// Copyright 2018-2026 the Deno authors. MIT license.
import { assertCallbackErrorUncaught } from "../_test_utils.ts";
import { existsSync, promises, readFile, readFileSync } from "node:fs";
import * as path from "@std/path";
import {
  assert,
  assertEquals,
  assertMatch,
  assertRejects,
  assertThrows,
} from "@std/assert";
import { open, readFile as readFilePromise } from "node:fs/promises";
import { Buffer } from "node:buffer";

const moduleDir = path.dirname(path.fromFileUrl(import.meta.url));
const testData = path.resolve(moduleDir, "testdata", "hello.txt");

Deno.test("readFileSuccess", async function () {
  const data = await new Promise((res, rej) => {
    readFile(testData, (err, data) => {
      if (err) {
        rej(err);
      }
      res(data);
    });
  });

  assert(data instanceof Uint8Array);
  assertEquals(new TextDecoder().decode(data as Uint8Array), "hello world");
});

Deno.test("readFileEncodeUtf8Success", async function () {
  const data = await new Promise((res, rej) => {
    readFile(testData, { encoding: "utf8" }, (err, data) => {
      if (err) {
        rej(err);
      }
      res(data);
    });
  });
  assertEquals(typeof data, "string");
  assertEquals(data as string, "hello world");
});

Deno.test("readFileEncodeHexSuccess", async function () {
  const data = await new Promise((res, rej) => {
    readFile(testData, { encoding: "hex" }, (err, data) => {
      if (err) {
        rej(err);
      }
      res(data);
    });
  });

  assertEquals(typeof data, "string");
  assertEquals(data as string, "68656c6c6f20776f726c64");
});

Deno.test("readFileEncodeBase64Success", async function () {
  const data = await new Promise((res, rej) => {
    readFile(testData, { encoding: "base64" }, (err, data) => {
      if (err) {
        rej(err);
      }
      res(data);
    });
  });
  assertEquals(typeof data, "string");
  assertEquals(data as string, "aGVsbG8gd29ybGQ=");
});

Deno.test("readFileEncodingAsString", async function () {
  const data = await new Promise((res, rej) => {
    readFile(testData, "utf8", (err, data) => {
      if (err) {
        rej(err);
      }
      res(data);
    });
  });

  assertEquals(typeof data, "string");
  assertEquals(data as string, "hello world");
});

Deno.test("readFileSyncSuccess", function () {
  const data = readFileSync(testData);
  assert(data instanceof Uint8Array);
  assertEquals(new TextDecoder().decode(data as Uint8Array), "hello world");
});

Deno.test("readFileEncodeUtf8Success", function () {
  const data = readFileSync(testData, { encoding: "utf8" });
  assertEquals(typeof data, "string");
  assertEquals(data as string, "hello world");
});

Deno.test("readFileEncodeHexSuccess", function () {
  const data = readFileSync(testData, { encoding: "hex" });
  assertEquals(typeof data, "string");
  assertEquals(data as string, "68656c6c6f20776f726c64");
});

Deno.test("readFileEncodeBase64Success", function () {
  const data = readFileSync(testData, { encoding: "base64" });
  assertEquals(typeof data, "string");
  assertEquals(data as string, "aGVsbG8gd29ybGQ=");
});

Deno.test("readFileEncodeAsString", function () {
  const data = readFileSync(testData, "utf8");
  assertEquals(typeof data, "string");
  assertEquals(data as string, "hello world");
});

Deno.test("[std/node/fs] readFile callback isn't called twice if error is thrown", async () => {
  const tempFile = await Deno.makeTempFile();
  const importUrl = new URL("node:fs", import.meta.url);
  await assertCallbackErrorUncaught({
    prelude: `import { readFile } from ${JSON.stringify(importUrl)}`,
    invocation: `readFile(${JSON.stringify(tempFile)}, `,
    async cleanup() {
      await Deno.remove(tempFile);
    },
  });
});

Deno.test("fs.promises.readFile with no arg call rejects with error correctly", async () => {
  // @ts-ignore no arg call needs to be supported
  await promises.readFile().catch((_e) => {});
});

Deno.test("fs.readFile error message contains path + syscall", async () => {
  const path = "/does/not/exist";
  const err = await new Promise((resolve) => {
    readFile(path, "utf-8", (err) => resolve(err));
  });
  if (err instanceof Error) {
    assert(err.message.includes(path), "Path not found in error message");
    assertMatch(err.message, /[,\s]open\s/);
  }
});

