import { describe, expect, test, vi } from "vitest";
import { act, screen, waitFor, within } from "@testing-library/react";
import { userEvent } from "@testing-library/user-event";
import { ChatModal } from "../../../components/chat/ChatModal.tsx";
import type { ChatMessage } from "../../../../shared/chat.ts";
import { calls, fail, route } from "../../fetch.ts";
import { makeChatMessage, makeSession, wire } from "../../fixtures.ts";
import { renderApp } from "../../render.tsx";
import { FakeWebSocket } from "../../ws.ts";

const me = makeSession({ id: "me", username: "me" });

async function setup(
  history: ChatMessage[] = [],
  {
    session = me,
    welcome = {} as Record<string, unknown>,
    focusId = undefined as string | undefined,
  } = {},
) {
  route("GET /api/chat", () => wire(history));
  const onClose = vi.fn();
  const user = userEvent.setup();
  renderApp(<ChatModal onClose={onClose} focusId={focusId} />, { session });
  const socket = FakeWebSocket.last;
  socket.welcome(welcome);
  await screen.findByRole("dialog", { name: "Chat" });
  await waitFor(() =>
    expect(screen.queryByText("Loading messages…")).not.toBeInTheDocument()
  );
  const composer = screen.getByPlaceholderText("Type a message…");
  return { user, socket, onClose, composer };
}

const sent = (socket: FakeWebSocket, type: string) =>
  socket.messages.filter((m) => m.type === type);

describe("ChatModal: history", () => {
  test("shows the latest messages under a day separator, grouping runs", async () => {
    const t0 = Date.now() - 60_000;
    await setup([
      makeChatMessage({
        id: "1",
        userId: "ann",
        authorUsername: "ann",
        body: "one",
        createdAt: new Date(t0),
      }),
      makeChatMessage({
        id: "2",
        userId: "ann",
        authorUsername: "ann",
        body: "two",
        createdAt: new Date(t0 + 1000),
      }),
      makeChatMessage({
        id: "3",
        userId: "bob",
        authorUsername: "bob",
        body: "three",
        createdAt: new Date(t0 + 2000),
      }),
    ]);
    expect(screen.getByText("Today")).toBeInTheDocument();
    // "two" continues ann's run: no second author link.
    expect(screen.getAllByRole("link", { name: "ann" })).toHaveLength(1);
    expect(screen.getByText("two").closest(".chat-message")).toHaveClass(
      "chat-message--grouped",
    );
    expect(calls("GET /api/chat")[0].url.searchParams.get("limit")).toBe("50");
  });

  test("empty and failed states", async () => {
    route("GET /api/chat", () => fail("down", 500), { once: true });
    route("GET /api/chat", () => []);
    const user = userEvent.setup();
    renderApp(<ChatModal onClose={() => {}} />, { session: me });
    await screen.findByText("Couldn't load the chat.");
    await user.click(screen.getByRole("button", { name: "Try again" }));
    await screen.findByText("No messages yet. Say hello!");
  });

  test("a full page offers older messages", async () => {
    const page = Array.from(
      { length: 50 },
      (_, i) =>
        makeChatMessage({
          id: `m${i + 10}`,
          body: `msg ${i + 10}`,
          createdAt: new Date(Date.now() - (50 - i) * 1000),
        }),
    );
    route(
      "GET /api/chat",
      (req) =>
        req.url.searchParams.has("before")
          ? wire([
            makeChatMessage({
              id: "m0",
              body: "the oldest",
              createdAt: new Date(Date.now() - 999_000),
            }),
          ])
          : wire(page),
    );
    const user = userEvent.setup();
    renderApp(<ChatModal onClose={() => {}} />, { session: me });
    await user.click(
      await screen.findByRole("button", { name: "Load older messages" }),
    );
    await screen.findByText("the oldest");
    const req = calls("GET /api/chat").find((r) =>
      r.url.searchParams.has("before")
    )!;
    expect(req.url.searchParams.get("beforeId")).toBe("m10");
    expect(screen.queryByRole("button", { name: "Load older messages" })).not
      .toBeInTheDocument();
  });

  test("the 'new' divider sits before the first unread message from someone else", async () => {
    const readAt = new Date(Date.now() - 30_000);
    await setup([
      makeChatMessage({
        id: "old",
        body: "seen",
        createdAt: new Date(Date.now() - 60_000),
      }),
      makeChatMessage({
        id: "new1",
        body: "unseen",
        createdAt: new Date(Date.now() - 10_000),
      }),
    ], { welcome: { chatReadAt: readAt.toISOString() } });
    const divider = document.querySelector(".chat-new-sep")!;
    expect(divider).toHaveTextContent("New");
    expect(divider.nextElementSibling).toHaveTextContent("unseen");
  });

