import { PipeTransform, Pipe, ElementRef } from '@angular/core';
import { DomSanitizer, SafeHtml } from '@angular/platform-browser';

@Pipe({ name: 'highlight' })
export class HighlightPipe implements PipeTransform {
    constructor(public sanitizer: DomSanitizer, private el: ElementRef) {
    }
    transform(text: string, keyword, field = '', findField = ''): SafeHtml {
        let needSearch = true;
        if (field && findField) {
            if (findField.indexOf(',') === -1) {
                needSearch = field === findField;
            } else {
                needSearch = findField.split(',').some(n => n === field);
            }
        }

        if (!needSearch) {
            return text;
        }

        if (keyword && text) {
            let pattern = keyword.replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, '\\$&');
            pattern = pattern.split(' ').filter((t) => {
                return t.length > 0;
            }).join('|');
            const regex = new RegExp(pattern, 'gi');
            return this.sanitizer.bypassSecurityTrustHtml(
                // text.replace(regex, (match) => `<span class="search-highlight">${match}</span>`)
                this.replaceContent(text, regex, (match) => `<span class="search-highlight">${match}</span>`)
            );

        } else {
            return text;
        }
    }

    parseHTML(html, context) {
        const t = (context || document).createElement('template');
        t.innerHTML = html;
        return t.content.cloneNode(true);
    }

    private replaceContent(strMatch1, regex, match) {
        const matchReg1 = />.*?\</gi; // 先查出><之间的内容
        const strs = strMatch1.match(matchReg1); // 拿到所有符合的键值
        if (strs && strs.length) {
            for (const aa of strs) {
                const rep_old = strs[aa]; // 拿到原始符合字符串
                const rep_new = strs[aa].replace(regex, match); // 替换成目的字符串
                const re2 = new RegExp(rep_old, 'g'); // 利用原始字符串生成正则
                strMatch1 = strMatch1.replace(re2, rep_new); // 将符合的原始字符串替换成新字符串
            }
            return strMatch1;
        } else {
            return strMatch1.replace(regex, match);
        }
    }
}