feat(auth): add multi-account support with PIN/password protection

components/PINEntryModal.tsx

@@ -0,0 +1,231 @@
+import {
+  BottomSheetBackdrop,
+  type BottomSheetBackdropProps,
+  BottomSheetModal,
+  BottomSheetView,
+} from "@gorhom/bottom-sheet";
+import type React from "react";
+import { useCallback, useEffect, useMemo, useRef, useState } from "react";
+import { useTranslation } from "react-i18next";
+import {
+  Alert,
+  Animated,
+  Keyboard,
+  Platform,
+  TouchableOpacity,
+  View,
+} from "react-native";
+import { useSafeAreaInsets } from "react-native-safe-area-context";
+import { useHaptic } from "@/hooks/useHaptic";
+import { verifyAccountPIN } from "@/utils/secureCredentials";
+import { Button } from "./Button";
+import { Text } from "./common/Text";
+import { PinInput } from "./inputs/PinInput";
+
+interface PINEntryModalProps {
+  visible: boolean;
+  onClose: () => void;
+  onSuccess: () => void;
+  onForgotPIN?: () => void;
+  serverUrl: string;
+  userId: string;
+  username: string;
+}
+
+export const PINEntryModal: React.FC<PINEntryModalProps> = ({
+  visible,
+  onClose,
+  onSuccess,
+  onForgotPIN,
+  serverUrl,
+  userId,
+  username,
+}) => {
+  const { t } = useTranslation();
+  const insets = useSafeAreaInsets();
+  const bottomSheetModalRef = useRef<BottomSheetModal>(null);
+  const [pinCode, setPinCode] = useState("");
+  const [error, setError] = useState<string | null>(null);
+  const [isVerifying, setIsVerifying] = useState(false);
+  const shakeAnimation = useRef(new Animated.Value(0)).current;
+  const errorHaptic = useHaptic("error");
+  const successHaptic = useHaptic("success");
+
+  const isAndroid = Platform.OS === "android";
+  const snapPoints = useMemo(
+    () => (isAndroid ? ["100%"] : ["50%"]),
+    [isAndroid],
+  );
+
+  useEffect(() => {
+    if (visible) {
+      bottomSheetModalRef.current?.present();
+      setPinCode("");
+      setError(null);
+    } else {
+      bottomSheetModalRef.current?.dismiss();
+    }
+  }, [visible]);
+
+  const handleSheetChanges = useCallback(
+    (index: number) => {
+      if (index === -1) {
+        setPinCode("");
+        setError(null);
+        onClose();
+      }
+    },
+    [onClose],
+  );
+
+  const renderBackdrop = useCallback(
+    (props: BottomSheetBackdropProps) => (
+      <BottomSheetBackdrop
+        {...props}
+        disappearsOnIndex={-1}
+        appearsOnIndex={0}
+      />
+    ),
+    [],
+  );
+
+  const shake = () => {
+    Animated.sequence([
+      Animated.timing(shakeAnimation, {
+        toValue: 10,
+        duration: 50,
+        useNativeDriver: true,
+      }),
+      Animated.timing(shakeAnimation, {
+        toValue: -10,
+        duration: 50,
+        useNativeDriver: true,
+      }),
+      Animated.timing(shakeAnimation, {
+        toValue: 10,
+        duration: 50,
+        useNativeDriver: true,
+      }),
+      Animated.timing(shakeAnimation, {
+        toValue: 0,
+        duration: 50,
+        useNativeDriver: true,
+      }),
+    ]).start();
+  };
+
+  const handlePinChange = async (value: string) => {
+    setPinCode(value);
+    setError(null);
+
+    // Auto-verify when 4 digits entered
+    if (value.length === 4) {
+      setIsVerifying(true);
+      try {
+        const isValid = await verifyAccountPIN(serverUrl, userId, value);
+        if (isValid) {
+          Keyboard.dismiss();
+          successHaptic();
+          onSuccess();
+          setPinCode("");
+        } else {
+          errorHaptic();
+          setError(t("pin.invalid_pin"));
+          shake();
+          setPinCode("");
+        }
+      } catch {
+        errorHaptic();
+        setError(t("pin.invalid_pin"));
+        shake();
+        setPinCode("");
+      } finally {
+        setIsVerifying(false);
+      }
+    }
+  };
+
+  const handleForgotPIN = () => {
+    Alert.alert(t("pin.forgot_pin"), t("pin.forgot_pin_desc"), [
+      { text: t("common.cancel"), style: "cancel" },
+      {
+        text: t("common.continue"),
+        style: "destructive",
+        onPress: () => {
+          onClose();
+          onForgotPIN?.();
+        },
+      },
+    ]);
+  };
+
+  return (
+    <BottomSheetModal
+      ref={bottomSheetModalRef}
+      snapPoints={snapPoints}
+      onChange={handleSheetChanges}
+      handleIndicatorStyle={{ backgroundColor: "white" }}
+      backgroundStyle={{ backgroundColor: "#171717" }}
+      backdropComponent={renderBackdrop}
+      keyboardBehavior={isAndroid ? "fillParent" : "interactive"}
+      keyboardBlurBehavior='restore'
+      android_keyboardInputMode='adjustResize'
+      topInset={isAndroid ? 0 : undefined}
+    >
+      <BottomSheetView
+        style={{
+          flex: 1,
+          paddingLeft: Math.max(16, insets.left),
+          paddingRight: Math.max(16, insets.right),
+          paddingBottom: Math.max(16, insets.bottom),
+        }}
+      >
+        <View className='flex-1'>
+          {/* Header */}
+          <View className='mb-6'>
+            <Text className='font-bold text-2xl text-neutral-100'>
+              {t("pin.enter_pin")}
+            </Text>
+            <Text className='text-neutral-400 mt-1'>
+              {t("pin.enter_pin_for", { username })}
+            </Text>
+          </View>
+
+          {/* PIN Input */}
+          <Animated.View
+            style={{ transform: [{ translateX: shakeAnimation }] }}
+            className='p-4 border border-neutral-800 rounded-xl bg-neutral-900 mb-4'
+          >
+            <PinInput
+              value={pinCode}
+              onChangeText={handlePinChange}
+              length={4}
+              style={{ paddingHorizontal: 16 }}
+              autoFocus
+            />
+            {error && (
+              <Text className='text-red-500 text-center mt-3'>{error}</Text>
+            )}
+            {isVerifying && (
+              <Text className='text-neutral-400 text-center mt-3'>
+                {t("common.verifying") || "Verifying..."}
+              </Text>
+            )}
+          </Animated.View>
+
+          {/* Forgot PIN */}
+          <TouchableOpacity onPress={handleForgotPIN} className='mb-4'>
+            <Text className='text-purple-400 text-center'>
+              {t("pin.forgot_pin")}
+            </Text>
+          </TouchableOpacity>
+
+          {/* Cancel Button */}
+          <Button onPress={onClose} color='black'>
+            {t("common.cancel")}
+          </Button>
+        </View>
+      </BottomSheetView>
+    </BottomSheetModal>
+  );
+};