/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include "uv.h"
#include "../internal.h"

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>

#include <net/if.h>
#include <sys/param.h>
#include <sys/sysinfo.h>
#include <unistd.h>
#include <fcntl.h>
#include <time.h>

#define HAVE_IFADDRS_H 1
#ifdef __UCLIBC__
# if __UCLIBC_MAJOR__ < 0 || __UCLIBC_MINOR__ < 9 || __UCLIBC_SUBLEVEL__ < 32
#  undef HAVE_IFADDRS_H
# endif
#endif
#ifdef HAVE_IFADDRS_H
# include <ifaddrs.h>
#endif

#undef NANOSEC
#define NANOSEC ((uint64_t) 1e9)

/* This is rather annoying: CLOCK_BOOTTIME lives in <linux/time.h> but we can't
 * include that file because it conflicts with <time.h>. We'll just have to
 * define it ourselves.
 */
#ifndef CLOCK_BOOTTIME
# define CLOCK_BOOTTIME 7
#endif

static char buf[MAXPATHLEN + 1];

static struct {
  char *str;
  size_t len;
} process_title;

static void read_models(unsigned int numcpus, uv_cpu_info_t* ci);
static void read_speeds(unsigned int numcpus, uv_cpu_info_t* ci);
static void read_times(unsigned int numcpus, uv_cpu_info_t* ci);
static unsigned long read_cpufreq(unsigned int cpunum);


int uv__platform_loop_init(uv_loop_t* loop, int default_loop) {
  loop->inotify_watchers = NULL;
  loop->inotify_fd = -1;
  return 0;
}


void uv__platform_loop_delete(uv_loop_t* loop) {
  if (loop->inotify_fd == -1) return;
  uv__io_stop(loop, &loop->inotify_read_watcher);
  close(loop->inotify_fd);
  loop->inotify_fd = -1;
}


uint64_t uv_hrtime() {
  struct timespec ts;
  clock_gettime(CLOCK_MONOTONIC, &ts);
  return (((uint64_t) ts.tv_sec) * NANOSEC + ts.tv_nsec);
}


void uv_loadavg(double avg[3]) {
  struct sysinfo info;

  if (sysinfo(&info) < 0) return;

  avg[0] = (double) info.loads[0] / 65536.0;
  avg[1] = (double) info.loads[1] / 65536.0;
  avg[2] = (double) info.loads[2] / 65536.0;
}


int uv_exepath(char* buffer, size_t* size) {
  ssize_t n;

  if (!buffer || !size) {
    return -1;
  }

  n = readlink("/proc/self/exe", buffer, *size - 1);
  if (n <= 0) return -1;
  buffer[n] = '\0';
  *size = n;

  return 0;
}


uint64_t uv_get_free_memory(void) {
  return (uint64_t) sysconf(_SC_PAGESIZE) * sysconf(_SC_AVPHYS_PAGES);
}


uint64_t uv_get_total_memory(void) {
  return (uint64_t) sysconf(_SC_PAGESIZE) * sysconf(_SC_PHYS_PAGES);
}


char** uv_setup_args(int argc, char** argv) {
  char **new_argv;
  char **new_env;
  size_t size;
  int envc;
  char *s;
  int i;

  for (envc = 0; environ[envc]; envc++);

  s = envc ? environ[envc - 1] : argv[argc - 1];

  process_title.str = argv[0];
  process_title.len = s + strlen(s) + 1 - argv[0];

  size = process_title.len;
  size += (argc + 1) * sizeof(char **);
  size += (envc + 1) * sizeof(char **);

  if ((s = (char *) malloc(size)) == NULL) {
    process_title.str = NULL;
    process_title.len = 0;
    return argv;
  }

  new_argv = (char **) s;
  new_env = new_argv + argc + 1;
  s = (char *) (new_env + envc + 1);
  memcpy(s, process_title.str, process_title.len);

  for (i = 0; i < argc; i++)
    new_argv[i] = s + (argv[i] - argv[0]);
  new_argv[argc] = NULL;

  s += environ[0] - argv[0];

  for (i = 0; i < envc; i++)
    new_env[i] = s + (environ[i] - environ[0]);
  new_env[envc] = NULL;

  environ = new_env;
  return new_argv;
}


uv_err_t uv_set_process_title(const char* title) {
  /* No need to terminate, last char is always '\0'. */
  if (process_title.len)
    strncpy(process_title.str, title, process_title.len - 1);

  return uv_ok_;
}


uv_err_t uv_get_process_title(char* buffer, size_t size) {
  if (process_title.str) {
    strncpy(buffer, process_title.str, size);
  } else {
    if (size > 0) {
      buffer[0] = '\0';
    }
  }

  return uv_ok_;
}


uv_err_t uv_resident_set_memory(size_t* rss) {
  FILE* f;
  int itmp;
  char ctmp;
  unsigned int utmp;
  size_t page_size = getpagesize();
  char *cbuf;
  int foundExeEnd;

  f = fopen("/proc/self/stat", "r");
  if (!f) return uv__new_sys_error(errno);