  test("a deep link opens on its message, flashed", async () => {
    await setup([
      makeChatMessage({ id: "m1", body: "hey @me" }),
      makeChatMessage({ id: "m2", body: "later" }),
    ], { focusId: "m1" });
    expect(screen.getByText(/hey/).closest(".chat-message")).toHaveClass(
      "chat-message--flash",
    );
    expect(screen.getByText("later").closest(".chat-message")).not.toHaveClass(
      "chat-message--flash",
    );
  });

  test("reading at the bottom moves the read marker", async () => {
    const { socket } = await setup([makeChatMessage({ body: "hi" })]);
    await waitFor(() => expect(sent(socket, "chat_read")).toHaveLength(1));
  });

  test("tells the server the chat is open, and closed", async () => {
    const { socket } = await setup();
    expect(sent(socket, "chat_focus")).toContainEqual({
      type: "chat_focus",
      open: true,
    });
  });
});

describe("ChatModal: sending", () => {
  test("Enter sends; the message shows as sending until its echo", async () => {
    const { user, socket, composer } = await setup();
    await user.type(composer, "hello there{Enter}");
    expect(composer).toHaveValue("");
    const [send] = sent(socket, "chat_send");
    expect(send).toMatchObject({ body: "hello there" });
    expect(screen.getByText("Sending…")).toBeInTheDocument();
    socket.receive({
      type: "chat_message",
      nonce: send.nonce,
      message: wire(
        makeChatMessage({
          id: "echo",
          userId: "me",
          authorUsername: "me",
          body: "hello there",
          createdAt: new Date(),
        }),
      ),
    });
    expect(screen.queryByText("Sending…")).not.toBeInTheDocument();
    expect(screen.getByText("hello there")).toBeInTheDocument();
  });

  test("Shift+Enter is a new line; blank and over-long messages don't send", async () => {
    const { user, socket, composer } = await setup();
    await user.type(composer, "line one{Shift>}{Enter}{/Shift}line two");
    expect(composer).toHaveValue("line one\nline two");
    await user.clear(composer);
    await user.type(composer, "   {Enter}");
    expect(sent(socket, "chat_send")).toHaveLength(0);
    await user.clear(composer);
    await user.click(composer);
    await user.paste("x".repeat(2001));
    expect(screen.getByRole("button", { name: "Send" })).toBeDisabled();
    expect(screen.getByText("2001 / 2000")).toBeInTheDocument();
  });

  test("a failed send can be retried, taken back or dropped", async () => {
    const { user, socket, composer } = await setup();
    await user.type(composer, "oops{Enter}");
    const [send] = sent(socket, "chat_send");
    socket.receive({
      type: "error",
      scope: "chat",
      nonce: send.nonce,
      message: "Slow down",
    });
    const failed = screen.getByText("Slow down").closest(
      ".chat-message",
    )! as HTMLElement;
    await user.click(within(failed).getByRole("button", { name: "Retry" }));
    expect(sent(socket, "chat_send")).toHaveLength(2);

    const [, retry] = sent(socket, "chat_send");
    socket.receive({
      type: "error",
      scope: "chat",
      nonce: retry.nonce,
      message: "Still no",
    });
    await user.type(composer, "draft");
    await user.click(screen.getByRole("button", { name: "Edit" }));
    expect(composer).toHaveValue("draft\n\noops");
    expect(screen.queryByText("Still no")).not.toBeInTheDocument();
  });

  test("typing is announced, and its end too", async () => {
    vi.useFakeTimers({
      toFake: ["setTimeout", "clearTimeout", "Date"],
      shouldAdvanceTime: true,
    });
    try {
      const { socket, composer } = await setup();
      const user = userEvent.setup({ advanceTimers: vi.advanceTimersByTime });
      await user.type(composer, "abc");
      expect(sent(socket, "chat_typing")).toEqual([{
        type: "chat_typing",
        typing: true,
      }]);
      act(() => vi.advanceTimersByTime(3_600));
      expect(sent(socket, "chat_typing").at(-1)).toEqual({
        type: "chat_typing",
        typing: false,
      });
    } finally {
      vi.useRealTimers();
    }
  });

