/*
 * Copyright (c) 2017-present Robert Jaros
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package pl.treksoft.kvision.html

import com.github.snabbdom.VNode
import org.w3c.dom.CanvasRenderingContext2D
import org.w3c.dom.HTMLCanvasElement
import pl.treksoft.kvision.core.Container
import pl.treksoft.kvision.core.StringPair
import pl.treksoft.kvision.core.Widget

/**
 * Canvas component.
 *
 * @constructor
 * @param canvasWidth the width of the canvas
 * @param canvasHeight the height of the canvas
 * @param classes a set of CSS class names
 */
open class Canvas(
    canvasWidth: Int? = null, canvasHeight: Int? = null, classes: Set<String> = setOf()
) : Widget(classes) {
    /**
     * The width of the canvas.
     */
    var canvasWidth by refreshOnUpdate(canvasWidth)
    /**
     * The height of the canvas.
     */
    var canvasHeight by refreshOnUpdate(canvasHeight)

    /**
     * The canvas rendering context.
     */
    lateinit var context2D: CanvasRenderingContext2D

    init {
        this.vnkey = "kv_canvas_${counter++}"
    }

    override fun render(): VNode {
        return render("canvas")
    }

    override fun getSnAttrs(): List<StringPair> {
        val pr = super.getSnAttrs().toMutableList()
        canvasWidth?.let {
            pr.add("width" to it.toString())
        }
        canvasHeight?.let {
            pr.add("height" to it.toString())
        }
        return pr
    }

    override fun afterInsertInternal(node: VNode) {
        super.afterInsertInternal(node)
        context2D = (node.elm as HTMLCanvasElement).getContext("2d") as CanvasRenderingContext2D
    }

    companion object {
        internal var counter = 0

        /**
         * DSL builder extension function.
         *
         * It takes the same parameters as the constructor of the built component.
         */
        fun Container.canvas(
            canvasWidth: Int? = null, canvasHeight: Int? = null, classes: Set<String> = setOf(),
            init: (Canvas.() -> Unit)? = null
        ): Canvas {
            val canvas =
                Canvas(canvasWidth, canvasHeight, classes).apply { init?.invoke(this) }
            this.add(canvas)
            return canvas
        }
    }
}