/*
 * Copyright 2023 The Emscripten Authors.  All rights reserved.
 * Emscripten is available under two separate licenses, the MIT license and the
 * University of Illinois/NCSA Open Source License.  Both these licenses can be
 * found in the LICENSE file.
 */

#include <emscripten/emscripten.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <assert.h>
#include <fcntl.h>

EM_JS(void, test_fs_open, (), {
  FS.writeFile('testfile', 'a=1\nb=2\n');
  var readStream = FS.open('testfile', 'r');
  var writeStream = FS.open('testfile', 'w');
  var writePlusStream = FS.open('testfile', 'w+');
  var appendStream = FS.open('testfile', 'a');

  assert(readStream && readStream.fd >= 0);
  assert(writeStream && writeStream.fd >= 0);
  assert(writePlusStream && writePlusStream.fd >= 0);
  assert(appendStream && appendStream.fd >= 0);

  var ex;
  try {
    FS.open('filenothere', 'r');
  } catch(err) {
    ex = err;
  }
  assert(ex.name === "ErrnoError" && ex.errno === 44 /* ENOENT */);

  var createFileNotHere = FS.open('filenothere', 'w+');

  assert(createFileNotHere && createFileNotHere.fd >= 0);
});

EM_JS(void, test_fs_readFile, (), {
  // Reading existing files is already covered by other tests here, so
  // just test the error conditions.
  var ex;
  try {
    var output = FS.readFile("root/no-exist", {encoding : 'utf8'});
  } catch (err) {
    ex = err;
  }
  assert(ex.name === "ErrnoError" && ex.errno === 44 /* ENOENT */);
});

// createPath should succeed when called on existing paths ( https://github.com/emscripten-core/emscripten/issues/23602 )
EM_JS(void, test_fs_createPath, (), {
  FS.createPath('/', 'home', true, true);
  FS.createPath('/', 'home', true, true); // Creating an already existing path
  FS.createPath('/home', 'nested1', true, true);
  FS.createPath('/home', 'nested2', true, true);
  FS.writeFile('/home/nested1/test.txt', 'a=1\nb=2\n');
  FS.writeFile('/home/nested2/test.txt', 'a=2\nb=4\n');
  var read1 = FS.readFile('/home/nested1/test.txt', {encoding:'utf8'});
  var read2 = FS.readFile('/home/nested2/test.txt', {encoding:'utf8'});
  console.log("r1",read1);
  console.log("r2",read2);
  assert(read1 == 'a=1\nb=2\n');
  assert(read2 == 'a=2\nb=4\n');
});

EM_JS(void, test_fs_rename, (), {
  FS.mkdir('renamedir');
  FS.writeFile('renamedir/renametestfile', "");

  FS.rename('renamedir/renametestfile', 'renamedir/newname');
  var newnameStream = FS.open('renamedir/newname', 'r');
  assert(newnameStream);

  var ex;
  try {
    FS.open('renamedir/renametestfile', 'r');
  } catch (err) {
    ex = err;
  }
  assert(ex.name === "ErrnoError" && ex.errno === 44 /* ENOENT */);

  try {
    FS.rename('renamedir', 'renamedir/newdirname');
  } catch (err) {
    ex = err;
  }
  // The old path should not be an ancestor of the new path.
  assert(ex.name === "ErrnoError" && ex.errno === 28 /* EINVAL */);

  FS.writeFile('toplevelfile', "");
  try {
    FS.rename('renamedir', 'toplevelfile');
  } catch (err) {
    ex = err;
  }
  assert(ex.name === "ErrnoError" && ex.errno === 54 /* ENOTDIR */);
});

