/*
 * Copyright 2019 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package androidx.biometric;

import android.content.Context;
import android.os.Build;

import androidx.annotation.IntDef;
import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.annotation.VisibleForTesting;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

/**
 * A class that contains biometric utilities. For authentication, see {@link BiometricPrompt}.
 * On devices running Q and above, this will query the framework's version of
 * {@link android.hardware.biometrics.BiometricManager}. On devices P and older, this will query
 * {@link androidx.core.hardware.fingerprint.FingerprintManagerCompat}.
 */
public class BiometricManager {

    // Only guaranteed to be non-null on SDK < 29
    @SuppressWarnings("deprecation")
    private final androidx.core.hardware.fingerprint.FingerprintManagerCompat mFingerprintManager;

    // Only guaranteed to be non-null on SDK >= 29 (Q)
    private final android.hardware.biometrics.BiometricManager mBiometricManager;

    /**
     * No error detected.
     */
    public static final int BIOMETRIC_SUCCESS =
            android.hardware.biometrics.BiometricManager.BIOMETRIC_SUCCESS;

    /**
     * The hardware is unavailable. Try again later.
     */
    public static final int BIOMETRIC_ERROR_HW_UNAVAILABLE =
            android.hardware.biometrics.BiometricManager.BIOMETRIC_ERROR_HW_UNAVAILABLE;

    /**
     * The user does not have any biometrics enrolled.
     */
    public static final int BIOMETRIC_ERROR_NONE_ENROLLED =
            android.hardware.biometrics.BiometricManager.BIOMETRIC_ERROR_NONE_ENROLLED;

    /**
     * There is no biometric hardware.
     */
    public static final int BIOMETRIC_ERROR_NO_HARDWARE =
            android.hardware.biometrics.BiometricManager.BIOMETRIC_ERROR_NO_HARDWARE;

    @Retention(RetentionPolicy.SOURCE)
    @IntDef({BIOMETRIC_SUCCESS, BIOMETRIC_ERROR_HW_UNAVAILABLE,
            BIOMETRIC_ERROR_NONE_ENROLLED, BIOMETRIC_ERROR_NO_HARDWARE})
    private @interface BiometricError {
    }

    @RequiresApi(Build.VERSION_CODES.Q)
    private static class Api29Impl {
        @NonNull
        static android.hardware.biometrics.BiometricManager create(Context context) {
            return context.getSystemService(android.hardware.biometrics.BiometricManager.class);
        }

        static @BiometricError int canAuthenticate(
                android.hardware.biometrics.BiometricManager biometricManager) {
            return biometricManager.canAuthenticate();
        }
    }

    /** @return A {@link BiometricManager} instance with the provided context. */
    @NonNull
    public static BiometricManager from(@NonNull Context context) {
        return new BiometricManager(context);
    }

    @SuppressWarnings("deprecation")
    private BiometricManager(Context context) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
            mBiometricManager = Api29Impl.create(context);
            mFingerprintManager = null;
        } else {
            mBiometricManager = null;
            mFingerprintManager =
                    androidx.core.hardware.fingerprint.FingerprintManagerCompat.from(context);
        }
    }

    @VisibleForTesting
    @RequiresApi(Build.VERSION_CODES.Q)
    BiometricManager(android.hardware.biometrics.BiometricManager biometricManager) {
        mBiometricManager = biometricManager;
        mFingerprintManager = null;
    }

    /**
     * Determines if biometrics can be used, or in other words, whether {@link BiometricPrompt}
     * can be expected to be shown (hardware available, templates enrolled, user-enabled).
     *
     * @return {@link #BIOMETRIC_SUCCESS} if a biometric can currently be used (enrolled and
     * available), {@link #BIOMETRIC_ERROR_NONE_ENROLLED} if the user does not have any enrolled,
     * or {@link #BIOMETRIC_ERROR_HW_UNAVAILABLE} or {@link #BIOMETRIC_ERROR_NO_HARDWARE} if none
     * are currently enabled/supported.
     */
    public @BiometricError int canAuthenticate() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
            return Api29Impl.canAuthenticate(mBiometricManager);
        } else {
            if (!mFingerprintManager.isHardwareDetected()) {
                return BIOMETRIC_ERROR_HW_UNAVAILABLE;
            } else if (!mFingerprintManager.hasEnrolledFingerprints()) {
                return BIOMETRIC_ERROR_NONE_ENROLLED;
            } else {
                return BIOMETRIC_SUCCESS;
            }
        }
    }
}

@@ -4132,22 +4132,20 @@
  or 
-in other words
+equivalently
 , wh
@@ -4177,34 +4177,19 @@
 mpt%7D
+ can
 %0A     *
- can be expected to
  be 
@@ -4458,51 +4458,8 @@
    *
- or %7B@link #BIOMETRIC_ERROR_HW_UNAVAILABLE%7D
  or 
@@ -4502,23 +4502,16 @@
  if none
-%0A     *
  are cur
@@ -4839,29 +4839,26 @@
 C_ERROR_
-HW_UNAVAILABL
+NO_HARDWAR
 E;%0A     

Fix error returned by BiometricManager on API < 28