/**
 * 文本提取 - 标题、价格、参数表、描述
 * 从 docs/extension/plan.md §6.6 移植（简化版）
 */
import type { SiteProfile, TextRule } from '../profiles/types';

export interface TextMaterial {
  kind: TextRule['kind'];
  content: string;
  pairs?: Array<{ key: string; value: string }>;  // table 模式的结构化结果
}

function clean(s: string): string {
  return s.replace(/\s+/g, ' ').trim();
}

function extractOne(rule: TextRule): TextMaterial | null {
  for (const sel of rule.selectors) {
    let nodes: NodeListOf<Element>;
    try {
      nodes = document.querySelectorAll(sel);
    } catch {
      continue;
    }
    if (!nodes.length) continue;

    // table 模式：参数表
    if (rule.extract === 'table') {
      const pairs: Array<{ key: string; value: string }> = [];
      nodes.forEach(row => {
        const k = clean(row.querySelector(rule.tableKeySelector ?? '')?.textContent ?? '');
        const v = clean(row.querySelector(rule.tableValueSelector ?? '')?.textContent ?? '');
        if (k && v) pairs.push({ key: k.replace(/[:：]$/, ''), value: v });
      });
      if (pairs.length) {
        return {
          kind: rule.kind,
          content: pairs.map(p => `${p.key}: ${p.value}`).join('\n'),
          pairs
        };
      }
      continue;
    }

    // join 模式：标题被拆成多个 span
    if (rule.extract === 'join') {
      let text = '';
      nodes.forEach(n => { text += n.textContent ?? ''; });
      text = clean(text);
      if (text) return { kind: rule.kind, content: text };
      continue;
    }

    // first 模式：只取第一个
    const first = clean(nodes[0].textContent ?? '');
    if (first) return { kind: rule.kind, content: first };
  }
  return null;
}

export function collectTexts(profile: SiteProfile): {
  materials: TextMaterial[];
  missingRequired: string[];
} {
  const materials: TextMaterial[] = [];
  const missingRequired: string[] = [];

  for (const rule of profile.textRules) {
    const m = extractOne(rule);
    if (m) materials.push(m);
    else if (rule.required) missingRequired.push(rule.kind);
  }

  return { materials, missingRequired };
}