Deno.test("fs.readFileSync error message contains path + syscall", () => {
  const path = "/does/not/exist";
  try {
    readFileSync(path, "utf-8");
  } catch (err) {
    if (err instanceof Error) {
      assert(err.message.includes(path), "Path not found in error message");
      assertMatch(err.message, /[,\s]open\s/);
    }
  }
});

Deno.test("fs.readFile returns Buffer when encoding is not provided", async () => {
  const data = await new Promise<Uint8Array>((res, rej) => {
    readFile(testData, (err, data) => {
      if (err) {
        rej(err);
      }
      res(data as Uint8Array);
    });
  });

  assert(data instanceof Uint8Array);
  assertEquals(Buffer.isBuffer(data), true);
  assertEquals(data.toString(), "hello world");
});

Deno.test("fs.readFile binary encoding returns string", async () => {
  const data = await new Promise<string>((res, rej) => {
    readFile(testData, { encoding: "binary" }, (err, data) => {
      if (err) {
        rej(err);
      }
      res(data as string);
    });
  });

  assertEquals(typeof data, "string");
  assertEquals(data, "hello world");
});

Deno.test("fs.readFileSync returns Buffer when encoding is not provided", () => {
  const data = readFileSync(testData);
  assert(data instanceof Uint8Array);
  assertEquals(Buffer.isBuffer(data), true);
  assertEquals(data.toString(), "hello world");
});

Deno.test("fs.readFileSync binary encoding returns string", () => {
  const data = readFileSync(testData, { encoding: "binary" });
  assertEquals(typeof data, "string");
  assertEquals(data, "hello world");
});

Deno.test("fs.readFile creates new file when passed 'w+' flag", async () => {
  const tmpDir = Deno.makeTempDirSync();
  const filePath = path.join(tmpDir, "newfile.txt");
  await new Promise((res, rej) => {
    readFile(filePath, { flag: "w+" }, (err, data) => {
      if (err) {
        rej(err);
      }
      res(data);
    });
  });

  assert(existsSync(filePath));
  Deno.removeSync(tmpDir, { recursive: true });
});

Deno.test(
  "fs.readFile throws ERR_INVALID_ARG_TYPE when path is undefined (e.g. fd.name)",
  async () => {
    const fh = await open(testData, "r");

    try {
      // Simulate user code that passes `fd.name` (which is undefined) into readFile
      const name = (fh as { name?: unknown }).name;

      // Check async (promises) variant rejects with ERR_INVALID_ARG_TYPE
      const err = await assertRejects(async () => {
        await readFilePromise(name as unknown as string);
      });
      const errObj = err as { code?: string };
      assertEquals(errObj.code, "ERR_INVALID_ARG_TYPE");

      // Also check sync variant throws the proper TypeError
      assertThrows(() => readFileSync(name as unknown as string), TypeError);
    } finally {
      await fh.close();
    }
  },
);

Deno.test("fs.readFileSync creates new file when passed 'w+' flag", () => {
  const tmpDir = Deno.makeTempDirSync();
  const filePath = path.join(tmpDir, "newfile.txt");
  readFileSync(filePath, { flag: "w+" });

  assert(existsSync(filePath));
  Deno.removeSync(tmpDir, { recursive: true });
});

// Regression for https://github.com/denoland/deno/issues/34246: when fs.readFile
// is given an fd + encoding, readFileFromFd used a shared buffer and pushed
// aliased subarrays, so files larger than the per-read chunk size came back
// with the right length but scrambled content.
Deno.test("fs.promises.readFile(path, encoding) returns intact content for >512KB files", async () => {
  const tmpDir = await Deno.makeTempDir();
  try {
    const filePath = path.join(tmpDir, "large.txt");
    // 600 KiB of ASCII so byte length == char length; enough to span multiple
    // reads through the fd-based path.
    let chunk = "";
    for (let i = 0; i < 1024; i++) chunk += i.toString().padStart(8, "0");
    const expected = chunk.repeat(75);
    await Deno.writeTextFile(filePath, expected);

    const viaPathUtf8 = await readFilePromise(filePath, "utf8");
    assertEquals(viaPathUtf8.length, expected.length);
    assertEquals(viaPathUtf8, expected);

    const fh = await open(filePath, "r");
    try {
      const viaFhUtf8 = await fh.readFile("utf8");
      assertEquals(viaFhUtf8, expected);
    } finally {
      await fh.close();
    }
  } finally {
    await Deno.remove(tmpDir, { recursive: true });
  }
});
