package me.weilunli.views;

import android.content.Context;

import android.content.res.TypedArray;

import android.graphics.Canvas;

import android.graphics.Paint;

import android.os.Build;

import android.util.AttributeSet;

import android.util.TypedValue;

import androidx.appcompat.widget.AppCompatTextView;

import java.util.ArrayList;

import java.util.List;

public class RubyTextView extends AppCompatTextView {

    private Paint textPaint;

    private Paint rubyTextPaint;

    private String combinedText = "";

    private float rubyTextSize= 28f;

    private int rubyTextColor ;

    private float spacing = 0f;

    private float lineSpacingExtra;

    // Need to address first line because it don't need extra spacing.

    private float lineheight = 0;

    private float firstLineheight = 0;

    StringBuilder originalText;

    List<String[]> combinedTextArray;

    public RubyTextView(Context context) {

        super(context);

        initialize();

        setValue();

    }

    public RubyTextView(Context context, AttributeSet attrs) {

        super(context, attrs);

        initialize();

        TypedArray ta = getContext().obtainStyledAttributes(attrs, R.styleable.RubyTextView);

        try {

            combinedText = ta.getString(R.styleable.RubyTextView_combinedText);

            rubyTextSize = ta.getDimension(R.styleable.RubyTextView_rubyTextSize, 28f);

            rubyTextColor = ta.getColor(R.styleable.RubyTextView_rubyTextColor, rubyTextColor);

            spacing = ta.getDimension(R.styleable.RubyTextView_spacing, 0);

            lineSpacingExtra = ta.getDimension(R.styleable.RubyTextView_lineSpacingExtra, 0);

        } finally {

            ta.recycle();

        }

        setValue();

    }

    private void initialize() {

        textPaint = getPaint();

        rubyTextPaint = new Paint();

        originalText = new StringBuilder();

        rubyTextColor = getCurrentTextColor();

        combinedTextArray = new ArrayList<>();

    }

    private void setValue() {

        textPaint.setColor(getCurrentTextColor());

        rubyTextPaint.setTextSize((getRubyTextSize()));

        rubyTextPaint.setColor(getRubyTextColor());

        lineheight = getTextSize() + getRubyTextSize() + getLineSpacingExtra() + getSpacing();

        firstLineheight = lineheight - getLineSpacingExtra();

        splitCombinedText();

        setLineHeight((int) lineheight);

    }

    public float getLineSpacingExtra() {

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {

            return super.getLineSpacingExtra();

        }

        return lineSpacingExtra;

    }

    private int getMySize(int measureSpec, int mBoundLength) {

        int result;

        int specMode = MeasureSpec.getMode(measureSpec);

        int specSize = MeasureSpec.getSize(measureSpec);

        if (specMode == MeasureSpec.EXACTLY) {

            result = specSize;

        } else if (specMode == MeasureSpec.AT_MOST) {

            result = Math.min(mBoundLength, specSize);

        } else {

            result = mBoundLength;

        }

        return result;

    }

    @Override

    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

        int width = MeasureSpec.getSize(widthMeasureSpec);

        float cur_x = 0;

        int lineCount = 1;

        float maxwidth = 0;

        for(String[] t : combinedTextArray) {

            float textWidth = textPaint.measureText(t[0]);

            float rubyWidth = rubyTextPaint.measureText(t[1]);

            float elementWidth = Math.max(textWidth, rubyWidth);

            // if t[0] == '\n'

            if(t[0].equals(System.getProperty("line.separator"))){

                cur_x = 0;

                lineCount++;

                continue;

            }

            if (cur_x + elementWidth > width){

                cur_x = 0;

                lineCount++;

            }

            cur_x += elementWidth;

            if(cur_x > maxwidth)

                maxwidth = cur_x;

        }

        // total height

        int height = getMySize(heightMeasureSpec,

                (int) (firstLineheight + lineheight * (lineCount-1)) + getLastBaselineToBottomHeight());

        setMeasuredDimension((int) maxwidth, height);

