//
//  ViewController.swift
//  ConvexLine
//
//  Created by MizushimaYusuke on 2017/09/24.
//  Copyright © 2017 MizushimaYusuke. All rights reserved.
//

import UIKit
import SpriteKit

class ViewController: UIViewController {

    weak var scene: SKScene?

    override func viewDidLoad() {
        super.viewDidLoad()
        setupScene()
        createLines()
    }

    func setupScene() {
        let sv = SKView(frame: view.bounds)
        let s = SKScene(size: sv.frame.size)
        sv.presentScene(s)
        view.addSubview(sv)
        scene = s
    }

    func createLines() {
        stride(from: 0, through: view.frame.maxY, by: 40).enumerated().forEach { i, y in
            let line = createConvexLine()
            line.position = CGPoint(x: view.center.x, y: y)
            let d = view.frame.maxX
            if (i%2 == 0) {
                line.zRotation = .pi
            }
            line.childNode(withName: "maskBar")?.run(.sequence([.wait(forDuration: 10.0), .moveBy(x: d, y: 0, duration: 10.0)]))

        }
    }

    func createConvexLine() -> SKNode {
        UIGraphicsBeginImageContextWithOptions(CGSize(width: 80, height: 40), false, 0)
        UIColor(hue: 0.5, saturation: 0.9, brightness: 0.7, alpha: 1).set()
        if let ctx = UIGraphicsGetCurrentContext() {
            ctx.fill(CGRect(x: 0, y: 0, width: 80, height: 40))
            ctx.setBlendMode(.clear)
            ctx.fill(CGRect(x: 20, y: 20, width: 40, height: 16))
            ctx.fill(CGRect(x: 30, y: 4, width: 20, height: 30))
        }
        let img = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()

        let texture = SKTexture(image: img)
        let node = SKNode()
        stride(from: 0, through: view.frame.maxX, by: 80).forEach { x in
            let part = SKSpriteNode(texture: texture)
            part.position = CGPoint(x: x - view.frame.midX, y: 0)
            node.addChild(part)
        }
        node.position = view.center
        scene?.addChild(node)

        let maskBar = SKSpriteNode(color: scene!.backgroundColor, size: CGSize(width: view.frame.maxX, height: 40))
        maskBar.name = "maskBar"
        node.addChild(maskBar)

        return node
    }
}