import type { ChapterListItem } from "@/lib/api/types";
import type { ChapterEntry } from "@/lib/workbench/chapter";
import { buildChapterEntries } from "@/lib/workbench/chapter";

export interface ReviewChapterOption {
  no: number;
  label: string;
  // 有草稿正文=可审；无草稿章置灰（审稿依赖草稿，选空章会 422）。
  disabled: boolean;
}

export function reviewChapterHref(projectId: string, chapterNo: number): string {
  return `/projects/${projectId}/review?chapter=${chapterNo}`;
}

// 旧签名：仅按大纲章 + 当前章构建（无草稿状态）。保留兼容，无 chapterList 时回退用。
export function reviewChapterOptions(
  chapters: readonly ChapterEntry[],
  currentChapterNo: number,
): ReviewChapterOption[] {
  return buildChapterEntries(chapters, currentChapterNo).map((chapter) => ({
    no: chapter.no,
    label: chapter.title
      ? `第 ${chapter.no} 章 · ${chapter.title}`
      : `第 ${chapter.no} 章`,
    disabled: false,
  }));
}

function statusSuffix(item: ChapterListItem | undefined): string {
  if (!item) return "";
  if (item.accepted) return " · 已验收";
  if (item.reviewed_at) return " · 已审";
  if (item.has_draft) return " · 草稿";
  return " · 空";
}

// 新签名：以「真实存在的章」(chapterList) 为准枚举，覆盖「写过但不在大纲」的章，
// 用大纲标题补短名，并标注可审/已审/已验收；无草稿章置灰（但当前章永不置灰）。
export function buildReviewChapterOptions(
  chapterList: readonly ChapterListItem[],
  outline: readonly ChapterEntry[],
  currentChapterNo: number,
): ReviewChapterOption[] {
  const titleByNo = new Map(outline.map((c) => [c.no, c.title]));
  const itemByNo = new Map(chapterList.map((c) => [c.chapter_no, c]));
  // 枚举真实写过的章(chapterList) ∪ 大纲章(outline，展示全书结构) ∪ 当前章。
  const nos = new Set<number>([
    ...chapterList.map((c) => c.chapter_no),
    ...outline.map((c) => c.no),
    currentChapterNo,
  ]);
  return [...nos]
    .sort((a, b) => a - b)
    .map((no) => {
      const item = itemByNo.get(no);
      const title = titleByNo.get(no);
      const base = title ? `第 ${no} 章 · ${title}` : `第 ${no} 章`;
      return {
        no,
        label: base + statusSuffix(item),
        // 无草稿的章不可审（审稿依赖草稿）；仅当前章例外，始终可停留。
        disabled: no !== currentChapterNo && !item?.has_draft,
      };
    });
}

// 无 ?chapter 时的默认章：优先最近一个有草稿的章，其次最大章号，兜底第 1 章。
export function defaultReviewChapter(
  chapterList: readonly ChapterListItem[],
): number {
  const withDraft = chapterList
    .filter((c) => c.has_draft)
    .map((c) => c.chapter_no);
  if (withDraft.length > 0) return Math.max(...withDraft);
  if (chapterList.length > 0) {
    return Math.max(...chapterList.map((c) => c.chapter_no));
  }
  return 1;
}