/**
 * 图片提取 - 主图、SKU、详情图、视频
 * 从 extension-v1 移植，新增：
 *   - srcset 处理（Ozon 画廊是 <img srcset> / <picture><source>）
 *   - toOriginalUrl 传平台规则（Ozon /wc\d+/）
 */
import {
  toAbsoluteUrl,
  toOriginalUrl,
  urlInBrackets,
  looksLikeImageUrl,
  dedupeKey,
  pickBestFromSrcset,
} from './url';
import { queryAllDeep } from './dom';
import type { ImageGroupKey, SiteProfile, SrcProp } from '../profiles/types';

export interface ImageMaterial {
  key: string;          // 'main-001'
  groupKey: ImageGroupKey; // 'main'
  groupName: string;    // '主图'
  variantName?: string; // SKU 规格名（仅 sku 组）
  url: string;          // 已还原为原图
  thumbUrl: string;     // 页面上的原始小图地址
  index: number;
  type: 'img' | 'video';
  width?: number;
  height?: number;
}

/** 从元素上读出图片地址与名称，按 srcProps 顺序降级 */
function readImageSource(
  el: Element,
  srcProps: SrcProp[],
  nameSelectors?: string[]
): { url: string; name: string; imgEl: HTMLImageElement | null } {
  let url = '';
  let name = '';
  let imgEl: HTMLImageElement | null = el instanceof HTMLImageElement ? el : null;

  for (const prop of srcProps) {
    if (url) break;

    if (prop === 'backgroundImage') {
      if (el.tagName === 'IMG') {
        const img = el as HTMLImageElement;
        url = img.currentSrc || img.src || '';
        name = img.alt || '';
      } else {
        const bg = getComputedStyle(el).backgroundImage || '';
        const cand = (urlInBrackets(bg) || bg).replace(/['"]/g, '');
        if (looksLikeImageUrl(cand)) url = cand;
      }
      continue;
    }

    if (prop === 'srcset') {
      // <img srcset> 或 <source srcset>
      const raw = el.getAttribute('srcset') || (el as any).srcset || '';
      if (raw) url = pickBestFromSrcset(raw);
      continue;
    }

    const raw = (el as any)[prop] || el.getAttribute(prop);
    if (raw) {
      // srcset 场景下 currentSrc 才是实际加载的那张
      url = prop === 'src' ? ((el as HTMLImageElement).currentSrc || (el as HTMLImageElement).src || '') : raw;
    }
  }

  // 选择器命中的是容器、图在子节点上
  if (!url && el.tagName !== 'IMG') {
    const inner = el.querySelector('img, source');
    if (inner) {
      const srcset = inner.getAttribute('srcset');
      url = srcset
        ? pickBestFromSrcset(srcset)
        : inner.getAttribute('data-src') || (inner as HTMLImageElement).currentSrc || (inner as HTMLImageElement).src || '';
      if (inner instanceof HTMLImageElement) imgEl = inner;
      if (!name && inner instanceof HTMLImageElement) name = inner.alt || '';
    }
  }

  // 名称统一取（SKU 规格名）
  if (!name && nameSelectors?.length) {
    for (const sel of nameSelectors) {
      const t = el.querySelector(sel)?.textContent?.trim();
      if (t) {
        name = t;
        break;
      }
    }
  }

  return { url: url ? toAbsoluteUrl(url) : '', name, imgEl };
}

export function collectImages(profile: SiteProfile): ImageMaterial[] {
  const result: ImageMaterial[] = [];

  for (const group of profile.imageGroups) {
    const srcProps = group.srcProps ?? profile.defaultSrcProps;
    // 去重按组独立：一张图同时是主图和 SKU 图是正常的
    const seen = new Set<string>();
    const activeSet = new Set(group.activeSelectors ? queryAllDeep(group.activeSelectors) : []);

    for (const el of queryAllDeep(group.selectors)) {
      if (activeSet.has(el)) continue;
      if (group.excludeWithin?.some((sel) => el.closest(sel))) continue;

      const { url: rawUrl, name, imgEl } = readImageSource(el, srcProps, group.nameSelectors);
      if (!rawUrl) continue;

      if (group.type === 'video' && !/\.(mp4|avi|mov|wmv|m3u8|webm)(\?|$)/i.test(rawUrl) && !/^blob:/i.test(rawUrl)) {
        continue;
      }

      const url = group.type === 'img' ? toOriginalUrl(rawUrl, profile.originalUrlRules) : rawUrl;

      // 尺寸过滤
      if (group.type === 'img' && (group.minWidth || group.minHeight)) {
        const measured = imgEl ?? (el as HTMLElement);
        const w = (measured as HTMLImageElement).naturalWidth || (measured as HTMLElement).offsetWidth || 0;
        const h = (measured as HTMLImageElement).naturalHeight || (measured as HTMLElement).offsetHeight || 0;
        if (w > 0 && h > 0 && (w < (group.minWidth ?? 0) || h < (group.minHeight ?? 0))) continue;
      }

      const k = group.key === 'sku' ? `${dedupeKey(url, profile.originalUrlRules)}::${name}` : dedupeKey(url, profile.originalUrlRules);
      if (seen.has(k)) continue;
      seen.add(k);

      result.push({
        key: `${group.key}-${String(result.filter((r) => r.groupKey === group.key).length + 1).padStart(3, '0')}`,
        groupKey: group.key,
        groupName: group.name,
        variantName: group.key === 'sku' ? name || undefined : undefined,
        url,
        thumbUrl: rawUrl,
        index: result.length,
        type: group.type,
      });
    }
  }

  return result;
}