import fs from "fs";
import { it, expect } from "bun:test";
import path from "path";

it("Bun.file not found returns ENOENT", async () => {
  try {
    await Bun.file("/does/not/exist.txt").text();
  } catch (exception) {
    expect(exception.code).toBe("ENOENT");
  }
});

it("Bun.write('out.txt', 'string')", async () => {
  for (let erase of [true, false]) {
    if (erase) {
      try {
        fs.unlinkSync(path.join("/tmp", "out.txt"));
      } catch (e) {}
    }

    await Bun.write("/tmp/out.txt", "string");
    const out = Bun.file("/tmp/out.txt");
    expect(await out.text()).toBe("string");
    expect(await out.text()).toBe(fs.readFileSync("/tmp/out.txt", "utf8"));
  }
});

it("Bun.write blob", async () => {
  await Bun.write(
    Bun.file("/tmp/response-file.test.txt"),
    Bun.file(path.join(import.meta.dir, "fetch.js.txt"))
  );
  await Bun.write(Bun.file("/tmp/response-file.test.txt"), "blah blah blha");
  await Bun.write(
    Bun.file("/tmp/response-file.test.txt"),
    new Uint32Array(1024)
  );
  await Bun.write("/tmp/response-file.test.txt", new Uint32Array(1024));
  expect(
    await Bun.write(
      new TextEncoder().encode("/tmp/response-file.test.txt"),
      new Uint32Array(1024)
    )
  ).toBe(new Uint32Array(1024).byteLength);
});

it("Bun.file -> Bun.file", async () => {
  try {
    fs.unlinkSync(path.join("/tmp", "fetch.js.in"));
  } catch (e) {}

  try {
    fs.unlinkSync(path.join("/tmp", "fetch.js.out"));
  } catch (e) {}

  const file = path.join(import.meta.dir, "fetch.js.txt");
  const text = fs.readFileSync(file, "utf8");
  fs.writeFileSync("/tmp/fetch.js.in", text, { mode: 0644 });
  {
    const result = await Bun.write(
      Bun.file("/tmp/fetch.js.out"),
      Bun.file("/tmp/fetch.js.in")
    );
    expect(await Bun.file("/tmp/fetch.js.out").text()).toBe(text);
  }

  {
    await Bun.write(
      Bun.file("/tmp/fetch.js.in").slice(0, (text.length / 2) | 0),
      Bun.file("/tmp/fetch.js.out")
    );
    expect(await Bun.file("/tmp/fetch.js.in").text()).toBe(
      text.substring(0, (text.length / 2) | 0)
    );
  }

  {
    await Bun.write("/tmp/fetch.js.in", Bun.file("/tmp/fetch.js.out"));
    expect(await Bun.file("/tmp/fetch.js.in").text()).toBe(text);
  }
});

it("Bun.file", async () => {
  const file = path.join(import.meta.dir, "fetch.js.txt");
  expect(await Bun.file(file).text()).toBe(fs.readFileSync(file, "utf8"));
});

it("Bun.file as a Blob", async () => {
  const filePath = path.join(import.meta.url, "../fetch.js.txt");
  const fixture = fs.readFileSync(filePath, "utf8");
  // this is a Blob object with the same interface as the one returned by fetch
  // internally, instead of a byte array, it stores the file path!
  // this enables several performance optimizations
  var blob = Bun.file(filePath);

  // no size because we haven't read it from disk yet
  expect(blob.size).toBe(0);
  // now it reads "./fetch.js.txt" from the filesystem
  // it's lazy, only loads once we ask for it
  // if it fails, the promise will reject at this point
  expect(await blob.text()).toBe(fixture);
  // now that it's loaded, the size updates
  expect(blob.size).toBe(fixture.length);
  // and it only loads once for _all_ blobs pointing to that file path
  // until all references are released
  expect((await blob.arrayBuffer()).byteLength).toBe(fixture.length);

  const array = new Uint8Array(await blob.arrayBuffer());
  const text = fixture;
  for (let i = 0; i < text.length; i++) {
    expect(array[i]).toBe(text.charCodeAt(i));
  }
  expect(blob.size).toBe(fixture.length);
  blob = null;
  Bun.gc(true);
  await new Promise((resolve) => setTimeout(resolve, 1));
  // now we're back
  var blob = Bun.file(filePath);
  expect(blob.size).toBe(0);
});

it("Response -> Bun.file", async () => {
  const file = path.join(import.meta.dir, "fetch.js.txt");
  const text = fs.readFileSync(file, "utf8");
  const response = new Response(Bun.file(file));
  expect(await response.text()).toBe(text);
});

it("Bun.file -> Response", async () => {
  // ensure the file doesn't already exist
  try {
    fs.unlinkSync("/tmp/fetch.js.out");
  } catch {}

  const file = path.join(import.meta.dir, "fetch.js.txt");
  const text = fs.readFileSync(file, "utf8");
  const resp = await fetch("https://example.com");
  expect(await Bun.write("/tmp/fetch.js.out", resp)).toBe(text.length);
  expect(await Bun.file("/tmp/fetch.js.out").text()).toBe(text);
});

it("Response -> Bun.file -> Response -> text", async () => {
  const file = path.join(import.meta.dir, "fetch.js.txt");
  const text = fs.readFileSync(file, "utf8");
  const response = new Response(Bun.file(file));
  const response2 = response.clone();
  expect(await response2.text()).toBe(text);
});