/*
 * Copyright (C) 2022 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import {BaseElement, element} from "../../../../base-ui/BaseElement.js";
import {TraceRowObject} from "./TraceRowObject.js";
import {TraceRow} from "./TraceRow.js";
import {log} from "../../../../log/Log.js";

@element("trace-row-recycler-view")
export class TraceRowRecyclerView extends BaseElement {
    private recycler: boolean = true;
    private gasketEL: HTMLDivElement | null | undefined;
    private container: HTMLDivElement | null | undefined;
    private visibleRowsCount: number = 0;
    private visibleObjects: TraceRowObject<any>[] = [];
    private totalHeight: number = 0;

    private _dataSource: Array<TraceRowObject<any>> = [];
    private _renderType: string = 'div';

    get dataSource(): Array<TraceRowObject<any>> {
        return this._dataSource;
    }

    set dataSource(value: Array<TraceRowObject<any>>) {
        log("dataSource TraceRowObject size :" +  value.length);
        this._dataSource = value;
        this.measureHeight();
        this.initUI();
        let els = [...(this.shadowRoot!.querySelectorAll<TraceRow<any>>(".recycler-cell"))];
        for (let i = 0; i < els.length; i++) {
            this.refreshRow(els[i], this.visibleObjects[i]);
        }
    }

    get renderType(): string {
        return this._renderType;
    }

    set renderType(value: string) {
        this._renderType = value;
    }

    refreshRow(el: TraceRow<any>, obj: TraceRowObject<any>) {
        if (!obj) {
            return;
        }
        el.obj = obj;
        el.folder = obj.folder;
        el.style.top = `${obj.top}px`;
        el.name = obj.name || '';
        if (obj.children) {
            el.setAttribute("children", ``);
        } else {
            el.removeAttribute("children");
        }
        el.style.visibility = 'visible';
        el.rowId = obj.rowId
        el.rowType = obj.rowType
        el.rowParentId = obj.rowParentId
        el.expansion = obj.expansion
        el.rowHidden = obj.rowHidden
        el.setAttribute("height", `${obj.rowHeight}`);
        requestAnimationFrame(() => {
        })
    }

    initElements(): void {
        this.container = this.shadowRoot?.querySelector<HTMLDivElement>(".container");
        this.gasketEL = this.shadowRoot?.querySelector<HTMLDivElement>(".gasket");
        let els: Array<TraceRow<any>> | undefined | null;
        this.container!.onscroll = (ev) => {
            let top = this.container!.scrollTop;
            let skip = 0;
            for (let i = 0; i < this.visibleObjects.length; i++) {
                if (this.visibleObjects[i].top >= top) {
                    skip = this.visibleObjects[i].rowIndex - 1;
                    break;
                }
            }
            if (skip < 0) skip = 0;
            if (!els) els = [...(this.shadowRoot!.querySelectorAll<TraceRow<any>>(".recycler-cell"))];
            for (let i = 0; i < els.length; i++) {
                let obj = this.visibleObjects[i + skip];
                this.refreshRow(els[i], obj);
            }
        }
    }


    measureHeight() {
        this.visibleObjects = this.dataSource.filter(it => !it.rowHidden);
        this.totalHeight = this.visibleObjects.map((it) => it.rowHeight).reduce((a, b) => a + b);
        let totalHeight = 0;
        for (let i = 0; i < this.visibleObjects.length; i++) {
            this.visibleObjects[i].top = totalHeight;
            this.visibleObjects[i].rowIndex = i;
            totalHeight += this.visibleObjects[i].rowHeight;
            this.visibleObjects[i].preObject = i == 0 ? null : this.visibleObjects[i - 1];
            this.visibleObjects[i].nextObject = i == this.visibleObjects.length - 1 ? null : this.visibleObjects[i + 1];
        }
        this.gasketEL && (this.gasketEL.style.height = `${this.totalHeight}px`);
    }

    initUI() {
        this.visibleRowsCount = Math.ceil(this.clientHeight / 40);
        if (this.visibleRowsCount >= this.visibleObjects.length) {
            this.visibleRowsCount = this.visibleObjects.length;
        }
        if (!this.recycler) this.visibleRowsCount = this.dataSource.length;
        for (let i = 0; i <= this.visibleRowsCount; i++) {
            let el = new TraceRow<any>({canvasNumber: 1, alpha: true, contextId: '2d', isOffScreen: true});
            el.className = "recycler-cell"
            this.container?.appendChild(el);
            el.addEventListener('expansion-change', (ev: any) => {
                el.obj!.expansion = ev.detail.expansion;
                for (let j = 0; j < this.dataSource.length; j++) {
                    if (this.dataSource[j].rowParentId == ev.detail.rowId) {
                        this.dataSource[j].rowHidden = !ev.detail.expansion;
                    }
                }
                this.measureHeight();
                let els = [...(this.shadowRoot!.querySelectorAll<TraceRow<any>>(".recycler-cell"))];
                let top = this.container!.scrollTop;
                let skip = 0;
                for (let i = 0; i < this.visibleObjects.length; i++) {
                    if (this.visibleObjects[i].top >= top) {
                        skip = this.visibleObjects[i].rowIndex - 1;
                        break;
                    }
                }
                if (skip < 0) skip = 0;
                for (let i = 0; i < els.length; i++) {
                    let obj = this.visibleObjects[i + skip];
                    this.refreshRow(els[i], obj);
                }
            })
        }
    }

    initHtml(): string {
        return `
        <style>
        :host{
            width:100%;
            height:100%;
            display: block;
            position:relative;
        }
        .container{
            width:100%;
            height:100%;
            overflow: auto;
            position: absolute;
            display: block;
        }
        .gasket{
            width:100%;
            height:auto;
            top: 0;
            left: 0;
            right:0;
            bottom:0;
            visibility: hidden;
        }
        .recycler-cell{
            position: absolute;
            width:100%;
            visibility: hidden;
            top: 0;
            left: 0;
        }
        </style>
        <div class="container">
            <div class="gasket"></div>
        </div>

        `;
    }

}