import { afterEach, beforeEach, describe, expect, test } from "bun:test";
import { mkdtemp, readdir, rm } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { newId, nowIso } from "@sttracker/db/ids";
import { forEachDialect } from "@sttracker/db/testing";
import type { Db } from "@sttracker/db/db";
import {
  listAttachments,
  readAttachment,
  storeAttachment,
  unlinkAttachment,
} from "../src/attachments.ts";
import { ValidationError } from "../src/errors.ts";

async function addUser(db: Db, username: string): Promise<string> {
  const id = newId();
  const now = nowIso();
  await db.k
    .insertInto("users")
    .values({
      id,
      username,
      display_name: username,
      password_hash: "x",
      role: "member",
      preferences: "{}",
      created_at: now,
      updated_at: now,
    })
    .execute();
  return id;
}

async function filesUnder(dir: string): Promise<string[]> {
  const all = await readdir(dir, { recursive: true, withFileTypes: true });
  return all.filter((e) => e.isFile()).map((e) => join(e.parentPath, e.name));
}

forEachDialect("attachments", (getDb) => {
  let dataDir: string;
  beforeEach(async () => {
    dataDir = await mkdtemp(join(tmpdir(), "sttracker-att-"));
  });
  afterEach(async () => {
    await rm(dataDir, { recursive: true, force: true });
  });

  const png = (s: string) => ({
    bytes: new TextEncoder().encode(s),
    mime: "image/png",
    filename: "a.png",
  });

  test("same bytes twice: one file, two links", async () => {
    const db = getDb();
    const u = await addUser(db, "u1");
    const a = await storeAttachment(db, dataDir, u, png("hello"), { entity: "work", entityId: "w1" });
    const b = await storeAttachment(db, dataDir, u, png("hello"), { entity: "entry", entityId: "e1" });
    expect(a.sha256).toBe(b.sha256);
    expect(a.id).not.toBe(b.id);
    const files = await filesUnder(join(dataDir, "attachments"));
    expect(files).toHaveLength(1);
    expect(files[0]).toBe(
      join(dataDir, "attachments", a.sha256.slice(0, 2), a.sha256.slice(2, 4), a.sha256),
    );
    const links = await db.k.selectFrom("attachment_links").selectAll().execute();
    expect(links).toHaveLength(2);
    expect(await listAttachments(db, u, "work", "w1")).toHaveLength(1);
  });

  test("rejects disallowed mime and oversize", async () => {
    const db = getDb();
    const u = await addUser(db, "u1");
    const link = { entity: "work", entityId: "w1" } as const;
    await expect(
      storeAttachment(db, dataDir, u, { ...png("x"), mime: "application/x-msdownload", filename: "a.exe" }, link),
    ).rejects.toBeInstanceOf(ValidationError);
    await expect(
      storeAttachment(db, dataDir, u, { ...png("x"), bytes: new Uint8Array(25 * 1024 * 1024 + 1) }, link),
    ).rejects.toBeInstanceOf(ValidationError);
  });

  test("reads own file; another user gets null", async () => {
    const db = getDb();
    const u1 = await addUser(db, "u1");
    const u2 = await addUser(db, "u2");
    const a = await storeAttachment(db, dataDir, u1, png("secret"), { entity: "work", entityId: "w1" });
    const r = await readAttachment(db, dataDir, u1, a.id);
    expect(r?.mime).toBe("image/png");
    expect(await r?.file.text()).toBe("secret");
    expect(await readAttachment(db, dataDir, u2, a.id)).toBeNull();
    expect(await readAttachment(db, dataDir, u1, "nope")).toBeNull();
  });

