package com.android.tv.settings.widget;

import android.content.Context;
import android.content.pm.PackageManager;
import android.content.res.ColorStateList;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.StateListDrawable;
import android.net.wifi.WifiConfiguration;
import android.os.Looper;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.util.SparseArray;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;

import androidx.annotation.Nullable;
import androidx.annotation.VisibleForTesting;
import androidx.preference.Preference;
import androidx.preference.PreferenceViewHolder;

import com.android.tv.settings.R;
import com.android.tv.settings.library.network.AccessPoint;
import com.android.tv.settings.library.network.AccessPoint.Speed;

public class AccessPointPreference extends Preference {

  private static final int[] STATE_SECURED = {
      R.attr.state_encrypted
  };

  private static final int[] STATE_METERED = {
      R.attr.state_metered
  };

  private static final int[] FRICTION_ATTRS = {
      R.attr.wifi_friction
  };

  private static final int[] WIFI_CONNECTION_STRENGTH = {
      R.string.accessibility_no_wifi,
      R.string.accessibility_wifi_one_bar,
      R.string.accessibility_wifi_two_bars,
      R.string.accessibility_wifi_three_bars,
      R.string.accessibility_wifi_signal_full
  };

  @Nullable
  private final StateListDrawable mFrictionSld;
  private final int mBadgePadding;
  private final UserBadgeCache mBadgeCache;
  private final IconInjector mIconInjector;
  private TextView mTitleView;
  private boolean mShowDivider;

  private boolean mForSavedNetworks = false;
  private AccessPoint mAccessPoint;
  private int mLevel;
  private CharSequence mContentDescription;
  private int mDefaultIconResId;
  private int mWifiSpeed = Speed.NONE;

  @Nullable
  private static StateListDrawable getFrictionStateListDrawable(Context context) {
    TypedArray frictionSld;
    try {
      frictionSld = context.getTheme().obtainStyledAttributes(FRICTION_ATTRS);
    } catch (Resources.NotFoundException e) {
      // Fallback for platforms that do not need friction icon resources.
      frictionSld = null;
    }
    return frictionSld != null ? (StateListDrawable) frictionSld.getDrawable(0) : null;
  }

  // Used for fake pref.
  public AccessPointPreference(Context context, AttributeSet attrs) {
    super(context, attrs);
    mFrictionSld = null;
    mBadgePadding = 0;
    mBadgeCache = null;
    mIconInjector = new IconInjector(context);
  }

  public AccessPointPreference(AccessPoint accessPoint, Context context, UserBadgeCache cache,
      boolean forSavedNetworks) {
    this(accessPoint, context, cache, 0 /* iconResId */, forSavedNetworks);
    refresh();
  }

  public AccessPointPreference(AccessPoint accessPoint, Context context, UserBadgeCache cache,
      int iconResId, boolean forSavedNetworks) {
    this(accessPoint, context, cache, iconResId, forSavedNetworks,
        getFrictionStateListDrawable(context), -1 /* level */, new IconInjector(context));
  }

  @VisibleForTesting
  AccessPointPreference(AccessPoint accessPoint, Context context, UserBadgeCache cache,
      int iconResId, boolean forSavedNetworks, StateListDrawable frictionSld,
      int level, IconInjector iconInjector) {
    super(context);
    setLayoutResource(R.layout.preference_access_point_tv);
    setWidgetLayoutResource(getWidgetLayoutResourceId());
    mBadgeCache = cache;
    mAccessPoint = accessPoint;
    mForSavedNetworks = forSavedNetworks;
    mLevel = level;
    mDefaultIconResId = iconResId;
    mFrictionSld = frictionSld;
    mIconInjector = iconInjector;
    mBadgePadding = context.getResources()
        .getDimensionPixelSize(R.dimen.wifi_preference_badge_padding);
  }

  protected int getWidgetLayoutResourceId() {
    return R.layout.access_point_friction_widget;
  }

  public AccessPoint getAccessPoint() {
    return mAccessPoint;
  }

  @Override
  public void onBindViewHolder(final PreferenceViewHolder view) {
    super.onBindViewHolder(view);
    if (mAccessPoint == null) {
      // Used for fake pref.
      return;
    }
    Drawable drawable = getIcon();
    if (drawable != null) {
      drawable.setLevel(mLevel);
    }

    mTitleView = (TextView) view.findViewById(android.R.id.title);
    if (mTitleView != null) {
      // Attach to the end of the title view
      mTitleView.setCompoundDrawablesRelativeWithIntrinsicBounds(null, null, null, null);
      mTitleView.setCompoundDrawablePadding(mBadgePadding);
    }
    view.itemView.setContentDescription(mContentDescription);

    ImageView frictionImageView = (ImageView) view.findViewById(R.id.friction_icon);
    bindFrictionImage(frictionImageView);

    final View divider = view.findViewById(R.id.two_target_divider);
    divider.setVisibility(shouldShowDivider() ? View.VISIBLE : View.INVISIBLE);
  }

  public boolean shouldShowDivider() {
    return mShowDivider;
  }

  public void setShowDivider(boolean showDivider) {
    mShowDivider = showDivider;
    notifyChanged();
  }

  protected void updateIcon(int level, Context context) {
    if (level == -1) {
      safeSetDefaultIcon();
      return;
    }

    Drawable drawable = mIconInjector.getIcon(level);
    if (!mForSavedNetworks && drawable != null) {
      drawable.setTintList(getColorAttr(context, android.R.attr.colorControlNormal));
      setIcon(drawable);
    } else {
      safeSetDefaultIcon();
    }
  }

