package c.e.widget;

import android.content.Context;
import android.content.res.TypedArray;
import android.os.Build;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import android.widget.LinearLayout;

import androidx.annotation.RequiresApi;


/**
 * <p>This class is used to create a multiple-exclusion scope for a set of radio
 * buttons. Checking one radio button that belongs to a radio group unchecks
 * any previously checked radio button within the same group.</p>
 * <p/>
 * <p>Intially, all of the radio buttons are unchecked. While it is not possible
 * to uncheck a particular radio button, the radio group can be cleared to
 * remove the checked state.</p>
 * <p/>
 * <p>The selection is identified by the unique id of the radio button as defined
 * in the XML layout file.</p>
 * <p/>
 * <p><strong>XML Attributes</strong></p>
 * <p>See {@link android.R.styleable # RadioGroup RadioLayoutGroup Attributes},
 * {@link android.R.styleable # LinearLayout LinearLayout Attributes},
 * {@link android.R.styleable # ViewGroup ViewGroup Attributes},
 * {@link android.R.styleable # View View Attributes}</p>
 * <p>Also see
 * {@link LinearLayout.LayoutParams LinearLayout.LayoutParams}
 * for layout attributes.</p>
 *
 * @see RadioLayout
 */

public class RadioLayoutGroup extends LinearLayout {

	// holds the checked id; the selection is empty by default
	private int mCheckedId = -1;
	// tracks children radio buttons checked state
	private CompoundLayout.OnCheckedChangeListener mChildOnCheckedChangeListener;
	// when true, mOnCheckedChangeListener discards events
	private boolean mProtectFromCheckedChange = false;
	private OnCheckedChangeListener mOnCheckedChangeListener;
	private PassThroughHierarchyChangeListener mPassThroughListener;

	/**
	 * {@inheritDoc}
	 */
	public RadioLayoutGroup(Context context){
		super(context);
		setOrientation(VERTICAL);
		init();
	}

	/**
	 * {@inheritDoc}
	 */
	public RadioLayoutGroup(Context context, AttributeSet attrs){
		super(context, attrs);
		// retrieve selected radio button as requested by the user in the
		// XML layout file
		TypedArray attributes = context.obtainStyledAttributes(attrs, R.styleable.RadioLayoutGroup, R.attr.radioButtonStyle, 0);
		int value = attributes.getResourceId(R.styleable.RadioLayoutGroup_checkedButton, View.NO_ID);
		if (value != View.NO_ID){
			mCheckedId = value;
		}
		final int index = attributes.getInt(R.styleable.RadioLayoutGroup_orientation, VERTICAL);
		setOrientation(index);

		attributes.recycle();

		init();
	}

	private void init(){
		mChildOnCheckedChangeListener = new CheckedStateTracker();
		mPassThroughListener = new PassThroughHierarchyChangeListener();
		super.setOnHierarchyChangeListener(mPassThroughListener);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void setOnHierarchyChangeListener(OnHierarchyChangeListener listener) {
		// the user listener is delegated to our pass-through listener
		mPassThroughListener.mOnHierarchyChangeListener = listener;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	protected void onFinishInflate() {
		super.onFinishInflate();

		// checks the appropriate radio button as requested in the XML file
		if (mCheckedId != -1){
			mProtectFromCheckedChange = true;
			setCheckedStateForView(mCheckedId, true);
			mProtectFromCheckedChange = false;
			setCheckedId(mCheckedId);
		}
	}

	@Override
	public void addView(View child, ViewGroup.LayoutParams params) {
		if (child instanceof RadioLayout){
			final RadioLayout button = (RadioLayout) child;
			if (button.isChecked()){
				mProtectFromCheckedChange = true;
				if (mCheckedId != -1){
					setCheckedStateForView(mCheckedId, false);
				}
				mProtectFromCheckedChange = false;
				setCheckedId(button.getId());
			}
		}
	}

	/**
	 * <p>Sets the selection to the radio button whose identifier is passed in
	 * parameter. Using -1 as the selection identifier clears the selection;
	 * such an operation is equivalent to invoking {@link #clearCheck()}.</p>
	 *
	 * @param id the unique id of the radio button to select in this group
	 * @see #getCheckedRadioLayoutId()
	 * @see #clearCheck()
	 */
	public void check(int id){
		// don't even bother
		if (id != -1 && (id == mCheckedId)){
			return;
		}

		if (mCheckedId != -1){
			setCheckedStateForView(mCheckedId, false);
		}

		if (id != -1){
			setCheckedStateForView(id, true);
		}
		setCheckedId(id);
	}

	private void setCheckedId(int id){
		mCheckedId = id;
		if (mOnCheckedChangeListener != null){
			mOnCheckedChangeListener.onCheckedChanged(this, mCheckedId);
		}
	}

	private void setCheckedStateForView(int viewId, boolean checked){
		View checkedView = findViewById(viewId);
		if (checkedView != null && checkedView instanceof RadioLayout){
			((RadioLayout)checkedView).setChecked(checked);
		}
	}

	/**
	 * <p>Returns the identifier of the selected radio button in this group.
	 * Upon empty selection, the returned value is -1.</p>
	 *
	 * @return the unique id of the selected radio button in this group
	 * @attr ref android.R.styleable#RadioGroup_checkedButton
	 * @see #check(int)
	 * @see #clearCheck()
	 */
	public int getCheckedRadioLayoutId(){
		return mCheckedId;
	}

	/**
	 * <p>Clears the selection. When the selection is cleared, no radio button
	 * in this group is selected and {@link #getCheckedRadioLayoutId()} returns
	 * null.</p>
	 *
	 * @see #check(int)
	 * @see #getCheckedRadioLayoutId()
	 */
	public void clearCheck(){
		check(-1);
	}

