import { DOMParser } from '@xmldom/xmldom';
import { CallTemplateFunctionArgs, Context, PluginDefinition } from '@yaakapp/api';
import xpath from 'xpath';

export const plugin: PluginDefinition = {
  templateFunctions: [{
    name: 'xml.xpath',
    description: 'Filter XML-formatted text using XPath syntax',
    args: [
      { type: 'text', name: 'input', label: 'Input', multiLine: true, placeholder: '<foo></foo>' },
      { type: 'text', name: 'query', label: 'Query', placeholder: '//foo' },
    ],
    async onRender(_ctx: Context, args: CallTemplateFunctionArgs): Promise<string | null> {
      try {
        const doc = new DOMParser().parseFromString(String(args.values.input), 'text/xml');
        let result = xpath.select(String(args.values.query), doc, false);
        if (Array.isArray(result)) {
          return String(result.map(c => String(c.firstChild))[0] ?? '');
        } else if (result instanceof Node) {
          return String(result.firstChild);
        } else {
          return String(result);
        }
      } catch (e) {
        return null;
      }
    },
  }],
};