  /**
   * Binds the friction icon drawable using a StateListDrawable.
   *
   * <p>Friction icons will be rebound when notifyChange() is called, and therefore
   * do not need to be managed in refresh()</p>.
   */
  private void bindFrictionImage(ImageView frictionImageView) {
    if (frictionImageView == null || mFrictionSld == null) {
      return;
    }
    if ((mAccessPoint.getSecurity() != AccessPoint.SECURITY_NONE)
        && (mAccessPoint.getSecurity() != AccessPoint.SECURITY_OWE)) {
      mFrictionSld.setState(STATE_SECURED);
    } else if (mAccessPoint.isMetered()) {
      mFrictionSld.setState(STATE_METERED);
    }
    Drawable drawable = mFrictionSld.getCurrent();
    frictionImageView.setImageDrawable(drawable);
  }

  private void safeSetDefaultIcon() {
    if (mDefaultIconResId != 0) {
      setIcon(mDefaultIconResId);
    } else {
      setIcon(null);
    }
  }

  protected void updateBadge(Context context) {
    WifiConfiguration config = mAccessPoint.getConfig();
    if (config != null) {
      // Fetch badge (may be null)
      // Get the badge using a cache since the PM will ask the UserManager for the list
      // of profiles every time otherwise.
    }
  }

  /**
   * Updates the title and summary; may indirectly call notifyChanged().
   */
  public void refresh() {
    setTitle(this, mAccessPoint);
    final Context context = getContext();
    int level = mAccessPoint.getLevel();
    int wifiSpeed = Speed.NONE;
    if (level != mLevel || wifiSpeed != mWifiSpeed) {
      mLevel = level;
      mWifiSpeed = wifiSpeed;
      updateIcon(mLevel, context);
      notifyChanged();
    }

    updateBadge(context);
    mContentDescription = buildContentDescription(getContext(), this /* pref */, mAccessPoint);
  }

  @Override
  protected void notifyChanged() {
    if (Looper.getMainLooper() != Looper.myLooper()) {
      // Let our BG thread callbacks call setTitle/setSummary.
      postNotifyChanged();
    } else {
      super.notifyChanged();
    }
  }

  @VisibleForTesting
  static void setTitle(AccessPointPreference preference, AccessPoint ap) {
    preference.setTitle(ap.getTitle());
  }

  /**
   * Helper method to generate content description string.
   */
  @VisibleForTesting
  static CharSequence buildContentDescription(Context context, Preference pref, AccessPoint ap) {
    CharSequence contentDescription = pref.getTitle();
    final CharSequence summary = pref.getSummary();
    if (!TextUtils.isEmpty(summary)) {
      contentDescription = TextUtils.concat(contentDescription, ",", summary);
    }
    int level = ap.getLevel();
    if (level >= 0 && level < WIFI_CONNECTION_STRENGTH.length) {
      contentDescription = TextUtils.concat(contentDescription, ",",
          context.getString(WIFI_CONNECTION_STRENGTH[level]));
    }
    return TextUtils.concat(contentDescription, ",",
        ap.getSecurity() == AccessPoint.SECURITY_NONE
            ? context.getString(R.string.accessibility_wifi_security_type_none)
            : context.getString(R.string.accessibility_wifi_security_type_secured));
  }

  public void onLevelChanged() {
    postNotifyChanged();
  }

  private void postNotifyChanged() {
    if (mTitleView != null) {
      mTitleView.post(mNotifyChanged);
    } // Otherwise we haven't been bound yet, and don't need to update.
  }

  private final Runnable mNotifyChanged = new Runnable() {
    @Override
    public void run() {
      notifyChanged();
    }
  };

  public static class UserBadgeCache {
    private final SparseArray<Drawable> mBadges = new SparseArray<>();
    private final PackageManager mPm;

    public UserBadgeCache(PackageManager pm) {
      mPm = pm;
    }
  }

  static class IconInjector {
    private final Context mContext;

    public IconInjector(Context context) {
      mContext = context;
    }

    public Drawable getIcon(int level) {
      return mContext.getDrawable(getWifiIconResource(level));
    }
  }

  static final int[] WIFI_PIE = {
      R.drawable.ic_wifi_signal_0,
      R.drawable.ic_wifi_signal_1,
      R.drawable.ic_wifi_signal_2,
      R.drawable.ic_wifi_signal_3,
      R.drawable.ic_wifi_signal_4
  };

  static final int[] SHOW_X_WIFI_PIE = {
      R.drawable.ic_show_x_wifi_signal_0,
      R.drawable.ic_show_x_wifi_signal_1,
      R.drawable.ic_show_x_wifi_signal_2,
      R.drawable.ic_show_x_wifi_signal_3,
      R.drawable.ic_show_x_wifi_signal_4
  };

  /**
   * Returns the Wifi icon resource for a given RSSI level.
   *
   * @param level The number of bars to show (0-4)
   * @throws IllegalArgumentException if an invalid RSSI level is given.
   */
  public static int getWifiIconResource(int level) {
    return getWifiIconResource(false /* showX */, level);
  }

  /**
   * Returns the Wifi icon resource for a given RSSI level.
   *
   * @param showX True if a connected Wi-Fi network has the problem which should show Pie+x
   *              signal icon to users.
   * @param level The number of bars to show (0-4)
   * @throws IllegalArgumentException if an invalid RSSI level is given.
   */
  public static int getWifiIconResource(boolean showX, int level) {
    if (level < 0 || level >= WIFI_PIE.length) {
      throw new IllegalArgumentException("No Wifi icon found for level: " + level);
    }
    return showX ? SHOW_X_WIFI_PIE[level] : WIFI_PIE[level];
  }

  public static ColorStateList getColorAttr(Context context, int attr) {
    TypedArray ta = context.obtainStyledAttributes(new int[]{attr});
    ColorStateList stateList = null;
    try {
      stateList = ta.getColorStateList(0);
    } finally {
      ta.recycle();
    }
    return stateList;
  }
}