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

import {
  advanceCatchUpWindow,
  chatBadge,
  mergeChatMessages,
  messageError,
  rootReadIsProven,
} from "./chat-utils";

describe("chat client state", () => {
  it("retains through across pages, then starts a new interval after exhaustion", () => {
    const first = advanceCatchUpWindow(
      { after: "5" },
      { next: "8", through: "10", hasMore: true },
    );
    expect(first).toEqual({ after: "8", through: "10" });
    const second = advanceCatchUpWindow(first, {
      next: "9",
      through: "10",
      hasMore: true,
    });
    expect(second).toEqual({ after: "9", through: "10" });
    expect(
      advanceCatchUpWindow(second, {
        next: "9",
        through: "10",
        hasMore: false,
      }),
    ).toEqual({ after: "10" });
  });

  it("does not lose the cursor on a stalled page or fold concurrent sends into the old interval", () => {
    const window = { after: "8", through: "10" };
    expect(
      advanceCatchUpWindow(window, { next: "8", through: "10", hasMore: true }),
    ).toBe(window);
    expect(
      advanceCatchUpWindow(window, {
        next: "10",
        through: "10",
        hasMore: false,
      }),
    ).toEqual({ after: "10" });
    expect(
      advanceCatchUpWindow(
        { after: "10" },
        { next: "11", through: "12", hasMore: true },
      ),
    ).toEqual({ after: "11", through: "12" });
  });
  it("never replaces a newer edit or tombstone with an older page", () => {
    const original = {
      id: "m",
      sequence: "1",
      revision: 1,
      body: "old",
      status: "active",
    };
    const edited = { ...original, revision: 2, body: "new" };
    const deleted = { ...edited, revision: 3, body: "", status: "deleted" };
    expect(mergeChatMessages([edited], [original])).toEqual([edited]);
    expect(mergeChatMessages([deleted], [edited])).toEqual([deleted]);
  });
  it("requires a channel-wide scan and does not claim unseen replies as read", () => {
    expect(rootReadIsProven("20", null, null, "0")).toBe(false);
    expect(rootReadIsProven("20", "19", null, "0")).toBe(false);
    expect(rootReadIsProven("20", "25", "18", "0")).toBe(false);
    expect(rootReadIsProven("20", "25", "22", "0")).toBe(true);
  });

  it("deduplicates history and catch-up in sequence order", () => {
    expect(
      mergeChatMessages(
        [
          { id: "b", sequence: "9" },
          { id: "a", sequence: "2" },
        ],
        [
          { id: "b", sequence: "9" },
          { id: "c", sequence: "10" },
        ],
      ).map((m) => m.id),
    ).toEqual(["a", "b", "c"]);
  });

  it("distinguishes unread dots from numeric direct and mention activity", () => {
    expect(
      chatBadge({ unreadCount: 3, mentionCount: 0, directUnreadCount: 0 }),
    ).toEqual({ dot: true, count: 0 });
    expect(
      chatBadge({ unreadCount: 3, mentionCount: 2, directUnreadCount: 1 }),
    ).toEqual({ dot: true, count: 3 });
  });

  it("maps failed sends to actionable messages", () => {
    expect(messageError("NOT_FOUND")).toMatch(/access/i);
    expect(messageError("CONFLICT")).toMatch(/different message/i);
    expect(messageError("INTERNAL_SERVER_ERROR")).toMatch(/retry/i);
  });
});