/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "common/util_c.h"
#include "expect.h"
#include "hdfs/hdfs.h"
#include "hdfspp/hdfs_ext.h"
#include "native_mini_dfs.h"
#include "os/thread.h"
#include "x-platform/c-api/syscall.h"

#include <errno.h>
#include <inttypes.h>
#include <pwd.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

#define TO_STR_HELPER(X) #X
#define TO_STR(X) TO_STR_HELPER(X)

#define TLH_MAX_THREADS 10000

#define TLH_MAX_DNS 16

#define TLH_DEFAULT_BLOCK_SIZE 1048576

#define TLH_DEFAULT_DFS_REPLICATION 3

#define TLH_DEFAULT_IPC_CLIENT_CONNECT_MAX_RETRIES 100

#define TLH_DEFAULT_IPC_CLIENT_CONNECT_RETRY_INTERVAL_MS 5

#define MAX_DIGITS_IN_INT 10

#ifndef RANDOM_ERROR_RATIO
#define RANDOM_ERROR_RATIO 1000000000
#endif

struct tlhThreadInfo {
  /** Thread index */
  int threadIdx;
  /** 0 = thread was successful; error code otherwise */
  int success;
  /** thread identifier */
  thread theThread;
  /** fs, shared with other threads **/
  hdfsFS hdfs;
  /** Filename */
  const char *fileNm;

};

static int hdfsNameNodeConnect(tPort port, hdfsFS *fs,
                               const char *username)
{
  int ret;
  hdfsFS hdfs;
  struct hdfsBuilder *bld;

  if (port < 0) {
    fprintf(stderr, "hdfsNameNodeConnect: nmdGetNameNodePort "
            "returned error %d\n", port);
    return port;
  }
  bld = hdfsNewBuilder();
  if (!bld)
    return -ENOMEM;
  hdfsBuilderSetForceNewInstance(bld);
  hdfsBuilderSetNameNode(bld, "localhost");
  hdfsBuilderSetNameNodePort(bld, port);
  hdfsBuilderConfSetStr(bld, "dfs.block.size",
                        TO_STR(TLH_DEFAULT_BLOCK_SIZE));
  hdfsBuilderConfSetStr(bld, "dfs.blocksize",
                        TO_STR(TLH_DEFAULT_BLOCK_SIZE));
  hdfsBuilderConfSetStr(bld, "dfs.replication",
                        TO_STR(TLH_DEFAULT_DFS_REPLICATION));
  hdfsBuilderConfSetStr(bld, "ipc.client.connect.max.retries",
                        TO_STR(TLH_DEFAULT_IPC_CLIENT_CONNECT_MAX_RETRIES));
  hdfsBuilderConfSetStr(bld, "ipc.client.connect.retry.interval",
                        TO_STR(TLH_DEFAULT_IPC_CLIENT_CONNECT_RETRY_INTERVAL_MS));
  if (username) {
    hdfsBuilderSetUserName(bld, username);
  }
  hdfs = hdfsBuilderConnect(bld);
  if (!hdfs) {
    ret = -errno;
    return ret;
  }
  *fs = hdfs;
  return 0;
}

#ifdef VALGRIND
static int hdfsCurlData(const char *host, const tPort port, const char *dirNm,
                         const char *fileNm, tSize fileSz)
{
  int ret;
  const char *content;
  content = fileNm;
  char tmpFile[14] = "stress_XXXXXX";

  // Retrieve user id (always successful)
  uid_t uid = geteuid();
  // Retrieve password struct entry
  struct passwd *pw;
  EXPECT_NONNULL(pw = getpwuid(uid));

  int fd = -1;
  EXPECT_NONNEGATIVE(fd = x_platform_syscall_create_and_open_temp_file(
                         tmpFile, sizeof tmpFile));

  tSize sz = 0;
  while (sz < fileSz) {
    EXPECT_NONNEGATIVE(ret = write(fd, content, strlen(content)));
    sz += ret;
  }

  int curlSize = 200;
  char curlStr[curlSize];
  ret = snprintf(curlStr,curlSize,"curl -L -i -X PUT -T %s \"http://%s:%d/webhdfs/v1%s?op=CREATE&overwrite=true&user.name=%s\"",tmpFile,host,(int)port,fileNm,pw->pw_name);
  //Check for errors during snprintf
  EXPECT_NONNEGATIVE(ret);
  //Check for truncation during snprintf
  EXPECT_INT_LT(ret, curlSize);

