import { css, customElement, LitElement, property, html } from 'lit-element';
import PTips from './p-tips';
/**
 * @event  change 选中改变
 * @event  tab-change-end 页签改变完成事件
 * 
 */
@customElement('p-radio')
export class PRadio extends LitElement {
    @property({ type: String, reflect: true }) value: string;
    @property({ type: String, reflect: true }) name: string;
    @property({ type: Boolean, reflect: true }) checked: boolean = false;
    @property({ type: Boolean, reflect: true }) disabled: boolean = false;
    static get styles() {
        return css`
          :host{ 
            display:inline-block;
            font-size:14px;
            color:var(--fontColor,#333);
            -webkit-tap-highlight-color: transparent;
        }
        :host([disabled]){ 
            pointer-events: none; 
            opacity:.6; 
        }
        :host([disabled]) label{ 
            pointer-events: all;  
            cursor: not-allowed; 
        }
        #radio{
            position:absolute;
            clip:rect(0,0,0,0);
        }
        :host(:focus-within) .cheked,:host(:not([disabled])) label:hover .cheked{ 
            border-color:var(--themeColor,#42b983);
            /*box-shadow: 0 0 10px rgba(0,0,0,0.1);*/
            z-index:1;
        }
        :host([disabled]) .cheked{ 
            background:rgba(0,0,0,.1);
        }
        label{
            box-sizing:border-box;
            cursor:pointer;
            display:flex;
            align-items:center;
            outline:0;
        }
        .cheked{
            position:relative;
            box-sizing: border-box;
            width: 16px;
            height: 16px;
            display: flex;
            border-radius:50%;
            border: 1px solid var(--borderColor,rgba(0,0,0,.2));
            transition:.3s;
            margin-right:.5em;
        }
        :host(:empty) .cheked{
            margin-right:0;
        }
        .cheked::before{
            content:'';
            width:8px;
            height:8px;
            margin:auto;
            border-radius:50%;
            background:var(--themeColor,#42b983);
            transform: scale(0);
            transition: .2s cubic-bezier(.12, .4, .29, 1.46) .1s;
        }
        :host([checked]) .cheked::before{
            transform: scale(1);
        }
         `;
    }
    tocheck() {//单选点击永远是选中,只能通过选择其他的来不选中
        const group = this.group;
        const selector = group ? `p-radio[checked]` : `p-radio[name="${this.name}"][checked]`;
        const parent: any = group || this.getRootNode();
        const prev = parent.querySelector(selector);
        if (prev) {
            prev.checked = false;
        }
        this.checked = true;
    }
    _changeEvent() {
        this.dispatchEvent(new CustomEvent('change', {
            bubbles:true,
            detail: {
                checked: this.checked
            }
        }))
    }
    firstUpdated() {
        this.radio.addEventListener('change', (ev: Event) => {
            this.tocheck();
            this._changeEvent();
        });
        this.radio.addEventListener('keydown', (ev: KeyboardEvent) => {
            switch (ev.keyCode) {
                case 13://Enter
                    ev.stopPropagation();
                    this.tocheck();
                    break;
                default:
                    break;
            }
        })
    }


    render() {
        return html`
           <input type="checkbox" ?checked=${this.checked}  ?disabled=${this.disabled} id="radio" /><label id="label" for="radio"><span class="cheked"></span><slot></slot></label>
        `;
    }

    get group() {
        return this.closest('p-radio-group');
    }
    get radio(): HTMLInputElement {
        return this.renderRoot.querySelector('#radio');
    }
    get form(): HTMLFormElement {
        return this.closest('p-form, form');
    }
    focus() {
        this.radio.focus();
    }
}


@customElement('p-radio-group')
export class PRadioGroup extends LitElement {

    static get styles() {
        return css`:host {
            display:inline-block;
        }
        :host(:focus-within) p-tips,:host(:hover) p-tips{
            z-index:2;
        }
        :host([disabled]){ 
            pointer-events: none; 
        }
        :host([disabled]) p-tips{
            pointer-events: all;
            cursor: not-allowed;
            outline: 0;
        }
        ::slotted(p-radio){
            transition: opacity .3s;
        }
        :host([disabled]) ::slotted(p-radio){
            pointer-events: none;
            opacity:.6;
        }
        p-tips[show='true']{
            --themeColor:var(--errorColor,#f4615c);
            --borderColor:var(--errorColor,#f4615c);
        }`;
    }
    @property({ type: String, reflect: true }) name: string;
    @property({ type: String, reflect: true }) value: string;
    @property({ type: Boolean, reflect: true }) disabled: boolean = false;
    @property({ type: Boolean, reflect: true }) novalidate: boolean = false;
    @property({ type: Boolean, reflect: true }) invalid: boolean = false;
    @property({ type: Boolean, reflect: true }) required: boolean = false;

    render() {
        return html`<p-tips id="tip" @change="${this._handlerChange}" type="error"><slot id='slot'></slot></p-tips>`;
    }
    attributeChangedCallback(name: string, old: string, value: string) {
        super.attributeChangedCallback(name, old, value);
    }
    setSelectValue() {
        const value = this.value;
        this.elements.forEach((el: PRadio) => {
            if (el.value === value) {
                el.checked = true;
            } else {
                el.checked = false;
            }
        });
    }
    private _handlerChange(event:Event){
        const p = event.target as PRadio;
        if (p.checked) {
            this.value = p.value;
        }
        this.dispatchEvent(new CustomEvent('change', {
            bubbles:true,
            detail: {
                value: this.value
            }
        }));
    }
    update(changedProperties: Map<string | number | symbol, unknown>) {
        super.update(changedProperties);
        if (this.elements && changedProperties.has('value') && this.value !== changedProperties.get('value')) {
            this.setSelectValue();
        }
    }
    firstUpdated() {
        const slotObj: HTMLSlotElement = this.shadowRoot.querySelector('#slot');
        slotObj.addEventListener('slotchange', () => {
            if (this.value !== undefined) {
                this.setSelectValue();
            }
        });
    }
    get validity() {
        return this.value !== '' && this.value !== undefined;
    }
    get elements(): NodeListOf<PRadio> {
        return this.querySelectorAll<PRadio>('p-radio');
    }
    get form(): HTMLFormElement {
        return this.closest('p-form,form');
    }
    get tip(): PTips {
        return this.renderRoot.querySelector('#tip');
    }
    checkValidity() {
        if (this.novalidate || this.disabled || !this.required || this.form && this.form.novalidate) {
            return true;
        }
        if (this.validity) {
            this.tip.show = 'false';
            this.invalid = false;
            return true;
        } else {
            this.focus();
            this.tip.show = 'true';
            this.invalid = true;
            this.tip.tips = '请选择1项';
            return false;
        }
    }
}