDetailsScreen.kt

@@ -7,6 +7,7 @@
 package com.aurora.store.compose.ui.details
 
 import android.content.ActivityNotFoundException
+import android.content.Context
 import android.content.Intent
 import androidx.compose.animation.AnimatedContent
 import androidx.compose.animation.fadeIn
@@ -135,6 +136,8 @@ fun AppDetailsScreen(
                 app = loadedApp,
                 error = err.error,
                 extra = err.extra,
+                isAnonymous = viewModel.authProvider.isAnonymous,
+                onBuy = { openPlayStore(context, loadedApp.packageName) },
                 onDismiss = viewModel::dismissInstallError
             )
         }
@@ -198,6 +201,21 @@ fun AppDetailsScreen(
     }
 }
 
+/**
+ * Opens the given app's Play Store listing, preferring the Play Store app when available and
+ * falling back to whichever activity can handle the web listing (e.g. a browser).
+ */
+private fun openPlayStore(context: Context, packageName: String) {
+    val uri = "${Constants.SHARE_URL}$packageName".toUri()
+    val intent = Intent(Intent.ACTION_VIEW).apply { data = uri }
+
+    if (intent.resolveActivity(context.packageManager) != null) {
+        context.startActivity(intent.apply { setPackage(Constants.PACKAGE_NAME_PLAY_STORE) })
+    } else {
+        context.startActivity(intent)
+    }
+}
+
 private fun stateKey(state: AppState, app: App?): String = when {
     state is AppState.Error -> "error"
     state is AppState.Loading || app == null -> "loading"
@@ -261,6 +279,11 @@ private fun ScreenContentApp(
     onForceRestart: () -> Unit = {}
 ) {
     val context = LocalContext.current
+
+    // Anonymous accounts can't purchase, so a paid app can neither be installed nor manually
+    // downloaded (any version) by them. Free apps are always acquirable.
+    val canAcquire = app.isFree || !isAnonymous
+
     var scaffoldDirective = calculatePaneScaffoldDirective(windowAdaptiveInfo)
 
     if (forceSinglePane) {
@@ -317,7 +340,11 @@ private fun ScreenContentApp(
 
     @Composable
     fun SetupMenu() {
-        AppDetailsMenu(isFavorite = isFavorite, state = state) { menuItem ->
+        AppDetailsMenu(
+            isFavorite = isFavorite,
+            state = state,
+            canManualDownload = canAcquire
+        ) { menuItem ->
             when (menuItem) {
                 MenuItem.FAVORITE -> onFavorite()
 
@@ -333,20 +360,7 @@ private fun ScreenContentApp(
                     ShortcutManagerUtil.requestPinShortcut(context, app.packageName)
                 }
 
-                MenuItem.PLAY_STORE -> {
+                MenuItem.PLAY_STORE -> openPlayStore(context, app.packageName)
-                    val uri = "${Constants.SHARE_URL}${app.packageName}".toUri()
-                    val intent = Intent(Intent.ACTION_VIEW).apply { data = uri }
-
-                    if (intent.resolveActivity(context.packageManager) != null) {
-                        context.startActivity(
-                            intent.apply {
-                                setPackage(Constants.PACKAGE_NAME_PLAY_STORE)
-                            }
-                        )
-                    } else {
-                        context.startActivity(intent)
-                    }
-                }
             }
         }
     }
@@ -413,6 +427,8 @@ private fun ScreenContentApp(
                     Actions(
                         primaryActionDisplayName = primaryActionName,
                         secondaryActionDisplayName = stringResource(R.string.title_manual_download),
+                        isPrimaryActionEnabled = canAcquire,
+                        isSecondaryActionEnabled = canAcquire,
                         onPrimaryAction = ::onInstall,
                         onSecondaryAction = { showExtraPane(ExtraScreen.ManualDownload) }
                     )

app/src/main/java/com/aurora/store/compose/ui/details/menu/AppDetailsMenu.kt

@@ -42,6 +42,7 @@ fun AppDetailsMenu(
     state: AppState = AppState.Unavailable,
     isFavorite: Boolean = false,
     isExpanded: Boolean = false,
+    canManualDownload: Boolean = true,
     onMenuItemClicked: (menuItem: MenuItem) -> Unit = {}
 ) {
     val context = LocalContext.current
@@ -80,7 +81,7 @@ fun AppDetailsMenu(
             DropdownMenuItem(
                 text = { Text(text = stringResource(R.string.title_manual_download)) },
                 onClick = { onClick(MenuItem.MANUAL_DOWNLOAD) },
-                enabled = !state.inProgress()
+                enabled = canManualDownload && !state.inProgress()
             )
             DropdownMenuItem(
                 text = { Text(text = stringResource(R.string.action_info)) },

app/src/main/java/com/aurora/store/compose/ui/sheets/InstallErrorSheet.kt

@@ -16,6 +16,7 @@ import androidx.compose.foundation.layout.requiredSize
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.Button
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.MaterialTheme
@@ -41,9 +42,20 @@ import com.aurora.store.R
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
-fun InstallErrorSheet(app: App, error: String?, extra: String?, onDismiss: () -> Unit) {
+fun InstallErrorSheet(
+    app: App,
+    error: String?,
+    extra: String?,
+    isAnonymous: Boolean = true,
+    onBuy: () -> Unit = {},
+    onDismiss: () -> Unit
+) {
     val context = LocalContext.current
 
+    // A paid app that failed to install for a signed-in (non-anonymous) account is almost
+    // always one that hasn't been purchased yet; offer a shortcut to buy it on the Play Store.
+    val canBuy = !app.isFree && !isAnonymous
+
     ModalBottomSheet(
         onDismissRequest = onDismiss,
         sheetState = rememberModalBottomSheetState(skipPartiallyExpanded = true)
@@ -53,7 +65,7 @@ fun InstallErrorSheet(app: App, error: String?, extra: String?, onDismiss: () ->
                 .fillMaxWidth()
                 .verticalScroll(rememberScrollState())
         ) {
-            Header(app = app)
+            Header(app = app, showBuy = canBuy, onBuy = onBuy)
 
             HorizontalDivider(
                 modifier = Modifier.padding(
@@ -101,7 +113,7 @@ fun InstallErrorSheet(app: App, error: String?, extra: String?, onDismiss: () ->
 }
 
 @Composable
-private fun Header(app: App) {
+private fun Header(app: App, showBuy: Boolean = false, onBuy: () -> Unit = {}) {
     Row(
         modifier = Modifier
             .fillMaxWidth()
@@ -137,5 +149,14 @@ private fun Header(app: App) {
                 overflow = TextOverflow.Ellipsis
             )
         }
+        if (showBuy) {
+            Button(onClick = onBuy) {
+                Text(
+                    text = stringResource(R.string.action_buy, app.price),
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis
+                )
+            }
+        }
     }
 }

app/src/main/res/values/strings.xml

@@ -52,6 +52,7 @@
     <string name="action_back">"Back"</string>
     <string name="action_blacklist">"Blacklist"</string>
     <string name="action_blacklist_add">"Add to blacklist"</string>
+    <string name="action_buy">"Buy @ %1$s"</string>
     <string name="action_cancel">"Cancel"</string>
     <string name="action_clear">"Clear"</string>
     <string name="action_close">"Close"</string>