  EXPECT_ZERO(system(curlStr));
  EXPECT_ZERO(unlink(tmpFile));

  return 0;
}
#else
static int hdfsWriteData(hdfsFS hdfs, const char *dirNm,
                         const char *fileNm, tSize fileSz)
{
  hdfsFile file;
  int ret, expected;
  const char *content;

  content = fileNm;

  if (hdfsExists(hdfs, dirNm) == 0) {
    EXPECT_ZERO(hdfsDelete(hdfs, dirNm, 1));
  }
  EXPECT_ZERO(hdfsCreateDirectory(hdfs, dirNm));

  file = hdfsOpenFile(hdfs, fileNm, O_WRONLY, 0, 0, 0);
  EXPECT_NONNULL(file);

  expected = (int)strlen(content);
  tSize sz = 0;
  while (sz < fileSz) {
    ret = hdfsWrite(hdfs, file, content, expected);
    if (ret < 0) {
      ret = errno;
      fprintf(stderr, "hdfsWrite failed and set errno %d\n", ret);
      return ret;
    }
    if (ret != expected) {
      fprintf(stderr, "hdfsWrite was supposed to write %d bytes, but "
              "it wrote %d\n", ret, expected);
      return EIO;
    }
    sz += ret;
  }
  EXPECT_ZERO(hdfsFlush(hdfs, file));
  EXPECT_ZERO(hdfsHSync(hdfs, file));
  EXPECT_ZERO(hdfsCloseFile(hdfs, file));
  return 0;
}
#endif

static int fileEventCallback1(const char * event, const char * cluster, const char * file, int64_t value, int64_t cookie)
{
  char * randomErrRatioStr = getenv("RANDOM_ERROR_RATIO");
  int64_t randomErrRatio = RANDOM_ERROR_RATIO;
  if (randomErrRatioStr) randomErrRatio = (int64_t)atoi(randomErrRatioStr);
  if (randomErrRatio == 0) return DEBUG_SIMULATE_ERROR;
  else if (randomErrRatio < 0) return LIBHDFSPP_EVENT_OK;
  return random() % randomErrRatio == 0 ? DEBUG_SIMULATE_ERROR : LIBHDFSPP_EVENT_OK;
}

static int fileEventCallback2(const char * event, const char * cluster, const char * file, int64_t value, int64_t cookie)
{
  /* no op */
  return LIBHDFSPP_EVENT_OK;
}

static int doTestHdfsMiniStress(struct tlhThreadInfo *ti, int randomErr)
{
  char tmp[4096];
  hdfsFile file;
  int ret, expected;
  hdfsFileInfo *fileInfo;
  uint64_t readOps, nErrs=0;
  tOffset seekPos;
  const char *content;

  content = ti->fileNm;
  expected = (int)strlen(content);

  fileInfo = hdfsGetPathInfo(ti->hdfs, ti->fileNm);
  EXPECT_NONNULL(fileInfo);

  file = hdfsOpenFile(ti->hdfs, ti->fileNm, O_RDONLY, 0, 0, 0);
  EXPECT_NONNULL(file);

  libhdfspp_file_event_callback callback = (randomErr != 0) ? &fileEventCallback1 : &fileEventCallback2;

  hdfsPreAttachFileMonitor(callback, 0);

  fprintf(stderr, "testHdfsMiniStress(threadIdx=%d): starting read loop\n",
          ti->threadIdx);
  for (readOps=0; readOps < 1000; ++readOps) {
    EXPECT_ZERO(hdfsCloseFile(ti->hdfs, file));
    file = hdfsOpenFile(ti->hdfs, ti->fileNm, O_RDONLY, 0, 0, 0);
    EXPECT_NONNULL(file);
    seekPos = (((double)random()) / RAND_MAX) * (fileInfo->mSize - expected);
    seekPos = (seekPos / expected) * expected;
    ret = hdfsSeek(ti->hdfs, file, seekPos);
    if (ret < 0) {
      ret = errno;
      fprintf(stderr, "hdfsSeek to %"PRIu64" failed and set"
              " errno %d\n", seekPos, ret);
      ++nErrs;
      continue;
    }
    ret = hdfsRead(ti->hdfs, file, tmp, expected);
    if (ret < 0) {
      ret = errno;
      fprintf(stderr, "hdfsRead failed and set errno %d\n", ret);
      ++nErrs;
      continue;
    }
    if (ret != expected) {
      fprintf(stderr, "hdfsRead was supposed to read %d bytes, but "
              "it read %d\n", ret, expected);
      ++nErrs;
      continue;
    }
    ret = memcmp(content, tmp, expected);
    if (ret) {
      fprintf(stderr, "hdfsRead result (%.*s) does not match expected (%.*s)",
              expected, tmp, expected, content);
      ++nErrs;
      continue;
    }
  }
  EXPECT_ZERO(hdfsCloseFile(ti->hdfs, file));
  fprintf(stderr, "testHdfsMiniStress(threadIdx=%d): finished read loop\n",
          ti->threadIdx);
  EXPECT_ZERO(nErrs);
  hdfsFreeFileInfo(fileInfo, 1);
  return 0;
}

