import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.text.Editable;
import android.text.InputFilter;
import android.text.InputType;
import android.text.TextPaint;
import android.text.method.DigitsKeyListener;
import android.util.AttributeSet;
import android.view.ActionMode;
import android.view.Menu;
import android.view.MenuItem;
import android.view.accessibility.AccessibilityNodeInfo;

import androidx.annotation.Nullable;
import androidx.appcompat.widget.AppCompatEditText;

public class PinEntryEditText extends AppCompatEditText {
    private float mCharSize = 40;
    private float mSpace = 10;
    private float mRadius = 8;
    private int mNumChars = 6;
    private int mBackgroundStyle = 1;
    private float mLineStroke = 0.5f;
    private float mLineStrokeSelected = 0.5f;
    private AccessibilityNodeInfo accessibilityNodeInfo;
    private OnClickListener mClickListener;
    private Paint mLinesPaint;

    public PinEntryEditText(Context context) {
        super(context);
        init(context, null);
    }

    public PinEntryEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs);
    }

    public PinEntryEditText(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs);
    }

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        accessibilityNodeInfo = createAccessibilityNodeInfo();
    }

    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        accessibilityNodeInfo = null;
    }

    private void init(Context context, @Nullable AttributeSet attrs) {
        float multi = context.getResources().getDisplayMetrics().density;
        mCharSize = multi * mCharSize; //convert to pixels for our density
        mSpace = multi * mSpace; //convert to pixels for our density
        mRadius = multi * mRadius;
        mLineStroke = multi * mLineStroke;
        mLineStrokeSelected = multi * mLineStrokeSelected;
        mLinesPaint = new Paint(getPaint());
        mLinesPaint.setStrokeWidth(mLineStroke);
        setBackgroundResource(0);
        setCursorVisible(false);
        setTextIsSelectable(false);
        setHint("");
        setTypeface(Typeface.DEFAULT_BOLD);

        if (attrs == null) {
            setInputType(InputType.TYPE_CLASS_NUMBER | InputType.TYPE_NUMBER_VARIATION_PASSWORD);
            setKeyListener(new DigitsKeyListener());
            setFilters(new InputFilter[]{new InputFilter.LengthFilter(mNumChars)});
        } else {
            mNumChars = attrs.getAttributeIntValue(android.R.attr.maxLength, mNumChars);
            //noinspection resource
            TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.PinEntryEditText);
            mBackgroundStyle = typedArray.getInt(R.styleable.PinEntryEditText_backgroundStyle, mBackgroundStyle);
            mCharSize = typedArray.getDimensionPixelSize(R.styleable.PinEntryEditText_charSize, (int) mCharSize);
            mSpace = typedArray.getDimensionPixelSize(R.styleable.PinEntryEditText_charSpace, (int) mSpace);
            typedArray.recycle();
        }
        if (mBackgroundStyle == 2) {
            mLinesPaint.setStyle(Paint.Style.FILL);
        } else {
            mLinesPaint.setStyle(Paint.Style.STROKE);
        }
        if (isPassword()) {
            getPaint().setFakeBoldText(true);
        }
        //Disable copy paste
        super.setCustomSelectionActionModeCallback(new ActionMode.Callback() {
            public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
                return false;
            }

            public void onDestroyActionMode(ActionMode mode) {
            }

            public boolean onCreateActionMode(ActionMode mode, Menu menu) {
                return false;
            }

            public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
                return false;
            }
        });
        // When tapped, move cursor to end of text.
        super.setOnClickListener(v -> {
            Editable text = getText();
            if (text != null) {
                setSelection(text.length());
            }
            if (mClickListener != null) {
                mClickListener.onClick(v);
            }
        });
    }

    private boolean isPassword() {
        return accessibilityNodeInfo != null && accessibilityNodeInfo.isPassword();
    }

    @Override
    public void setOnClickListener(OnClickListener l) {
        mClickListener = l;
    }

    @Override
    public void setCustomSelectionActionModeCallback(ActionMode.Callback actionModeCallback) {
        throw new RuntimeException("setCustomSelectionActionModeCallback() not supported.");
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        int width = getMeasuredWidth();
        int height = (int) mCharSize + getPaddingTop() + getPaddingBottom();
        System.out.println("onMeasure: " + width + "," + height);
        setMeasuredDimension(width, height);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        int availableWidth = getWidth() - getPaddingRight() - getPaddingLeft();
        float space = mSpace * (mNumChars - 1);
        float charWidth = mCharSize * mNumChars;
        if (availableWidth < charWidth) {
            return;
        }
        if (availableWidth - charWidth < space) {
            space = availableWidth - charWidth;
            mSpace = space / (mNumChars - 1);
        }
        float leftOffset = (availableWidth - charWidth - space) / 2;
        int startX = (int) (getPaddingLeft() + leftOffset);
        int bottom = getHeight() - getPaddingBottom();
        int top = getPaddingTop();
        Editable text = getText();
        if (text == null) return;
        int textLength = text.length();
        TextPaint textPaint = getPaint();
        for (int i = 0; i < mNumChars; i++) {
            updateColorForLines(i == textLength);

            if (mBackgroundStyle == 0) {
                canvas.drawLine(startX, bottom, startX + mCharSize, bottom, mLinesPaint);
            } else if (mBackgroundStyle == 1) {
                canvas.drawRoundRect(startX, top, startX + mCharSize, bottom, mRadius, mRadius, mLinesPaint);
            } else {
                canvas.drawRoundRect(startX, top, startX + mCharSize, bottom, mRadius, mRadius, mLinesPaint);
            }

            if (textLength > i) {
                float textWidth;
                boolean isPassword = isPassword();
                if (isPassword) {
                    textWidth = textPaint.measureText("•");
                } else {
                    textWidth = textPaint.measureText(text.charAt(i) + "");
                }
                Paint.FontMetrics metrics = textPaint.getFontMetrics();
                float textHeight = metrics.bottom - metrics.top;
                float middle = startX + mCharSize / 2;
                float x = middle - textWidth / 2;
                float y = bottom - mCharSize / 2 + textHeight / 2 - metrics.descent;
                String ch = isPassword ? "•" : Character.toString(text.charAt(i));
                canvas.drawText(ch, x, y, textPaint);
            }

            if (mSpace < 0) {
                startX += (int) (mCharSize * 2);
            } else {
                startX += (int) (mCharSize + mSpace);
            }
        }
    }

    /**
     * @param next Is the current char the next character to be input?
     */
    private void updateColorForLines(boolean next) {
        if (isFocused()) {
            mLinesPaint.setStrokeWidth(mLineStrokeSelected);
            if (mBackgroundStyle == 2) {
                mLinesPaint.setColor(Color.parseColor("#ffF4F6F8"));
            } else {
                mLinesPaint.setColor(Color.parseColor("#666666"));
                if (next) {
                    mLinesPaint.setColor(Color.parseColor("#008CFF"));
                }
            }
        } else {
            mLinesPaint.setStrokeWidth(mLineStroke);
            if (mBackgroundStyle == 2) {
                mLinesPaint.setColor(Color.parseColor("#ffF4F6F8"));
            } else {
                mLinesPaint.setColor(Color.parseColor("#666666"));
            }
        }
    }
}