EM_JS(void, test_fs_readlink,(), {
  FS.writeFile('/readlinktestfile', "");
  FS.symlink('/readlinktestfile', '/readlinksymlink');

  var symlinkString = FS.readlink('readlinksymlink');
  assert(symlinkString === '/readlinktestfile');

  var ex;
  try {
    FS.readlink('nonexistent');
  } catch (err) {
    ex = err;
  }
  assert(ex.name === "ErrnoError" && ex.errno === 44 /* ENOENT */);

  try {
    FS.readlink('readlinktestfile');
  } catch (err) {
    ex = err;
  }
  assert(ex.name === "ErrnoError" && ex.errno === 28 /* EINVAL */);
});

EM_JS(void, test_fs_read, (), {
  FS.writeFile("readtestfile", 'a=1_b=2_');

  // Test read variant, checking that the file offset moves correctly.
  var buf = new Uint8Array(8);
  var stream = FS.open("readtestfile", "r");
  var numRead = FS.read(stream, buf, 0, 4);
  assert(numRead == 4);
  assert((new TextDecoder().decode(buf.subarray(0, 4))) === "a=1_");
  numRead = FS.read(stream, buf, 4, 4);
  assert(numRead == 4);
  assert((new TextDecoder().decode(buf)) == 'a=1_b=2_');

  // Test pread variant.
  stream = FS.open("readtestfile", "r");
  var extraBuf = new Uint8Array(8);
  numRead = FS.read(stream, extraBuf, 0, 4, 0);
  assert(numRead == 4);
  assert((new TextDecoder().decode(extraBuf.subarray(0, 4))) == 'a=1_');

  // Check that pread did not move the file offset (Offset begins at 0).
  var doubleBuf = new Uint8Array(8);
  var firstNumRead = FS.read(stream, doubleBuf, 0, 4);
  var secondNumRead = FS.read(stream, doubleBuf, 4, 4);
  assert(firstNumRead == 4 && secondNumRead == 4);
  assert((new TextDecoder().decode(doubleBuf)) == 'a=1_b=2_');

  // Check that full read works.
  stream = FS.open("readtestfile", "r");
  var fullBuf = new Uint8Array(8);
  numRead = FS.read(stream, fullBuf, 0, 8);
  assert(numRead == 8);
  assert((new TextDecoder().decode(fullBuf)) == 'a=1_b=2_');

  FS.close(stream);
  var ex;
  try {
    FS.read(stream, buf, 4, 4);
  } catch (err) {
    ex = err;
  }
  assert(ex.name === 'ErrnoError' && ex.errno == 8 /* EBADF */);
});

void test_fs_rmdir() {
  EM_ASM(
    // Create multiple directories
    FS.mkdir('/dir1');
    FS.mkdir('/dir2');
  );

  struct stat s;
  stat("/dir1", &s);
  assert(S_ISDIR(s.st_mode));
  stat("/dir2", &s);
  assert(S_ISDIR(s.st_mode));

  EM_ASM(
    // Remove the multiple directories
    FS.rmdir('/dir1');
    FS.rmdir('/dir2');
  );

  int err = open("/dir1", O_RDWR);
  assert(err);
  err = open("/dir2", O_RDWR);
  assert(err);

  EM_ASM(
    // Create a directory with a file inside it
    FS.mkdir('/test_dir');
    FS.writeFile('/test_dir/file.txt', 'Hello World!');

    // Attempt to remove the directory (should fail)
    var ex;
    try {
    FS.rmdir('/test_dir');
    } catch (err) {
    ex = err;
    }
    assert(ex.name === "ErrnoError" && ex.errno === 55 /* ENOTEMPTY */);

    // Remove the file and then the directory
    FS.unlink('/test_dir/file.txt');
    FS.rmdir('/test_dir');

    // Attempt to remove a non-existent directory (should fail)
    try {
    FS.rmdir('/non_existent_dir');
    } catch (err) {
    ex = err;
    }
    assert(ex.name === "ErrnoError" && ex.errno === 44 /* ENOENT */);
  );
}