static int testHdfsMiniStressImpl(struct tlhThreadInfo *ti)
{
  fprintf(stderr, "testHdfsMiniStress(threadIdx=%d): starting\n",
          ti->threadIdx);
  EXPECT_NONNULL(ti->hdfs);
  // Error injection on, some failures are expected in the read path.
  // The expectation is that any memory stomps will cascade and cause
  // the following test to fail.  Ideally RPC errors would be separated
  // from BlockReader errors (RPC is expected to recover from disconnects).
  doTestHdfsMiniStress(ti, 1);
  // No error injection
  EXPECT_ZERO(doTestHdfsMiniStress(ti, 0));
  return 0;
}

static void testHdfsMiniStress(void *v)
{
  struct tlhThreadInfo *ti = (struct tlhThreadInfo*)v;
  int ret = testHdfsMiniStressImpl(ti);
  ti->success = ret;
}

static int checkFailures(struct tlhThreadInfo *ti, int tlhNumThreads)
{
  int i, threadsFailed = 0;
  const char *sep = "";

  for (i = 0; i < tlhNumThreads; i++) {
    if (ti[i].success != 0) {
      threadsFailed = 1;
    }
  }
  if (!threadsFailed) {
    fprintf(stderr, "testLibHdfsMiniStress: all threads succeeded.  SUCCESS.\n");
    return EXIT_SUCCESS;
  }
  fprintf(stderr, "testLibHdfsMiniStress: some threads failed: [");
  for (i = 0; i < tlhNumThreads; i++) {
    if (ti[i].success != 0) {
      fprintf(stderr, "%s%d", sep, i);
      sep = ", ";
    }
  }
  fprintf(stderr, "].  FAILURE.\n");
  return EXIT_FAILURE;
}

/**
 * Test intended to stress libhdfs client with concurrent requests. Currently focused
 * on concurrent reads. In order to run this test under valgrind and avoid JVM issues
 * we fork a child process that runs a mini dfs cluster, and the parent process
 * communicates with it using a socket pair.
 */
int main(int argc, char *argv[])
{
  tPort port;
#ifdef VALGRIND
  int httpPort;
  char * httpHost;
  size_t hostSize;
  int fds[2];
  static const int parentsocket = 0;
  static const int childsocket = 1;
  int status;
  // If there is an argument, the child code executes and starts a mini dfs cluster
  if (argc > 1) {
    // The argument contains child socket
    fds[childsocket] = (int) strtol(argv[1],NULL,10);
#endif
    const char *tlhNumDNsStr;
    struct NativeMiniDfsCluster* tlhCluster;
    struct NativeMiniDfsConf conf = {
      1, /* doFormat */
      1, /* webhdfs */
      0, /* webhdfs port */
      1  /* shortcircuit */
    };
    tlhNumDNsStr = getenv("TLH_NUM_DNS");
    if (!tlhNumDNsStr) {
      tlhNumDNsStr = "1";
    }
    conf.numDataNodes = atoi(tlhNumDNsStr);
    if ((conf.numDataNodes <= 0) || (conf.numDataNodes > TLH_MAX_DNS)) {
      fprintf(stderr, "testLibHdfsMiniStress: must have a number of datanodes "
              "between 1 and %d inclusive, not %d\n",
              TLH_MAX_DNS, conf.numDataNodes);
      return EXIT_FAILURE;
    }
    tlhCluster = nmdCreate(&conf);
    EXPECT_NONNULL(tlhCluster);
    EXPECT_ZERO(nmdWaitClusterUp(tlhCluster));
    port = (tPort)nmdGetNameNodePort(tlhCluster);
#ifdef VALGRIND
    EXPECT_ZERO(nmdGetNameNodeHttpAddress(tlhCluster, &httpPort, (const char **) &httpHost));
    hostSize = strlen(httpHost) + 1;
    // The child is sending hdfs port, webhdfs port, hostname size, and hostname to the parent
    ASSERT_INT64_EQ(write(fds[childsocket], &port, sizeof(tPort)), sizeof(tPort));
    ASSERT_INT64_EQ(write(fds[childsocket], &httpPort, sizeof(int)), sizeof(int));
    ASSERT_INT64_EQ(write(fds[childsocket], &hostSize, sizeof(size_t)), sizeof(size_t));
    ASSERT_INT64_EQ(write(fds[childsocket], httpHost, hostSize), hostSize);
    free(httpHost);
    // The child is waiting for the parent to finish and send a message
    ASSERT_INT64_EQ(read(fds[childsocket], &port, sizeof(tPort)), sizeof(tPort));
    EXPECT_ZERO(nmdShutdown(tlhCluster));
    nmdFree(tlhCluster);
  } else { // If there is no argument, the parent code executes
#endif
    hdfsFS hdfs = NULL;
    int i, tlhNumThreads;
    char *dirNm, *fileNm;
    tSize fileSz;
    const char *tlhNumThreadsStr;
    struct tlhThreadInfo ti[TLH_MAX_THREADS];