  /* PID */
  if (fscanf(f, "%d ", &itmp) == 0) goto error; /* coverity[secure_coding] */
  /* Exec file */
  cbuf = buf;
  foundExeEnd = 0;
  if (fscanf (f, "%c", cbuf++) == 0) goto error;
  while (1) {
    if (fscanf(f, "%c", cbuf) == 0) goto error;
    if (*cbuf == ')') {
      foundExeEnd = 1;
    } else if (foundExeEnd && *cbuf == ' ') {
      *cbuf = 0;
      break;
    }

    cbuf++;
  }
  /* State */
  if (fscanf (f, "%c ", &ctmp) == 0) goto error; /* coverity[secure_coding] */
  /* Parent process */
  if (fscanf (f, "%d ", &itmp) == 0) goto error; /* coverity[secure_coding] */
  /* Process group */
  if (fscanf (f, "%d ", &itmp) == 0) goto error; /* coverity[secure_coding] */
  /* Session id */
  if (fscanf (f, "%d ", &itmp) == 0) goto error; /* coverity[secure_coding] */
  /* TTY */
  if (fscanf (f, "%d ", &itmp) == 0) goto error; /* coverity[secure_coding] */
  /* TTY owner process group */
  if (fscanf (f, "%d ", &itmp) == 0) goto error; /* coverity[secure_coding] */
  /* Flags */
  if (fscanf (f, "%u ", &utmp) == 0) goto error; /* coverity[secure_coding] */
  /* Minor faults (no memory page) */
  if (fscanf (f, "%u ", &utmp) == 0) goto error; /* coverity[secure_coding] */
  /* Minor faults, children */
  if (fscanf (f, "%u ", &utmp) == 0) goto error; /* coverity[secure_coding] */
  /* Major faults (memory page faults) */
  if (fscanf (f, "%u ", &utmp) == 0) goto error; /* coverity[secure_coding] */
  /* Major faults, children */
  if (fscanf (f, "%u ", &utmp) == 0) goto error; /* coverity[secure_coding] */
  /* utime */
  if (fscanf (f, "%d ", &itmp) == 0) goto error; /* coverity[secure_coding] */
  /* stime */
  if (fscanf (f, "%d ", &itmp) == 0) goto error; /* coverity[secure_coding] */
  /* utime, children */
  if (fscanf (f, "%d ", &itmp) == 0) goto error; /* coverity[secure_coding] */
  /* stime, children */
  if (fscanf (f, "%d ", &itmp) == 0) goto error; /* coverity[secure_coding] */
  /* jiffies remaining in current time slice */
  if (fscanf (f, "%d ", &itmp) == 0) goto error; /* coverity[secure_coding] */
  /* 'nice' value */
  if (fscanf (f, "%d ", &itmp) == 0) goto error; /* coverity[secure_coding] */
  /* jiffies until next timeout */
  if (fscanf (f, "%u ", &utmp) == 0) goto error; /* coverity[secure_coding] */
  /* jiffies until next SIGALRM */
  if (fscanf (f, "%u ", &utmp) == 0) goto error; /* coverity[secure_coding] */
  /* start time (jiffies since system boot) */
  if (fscanf (f, "%d ", &itmp) == 0) goto error; /* coverity[secure_coding] */

  /* Virtual memory size */
  if (fscanf (f, "%u ", &utmp) == 0) goto error; /* coverity[secure_coding] */

  /* Resident set size */
  if (fscanf (f, "%u ", &utmp) == 0) goto error; /* coverity[secure_coding] */
  *rss = (size_t) utmp * page_size;

  /* rlim */
  if (fscanf (f, "%u ", &utmp) == 0) goto error; /* coverity[secure_coding] */
  /* Start of text */
  if (fscanf (f, "%u ", &utmp) == 0) goto error; /* coverity[secure_coding] */
  /* End of text */
  if (fscanf (f, "%u ", &utmp) == 0) goto error; /* coverity[secure_coding] */
  /* Start of stack */
  if (fscanf (f, "%u ", &utmp) == 0) goto error; /* coverity[secure_coding] */

  fclose (f);
  return uv_ok_;

error:
  fclose (f);
  return uv__new_sys_error(errno);
}


uv_err_t uv_uptime(double* uptime) {
  static volatile int no_clock_boottime;
  struct timespec now;
  int r;

