import {
    Component,
    OnInit,
    Input,
    SimpleChanges,
    Renderer2,
    Inject,
    ElementRef,
    Output,
    EventEmitter,
    ViewChild,
    HostBinding,
    HostListener
} from '@angular/core'
import { DOCUMENT } from '@angular/common'

import { BaseComponent } from '../base-component'
import { Color } from '../../helpers/color.class'
@Component({
    selector: 'sv-panel',
    templateUrl: './sv-panel.component.html',
    styleUrls: [`./sv-panel.component.scss`]
})
export class SvPanelComponent extends BaseComponent implements OnInit {
    @Input()
    public hue: Color

    @Input()
    public color: Color

    @Output()
    public colorChange = new EventEmitter<Color>(false)

    @ViewChild('cursor')
    public cursor: ElementRef

    constructor(
        renderer: Renderer2,
        @Inject(DOCUMENT) document,
        elementRef: ElementRef
    ) {
        super(document, elementRef, renderer)
    }

    @HostBinding('style.backgroundColor')
    public get backgroundColor(): string {
        return this.hue ? this.hue.toRgbaString() : '#3f51b5'
    }

    @HostListener('mousedown', ['$event'])
    @HostListener('touchstart', ['$event'])
    public onClick(event: any): void {
        this.onEventChange(event)
    }

    ngOnInit(): void {
        // if (!this.hue) {
        //     this.hue = Color.from(this.color.getHsva())
        // }
        // this.renderer.setStyle(
        //     this.elementRef.nativeElement,
        //     'backgroundColor',
        //     this.backgroundColor
        // )
    }
    // color 改变时更改 cursor 位置
    public ngOnChanges(changes: SimpleChanges): void {
        if (
            changes.color &&
            changes.color.previousValue !== changes.color.currentValue
        ) {
            const hsva = this.color.getHsva()
            this.changePointerPosition(hsva.saturation, hsva.value)
        }
    }

    public movePointer({ x, y, height, width }): void {
        const saturation = (x * 100) / width
        const bright = -((y * 100) / height) + 100

        this.changePointerPosition(saturation, bright)
        const hsva = this.hue.getHsva()
        const color = this.color.getHsva()
        const newColor = new Color().setHsva(
            hsva.hue,
            saturation,
            bright,
            color.alpha
        )
        this.colorChange.emit(newColor)
    }

    private changePointerPosition(x: number, y: number): void {
        x = Math.max(0, Math.min(x, 100))
        y = Math.max(0, Math.min(y, 100))
        this.renderer.setStyle(this.cursor.nativeElement, 'top', `${100 - y}%`)
        this.renderer.setStyle(this.cursor.nativeElement, 'left', `${x}%`)
    }
}