import type { ReactNode } from "react";
import { ExternalLink } from "lucide-react";
import {
  groupTimelineByDate,
  type TimelineItem,
} from "@/lib/timelineBlocks";
import { timelineDayId } from "@/lib/toc";

type MdTimelineProps = {
  items: TimelineItem[];
  /** 每项正文已渲染的 React 节点（与 items 等长）；缺省则只显示纯文本 */
  renderBody?: (item: TimelineItem, index: number) => ReactNode;
};

const PREFIX_RE =
  /^(feat|fix|polish|chore|docs|refactor|style|perf|test)(?:\(([^)]*)\))?\s*:?\s*/i;

function splitTitlePrefix(title: string): { kind?: string; scope?: string; rest: string } {
  const m = PREFIX_RE.exec(title);
  if (!m) return { rest: title };
  const rest = title.slice(m[0].length).trim() || title;
  return {
    kind: m[1].toLowerCase(),
    scope: m[2]?.trim() || undefined,
    rest,
  };
}

/**
 * 按日分组的垂直时间线（更新树）。
 * 日分组 id 与 extractToc 的 tl-YYYY-MM-DD 对齐，供右侧目录跳转。
 * 条目用普通段落而非 h3，避免被 .prose-content 标题样式放大。
 */
export default function MdTimeline({ items, renderBody }: MdTimelineProps) {
  if (!items.length) {
    return <p className="meta px-1 py-2">暂无时间线条目</p>;
  }
  const groups = groupTimelineByDate(items);
  let flat = 0;

  return (
    <div className="j13-timeline" role="list" aria-label="时间线">
      {groups.map((g) => (
        <section
          key={g.date}
          id={timelineDayId(g.date)}
          className="j13-timeline-day"
          style={{ scrollMarginTop: 90 }}
          aria-labelledby={`${timelineDayId(g.date)}-label`}
        >
          <div className="j13-timeline-day-label" id={`${timelineDayId(g.date)}-label`}>
            <time dateTime={/^\d{4}-\d{2}-\d{2}$/.test(g.date) ? g.date : undefined}>
              {g.date}
            </time>
            <span className="j13-timeline-day-count">{g.items.length}</span>
          </div>
          <ul className="j13-timeline-items">
            {g.items.map((it) => {
              const idx = flat++;
              const { kind, scope, rest } = splitTitlePrefix(it.title);
              const bodyNode = renderBody
                ? renderBody(it, idx)
                : it.body.trim()
                  ? <span className="whitespace-pre-wrap">{it.body}</span>
                  : null;

              return (
                <li key={`${g.date}-${idx}-${it.title}`} className="j13-timeline-item" role="listitem">
                  <span className="j13-timeline-dot" aria-hidden />
                  <div className="j13-timeline-card">
                    <div className="j13-timeline-head">
                      {kind ? (
                        <span className={`j13-timeline-chip is-${kind}`}>
                          {kind}
                          {scope ? <span className="j13-timeline-chip-scope">({scope})</span> : null}
                        </span>
                      ) : null}
                      <p className="j13-timeline-summary">{rest}</p>
                      {it.sourceUrl ? (
                        <a
                          href={it.sourceUrl}
                          className="j13-timeline-src"
                          target="_blank"
                          rel="noopener noreferrer"
                          data-tip="查看提交"
                          aria-label="查看提交"
                        >
                          <ExternalLink size={12} />
                        </a>
                      ) : null}
                    </div>
                    {bodyNode ? <div className="j13-timeline-body">{bodyNode}</div> : null}
                  </div>
                </li>
              );
            })}
          </ul>
        </section>
      ))}
    </div>
  );
}