EM_JS(void, test_fs_close, (), {
  FS.writeFile("closetestfile", 'a=1\nb=2\n');
  FS.mkdir("/testdir");
  var file = FS.open("closetestfile", "r");
  var error = FS.close(file);
  assert(!error);

  file = FS.open("/testdir", "r");
  error = FS.close(file);
  assert(!error);

  var ex;
  try {
    FS.close(file);
  } catch(err) {
    ex = err;
  }
  assert(ex.name === "ErrnoError" && ex.errno === 8 /* EBADF */);
});

void test_fs_mknod() {
  EM_ASM(
    FS.mknod("mknodtest", 0o100000 | 0o777 /* S_IFREG | S_RWXU | S_RWXG | S_RWXO */);

    FS.create("createtest", 0o400 /* S_IRUSR */);
  );
  struct stat s;
  stat("mknodtest", &s);

  assert(S_ISREG(s.st_mode));
  assert(s.st_mode & 0o777);

  stat("createtest", &s);
  assert(S_ISREG(s.st_mode));
  assert(s.st_mode & 0o400);

  remove("mknodtest");
  remove("createtest");
}

void test_fs_truncate() {
  EM_ASM(
    FS.writeFile('truncatetest', 'a=1\nb=2\n');
  );

  struct stat s;
  stat("truncatetest", &s);
  assert(s.st_size == 8);

  EM_ASM(
    FS.truncate('truncatetest', 2);
  );
  stat("truncatetest", &s);
  assert(s.st_size == 2);

  EM_ASM(
    FS.truncate('truncatetest', 10);
  );
  stat("truncatetest", &s);
  assert(s.st_size == 10);

  EM_ASM(
    var truncateStream = FS.open('truncatetest', 'w');
    FS.ftruncate(truncateStream.fd, 4);
  );
  stat("truncatetest", &s);
  assert(s.st_size == 4);

  EM_ASM(
    var ex;
    try {
      FS.truncate('truncatetest', -10);
    } catch(err) {
      ex = err;
    }
    assert(ex.name === "ErrnoError" && ex.errno === 28 /* EINVAL */);

    try {
      var truncateStream = FS.open('truncatetest', 'w');
      FS.ftruncate(truncateStream.fd, -10);
    } catch(err) {
      ex = err;
    }
    assert(ex.name === "ErrnoError" && ex.errno === 28 /* EINVAL */);

    try {
      FS.truncate('nonexistent', 10);
    } catch(err) {
      ex = err;
    }
    assert(ex.name === "ErrnoError" && ex.errno === 44 /* ENOENT */);

    var ex;
    try {
      FS.ftruncate(99, 10);
    } catch(err) {
      ex = err;
    }
    assert(ex.name === "ErrnoError" && ex.errno === 8 /* EBADF */);
  );

  remove("truncatetest");
}

void test_fs_mmap() {
  EM_ASM(
    FS.writeFile('mmaptest', 'a=1_b=2_');

    var stream = FS.open('mmaptest', 'r+');
    assert(stream);

    var mapped = FS.mmap(stream, 12, 0, 1 | 2 /* PROT_READ | PROT_WRITE */, 1 /* MAP_SHARED */);
    var ret = new Uint8Array(HEAPU8.subarray(mapped.ptr, mapped.ptr + 12));
    var fileContents = "";
    for (var i = 0; i < 12; i++) {
      fileContents += String.fromCharCode(ret[i]);
    }
    assert(fileContents === 'a=1_b=2_\0\0\0\0');

    ret[8] = ':'.charCodeAt(0);
    ret[9] = 'x'.charCodeAt(0);
    ret[10] = 'y'.charCodeAt(0);
    ret[11] = 'z'.charCodeAt(0);
    HEAPU8.set(ret, mapped.ptr);

    // The WasmFS msync syscall requires a pointer to the mapped memory, while the legacy JS API takes in any Uint8Array
    // buffer to write to a file.
#if WASMFS
    FS.msync(stream, mapped.ptr, 0, 12, 1 /* MAP_SHARED */);

    var ex;
    try {
      FS.munmap(mapped.ptr, 4);
    } catch (err) {
      ex = err;
    }
    assert(ex.name === "ErrnoError" && ex.errno === 28 /* EINVAL */);

