package com.example.acapendulum20.canvas

import android.content.Context
import android.graphics.Canvas
import android.graphics.Color
import android.graphics.Paint
import android.util.AttributeSet
import android.view.View
import kotlin.math.cos
import kotlin.math.sin


class CanvasPendulum @JvmOverloads constructor(
    context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : View(context, attrs, defStyleAttr) {

    private val paint: Paint = Paint()
    private lateinit var canvas: Canvas
    private val mPendulum: Pendulum = Pendulum()

    override fun onDraw(canvas: Canvas?) {
        super.onDraw(canvas)

        //if canvas not NULL then this canvas = it
        canvas?.let {
            this.canvas = it
        }

        //println("ONDRAW")
        //draw line
        mPendulum.startPosition.x = (width / 2).toFloat()
        paint.isAntiAlias = true
        paint.style = Paint.Style.STROKE
        paint.color = Color.RED
        paint.strokeWidth = 10f
        this.canvas.drawLine(
            mPendulum.startPosition.x,
            mPendulum.startPosition.y,
            mPendulum.stopPosition.x,
            mPendulum.stopPosition.y,
            paint
        )

        //draw circle
        paint.style = Paint.Style.FILL_AND_STROKE
        paint.strokeWidth = 1f
        paint.color = Color.GRAY
        canvas?.drawCircle(
            mPendulum.stopPosition.x,
            mPendulum.stopPosition.y,
            mPendulum.ballr,
            paint
        )

        //draw sensor left
        paint.style = Paint.Style.FILL_AND_STROKE
        paint.strokeWidth = 1f
        paint.color = Color.RED
        if (mPendulum.angleVelocity > 0) {
            if (mPendulum.stopPosition.x < (width / 3) - 30f && mPendulum.stopPosition.x + 30 > (width / 3) - 30f - mPendulum.ballr) {
                paint.style = Paint.Style.FILL_AND_STROKE
                paint.strokeWidth = 10f
                paint.color = Color.GREEN
            }
        }
        canvas?.drawCircle((width / 3).toFloat(), 910f, 30f, paint)

        //draw sensor right
        paint.style = Paint.Style.FILL_AND_STROKE
        paint.strokeWidth = 1f
        paint.color = Color.RED
        if (mPendulum.angleVelocity < 0) {
            if (mPendulum.stopPosition.x > (width / 1.5) - 30f && mPendulum.stopPosition.x + 30 < (width / 1.5) + 30f + mPendulum.ballr) {
                paint.style = Paint.Style.FILL_AND_STROKE
                paint.strokeWidth = 10f
                paint.color = Color.GREEN
            }
        }
        canvas?.drawCircle((width / 1.5).toFloat(), 910f, 30f, paint)

        startPendulum()
        invalidate()
    }

    fun startPendulum() {

        if (mPendulum.magneticField) {

            var gravity = 0.981f
            var damping = 0.996f

            if (mPendulum.stopPosition.x > canvas.width / 4.toFloat() && mPendulum.stopPosition.x <= canvas.width * 0.75.toFloat()) {
                    gravity = 1.981f

                if (mPendulum.stopPosition.x > canvas.width / 3.toFloat() && mPendulum.stopPosition.x <= canvas.width / 1.5.toFloat()) {
                    gravity = 2.981f

                    if (mPendulum.stopPosition.x >= canvas.width / 2.toFloat() - 3 && mPendulum.stopPosition.x <= canvas.width / 2.toFloat() + 3) {
                        damping = 0.3f
                    }
                }
            }

            mPendulum.angleAcceleration =
                ((-1 * gravity / mPendulum.r) * (mPendulum.angle)).toFloat()
            mPendulum.angleVelocity += mPendulum.angleAcceleration
            mPendulum.angleVelocity *= damping
            mPendulum.angle += mPendulum.angleVelocity
            //Polar to cartesian conversion
            mPendulum.stopPosition.x = mPendulum.r * (sin(mPendulum.angle)).toFloat()
            mPendulum.stopPosition.y = mPendulum.r * (cos(mPendulum.angle)).toFloat()
            //Origin transition
            mPendulum.stopPosition.x += mPendulum.startPosition.x
        }

        if (!mPendulum.magneticField) {
            val gravity = 0.981f
            val damping = 0.996f

            mPendulum.angleAcceleration =
                ((-1 * gravity / mPendulum.r) * (mPendulum.angle)).toFloat()
            mPendulum.angleVelocity += mPendulum.angleAcceleration
            mPendulum.angleVelocity *= damping
            mPendulum.angle += mPendulum.angleVelocity
            //Polar to cartesian conversion
            mPendulum.stopPosition.x = mPendulum.r * (sin(mPendulum.angle)).toFloat()
            mPendulum.stopPosition.y = mPendulum.r * (cos(mPendulum.angle)).toFloat()
            //Origin transition
            mPendulum.stopPosition.x += mPendulum.startPosition.x
        }

    }

    fun startMagnet(magnet: Boolean) {
        println("startMagnet")
        println(magnet)
        mPendulum.magneticField = magnet
    }

    fun stopMagnet(magnet: Boolean) {
        println("stopMagnet")
        println(magnet)
        mPendulum.magneticField = magnet
    }
}

class Position(var x: Float, var y: Float) {

}

class Pendulum {

    var startPosition: Position = Position(0f, 0f)
    var stopPosition: Position = Position(0f, 0f)
    var r = 800f

    //PI/6 Max ausschwingen
    var angle: Double = Math.PI / 12
    var angleVelocity: Float = 0.0f   //
    var angleAcceleration: Float = 0.0f    //
    var ballr: Float = 70.0f    //

    var magneticField: Boolean = false
}