import BaseUIElement from "../BaseUIElement";
import {Utils} from "../../Utils";
import Translations from "../i18n/Translations";
import {UIEventSource} from "../../Logic/UIEventSource";

export default class Table extends BaseUIElement {

    private readonly _header: BaseUIElement[];
    private readonly _contents: BaseUIElement[][];
    private readonly _contentStyle: string[][];
    private readonly _sortable: boolean;
    
    constructor(header: (BaseUIElement | string)[],
                contents: (BaseUIElement | string)[][],
                options?: {
                    contentStyle?: string[][],
                    sortable?: false | boolean
                }) {
        super();
        this._contentStyle = options?.contentStyle ?? [["min-width: 9rem"]];
        this._header = header?.map(Translations.W);
        this._contents = contents.map(row => row.map(Translations.W));
        this._sortable = options?.sortable ?? false
    }

    AsMarkdown(): string {

        const headerMarkdownParts = this._header.map(hel => hel?.AsMarkdown() ?? " ")
        const header = headerMarkdownParts.join(" | ");
        const headerSep = headerMarkdownParts.map(part => '-'.repeat(part.length + 2)).join(" | ")
        const table = this._contents.map(row => row.map(el => el.AsMarkdown() ?? " ").join(" | ")).join("\n")

        return "\n\n" + [header, headerSep, table, ""].join("\n")
    }

    protected InnerConstructElement(): HTMLElement {
        const table = document.createElement("table")

        /**
         * Sortmode: i: sort column i ascending; 
         * if i is negative : sort column (-i - 1) descending
         */
        const sortmode = new UIEventSource<number>(undefined);
        const self = this;
        const headerElems = Utils.NoNull((this._header ?? []).map((elem, i) => {
            if(self._sortable){
                elem.onClick(() => {
                    const current = sortmode.data
                    if(current == i){
                        sortmode.setData(- 1 - i )
                    }else{
                        sortmode.setData(i)
                    }
                })
            }
            return elem.ConstructElement();
        }))
        if (headerElems.length > 0) {

            const thead = document.createElement("thead")

            const tr = document.createElement("tr");
            headerElems.forEach(headerElem => {
                const td = document.createElement("th")
                td.appendChild(headerElem)
                tr.appendChild(td)
            })
            thead.appendChild(tr)
            table.appendChild(thead)

        }

        for (let i = 0; i < this._contents.length; i++) {
            let row = this._contents[i];
            const tr = document.createElement("tr")
            for (let j = 0; j < row.length; j++) {
                try {

                    let elem = row[j];
                    const htmlElem = elem?.ConstructElement()
                    if (htmlElem === undefined) {
                        continue;
                    }

                    let style = undefined;
                    if (this._contentStyle !== undefined && this._contentStyle[i] !== undefined && this._contentStyle[j] !== undefined) {
                        style = this._contentStyle[i][j]
                    }

                    const td = document.createElement("td")
                    td.style.cssText = style;
                    td.appendChild(htmlElem)
                    tr.appendChild(td)
                } catch (e) {
                    console.error("Could not render an element in a table due to", e, row[j])
                }
            }
            table.appendChild(tr)
        }
        
        sortmode.addCallback(sortCol => {
            if(sortCol === undefined){
                return
            }
            const descending = sortCol < 0
            const col = descending ?  - sortCol - 1: sortCol;
            let rows: HTMLTableRowElement[] = Array.from(table.rows)
            rows.splice(0,1) // remove header row
            rows = rows.sort((a, b) => {
                const ac = a.cells[col]?.innerText?.toLowerCase()
                const bc = b.cells[col]?.innerText?.toLowerCase()
                if(ac === bc){
                    return 0
                }
                return( ac < bc !== descending) ? -1 : 1;
            })
            for (let j = rows.length ; j > 1; j--) {
                table.deleteRow(j)
            }
            for (const row of rows) {
                table.appendChild(row)
            }
        })
     

        return table;
    }

}