/**
 * 文本提取 - 标题、价格、参数表、卖点、描述、品牌
 * 从 extension-v1 移植（DOM 兜底路径）
 */
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 };
}

/** 合并去重：以 kind 为键，结构化来源优先，DOM 来源兜底。
 *  参数表（params）特殊处理：两边的 pairs 做并集合并（按 key 去重），
 *  因为「关于商品」只给前几项，完整「特征」在 DOM 里，需要合并才能拿全。
 */
export function mergeTexts(
  primary: TextMaterial[],
  fallback: TextMaterial[]
): TextMaterial[] {
  const map = new Map<string, TextMaterial>();
  for (const m of [...primary, ...fallback]) {
    if (m.kind === 'params') {
      const existing = map.get('params');
      if (!existing) {
        map.set('params', { ...m, pairs: [...(m.pairs ?? [])] });
      } else {
        const merged = [...(existing.pairs ?? [])];
        const seen = new Set(merged.map((p) => p.key));
        for (const p of m.pairs ?? []) {
          if (!seen.has(p.key)) {
            merged.push(p);
            seen.add(p.key);
          }
        }
        existing.pairs = merged;
        existing.content = merged.map((p) => `${p.key}: ${p.value}`).join('\n');
      }
      continue;
    }
    if (!map.has(m.kind)) map.set(m.kind, m);
  }
  return Array.from(map.values());
}