/*
 * Copyright (c) 2020 TAOS Data, Inc. <jhtao@taosdata.com>
 *
 * This program is free software: you can use, redistribute, and/or modify
 * it under the terms of the GNU Affero General Public License, version 3
 * or later ("AGPL"), as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#define _DEFAULT_SOURCE
#include "os.h"
#include "osTime.h"
#include "tbuffer.h"
#include "tglobal.h"
#include "tsocket.h"
#include "dnodeCfg.h"
#include "dnodeTelemetry.h"
#include "mnode.h"

#define TELEMETRY_SERVER "telemetry.taosdata.com"
#define TELEMETRY_PORT 80
#define REPORT_INTERVAL 86400

static void dnodeBeginObject(SBufferWriter* bw) { tbufWriteChar(bw, '{'); }

static void dnodeCloseObject(SBufferWriter* bw) {
  size_t len = tbufTell(bw);
  if (tbufGetData(bw, false)[len - 1] == ',') {
    tbufWriteCharAt(bw, len - 1, '}');
  } else {
    tbufWriteChar(bw, '}');
  }
  tbufWriteChar(bw, ',');
}

#if 0
static void beginArray(SBufferWriter* bw) {
  tbufWriteChar(bw, '[');
}

static void closeArray(SBufferWriter* bw) {
  size_t len = tbufTell(bw);
  if (tbufGetData(bw, false)[len - 1] == ',') {
    tbufWriteCharAt(bw, len - 1, ']');
  } else {
    tbufWriteChar(bw, ']');
  }
  tbufWriteChar(bw, ',');
}
#endif

static void dnodeWriteString(SBufferWriter* bw, const char* str) {
  tbufWriteChar(bw, '"');
  tbufWrite(bw, str, strlen(str));
  tbufWriteChar(bw, '"');
}

static void dnodeAddIntField(SBufferWriter* bw, const char* k, int64_t v) {
  dnodeWriteString(bw, k);
  tbufWriteChar(bw, ':');
  char buf[32];
  sprintf(buf, "%" PRId64, v);
  tbufWrite(bw, buf, strlen(buf));
  tbufWriteChar(bw, ',');
}

static void dnodeAddStringField(SBufferWriter* bw, const char* k, const char* v) {
  dnodeWriteString(bw, k);
  tbufWriteChar(bw, ':');
  dnodeWriteString(bw, v);
  tbufWriteChar(bw, ',');
}

static void dnodeAddCpuInfo(SBufferWriter* bw) {
  char*   line = NULL;
  size_t  size = 0;
  int32_t done = 0;

  FILE* fp = fopen("/proc/cpuinfo", "r");
  if (fp == NULL) {
    return;
  }

  while (done != 3 && (size = tgetline(&line, &size, fp)) != -1) {
    line[size - 1] = '\0';
    if (((done & 1) == 0) && strncmp(line, "model name", 10) == 0) {
      const char* v = strchr(line, ':') + 2;
      dnodeAddStringField(bw, "cpuModel", v);
      done |= 1;
    } else if (((done & 2) == 0) && strncmp(line, "cpu cores", 9) == 0) {
      const char* v = strchr(line, ':') + 2;
      dnodeWriteString(bw, "numOfCpu");
      tbufWriteChar(bw, ':');
      tbufWrite(bw, v, strlen(v));
      tbufWriteChar(bw, ',');
      done |= 2;
    }
  }

  free(line);
  fclose(fp);
}

static void dnodeAddOsInfo(SBufferWriter* bw) {
  char*  line = NULL;
  size_t size = 0;

  FILE* fp = fopen("/etc/os-release", "r");
  if (fp == NULL) {
    return;
  }

  while ((size = tgetline(&line, &size, fp)) != -1) {
    line[size - 1] = '\0';
    if (strncmp(line, "PRETTY_NAME", 11) == 0) {
      const char* p = strchr(line, '=') + 1;
      if (*p == '"') {
        p++;
        line[size - 2] = 0;
      }
      dnodeAddStringField(bw, "os", p);
      break;
    }
  }

  free(line);
  fclose(fp);
}

static void dnodeAddMemoryInfo(SBufferWriter* bw) {
  char*  line = NULL;
  size_t size = 0;

  FILE* fp = fopen("/proc/meminfo", "r");
  if (fp == NULL) {
    return;
  }

  while ((size = tgetline(&line, &size, fp)) != -1) {
    line[size - 1] = '\0';
    if (strncmp(line, "MemTotal", 8) == 0) {
      const char* p = strchr(line, ':') + 1;
      while (*p == ' ') p++;
      dnodeAddStringField(bw, "memory", p);
      break;
    }
  }

  free(line);
  fclose(fp);
}

static void dnodeAddVersionInfo(DnTelem* telem, SBufferWriter* bw) {
  dnodeAddStringField(bw, "version", version);
  dnodeAddStringField(bw, "buildInfo", buildinfo);
  dnodeAddStringField(bw, "gitInfo", gitinfo);
  dnodeAddStringField(bw, "email", telem->email);
}

static void dnodeAddRuntimeInfo(DnTelem* telem, SBufferWriter* bw) {
  SMnodeStat stat = {0};
  if (mnodeGetStatistics(telem->dnode->mnode, &stat) != 0) {
    return;
  }

