/*  Copyright (C) 2023 José Rebelo

    This file is part of Gadgetbridge.

    Gadgetbridge is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published
    by the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Gadgetbridge is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
package nodomain.freeyourgadget.gadgetbridge.activities.devicesettings;

import android.text.InputFilter;
import android.text.InputType;
import android.text.Spanned;

import androidx.preference.EditTextPreference;
import androidx.preference.ListPreference;
import androidx.preference.MultiSelectListPreference;
import androidx.preference.Preference;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

import nodomain.freeyourgadget.gadgetbridge.R;
import nodomain.freeyourgadget.gadgetbridge.util.Prefs;

public final class DeviceSettingsUtils {
    private static final Logger LOG = LoggerFactory.getLogger(DeviceSettingsUtils.class);

    private DeviceSettingsUtils() {
        // utility class
    }

    /**
     * Returns the preference key where to save the list of possible value for a preference, comma-separated.
     */
    public static String getPrefPossibleValuesKey(final String key) {
        return String.format(Locale.ROOT, "%s_possible_values", key);
    }

    /**
     * Returns the preference key where to that a config was reported as supported (boolean).
     */
    public static String getPrefKnownConfig(final String key) {
        return String.format(Locale.ROOT, "%s_is_known", key);
    }

    /**
     * Removes all unsupported elements from a list preference. If they are not known, the preference
     * is hidden.
     */
    public static void removeUnsupportedElementsFromListPreference(final String prefKey,
                                                                   final DeviceSpecificSettingsHandler handler,
                                                                   final Prefs prefs) {
        final Preference pref = handler.findPreference(prefKey);
        if (pref == null) {
            return;
        }

        // Get the list of possible values for this preference, as reported by the band
        final List<String> possibleValues = prefs.getList(getPrefPossibleValuesKey(prefKey), null);
        if (possibleValues == null || possibleValues.isEmpty()) {
            // The band hasn't reported this setting, so we don't know the possible values.
            // Hide it
            pref.setVisible(false);

            return;
        }

        final CharSequence[] originalEntries;
        final CharSequence[] originalValues;

        if (pref instanceof ListPreference) {
            originalEntries = ((ListPreference) pref).getEntries();
            originalValues = ((ListPreference) pref).getEntryValues();
        } else if (pref instanceof MultiSelectListPreference) {
            originalEntries = ((MultiSelectListPreference) pref).getEntries();
            originalValues = ((MultiSelectListPreference) pref).getEntryValues();
        } else {
            LOG.error("Unknown list pref class {}", pref.getClass().getName());
            return;
        }

        final List<String> prefValues = new ArrayList<>(originalValues.length);
        for (final CharSequence entryValue : originalValues) {
            prefValues.add(entryValue.toString());
        }

        final CharSequence[] entries = new CharSequence[possibleValues.size()];
        final CharSequence[] values = new CharSequence[possibleValues.size()];
        for (int i = 0; i < possibleValues.size(); i++) {
            final String possibleValue = possibleValues.get(i);
            final int idxPrefValue = prefValues.indexOf(possibleValue);

            if (idxPrefValue >= 0) {
                entries[i] = originalEntries[idxPrefValue];
            } else {
                entries[i] = handler.getContext().getString(R.string.menuitem_unknown_app, possibleValue);
            }
            values[i] = possibleValue;
        }

        if (pref instanceof ListPreference) {
            ((ListPreference) pref).setEntries(entries);
            ((ListPreference) pref).setEntryValues(values);
        } else if (pref instanceof MultiSelectListPreference) {
            ((MultiSelectListPreference) pref).setEntries(entries);
            ((MultiSelectListPreference) pref).setEntryValues(values);
        }
    }

    /**
     * Hides the the prefToHide preference if none of the preferences in the preferences list are
     * visible.
     */
    public static void hidePrefIfNoneVisible(final DeviceSpecificSettingsHandler handler,
                                             final String prefToHide,
                                             final List<String> subPrefs) {
        final Preference pref = handler.findPreference(prefToHide);
        if (pref == null) {
            return;
        }

        for (final String subPrefKey : subPrefs) {
            final Preference subPref = handler.findPreference(subPrefKey);
            if (subPref == null) {
                continue;
            }
            if (subPref.isVisible()) {
                // At least one preference is visible
                return;
            }
        }

        // No preference was visible, hide
        pref.setVisible(false);
    }

    public static void enforceMinMax(final EditTextPreference pref, final int minValue, final int maxValue) {
        if (minValue >= maxValue) {
            LOG.warn("Invalid min/max values for {}: {}/{}", pref.getKey(), minValue, maxValue);
            return;
        }

        pref.setOnBindEditTextListener(p -> {
            p.setInputType(InputType.TYPE_CLASS_NUMBER);
            p.setFilters(new InputFilter[]{new MinMaxInputFilter(minValue, maxValue)});
            p.setSelection(p.getText().length());
        });
    }

    public static final class MinMaxInputFilter implements InputFilter {
        private final int min;
        private final int max;

        public MinMaxInputFilter(final int min, final int max) {
            this.min = min;
            this.max = max;
        }

        @Override
        public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
            try {
                final int input = Integer.parseInt(dest.toString() + source.toString());
                if (input >= min && input <= max) {
                    return null;
                }
            } catch (final NumberFormatException ignored) {
            }
            return "";
        }
    }
}