    FS.munmap(mapped.ptr, 12);

    // WasmFS correctly handles unmapping, while the legacy JS API does not.
    try {
      FS.msync(stream, mapped.ptr, 0, 12, 1 /* MAP_SHARED */);
    } catch (err) {
      ex = err;
    }
    assert(ex.name === "ErrnoError" && ex.errno === 28 /* EINVAL */);
#else
    FS.msync(stream, new Uint8Array(ret), 0, 12, 1 /* MAP_SHARED */);
    FS.munmap(stream);
#endif
  );

  FILE *fptr = fopen("mmaptest", "r");
  char res[13];
  fgets(res, 13, fptr);
  assert(strcmp(res, "a=1_b=2_:xyz") == 0);

  remove("mmaptest");
}

void test_fs_mkdirTree() {
  EM_ASM(
    FS.mkdirTree("/test1/test2/test3"); // Abs path
    FS.mkdirTree("/readable", 0o400 /* S_IRUSR */);
  );

  struct stat s;
  assert(stat("/test1", &s) == 0);
  assert(S_ISDIR(s.st_mode));
  assert(stat("/test1/test2", &s) == 0);
  assert(S_ISDIR(s.st_mode));
  assert(stat("/test1/test2/test3", &s) == 0);
  assert(S_ISDIR(s.st_mode));

  assert(stat("/readable", &s) == 0);
  assert(s.st_mode & 0o400 /* S_IRUSR */);

  EM_ASM(
    var ex;
    try {
      FS.mkdirTree("/readable/forbidden");
    } catch (err) {
      ex = err;
    }
    assert(ex.name === "ErrnoError" && ex.errno === 2 /* EACCES */);
  );

  chdir("/test1");
  EM_ASM(
    FS.mkdirTree("foo/bar"); // Relative path
  );
  chdir("/");

  assert(stat("/test1/foo", &s) == 0);
  assert(S_ISDIR(s.st_mode));

  assert(stat("/test1/foo/bar", &s) == 0);
  assert(S_ISDIR(s.st_mode));

  remove("/test1/test2/test3");
  remove("/test1/test2");
  remove("/test1/foo/bar");
  remove("/test1/foo");
  remove("/test1");
  remove("/readable");
}

void test_fs_utime() {
  EM_ASM(
    FS.writeFile('utimetest', 'a=1\nb=2\n');
  );

  EM_ASM(
    FS.utime('utimetest', 10500, 8000);
  );
  struct stat utimeStats;
  stat("utimetest", &utimeStats);

  assert(utimeStats.st_atime == 10);
  assert(utimeStats.st_atim.tv_sec == 10);

  assert(utimeStats.st_atim.tv_nsec == 500000000);

  assert(utimeStats.st_mtime == 8);
  assert(utimeStats.st_mtim.tv_sec == 8);

  remove("utimetest");
}

#if !defined(NODERAWFS)
// NODERAWFS don't support absolute paths since we cannot write the
// actual root directory.
// In addition, abs paths testing is not really running correctly
// when we build run with NODEFS because the NODEFS filesystem is mounted
// at /nodefs in that case.
// TODO(sbc): Refactor these tests such that they test both relative
// and absolute paths, and don't depend on write access to the root
// directory.
#define ABS_PATH_OK
#endif

int main() {
#ifdef ABS_PATH_OK
  test_fs_createPath();
  test_fs_mkdirTree();
  test_fs_close();
  test_fs_readlink();
  test_fs_rmdir();
#endif
  test_fs_open();
  test_fs_readFile();
  test_fs_rename();
  test_fs_read();
  test_fs_mknod();
  test_fs_truncate();
#if WASMFS
  // TODO: Fix legacy API FS.mmap bug involving emscripten_builtin_memalign
  test_fs_mmap();
#endif

  test_fs_utime();

  puts("success");
}