	/**
	 * <p>Register a callback to be invoked when the checked radio button
	 * changes in this group.</p>
	 *
	 * @param listener the callback to call on checked state change
	 */
	public void setOnCheckedChangeListener(OnCheckedChangeListener listener) {
		mOnCheckedChangeListener = listener;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public LayoutParams generateLayoutParams(AttributeSet attrs) {
		return new RadioLayoutGroup.LayoutParams(getContext(), attrs);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
		return p instanceof RadioLayoutGroup.LayoutParams;
	}

	@Override
	protected LayoutParams generateDefaultLayoutParams() {
		return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
	}

	@Override
	public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
		super.onInitializeAccessibilityEvent(event);
		event.setClassName(RadioLayoutGroup.class.getName());
	}

	@Override
	public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
		super.onInitializeAccessibilityNodeInfo(info);
		info.setClassName(RadioLayoutGroup.class.getName());
	}

	/**
	 * <p>This set of layout parameters defaults the width and the height of
	 * the children to {@link #WRAP_CONTENT} when they are not specified in the
	 * XML file. Otherwise, this class ussed the value read from the XML file.</p>
	 * <p/>
	 * <p>See
	 * {@link android.R.styleable # LinearLayout_Layout LinearLayout Attributes}
	 * for a list of all child view attributes that this class supports.</p>
	 */
	public static class LayoutParams extends LinearLayout.LayoutParams{
		/**
		 * {@inheritDoc}
		 */
		public LayoutParams(Context c, AttributeSet attrs){
			super(c, attrs);
		}

		/**
		 * {@inheritDoc}
		 */
		public LayoutParams(int w, int h){
			super(w, h);
		}

		/**
		 * {@inheritDoc}
		 */
		public LayoutParams(int w, int h, float initWeight) {
			super(w, h, initWeight);
		}

		/**
		 * {@inheritDoc}
		 */
		public LayoutParams(ViewGroup.LayoutParams p) {
			super(p);
		}

		/**
		 * {@inheritDoc}
		 */
		public LayoutParams(MarginLayoutParams source) {
			super(source);
		}

		/**
		 * <p>Fixes the child's width to
		 * {@link ViewGroup.LayoutParams#WRAP_CONTENT} and the child's
		 * height to  {@link ViewGroup.LayoutParams#WRAP_CONTENT}
		 * when not specified in the XML file.</p>
		 *
		 * @param a          the styled attributes set
		 * @param widthAttr  the width attribute to fetch
		 * @param heightAttr the height attribute to fetch
		 */
		@Override
		protected void setBaseAttributes(TypedArray a,
		                                 int widthAttr, int heightAttr) {

			if (a.hasValue(widthAttr)) {
				width = a.getLayoutDimension(widthAttr, "layout_width");
			} else {
				width = WRAP_CONTENT;
			}

			if (a.hasValue(heightAttr)) {
				height = a.getLayoutDimension(heightAttr, "layout_height");
			} else {
				height = WRAP_CONTENT;
			}
		}

	}


	/**
	 * <p>Interface definition for a callback to be invoked when the checked
	 * radio button changed in this group.</p>
	 */
	public interface OnCheckedChangeListener {
		/**
		 * <p>Called when the checked radio button has changed. When the
		 * selection is cleared, checkedId is -1.</p>
		 *
		 * @param group     the group in which the checked radio button has changed
		 * @param checkedId the unique identifier of the newly checked radio button
		 */
		public void onCheckedChanged(RadioLayoutGroup group, int checkedId);
	}

	private class CheckedStateTracker implements CompoundLayout.OnCheckedChangeListener{

		@Override
		public void onCheckedChanged(CompoundLayout buttonView, boolean checked) {
			// prevents from infinite recursion
			if (mProtectFromCheckedChange) {
				return;
			}
			mProtectFromCheckedChange = true;
			if (mCheckedId != -1){
				setCheckedStateForView(mCheckedId, false);
			}
			mProtectFromCheckedChange = false;

			int id = buttonView.getId();
			setCheckedId(id);
		}
	}

	/**
	 * <p>A pass-through listener acts upon the events and dispatches them
	 * to another listener. This allows the table layout to set its own internal
	 * hierarchy change listener without preventing the user to setup his.</p>
	 */
	private class PassThroughHierarchyChangeListener implements OnHierarchyChangeListener {
		private OnHierarchyChangeListener mOnHierarchyChangeListener;

		/**
		 *  {@inheritDoc}
		 */
		@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR1)
		@Override
		public void onChildViewAdded(View parent, View child) {
			if (parent == RadioLayoutGroup.this && child instanceof RadioLayout){
				int id = child.getId();
				// generates an id if it's missing
				if (id == View.NO_ID){
					id = View.generateViewId();
					child.setId(id);
				}
				((RadioLayout)child).setOnCheckedChangeListener(mChildOnCheckedChangeListener);
			}

			if (mOnHierarchyChangeListener != null){
				mOnHierarchyChangeListener.onChildViewAdded(parent, child);
			}
		}

		/**
		 * {@inheritDoc}
		 */
		@Override
		public void onChildViewRemoved(View parent, View child) {
			if (parent == RadioLayoutGroup.this && child instanceof RadioLayout){
				((RadioLayout)child).setOnCheckedChangeWidgetListener(null);
			}

			if (mOnHierarchyChangeListener != null){
				mOnHierarchyChangeListener.onChildViewRemoved(parent, child);
			}
		}
	}




}
