import { describe, expect, it } from "vitest";

import {
  buildReviewChapterOptions,
  defaultReviewChapter,
  reviewChapterHref,
  reviewChapterOptions,
} from "./chapterNav";
import type { ChapterListItem } from "@/lib/api/types";
import type { ChapterEntry } from "@/lib/workbench/chapter";

const item = (
  chapter_no: number,
  over: Partial<ChapterListItem> = {},
): ChapterListItem => ({
  chapter_no,
  has_draft: true,
  accepted: false,
  reviewed_at: null,
  ...over,
});

describe("reviewChapterHref", () => {
  it("builds the review route for a chapter number", () => {
    expect(reviewChapterHref("proj-1", 3)).toBe(
      "/projects/proj-1/review?chapter=3",
    );
  });

  it("always targets the review page (not write)", () => {
    expect(reviewChapterHref("p", 1)).toContain("/review?chapter=1");
  });
});

describe("reviewChapterOptions (legacy, outline-only)", () => {
  const chapters: ChapterEntry[] = [
    { no: 1, title: "开篇" },
    { no: 2 },
    { no: 3, title: "转折" },
  ];

  it("merges outline chapters with the current chapter, sorted ascending", () => {
    const opts = reviewChapterOptions(chapters, 2);
    expect(opts.map((o) => o.no)).toEqual([1, 2, 3]);
  });

  it("includes the current chapter even when it is outside the outline", () => {
    const opts = reviewChapterOptions(chapters, 9);
    expect(opts.map((o) => o.no)).toEqual([1, 2, 3, 9]);
  });

  it("labels each option with chapter number and optional title (never disabled)", () => {
    const opts = reviewChapterOptions(chapters, 1);
    expect(opts[0]).toEqual({ no: 1, label: "第 1 章 · 开篇", disabled: false });
    expect(opts[1]).toEqual({ no: 2, label: "第 2 章", disabled: false });
  });
});

describe("buildReviewChapterOptions (real chapters + outline titles)", () => {
  const outline: ChapterEntry[] = [
    { no: 1, title: "开篇" },
    { no: 2, title: "转折" },
  ];

  it("enumerates real chapters, sorted, with outline titles + status suffix", () => {
    const list = [
      item(1, { accepted: true }),
      item(2, { reviewed_at: "2026-01-01T00:00:00Z" }),
    ];
    const opts = buildReviewChapterOptions(list, outline, 2);
    expect(opts).toEqual([
      { no: 1, label: "第 1 章 · 开篇 · 已验收", disabled: false },
      { no: 2, label: "第 2 章 · 转折 · 已审", disabled: false },
    ]);
  });

  it("covers chapters written but not in the outline, and shows outline structure", () => {
    const list = [item(1), item(5)]; // 第 5 章 写过但大纲没有；大纲有第 2 章但未写
    const opts = buildReviewChapterOptions(list, outline, 1);
    expect(opts.map((o) => o.no)).toEqual([1, 2, 5]);
    expect(opts.find((o) => o.no === 5)?.label).toBe("第 5 章 · 草稿");
    // 大纲有、未写的章出现在结构里但置灰（不可审）
    expect(opts.find((o) => o.no === 2)?.disabled).toBe(true);
  });

  it("disables chapters with no draft, but never the current chapter", () => {
    const list = [item(1), item(2, { has_draft: false })];
    const optsOnOther = buildReviewChapterOptions(list, outline, 1);
    expect(optsOnOther.find((o) => o.no === 2)?.disabled).toBe(true);
    // 当前就在第 2 章时不置灰（否则无法停留）
    const optsOnEmpty = buildReviewChapterOptions(list, outline, 2);
    expect(optsOnEmpty.find((o) => o.no === 2)?.disabled).toBe(false);
  });

  it("always includes the current chapter even if absent from list and outline", () => {
    const opts = buildReviewChapterOptions([item(1)], outline, 7);
    expect(opts.map((o) => o.no)).toEqual([1, 2, 7]);
    expect(opts.find((o) => o.no === 7)).toEqual({
      no: 7,
      label: "第 7 章",
      disabled: false,
    });
  });
});

describe("defaultReviewChapter", () => {
  it("prefers the latest chapter that has a draft", () => {
    const list = [item(1), item(2), item(3, { has_draft: false })];
    expect(defaultReviewChapter(list)).toBe(2);
  });

  it("falls back to the max chapter number when none have drafts", () => {
    const list = [item(1, { has_draft: false }), item(4, { has_draft: false })];
    expect(defaultReviewChapter(list)).toBe(4);
  });

  it("defaults to chapter 1 for an empty list", () => {
    expect(defaultReviewChapter([])).toBe(1);
  });
});