    dirNm = "/tlhMiniStressData";
    fileNm = "/tlhMiniStressData/file";
    fileSz = 2*1024*1024;

    tlhNumThreadsStr = getenv("TLH_NUM_THREADS");
    if (!tlhNumThreadsStr) {
      tlhNumThreadsStr = "8";
    }
    tlhNumThreads = atoi(tlhNumThreadsStr);
    if ((tlhNumThreads <= 0) || (tlhNumThreads > TLH_MAX_THREADS)) {
      fprintf(stderr, "testLibHdfsMiniStress: must have a number of threads "
              "between 1 and %d inclusive, not %d\n",
              TLH_MAX_THREADS, tlhNumThreads);
      return EXIT_FAILURE;
    }
    memset(&ti[0], 0, sizeof(ti));
    for (i = 0; i < tlhNumThreads; i++) {
      ti[i].threadIdx = i;
    }

#ifdef VALGRIND
    EXPECT_ZERO(socketpair(PF_LOCAL, SOCK_STREAM, 0, fds));
    // Forking off a child to execute JVM stuff
    pid_t pid = fork();
    if(pid == 0){
      // The child execs this program from the beginning and passes
      // its file descriptor as a command line argument.
      char ch_fd[MAX_DIGITS_IN_INT + 1];
      sprintf(ch_fd, "%d", fds[childsocket]);
      // This has to be done with exec() to prevent valgrind from tracing the child
      execl(argv[0], argv[0], ch_fd, NULL);
      // This code should never execute
      fprintf(stderr, "execl() failed.\n");
      return EXIT_FAILURE;
    }
    close(fds[childsocket]);
    // The parent is receiving hdfs port, webhdfs port, hostname size, and hostname from the child
    ASSERT_INT64_EQ(read(fds[parentsocket], &port, sizeof(tPort)), sizeof(tPort));
    ASSERT_INT64_EQ(read(fds[parentsocket], &httpPort, sizeof(int)), sizeof(int));
    ASSERT_INT64_EQ(read(fds[parentsocket], &hostSize, sizeof(size_t)), sizeof(size_t));
    httpHost = malloc(hostSize);
    ASSERT_INT64_EQ(read(fds[parentsocket], httpHost, hostSize), hostSize);
    EXPECT_ZERO(hdfsNameNodeConnect(port, &hdfs, NULL));
    EXPECT_ZERO(hdfsCurlData(httpHost, httpPort, dirNm, fileNm, fileSz));
    free(httpHost);
#else
    EXPECT_ZERO(hdfsNameNodeConnect(port, &hdfs, NULL));
    EXPECT_ZERO(hdfsWriteData(hdfs, dirNm, fileNm, fileSz));
#endif

    // Multi-threaded reads.
    for (i = 0; i < tlhNumThreads; i++) {
      ti[i].theThread.start = testHdfsMiniStress;
      ti[i].theThread.arg = &ti[i];
      ti[i].hdfs = hdfs;
      ti[i].fileNm = fileNm;
      EXPECT_ZERO(threadCreate(&ti[i].theThread));
    }
    for (i = 0; i < tlhNumThreads; i++) {
      EXPECT_ZERO(threadJoin(&ti[i].theThread));
    }

    EXPECT_ZERO(hdfsDisconnect(hdfs));
    EXPECT_ZERO(checkFailures(ti, tlhNumThreads));
#ifdef VALGRIND
    //Send this message to the child to notify it that it can now shut down
    ASSERT_INT64_EQ(write(fds[parentsocket], &port, sizeof(tPort)), sizeof(tPort));
    // Wait for the child to exit and verify it returned EXIT_SUCCESS
    waitpid(pid, &status, 0);
    EXPECT_ZERO(status);
  }
#else
    EXPECT_ZERO(nmdShutdown(tlhCluster));
    nmdFree(tlhCluster);
#endif
  // Clean up static data and prevent valgrind memory leaks
  ShutdownProtobufLibrary_C();
  return EXIT_SUCCESS;
}