    }

    @Override

    protected void onDraw(Canvas canvas) {

        boolean isFirstLine = true;

        float cur_x = 0;

        float cur_y = firstLineheight;

        for(String[] t : combinedTextArray) {

            /* **********

             * Draw text *

             * ***********/

            float textWidth = textPaint.measureText(t[0]);

            float rubyWidth = rubyTextPaint.measureText(t[1]);

            float elementWidth = Math.max(textWidth, rubyWidth);

            if(t[0].equals(System.getProperty("line.separator"))){

                cur_x = 0;

                if(isFirstLine) isFirstLine = false;

                cur_y += lineheight;

                continue;

            }

            if (cur_x + textWidth > getWidth()) {

                cur_x = 0;

                if(isFirstLine) isFirstLine = false;

                cur_y += lineheight;

            }

            float text_posX = cur_x + (1 / 2f) * (elementWidth - textWidth);

            canvas.drawText(t[0], text_posX, cur_y, textPaint);

            /* ****************

             * Draw ruby text *

             * ****************/

            float rubyText_posX = cur_x + (1 / 2f) * (elementWidth - rubyWidth);

            canvas.drawText(t[1], rubyText_posX, cur_y - getTextSize() - getSpacing(), rubyTextPaint);

            // update cur_x position

            cur_x += elementWidth;

        }

    }

    public String getCombinedText() {

        return combinedText;

    }

    public float getRubyTextSize() {

        return rubyTextSize;

    }

    public float getSpacing() {

        return spacing;

    }

    public int getRubyTextColor() {

        return rubyTextColor;

    }

    private void updateLineheight(){

        lineheight = getTextSize() + getRubyTextSize() + getLineSpacingExtra() + getSpacing();

        firstLineheight = lineheight - getLineSpacingExtra();

    }

    public void setCombinedText(String text) {

        combinedText = text;

        splitCombinedText();

        requestLayout();

        invalidate();

    }

    public void setRubyTextSize(float textSize) {

        rubyTextSize = sp2px(textSize);

        rubyTextPaint.setTextSize(rubyTextSize);

        updateLineheight();

        invalidate();

        requestLayout();

    }

    public void setRubyTextColor(int color) {

        rubyTextColor = color;

        rubyTextPaint.setColor(rubyTextColor);

        invalidate();

    }

    @Override

    public void setLetterSpacing(float letterSpacing) {

        super.setLetterSpacing(letterSpacing);

        invalidate();

        requestLayout();

    }

    @Override

    public void setTextSize(float size) {

        super.setTextSize(size);

        updateLineheight();

        requestLayout();

        invalidate();

    }

    public void setSpacing(float spacing) {

        this.spacing = dp2px(spacing);

        updateLineheight();

        invalidate();

        requestLayout();

    }

    @Override

    public void setTextColor(int color) {

        textPaint.setColor(color);

        super.setTextColor(color);

    }

    public void splitCombinedText() {

        combinedTextArray.clear();

        originalText.setLength(0);

        if(getCombinedText() == null)

            return;

        String[] split = getCombinedText().split(" ");

        for (String value : split) {

            String[] t = value.split("\\|");

            if (t.length == 2) {

                if ((t[1].equals("-"))) {

                    combinedTextArray.add(new String[]{t[0], ""});

                } else {

                    combinedTextArray.add(new String[]{t[0], t[1]});

                }

            } else {

                for (int j = 0; j < t[0].length(); j++) {

                    String s = String.valueOf(t[0].charAt(j));

                    combinedTextArray.add(new String[]{s, ""});

                }

            }

            originalText.append(t[0]);

        }

        setText(originalText);

    }

    /**

     * convert dp to its equivalent px

     */

    private float dp2px(float dp) {

        return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, getResources().getDisplayMetrics());

    }

    /**

     * convert sp to its equivalent px

     */

    private float sp2px(float sp) {

        return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, sp, getResources().getDisplayMetrics());

    }

}