Generalize automatic-tax billing address primitives (MOBILESDK-4667)

Committed-By-Agent: codex
Co-authored-by: codex <noreply@openai.com>

Author: cttsai-stripe

payments-ui-core/src/main/java/com/stripe/android/ui/core/elements/AutomaticTaxBillingFields.kt

@@ -0,0 +1,23 @@
+package com.stripe.android.ui.core.elements
+
+import androidx.annotation.RestrictTo
+import com.stripe.android.uicore.elements.IdentifierSpec
+
+/**
+ * Billing address fields required in addition to country for automatic tax calculation.
+ * Countries absent from this map require country only.
+ *
+ * Source: https://docs.stripe.com/tax/customer-locations
+ */
+private val additionalAutomaticTaxFieldsByCountry: Map<String, Set<IdentifierSpec>> = mapOf(
+    "CA" to setOf(IdentifierSpec.PostalCode),
+    "GB" to setOf(IdentifierSpec.PostalCode),
+    "IN" to setOf(IdentifierSpec.PostalCode),
+    "PR" to setOf(IdentifierSpec.Line1, IdentifierSpec.City, IdentifierSpec.PostalCode),
+    "US" to setOf(IdentifierSpec.Line1, IdentifierSpec.City, IdentifierSpec.State, IdentifierSpec.PostalCode),
+)
+
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+fun automaticTaxRequiredFields(countryCode: String): Set<IdentifierSpec> {
+    return additionalAutomaticTaxFieldsByCountry[countryCode].orEmpty()
+}

…re/elements/CardBillingAddressElement.kt …i/core/elements/BillingAddressElement.ktpayments-ui-core/src/main/java/com/stripe/android/ui/core/elements/CardBillingAddressElement.kt renamed to payments-ui-core/src/main/java/com/stripe/android/ui/core/elements/BillingAddressElement.kt payments-ui-core/src/main/java/com/stripe/android/ui/core/elements/CardBillingAddressElement.kt renamed to payments-ui-core/src/main/java/com/stripe/android/ui/core/elements/BillingAddressElement.kt

@@ -30,26 +30,20 @@ import com.stripe.android.uicore.utils.mapAsStateFlow
 import kotlinx.coroutines.flow.StateFlow
 
 /**
- * This is a special type of AddressElement that
- * removes fields from the address based on the country.  It
- * is only intended to be used with the card payment method.
+ * An address element that dynamically removes fields based on the selected country and collection mode.
  */
 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
-class CardBillingAddressElement(
+open class BillingAddressElement(
     override val identifier: IdentifierSpec,
-    rawValuesMap: Map<IdentifierSpec, String?> = emptyMap(),
-    countryCodes: Set<String> = emptySet(),
-    countryDropdownFieldController: DropdownFieldController = DropdownFieldController(
-        CountryConfig(countryCodes),
-        rawValuesMap[IdentifierSpec.Country]
-    ),
+    rawValuesMap: Map<IdentifierSpec, String?>,
+    countryCodes: Set<String>,
+    countryElement: CountryElement,
     autocompleteAddressInteractorFactory: AutocompleteAddressInteractor.Factory?,
     sameAsShippingElement: SameAsShippingElement?,
     shippingValuesMap: Map<IdentifierSpec, String?>?,
-    private val collectionConfiguration: BillingDetailsCollectionConfiguration =
-        BillingDetailsCollectionConfiguration(),
-    private val shouldHideCountryOnNoAddressCollection: Boolean = true,
-    private val requiresBillingAddressForAutomaticTax: Boolean = false,
+    private val collectionConfiguration: BillingDetailsCollectionConfiguration,
+    private val shouldHideCountryOnNoAddressCollection: Boolean,
+    private val requiresBillingAddressForAutomaticTax: Boolean,
 ) : AddressFieldsElement {
     private val nameConfig = if (collectionConfiguration.collectName) {
         AddressFieldConfiguration.REQUIRED
@@ -80,7 +74,7 @@ class CardBillingAddressElement(
             nameConfig = nameConfig,
             phoneNumberConfig = phoneNumberConfig,
             emailConfig = emailConfig,
-            countryDropdownFieldController = countryDropdownFieldController,
+            countryDropdownFieldController = countryElement.controller,
             interactorFactory = factory,
             shippingValuesMap = shippingValuesMap,
             sameAsShippingElement = sameAsShippingElement,
@@ -95,10 +89,7 @@ class CardBillingAddressElement(
                 phoneNumberConfig = phoneNumberConfig,
                 emailConfig = emailConfig,
             ),
-            countryElement = CountryElement(
-                identifier = IdentifierSpec.Country,
-                controller = countryDropdownFieldController,
-            ),
+            countryElement = countryElement,
             shippingValuesMap = shippingValuesMap,
             sameAsShippingElement = sameAsShippingElement,
             hideCountry = shouldHideCountryOnNoAddressCollection &&
@@ -107,7 +98,7 @@ class CardBillingAddressElement(
     }
 
