/*
 * Copyright 2021 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.car.app.model.signin;

import static java.util.Objects.requireNonNull;

import androidx.annotation.Keep;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.car.app.annotations.ExperimentalCarApi;
import androidx.car.app.annotations.RequiresCarApi;
import androidx.car.app.model.Action;

import java.util.Objects;

/**
 * A {@link SignInTemplate.SignInMethod} that allows the user to initiate sign-in with a
 * authentication provider.
 *
 * <p>Not all providers will be available on all devices. It is the developer's responsibility to
 * verify the presence of the corresponding provider by using the provider's own APIs. For
 * example, for Google Sign In, check
 * <a href="https://developers.google.com/identity/sign-in/android/sign-in">Integrating Google
 * Sign-In into Your Android App</a>).
 */
@ExperimentalCarApi
@RequiresCarApi(2)
public final class ProviderSignInMethod implements SignInTemplate.SignInMethod {
    @Keep
    @Nullable
    private final Action mAction;

    /**
     * Returns the {@link Action} the user can use to initiate the sign-in with a given provider
     * or {@code null} if not set.
     *
     * @see Builder#Builder(Action)
     */
    @NonNull
    public Action getAction() {
        return requireNonNull(mAction);
    }

    @NonNull
    @Override
    public String toString() {
        return "[action:" + mAction + "]";
    }

    @Override
    public boolean equals(Object other) {
        if (this == other) {
            return true;
        }

        if (!(other instanceof ProviderSignInMethod)) {
            return false;
        }

        ProviderSignInMethod that = (ProviderSignInMethod) other;
        return Objects.equals(mAction, that.mAction);
    }

    @Override
    public int hashCode() {
        return Objects.hash(mAction);
    }

    ProviderSignInMethod(Builder builder) {
        mAction = builder.mAction;
    }

    /** Constructs an empty instance, used by serialization code. */
    private ProviderSignInMethod() {
        mAction = null;
    }

    /** A builder of {@link ProviderSignInMethod}. */
    public static final class Builder {
        final Action mAction;

        /**
         * Returns a {@link ProviderSignInMethod} instance.
         */
        @NonNull
        public ProviderSignInMethod build() {
            return new ProviderSignInMethod(this);
        }

        /**
         * Returns a {@link ProviderSignInMethod.Builder} instance.
         *
         * <h4>Requirements</h4>
         *
         * The provider action must not be a standard action, and it must use a
         * {@link androidx.car.app.model.ParkedOnlyOnClickListener}.
         *
         * @throws IllegalArgumentException if {@code action} does not meet the requirements
         * @throws NullPointerException     if {@code action} is {@code null}
         * @see Action
         * @see androidx.car.app.model.ParkedOnlyOnClickListener
         */
        public Builder(@NonNull Action action) {
            if (requireNonNull(action).getType() != Action.TYPE_CUSTOM) {
                throw new IllegalArgumentException("The action must not be a standard action");
            }
            if (!requireNonNull(action.getOnClickDelegate()).isParkedOnly()) {
                throw new IllegalArgumentException("The action must use a "
                        + "ParkedOnlyOnClickListener");
            }
            mAction = action;
        }
    }
}