  test("unlink removes link, orphan row and unshared file", async () => {
    const db = getDb();
    const u = await addUser(db, "u1");
    const a = await storeAttachment(db, dataDir, u, png("bye"), { entity: "work", entityId: "w1" });
    const b = await storeAttachment(db, dataDir, u, png("bye"), { entity: "work", entityId: "w2" });
    await unlinkAttachment(db, dataDir, u, a.id, "work", "w1");
    expect(await listAttachments(db, u, "work", "w1")).toHaveLength(0);
    expect(await filesUnder(join(dataDir, "attachments"))).toHaveLength(1);
    await unlinkAttachment(db, dataDir, u, b.id, "work", "w2");
    expect(await filesUnder(join(dataDir, "attachments"))).toHaveLength(0);
    expect(await db.k.selectFrom("attachments").selectAll().execute()).toHaveLength(0);
  });

  test("rejects svg and normalizes mime", async () => {
    const db = getDb();
    const u = await addUser(db, "u1");
    const link = { entity: "work", entityId: "w1" } as const;
    for (const mime of ["image/svg+xml", "IMAGE/SVG+XML; charset=utf-8"]) {
      await expect(storeAttachment(db, dataDir, u, { ...png("x"), mime }, link)).rejects.toBeInstanceOf(
        ValidationError,
      );
    }
    const a = await storeAttachment(db, dataDir, u, { ...png("x"), mime: "Image/PNG; foo=bar" }, link);
    expect(a.mime).toBe("image/png");
    expect((await listAttachments(db, u, "work", "w1"))[0]?.mime).toBe("image/png");
  });

  test("shared bytes across users survive the other's unlink", async () => {
    const db = getDb();
    const ua = await addUser(db, "a");
    const ub = await addUser(db, "b");
    const a = await storeAttachment(db, dataDir, ua, png("same"), { entity: "work", entityId: "w1" });
    const b = await storeAttachment(db, dataDir, ub, png("same"), { entity: "work", entityId: "w1" });
    await unlinkAttachment(db, dataDir, ua, a.id, "work", "w1");
    expect(await filesUnder(join(dataDir, "attachments"))).toHaveLength(1);
    const r = await readAttachment(db, dataDir, ub, b.id);
    expect(await r?.file.text()).toBe("same");
  });

  test("another user's unlink is a no-op", async () => {
    const db = getDb();
    const ua = await addUser(db, "a");
    const ub = await addUser(db, "b");
    const a = await storeAttachment(db, dataDir, ua, png("mine"), { entity: "work", entityId: "w1" });
    await unlinkAttachment(db, dataDir, ub, a.id, "work", "w1");
    expect(await listAttachments(db, ua, "work", "w1")).toHaveLength(1);
    expect(await filesUnder(join(dataDir, "attachments"))).toHaveLength(1);
  });

  test("listAttachments is scoped to the user", async () => {
    const db = getDb();
    const ua = await addUser(db, "a");
    const ub = await addUser(db, "b");
    await storeAttachment(db, dataDir, ua, png("one"), { entity: "work", entityId: "w1" });
    expect(await listAttachments(db, ub, "work", "w1")).toHaveLength(0);
    expect(await listAttachments(db, ua, "work", "w1")).toHaveLength(1);
  });

  test("concurrent store and unlink never leave a row without its file", async () => {
    const db = getDb();
    const u = await addUser(db, "u1");
    const first = await storeAttachment(db, dataDir, u, png("race"), { entity: "work", entityId: "w1" });
    const [, second] = await Promise.all([
      unlinkAttachment(db, dataDir, u, first.id, "work", "w1"),
      storeAttachment(db, dataDir, u, png("race"), { entity: "work", entityId: "w2" }),
    ]);
    const r = await readAttachment(db, dataDir, u, second.id);
    expect(await r?.file.text()).toBe("race");
  });

  test("leaves no temp files behind", async () => {
    const db = getDb();
    const u = await addUser(db, "u1");
    await storeAttachment(db, dataDir, u, png("clean"), { entity: "work", entityId: "w1" });
    const files = await filesUnder(join(dataDir, "attachments"));
    expect(files.some((f) => f.includes(".tmp-"))).toBe(false);
  });
});