  dnodeAddIntField(bw, "numOfDnode", stat.numOfDnode);
  dnodeAddIntField(bw, "numOfMnode", stat.numOfMnode);
  dnodeAddIntField(bw, "numOfVgroup", stat.numOfVgroup);
  dnodeAddIntField(bw, "numOfDatabase", stat.numOfDatabase);
  dnodeAddIntField(bw, "numOfSuperTable", stat.numOfSuperTable);
  dnodeAddIntField(bw, "numOfChildTable", stat.numOfChildTable);
  dnodeAddIntField(bw, "numOfColumn", stat.numOfColumn);
  dnodeAddIntField(bw, "numOfPoint", stat.totalPoints);
  dnodeAddIntField(bw, "totalStorage", stat.totalStorage);
  dnodeAddIntField(bw, "compStorage", stat.compStorage);
}

static void dnodeSendTelemetryReport(DnTelem* telem) {
  char     buf[128] = {0};
  uint32_t ip = taosGetIpv4FromFqdn(TELEMETRY_SERVER);
  if (ip == 0xffffffff) {
    dTrace("failed to get IP address of " TELEMETRY_SERVER ", reason:%s", strerror(errno));
    return;
  }
  SOCKET fd = taosOpenTcpClientSocket(ip, TELEMETRY_PORT, 0);
  if (fd < 0) {
    dTrace("failed to create socket for telemetry, reason:%s", strerror(errno));
    return;
  }

  SBufferWriter bw = tbufInitWriter(NULL, false);
  dnodeBeginObject(&bw);
  dnodeAddStringField(&bw, "instanceId", telem->dnode->cfg->clusterId);
  dnodeAddIntField(&bw, "reportVersion", 1);
  dnodeAddOsInfo(&bw);
  dnodeAddCpuInfo(&bw);
  dnodeAddMemoryInfo(&bw);
  dnodeAddVersionInfo(telem, &bw);
  dnodeAddRuntimeInfo(telem, &bw);
  dnodeCloseObject(&bw);

  const char* header =
      "POST /report HTTP/1.1\n"
      "Host: " TELEMETRY_SERVER
      "\n"
      "Content-Type: application/json\n"
      "Content-Length: ";

  taosWriteSocket(fd, header, (int32_t)strlen(header));
  int32_t contLen = (int32_t)(tbufTell(&bw) - 1);
  sprintf(buf, "%d\n\n", contLen);
  taosWriteSocket(fd, buf, (int32_t)strlen(buf));
  taosWriteSocket(fd, tbufGetData(&bw, false), contLen);
  tbufCloseWriter(&bw);

  // read something to avoid nginx error 499
  if (taosReadSocket(fd, buf, 10) < 0) {
    dTrace("failed to receive response since %s", strerror(errno));
  }

  taosCloseSocket(fd);
}

static void* dnodeTelemThreadFp(void* param) {
  DnTelem* telem = param;

  struct timespec end = {0};
  clock_gettime(CLOCK_REALTIME, &end);
  end.tv_sec += 300;  // wait 5 minutes before send first report

  setThreadName("dnode-telem");

  while (!telem->exit) {
    int32_t         r = 0;
    struct timespec ts = end;
    pthread_mutex_lock(&telem->lock);
    r = pthread_cond_timedwait(&telem->cond, &telem->lock, &ts);
    pthread_mutex_unlock(&telem->lock);
    if (r == 0) break;
    if (r != ETIMEDOUT) continue;

    if (mnodeIsServing(telem->dnode->mnode)) {
      dnodeSendTelemetryReport(telem);
    }
    end.tv_sec += REPORT_INTERVAL;
  }

  return NULL;
}

static void dnodeGetEmail(DnTelem* telem, char* filepath) {
  int32_t fd = open(filepath, O_RDONLY);
  if (fd < 0) {
    return;
  }

  if (taosRead(fd, (void*)telem->email, TSDB_FQDN_LEN) < 0) {
    dError("failed to read %d bytes from file %s since %s", TSDB_FQDN_LEN, filepath, strerror(errno));
  }

  taosClose(fd);
}

int32_t dnodeInitTelemetry(Dnode* dnode, DnTelem** out) {
  DnTelem* telem = calloc(1, sizeof(DnTelem));
  if (telem == NULL) return -1;

  telem->dnode = dnode;
  telem->enable = tsEnableTelemetryReporting;
  *out = telem;

  if (!telem->enable) return 0;

  telem->exit = 0;
  pthread_mutex_init(&telem->lock, NULL);
  pthread_cond_init(&telem->cond, NULL);
  telem->email[0] = 0;

  dnodeGetEmail(telem, "/usr/local/taos/email");

  pthread_attr_t attr;
  pthread_attr_init(&attr);
  pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);

  int32_t code = pthread_create(&telem->thread, &attr, dnodeTelemThreadFp, telem);
  pthread_attr_destroy(&attr);
  if (code != 0) {
    dTrace("failed to create telemetry thread since :%s", strerror(code));
  }

  dInfo("dnode telemetry is initialized");
  return 0;
}

void dnodeCleanupTelemetry(DnTelem** out) {
  DnTelem* telem = *out;
  *out = NULL;

  if (!telem->enable) {
    free(telem);
    return;
  }

  if (taosCheckPthreadValid(telem->thread)) {
    pthread_mutex_lock(&telem->lock);
    telem->exit = 1;
    pthread_cond_signal(&telem->cond);
    pthread_mutex_unlock(&telem->lock);

    pthread_join(telem->thread, NULL);
  }

  pthread_mutex_destroy(&telem->lock);
  pthread_cond_destroy(&telem->cond);

  free(telem);
}