package com.example.rxjava;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Shader;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;

import java.util.Calendar;

public class ClockView extends View implements Runnable {

    private Shader shader;
    private Paint paint;
    private Matrix matrix;
    private Calendar calendar;
    private int currentHours;
    private int currentMinutes;
    private int currentSeconds;
    private float calibrationStrokeWidth = getResources().getDisplayMetrics().density * 2f;
    private float calibrationLineLength = getResources().getDisplayMetrics().density * 8f;
    private float hourPointerLengthStrokeWidth = getResources().getDisplayMetrics().density * 6;
    private float hourPointerGap = getResources().getDisplayMetrics().density * 21;

    private float minutePointerLengthStrokeWidth = getResources().getDisplayMetrics().density * 4f;
    private float minutePointerGap = getResources().getDisplayMetrics().density * 6;

    private float secondPointerLengthStrokeWidth = getResources().getDisplayMetrics().density * 1f;
    private float secondPointerGap = getResources().getDisplayMetrics().density * 12f;
    private float hourPointerLength;
    private float minutePointerLength;
    private float secondPointerLength;

    public ClockView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        matrix = new Matrix();
    }


    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        shader = new LinearGradient(0, 0, 0, h, new int[]{0xffff8ea0, 0xffffa551}, new float[]{0.3f, 1f}, Shader.TileMode.MIRROR);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        //draw circle

        if (calendar == null) {
            calendar = Calendar.getInstance();
            currentHours = calendar.get(Calendar.HOUR_OF_DAY);
            currentMinutes = calendar.get(Calendar.MINUTE);
            currentSeconds = calendar.get(Calendar.SECOND);
            postDelayed(this, 1000);
        }
        canvas.save();
        final float circleRadius = getWidth() * 0.5f;
        final float decrementRadius = getWidth() * 0.5f * 0.09f;
        final float minimumShaderRadius = decrementRadius * 2;
        matrix.reset();
        paint.setShader(shader);
        float previousRadius = circleRadius;
        for (int i = 0; i < 4; i++) {
            float currentRadius = circleRadius - decrementRadius * i;
            float calculateScaleRatio = currentRadius / previousRadius;
            canvas.scale(calculateScaleRatio, calculateScaleRatio, getWidth() * 0.5f, getHeight() * 0.5f);
            matrix.postScale(calculateScaleRatio, calculateScaleRatio, getWidth() * 0.5f, getHeight() * 0.5f);
            shader.setLocalMatrix(matrix);
            if (i == 3) {
                paint.setShader(null);
                paint.setAlpha(255);
                paint.setColor(Color.WHITE);
            } else {
                float alphaRatio = 0.2f + ((circleRadius - currentRadius) / minimumShaderRadius) * 0.8f;
                paint.setAlpha((int) (alphaRatio * 255));
            }
            canvas.drawCircle(getWidth() * 0.5f, getHeight() * 0.5f, circleRadius, paint);
            previousRadius = currentRadius;
        }

        float calculateScale = circleRadius / previousRadius;
        paint.setShader(shader);
        paint.setStrokeWidth(calibrationStrokeWidth * calculateScale);
        paint.setStrokeCap(Paint.Cap.ROUND);
        //刻度
        for (int i = 0; i < 12; i++) {
            canvas.drawLine(getWidth(), getHeight() * 0.5f, getWidth() - calibrationLineLength * calculateScale, getHeight() * 0.5f, paint);
            canvas.rotate(30, getWidth() * 0.5f, getHeight() * 0.5f);
            matrix.postRotate(-30, getWidth() * 0.5f, getHeight() * 0.5f);
            shader.setLocalMatrix(matrix);
        }
        //canvas,shaderMatrix回归最开始状态
        canvas.restore();
        matrix.reset();

        //画时分秒针
        canvas.rotate(-90f, circleRadius, circleRadius);
        float angleRotate;
        canvas.save();
        //计算时针旋转角度
        angleRotate = currentHours * 30f + currentMinutes / 60f * 30f + currentSeconds / 3600f * 30f;
        canvas.rotate(angleRotate, circleRadius, circleRadius);
        paint.setStrokeWidth(hourPointerLengthStrokeWidth);
        paint.setColor(Color.BLACK);
        paint.setShader(null);
        canvas.drawLine(circleRadius + previousRadius - hourPointerGap, circleRadius, circleRadius - getResources().getDisplayMetrics().density * 9, circleRadius, paint);
        canvas.restore();
        //分针

        canvas.save();
        matrix.setRotate(90f, circleRadius, circleRadius);
        shader.setLocalMatrix(matrix);
        paint.setShader(shader);
        paint.setStrokeWidth(minutePointerLengthStrokeWidth);
        angleRotate = currentMinutes * 6f + currentSeconds / 60f * 6f;
        canvas.rotate(angleRotate, circleRadius, circleRadius);
        canvas.drawLine(circleRadius + previousRadius - minutePointerGap, circleRadius, circleRadius - getResources().getDisplayMetrics().density * 13, circleRadius, paint);
        canvas.restore();

        //秒针
        canvas.save();
        paint.setShader(null);
        paint.setColor(Color.parseColor("#03a9fe"));
        paint.setStrokeWidth(secondPointerLengthStrokeWidth);
        angleRotate=currentSeconds*6f;
        canvas.rotate(angleRotate,circleRadius,circleRadius);
        canvas.drawLine(circleRadius + previousRadius - secondPointerGap, circleRadius, circleRadius - getResources().getDisplayMetrics().density * 20f, circleRadius, paint);
        canvas.restore();

        paint.setStrokeWidth(0);
        paint.setStyle(Paint.Style.FILL);
        paint.setColor(Color.parseColor("#03a9fe"));
        canvas.drawCircle(circleRadius, circleRadius, minutePointerLengthStrokeWidth * 0.5f, paint);


    }

    @Override
    public void run() {
        calendar = Calendar.getInstance();
        currentHours = calendar.get(Calendar.HOUR_OF_DAY);
        currentMinutes = calendar.get(Calendar.MINUTE);
        currentSeconds = calendar.get(Calendar.SECOND);
        invalidate();
        postDelayed(this, 1000);
    }
}