import { testPerm, assert, assertEqual } from "./test_util.ts";
import * as deno from "deno";

function readFileString(filename: string): string {
  const dataRead = deno.readFileSync(filename);
  const dec = new TextDecoder("utf-8");
  return dec.decode(dataRead);
}

function writeFileString(filename: string, s: string) {
  const enc = new TextEncoder();
  const data = enc.encode(s);
  deno.writeFileSync(filename, data, 0o666);
}

function assertSameContent(filename1: string, filename2: string) {
  const data1 = deno.readFileSync(filename1);
  const data2 = deno.readFileSync(filename2);
  assertEqual(data1, data2);
}

testPerm({ write: true }, function copyFileSyncSuccess() {
  const tempDir = deno.makeTempDirSync();
  const fromFilename = tempDir + "/from.txt";
  const toFilename = tempDir + "/to.txt";
  writeFileString(fromFilename, "Hello world!");
  deno.copyFileSync(fromFilename, toFilename);
  // No change to original file
  assertEqual(readFileString(fromFilename), "Hello world!");
  // Original == Dest
  assertSameContent(fromFilename, toFilename);
});

testPerm({ write: true }, function copyFileSyncFailure() {
  const tempDir = deno.makeTempDirSync();
  const fromFilename = tempDir + "/from.txt";
  const toFilename = tempDir + "/to.txt";
  // We skip initial writing here, from.txt does not exist
  let err;
  try {
    deno.copyFileSync(fromFilename, toFilename);
  } catch (e) {
    err = e;
  }
  assert(!!err);
  // Rust deem non-existent path as invalid input
  assertEqual(err.kind, deno.ErrorKind.InvalidInput);
  assertEqual(err.name, "InvalidInput");
});

testPerm({ write: true }, function copyFileSyncOverwrite() {
  const tempDir = deno.makeTempDirSync();
  const fromFilename = tempDir + "/from.txt";
  const toFilename = tempDir + "/to.txt";
  writeFileString(fromFilename, "Hello world!");
  // Make Dest exist and have different content
  writeFileString(toFilename, "Goodbye!");
  deno.copyFileSync(fromFilename, toFilename);
  // No change to original file
  assertEqual(readFileString(fromFilename), "Hello world!");
  // Original == Dest
  assertSameContent(fromFilename, toFilename);
});

testPerm({ write: false }, function copyFileSyncPerm() {
  let err;
  try {
    deno.copyFileSync("/from.txt", "/to.txt");
  } catch (e) {
    err = e;
  }
  assert(!!err);
  assertEqual(err.kind, deno.ErrorKind.PermissionDenied);
  assertEqual(err.name, "PermissionDenied");
});

testPerm({ write: true }, async function copyFileSuccess() {
  const tempDir = deno.makeTempDirSync();
  const fromFilename = tempDir + "/from.txt";
  const toFilename = tempDir + "/to.txt";
  writeFileString(fromFilename, "Hello world!");
  await deno.copyFile(fromFilename, toFilename);
  // No change to original file
  assertEqual(readFileString(fromFilename), "Hello world!");
  // Original == Dest
  assertSameContent(fromFilename, toFilename);
});

testPerm({ write: true }, async function copyFileFailure() {
  const tempDir = deno.makeTempDirSync();
  const fromFilename = tempDir + "/from.txt";
  const toFilename = tempDir + "/to.txt";
  // We skip initial writing here, from.txt does not exist
  let err;
  try {
    await deno.copyFile(fromFilename, toFilename);
  } catch (e) {
    err = e;
  }
  assert(!!err);
  // Rust deem non-existent path as invalid input
  assertEqual(err.kind, deno.ErrorKind.InvalidInput);
  assertEqual(err.name, "InvalidInput");
});

testPerm({ write: true }, async function copyFileOverwrite() {
  const tempDir = deno.makeTempDirSync();
  const fromFilename = tempDir + "/from.txt";
  const toFilename = tempDir + "/to.txt";
  writeFileString(fromFilename, "Hello world!");
  // Make Dest exist and have different content
  writeFileString(toFilename, "Goodbye!");
  await deno.copyFile(fromFilename, toFilename);
  // No change to original file
  assertEqual(readFileString(fromFilename), "Hello world!");
  // Original == Dest
  assertSameContent(fromFilename, toFilename);
});

testPerm({ write: false }, async function copyFilePerm() {
  let err;
  try {
    await deno.copyFile("/from.txt", "/to.txt");
  } catch (e) {
    err = e;
  }
  assert(!!err);
  assertEqual(err.kind, deno.ErrorKind.PermissionDenied);
  assertEqual(err.name, "PermissionDenied");
});