  test("the draft and reply outlive the chat", async () => {
    const first = await setup([
      makeChatMessage({ id: "a", authorUsername: "ann", body: "question?" }),
    ]);
    await first.user.type(first.composer, "half a thought");
    const stored = JSON.parse(sessionStorage.getItem("chat-draft:me")!);
    expect(stored.draft).toBe("half a thought");
  });
});

describe("ChatModal: replies, edits, deletes", () => {
  const theirs = () =>
    makeChatMessage({
      id: "t1",
      userId: "ann",
      authorUsername: "ann",
      body: "ask me **anything**",
      createdAt: new Date(Date.now() - 20_000),
    });
  const mine = () =>
    makeChatMessage({
      id: "m1",
      userId: "me",
      authorUsername: "me",
      body: "my words",
      createdAt: new Date(Date.now() - 10_000),
    });

  test("replying: the bar, the reference, and Escape cancelling just the reply", async () => {
    const { user, socket, composer, onClose } = await setup([theirs()]);
    const msg = screen.getByText("anything").closest(
      ".chat-message",
    )! as HTMLElement;
    await user.click(within(msg).getByRole("button", { name: "Reply" }));
    expect(screen.getByText("Replying to")).toBeInTheDocument();
    expect(document.querySelector(".chat-reply-bar-snippet")).toHaveTextContent(
      "ask me anything",
    );
    await user.keyboard("{Escape}");
    expect(screen.queryByText("Replying to")).not.toBeInTheDocument();
    expect(onClose).not.toHaveBeenCalled();

    await user.click(within(msg).getByRole("button", { name: "Reply" }));
    await user.type(composer, "sure{Enter}");
    expect(sent(socket, "chat_send")[0]).toMatchObject({
      body: "sure",
      replyToId: "t1",
    });
  });

  test("only your own messages can be edited and deleted", async () => {
    await setup([theirs(), mine()]);
    const t = screen.getByText("anything").closest(
      ".chat-message",
    )! as HTMLElement;
    const m = screen.getByText("my words").closest(
      ".chat-message",
    )! as HTMLElement;
    expect(within(t).queryByRole("button", { name: "Edit" })).not
      .toBeInTheDocument();
    expect(within(m).getByRole("button", { name: "Edit" })).toBeInTheDocument();
    expect(within(m).getByRole("button", { name: "Delete" }))
      .toBeInTheDocument();
  });

  test("moderators can delete anyone's", async () => {
    await setup([theirs()], {
      session: makeSession({ id: "mod", role: "moderator" }),
    });
    const t = screen.getByText("anything").closest(
      ".chat-message",
    )! as HTMLElement;
    expect(within(t).getByRole("button", { name: "Delete" }))
      .toBeInTheDocument();
  });

  test("Up in an empty composer edits your last message; Enter saves", async () => {
    const { user, socket, composer } = await setup([theirs(), mine()]);
    await user.click(composer);
    await user.keyboard("{ArrowUp}");
    const box = await screen.findByDisplayValue("my words");
    await user.clear(box);
    await user.type(box, "better words{Enter}");
    expect(sent(socket, "chat_edit")).toEqual([{
      type: "chat_edit",
      id: "m1",
      body: "better words",
    }]);
    expect(screen.queryByDisplayValue("better words")).not.toBeInTheDocument();
  });

  test("an unchanged edit sends nothing; Escape leaves the edit, not the chat", async () => {
    const { user, socket, onClose } = await setup([mine()]);
    const m = screen.getByText("my words").closest(
      ".chat-message",
    )! as HTMLElement;
    await user.click(within(m).getByRole("button", { name: "Edit" }));
    await user.click(screen.getByRole("button", { name: "Save" }));
    expect(sent(socket, "chat_edit")).toHaveLength(0);
    await user.click(within(m).getByRole("button", { name: "Edit" }));
    await user.keyboard("{Escape}");
    expect(screen.queryByRole("button", { name: "Save" })).not
      .toBeInTheDocument();
    expect(onClose).not.toHaveBeenCalled();
  });

  test("deleting asks first; Escape on the question keeps the chat open", async () => {
    const { user, socket, onClose } = await setup([mine()]);
    const m = screen.getByText("my words").closest(
      ".chat-message",
    )! as HTMLElement;
    await user.click(within(m).getByRole("button", { name: "Delete" }));
    expect(screen.getByRole("alertdialog")).toHaveTextContent(
      "Delete this message?",
    );
    await user.keyboard("{Escape}");
    expect(screen.queryByRole("alertdialog")).not.toBeInTheDocument();
    expect(onClose).not.toHaveBeenCalled();
    await user.click(within(m).getByRole("button", { name: "Delete" }));
    await user.click(
      within(screen.getByRole("alertdialog")).getByRole("button", {
        name: "Delete",
      }),
    );
    expect(sent(socket, "chat_delete")).toEqual([{
      type: "chat_delete",
      id: "m1",
    }]);
    socket.receive({ type: "chat_message_deleted", id: "m1" });
    expect(screen.queryByText("my words")).not.toBeInTheDocument();
  });

