import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
import * as fs from "node:fs";
import * as path from "node:path";
import * as os from "node:os";
import type { Message, Collection, Attachment } from "discord.js";

// ---------------------------------------------------------------------------
// Helpers
// ---------------------------------------------------------------------------

function makeMessage(attachments: Attachment[] = []): Message {
  const col = new Map(attachments.map((a) => [a.id, a]));
  return {
    attachments: {
      size: attachments.length,
      values: () => col.values(),
    },
  } as unknown as Message;
}

function makeAttachment(id: string, name: string, url: string): Attachment {
  return { id, name, url } as unknown as Attachment;
}

// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------

describe("processAttachments", () => {
  let tmpDir: string;

  beforeEach(() => {
    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), "disclaw-inbox-test-"));
  });

  afterEach(() => {
    fs.rmSync(tmpDir, { recursive: true, force: true });
    vi.restoreAllMocks();
  });

  it("returns an empty array when message has no attachments", async () => {
    const { processAttachments } = await import("../../src/discord/attachment-inbox");
    const message = makeMessage([]);
    const hints = await processAttachments(message, tmpDir);
    expect(hints).toEqual([]);
    // No inbox directory created
    expect(fs.existsSync(path.join(tmpDir, ".disclaw-inbox"))).toBe(false);
  });

  it("saves an attachment to .disclaw-inbox/ and returns a hint", async () => {
    // Mock global fetch
    const fileContent = "print('hello')\n";
    const contentBytes = Buffer.from(fileContent, "utf-8");
    // Allocate a clean ArrayBuffer (not the Node shared pool) so Buffer.from() round-trips correctly
    const cleanArrayBuffer = contentBytes.buffer.slice(
      contentBytes.byteOffset,
      contentBytes.byteOffset + contentBytes.byteLength
    );
    vi.stubGlobal(
      "fetch",
      vi.fn().mockResolvedValue({
        ok: true,
        arrayBuffer: async () => cleanArrayBuffer,
      })
    );

    const { processAttachments } = await import("../../src/discord/attachment-inbox");
    const attachment = makeAttachment("att-1", "example.py", "https://cdn.discord.com/example.py");
    const message = makeMessage([attachment]);

    const hints = await processAttachments(message, tmpDir);

    expect(hints).toHaveLength(1);
    expect(hints[0]).toMatch(/^\[Datei verfügbar: \.disclaw-inbox\//);
    expect(hints[0]).toContain("example.py");

    // File must exist in inbox
    const inboxDir = path.join(tmpDir, ".disclaw-inbox");
    const files = fs.readdirSync(inboxDir);
    expect(files).toHaveLength(1);
    expect(files[0]).toMatch(/example\.py$/);

    // File content must match
    const savedContent = fs.readFileSync(path.join(inboxDir, files[0]), "utf-8");
    expect(savedContent).toBe(fileContent);
  });

  it("skips an attachment when fetch fails", async () => {
    vi.stubGlobal(
      "fetch",
      vi.fn().mockResolvedValue({
        ok: false,
        status: 403,
      })
    );

    const { processAttachments } = await import("../../src/discord/attachment-inbox");
    const attachment = makeAttachment("att-1", "secret.txt", "https://cdn.discord.com/secret.txt");
    const message = makeMessage([attachment]);

    const hints = await processAttachments(message, tmpDir);
    expect(hints).toEqual([]);
  });
});

describe("cleanupInbox", () => {
  let tmpDir: string;

  beforeEach(() => {
    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), "disclaw-cleanup-test-"));
  });

  afterEach(() => {
    fs.rmSync(tmpDir, { recursive: true, force: true });
    vi.restoreAllMocks();
  });

  it("does nothing when inbox directory does not exist", async () => {
    const { cleanupInbox } = await import("../../src/discord/attachment-inbox");
    expect(() => cleanupInbox(tmpDir)).not.toThrow();
  });

  it("deletes files older than 24 hours and keeps newer files", async () => {
    const { cleanupInbox } = await import("../../src/discord/attachment-inbox");

    const inboxDir = path.join(tmpDir, ".disclaw-inbox");
    fs.mkdirSync(inboxDir);

    const oldFile = path.join(inboxDir, "old-file.txt");
    const newFile = path.join(inboxDir, "new-file.txt");

    fs.writeFileSync(oldFile, "old");
    fs.writeFileSync(newFile, "new");

    // Backdate old file by 25 hours
    const oldTime = new Date(Date.now() - 25 * 60 * 60 * 1000);
    fs.utimesSync(oldFile, oldTime, oldTime);

    cleanupInbox(tmpDir);

    expect(fs.existsSync(oldFile)).toBe(false);
    expect(fs.existsSync(newFile)).toBe(true);
  });
});