/**
* CSS Unique Strategy - 基于唯一 ID 或 class 组合的选择器策略
*/
import type { SelectorCandidate, SelectorStrategy } from '../types';
const MAX_CLASS_COUNT = 24;
const MAX_COMBO_CLASSES = 8;
const MAX_CANDIDATES = 6;
function isValidClassToken(token: string): boolean {
return /^[a-zA-Z0-9_-]+$/.test(token);
}
export const cssUniqueStrategy: SelectorStrategy = {
id: 'css-unique',
generate(ctx) {
if (!ctx.options.includeCssUnique) return [];
const { element, helpers } = ctx;
const out: SelectorCandidate[] = [];
const tag = element.tagName?.toLowerCase?.() ?? '';
// 1) Unique ID selector
const id = element.id?.trim();
if (id) {
const sel = `#${helpers.cssEscape(id)}`;
if (helpers.isUnique(sel)) {
out.push({ type: 'css', value: sel, source: 'generated', strategy: 'css-unique' });
}
}
if (out.length >= MAX_CANDIDATES) return out;
// 2) Unique class selectors
const classList = Array.from(element.classList || [])
.map((c) => String(c).trim())
.filter((c) => c.length > 0 && isValidClassToken(c))
.slice(0, MAX_CLASS_COUNT);
for (const cls of classList) {
if (out.length >= MAX_CANDIDATES) break;
const sel = `.${helpers.cssEscape(cls)}`;
if (helpers.isUnique(sel)) {
out.push({ type: 'css', value: sel, source: 'generated', strategy: 'css-unique' });
}
}
if (tag) {
for (const cls of classList) {
if (out.length >= MAX_CANDIDATES) break;
const sel = `${tag}.${helpers.cssEscape(cls)}`;
if (helpers.isUnique(sel)) {
out.push({ type: 'css', value: sel, source: 'generated', strategy: 'css-unique' });
}
}
}
if (out.length >= MAX_CANDIDATES) return out;
// 3) Class combinations (depth 2/3), limited to avoid heavy queries.
const comboSource = classList.slice(0, MAX_COMBO_CLASSES).map((c) => helpers.cssEscape(c));
const tryPush = (selector: string): void => {
if (out.length >= MAX_CANDIDATES) return;
if (!helpers.isUnique(selector)) return;
out.push({ type: 'css', value: selector, source: 'generated', strategy: 'css-unique' });
};
const tryPushWithTag = (selector: string): void => {
tryPush(selector);
if (tag) tryPush(`${tag}${selector}`);
};
// Depth 2
for (let i = 0; i < comboSource.length && out.length < MAX_CANDIDATES; i++) {
for (let j = i + 1; j < comboSource.length && out.length < MAX_CANDIDATES; j++) {
tryPushWithTag(`.${comboSource[i]}.${comboSource[j]}`);
}
}
// Depth 3
for (let i = 0; i < comboSource.length && out.length < MAX_CANDIDATES; i++) {
for (let j = i + 1; j < comboSource.length && out.length < MAX_CANDIDATES; j++) {
for (let k = j + 1; k < comboSource.length && out.length < MAX_CANDIDATES; k++) {
tryPushWithTag(`.${comboSource[i]}.${comboSource[j]}.${comboSource[k]}`);
}
}
}
return out;
},
};
