// Copyright 2016 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "spec_utils.h"
#include <dirent.h>
#include <errno.h>
#include <glog/logging.h>
#include <limits.h>
#include <string>
#include <sys/stat.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>

int DeleteDir(std::string dirname) {
  DLOG(INFO) << "Deleting: " << dirname;
  DIR* dir = opendir(dirname.c_str());
  if (dir == NULL) {
    return errno;
  }

  struct dirent* de;
  struct stat stat_buf;
  while ((de = readdir(dir)) != NULL) {
    if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) {
      continue;
    }

    std::string name = dirname + "/" + de->d_name;
    if (stat(name.c_str(), &stat_buf) == 0 && S_ISDIR(stat_buf.st_mode)) {
      if (DeleteDir(name) != 0) {
        return errno;
      }
    } else {
      if (unlink(name.c_str()) != 0) {
        return errno;
      }
    }
  }

  if (closedir(dir) != 0) {
    return errno;
  }
  if (rmdir(dirname.c_str()) != 0) {
    return errno;
  }
  return 0;
}

int CopyDir(std::string dest_dirname, std::string src_dirname) {
  DIR* dir = opendir(src_dirname.c_str());
  if (dir == NULL) {
    return errno;
  }

  DLOG(INFO) << "Copy " << src_dirname << " to " << dest_dirname;
  struct dirent* de;
  struct stat stat_buf;
  while ((de = readdir(dir)) != NULL) {
    std::string name = src_dirname + "/" + de->d_name;
    if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) {
      continue;
    }

    if (stat(name.c_str(), &stat_buf) != 0) {
      return errno;
    }
    if (S_ISDIR(stat_buf.st_mode)) {
      std::string sub_dir = dest_dirname + "/" + de->d_name;
      if (mkdir(sub_dir.c_str(), 0600) != 0) {
        return errno;
      }
      if (CopyDir(sub_dir, name) != 0) {
        return errno;
      }
    } else if (S_ISREG(stat_buf.st_mode)) {
      if (CopyFile(dest_dirname + "/" + de->d_name, name) != 0) {
        return errno;
      }
    }
  }
  if (closedir(dir) != 0) {
    return errno;
  }
  return 0;
}

int CopyFile(std::string dest, std::string src) {
  int page_size = getpagesize();
  char buf[page_size];
  size_t size;
  DLOG(INFO) << "Copy " << src << " to " << dest;
  FILE* srcfile = fopen(src.c_str(), "rb");
  if (srcfile == NULL) {
    return errno;
  }
  FILE* destfile = fopen(dest.c_str(), "wb");
  if (destfile == NULL) {
    return errno;
  }

  while ((size = fread(buf, 1, page_size, srcfile))) {
    if (fwrite(buf, 1, size, destfile) != size) {
      return errno;
    }
  }

  if (fclose(srcfile) != 0) {
    return errno;
  }
  if (fflush(destfile) != 0) {
    return errno;
  }
  if (fclose(destfile) != 0) {
    return errno;
  }
  return 0;
}