     private val addressElementSectionController = addressElement.sectionFieldErrorController()
-    private val cardBillingAddressElementSectionErrorController =
+    private val billingAddressElementSectionErrorController =
         object : SectionFieldValidationController by addressElementSectionController, SectionFieldComposable {
             override val validationMessage: StateFlow<FieldValidationMessage?> =
                 addressElement.addressController
@@ -163,7 +154,7 @@ class CardBillingAddressElement(
     // Save for future use puts this in the controller rather than element
     // card and achv2 uses save for future use
     val hiddenIdentifiers: StateFlow<Set<IdentifierSpec>> =
-        countryDropdownFieldController.rawFieldValue.mapAsStateFlow { countryCode ->
+        countryElement.controller.rawFieldValue.mapAsStateFlow { countryCode ->
             when (collectionConfiguration.address) {
                 BillingDetailsCollectionConfiguration.AddressCollectionMode.Never -> {
                     FieldType.entries
@@ -203,7 +194,7 @@ class CardBillingAddressElement(
     override fun getFormFieldValueFlow() = addressElement.getFormFieldValueFlow()
 
     override fun sectionFieldErrorController(): SectionFieldValidationController =
-        cardBillingAddressElementSectionErrorController
+        billingAddressElementSectionErrorController
 
     override fun setRawValue(rawValuesMap: Map<IdentifierSpec, String?>) = addressElement.setRawValue(rawValuesMap)
 
@@ -215,23 +206,36 @@ class CardBillingAddressElement(
 }
 
 /**
- * Billing address fields required in addition to the country, for a Checkout Session using
- * automatic tax with the billing address as the tax source. Most countries only need the
- * country. Source: https://docs.stripe.com/tax/customer-locations
- *
- * Billing only - shipping is out of scope, since it's always collected in full for delivery
- * regardless of tax, so there's no omittable mode there for tax to rescue.
+ * The card-specific name is retained for compatibility. New payment-method forms should use
+ * [BillingAddressElement] directly.
  */
-private val additionalAutomaticTaxFieldsByCountry: Map<String, Set<IdentifierSpec>> = mapOf(
-    "CA" to setOf(IdentifierSpec.PostalCode),
-    "GB" to setOf(IdentifierSpec.PostalCode),
-    "IN" to setOf(IdentifierSpec.PostalCode),
-    "PR" to setOf(IdentifierSpec.Line1, IdentifierSpec.City, IdentifierSpec.PostalCode),
-    "US" to setOf(IdentifierSpec.Line1, IdentifierSpec.City, IdentifierSpec.State, IdentifierSpec.PostalCode),
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+class CardBillingAddressElement(
+    identifier: IdentifierSpec,
+    rawValuesMap: Map<IdentifierSpec, String?> = emptyMap(),
+    countryCodes: Set<String> = emptySet(),
+    countryDropdownFieldController: DropdownFieldController = DropdownFieldController(
+        CountryConfig(countryCodes),
+        rawValuesMap[IdentifierSpec.Country]
+    ),
+    autocompleteAddressInteractorFactory: AutocompleteAddressInteractor.Factory?,
+    sameAsShippingElement: SameAsShippingElement?,
+    shippingValuesMap: Map<IdentifierSpec, String?>?,
+    collectionConfiguration: BillingDetailsCollectionConfiguration = BillingDetailsCollectionConfiguration(),
+    shouldHideCountryOnNoAddressCollection: Boolean = true,
+    requiresBillingAddressForAutomaticTax: Boolean = false,
+) : BillingAddressElement(
+    identifier = identifier,
+    rawValuesMap = rawValuesMap,
+    countryCodes = countryCodes,
+    countryElement = CountryElement(
+        identifier = IdentifierSpec.Country,
+        controller = countryDropdownFieldController,
+    ),
+    autocompleteAddressInteractorFactory = autocompleteAddressInteractorFactory,
+    sameAsShippingElement = sameAsShippingElement,
+    shippingValuesMap = shippingValuesMap,
+    collectionConfiguration = collectionConfiguration,
+    shouldHideCountryOnNoAddressCollection = shouldHideCountryOnNoAddressCollection,
+    requiresBillingAddressForAutomaticTax = requiresBillingAddressForAutomaticTax,
 )
-
-private fun automaticTaxRequiredFields(countryCode: String): Set<IdentifierSpec> {
-    // Matches the raw, non-uppercased comparison the AVS check above uses - countryCode is
-    // already an uppercase ISO code in practice (from CountryConfig).
-    return additionalAutomaticTaxFieldsByCountry[countryCode].orEmpty()
-}