  test("a reply to a deleted message says so", async () => {
    const { socket } = await setup([
      theirs(),
      makeChatMessage({
        id: "r",
        body: "a reply",
        replyToId: "t1",
        replyToAuthor: "ann",
        replyToBody: "ask me",
      }),
    ]);
    socket.receive({ type: "chat_message_deleted", id: "t1" });
    expect(screen.getByText("deleted message").closest("button"))
      .toBeDisabled();
  });
});

describe("ChatModal: live", () => {
  test("new messages arrive, and a mention of me stands out", async () => {
    const { socket } = await setup();
    socket.receive({
      type: "chat_message",
      message: wire(
        makeChatMessage({
          id: "x",
          body: "hey @me look",
          createdAt: new Date(),
        }),
      ),
    });
    expect(screen.getByText(/look/).closest(".chat-message")).toHaveClass(
      "chat-message--mention",
    );
  });

  test("@everyone stands out only when the server flagged it", async () => {
    const { socket } = await setup();
    for (
      const [id, body, mentionsEveryone] of [
        ["e1", "@everyone typed by anyone", undefined],
        ["e2", "@everyone from a moderator", true],
      ] as const
    ) {
      socket.receive({
        type: "chat_message",
        message: wire(
          makeChatMessage({
            id,
            body,
            createdAt: new Date(),
            mentionsEveryone,
          }),
        ),
      });
    }
    const row = (text: RegExp) =>
      screen.getByText(text).closest(".chat-message");
    expect(row(/typed by anyone/)).not.toHaveClass("chat-message--mention");
    expect(row(/from a moderator/)).toHaveClass("chat-message--mention");
    expect(screen.getByText("@everyone")).toHaveClass("md-everyone");
  });

  test("an emoji-only message is shown large", async () => {
    await setup([makeChatMessage({ body: "🎉🎉" })]);
    expect(document.querySelector(".chat-message-text--jumbo"))
      .toHaveTextContent("🎉🎉");
  });

  test("who's typing", async () => {
    const { socket } = await setup();
    socket.receive({
      type: "chat_typing_update",
      users: [{ userId: "ann", username: "ann", hasAvatar: false }],
    });
    expect(screen.getByText("ann is typing…")).toBeInTheDocument();
    socket.receive({
      type: "chat_typing_update",
      users: [
        { userId: "ann", username: "ann", hasAvatar: false },
        { userId: "bob", username: "bob", hasAvatar: false },
      ],
    });
    expect(screen.getByText("ann and bob are typing…")).toBeInTheDocument();
    socket.receive({
      type: "chat_typing_update",
      users: [{ userId: "me", username: "me", hasAvatar: false }],
    });
    expect(screen.queryByText(/typing…/)).not.toBeInTheDocument();
  });

  test("a failed edit or delete is shown until dismissed", async () => {
    const { user, socket } = await setup();
    socket.receive({ type: "error", scope: "chat", message: "Not allowed" });
    expect(screen.getByRole("alert")).toHaveTextContent("Not allowed");
    await user.click(screen.getByRole("button", { name: "Dismiss" }));
    expect(screen.queryByText("Not allowed")).not.toBeInTheDocument();
  });

  test("disconnected, it says so; a reconnect resyncs from the oldest loaded message", async () => {
    const old = makeChatMessage({
      id: "o",
      body: "kept",
      createdAt: new Date(Date.now() - 50_000),
    });
    const edited = makeChatMessage({
      id: "e",
      body: "before",
      createdAt: new Date(Date.now() - 40_000),
    });
    const { socket } = await setup([old, edited]);
    route("GET /api/chat", () => wire([old, { ...edited, body: "after" }]));
    socket.drop();
    expect(screen.getByText("Disconnected — reconnecting…"))
      .toBeInTheDocument();
    await act(() => new Promise((r) => setTimeout(r, 600)));
    FakeWebSocket.last.welcome();
    await screen.findByText("after");
    const resync = calls("GET /api/chat").at(-1)!;
    expect(resync.url.searchParams.get("after")).toBe(
      old.createdAt.toISOString(),
    );
  });
});