/*
 * Copyright (C) 2025 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 com.android.settings.inputmethod;

import android.content.ContentResolver;
import android.content.Context;
import android.database.ContentObserver;
import android.hardware.input.InputSettings;
import android.net.Uri;
import android.os.Handler;
import android.os.Looper;
import android.provider.Settings;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.VisibleForTesting;
import androidx.lifecycle.DefaultLifecycleObserver;
import androidx.lifecycle.LifecycleOwner;
import androidx.preference.Preference;
import androidx.preference.PreferenceScreen;

import com.android.server.accessibility.Flags;
import com.android.settings.core.SliderPreferenceController;
import com.android.settingslib.widget.SliderPreference;

/** Controller class that controls mouse keys acceleration slider settings. */
public class MouseKeysAccelerationController extends SliderPreferenceController implements
        DefaultLifecycleObserver {

    private static final int MAX_ACCELERATION_POSITION = 10;
    private static final int MIN_ACCELERATION_POSITION = 0;

    static final float ACCELERATION_STEP = 0.1f;
    static final Uri ACCESSIBILITY_MOUSE_KEYS_ACCELERATION_URI =
            Settings.Secure.getUriFor(Settings.Secure.ACCESSIBILITY_MOUSE_KEYS_ACCELERATION);

    private final ContentResolver mContentResolver;
    private @Nullable SliderPreference mPreference;

    public MouseKeysAccelerationController(@NonNull Context context,
            @NonNull String preferenceKey) {
        super(context, preferenceKey);
        mContentResolver = context.getContentResolver();
    }

    final ContentObserver mSettingsObserver =
            new ContentObserver(new Handler(Looper.getMainLooper())) {
                @Override
                public void onChange(boolean selfChange, @Nullable Uri uri) {
                    if (mPreference == null || uri == null) {
                        return;
                    }
                    updateState(mPreference);
                }
            };

    @Override
    public void displayPreference(@NonNull PreferenceScreen screen) {
        super.displayPreference(screen);
        mPreference = screen.findPreference(getPreferenceKey());
        if (mPreference == null) {
            return;
        }

        mPreference.setTickVisible(true);
        updateState(mPreference);
    }

    @Override
    public void onStart(@NonNull LifecycleOwner owner) {
        mContentResolver.registerContentObserver(
                ACCESSIBILITY_MOUSE_KEYS_ACCELERATION_URI,
                /* notifyForDescendants= */ false,
                mSettingsObserver);
    }

    @Override
    public void onStop(@NonNull LifecycleOwner owner) {
        mContentResolver.unregisterContentObserver(mSettingsObserver);
    }

    @Override
    public boolean setSliderPosition(int position) {
        if (position < getMin() || position > getMax()) {
            return false;
        }

        float acceleration = convertProgressToAcceleration(position);
        updateAccelerationValue(acceleration);
        return true;
    }

    @Override
    public int getSliderPosition() {
        final float accelerationFromSettings = getAccelerationFromSettings();
        return convertAccelerationToProgress(accelerationFromSettings);
    }

    private void updateAccelerationValue(float acceleration) {
        Settings.Secure.putFloat(mContentResolver,
                Settings.Secure.ACCESSIBILITY_MOUSE_KEYS_ACCELERATION, acceleration);
    }

    private float getAccelerationFromSettings() {
        return Settings.Secure.getFloat(mContentResolver,
                Settings.Secure.ACCESSIBILITY_MOUSE_KEYS_ACCELERATION,
                InputSettings.DEFAULT_MOUSE_KEYS_ACCELERATION);
    }

    @Override
    public int getAvailabilityStatus() {
        return Flags.enableMouseKeyEnhancement() ? AVAILABLE : CONDITIONALLY_UNAVAILABLE;
    }

    @Override
    public int getMin() {
        return MIN_ACCELERATION_POSITION;
    }

    @Override
    public int getMax() {
        return MAX_ACCELERATION_POSITION;
    }

    /** Helper function to convert float acceleration to integer progress */
    @VisibleForTesting
    int convertAccelerationToProgress(float acceleration) {
        return Math.round((acceleration - getMin()) / ACCELERATION_STEP);
    }

    /** Helper function to convert integer progress back to float acceleration */
    private float convertProgressToAcceleration(int progress) {
        return getMin() + (progress * ACCELERATION_STEP);
    }
}