  /* Try CLOCK_BOOTTIME first, fall back to CLOCK_MONOTONIC if not available
   * (pre-2.6.39 kernels). CLOCK_MONOTONIC doesn't increase when the system
   * is suspended.
   */
  if (no_clock_boottime) {
    retry: r = clock_gettime(CLOCK_MONOTONIC, &now);
  }
  else if ((r = clock_gettime(CLOCK_BOOTTIME, &now)) && errno == EINVAL) {
    no_clock_boottime = 1;
    goto retry;
  }

  if (r)
    return uv__new_sys_error(errno);

  *uptime = now.tv_sec;
  *uptime += (double)now.tv_nsec / 1000000000.0;
  return uv_ok_;
}


uv_err_t uv_cpu_info(uv_cpu_info_t** cpu_infos, int* count) {
  unsigned int numcpus;
  uv_cpu_info_t* ci;

  *cpu_infos = NULL;
  *count = 0;

  numcpus = sysconf(_SC_NPROCESSORS_ONLN);
  assert(numcpus != (unsigned int) -1);
  assert(numcpus != 0);

  ci = calloc(numcpus, sizeof(*ci));
  if (ci == NULL)
    return uv__new_sys_error(ENOMEM);

  read_speeds(numcpus, ci);
  read_models(numcpus, ci);
  read_times(numcpus, ci);

  *cpu_infos = ci;
  *count = numcpus;

  return uv_ok_;
}


static void read_speeds(unsigned int numcpus, uv_cpu_info_t* ci) {
  unsigned int num;

  for (num = 0; num < numcpus; num++)
    ci[num].speed = read_cpufreq(num) / 1000;
}


static void read_models(unsigned int numcpus, uv_cpu_info_t* ci) {
#if defined(__i386__) || defined(__x86_64__)
  static const char marker[] = "model name\t: ";
#elif defined(__arm__)
  static const char marker[] = "Processor\t: ";
#elif defined(__mips__)
  static const char marker[] = "cpu model\t\t: ";
#else
# warning uv_cpu_info() is not supported on this architecture.
  static const char marker[] = "(dummy)";
#endif
  unsigned int num;
  char buf[1024];
  char* model;
  FILE* fp;

  fp = fopen("/proc/cpuinfo", "r");
  if (fp == NULL)
    return;

  num = 0;

  while (fgets(buf, sizeof(buf), fp)) {
    if (num >= numcpus)
      break;

    if (strncmp(buf, marker, sizeof(marker) - 1))
      continue;

    model = buf + sizeof(marker) - 1;
    model = strndup(model, strlen(model) - 1); /* strip newline */
    ci[num++].model = model;
  }
  fclose(fp);
}


static void read_times(unsigned int numcpus, uv_cpu_info_t* ci) {
  unsigned long clock_ticks;
  struct uv_cpu_times_s ts;
  unsigned long user;
  unsigned long nice;
  unsigned long sys;
  unsigned long idle;
  unsigned long dummy;
  unsigned long irq;
  unsigned int num;
  unsigned int len;
  char buf[1024];
  FILE* fp;

  clock_ticks = sysconf(_SC_CLK_TCK);
  assert(clock_ticks != (unsigned long) -1);
  assert(clock_ticks != 0);

  fp = fopen("/proc/stat", "r");
  if (fp == NULL)
    return;

  if (!fgets(buf, sizeof(buf), fp))
    abort();

  num = 0;

  while (fgets(buf, sizeof(buf), fp)) {
    if (num >= numcpus)
      break;

    if (strncmp(buf, "cpu", 3))
      break;

    /* skip "cpu<num> " marker */
    {
      unsigned int n = num;
      for (len = sizeof("cpu0"); n /= 10; len++);
      assert(sscanf(buf, "cpu%u ", &n) == 1 && n == num);
    }

    /* Line contains user, nice, system, idle, iowait, irq, softirq, steal,
     * guest, guest_nice but we're only interested in the first four + irq.
     *
     * Don't use %*s to skip fields or %ll to read straight into the uint64_t
     * fields, they're not allowed in C89 mode.
     */
    if (6 != sscanf(buf + len,
                    "%lu %lu %lu %lu %lu %lu",
                    &user,
                    &nice,
                    &sys,
                    &idle,
                    &dummy,
                    &irq))
      abort();

    ts.user = clock_ticks * user;
    ts.nice = clock_ticks * nice;
    ts.sys  = clock_ticks * sys;
    ts.idle = clock_ticks * idle;
    ts.irq  = clock_ticks * irq;
    ci[num++].cpu_times = ts;
  }
  fclose(fp);
}


static unsigned long read_cpufreq(unsigned int cpunum) {
  unsigned long val;
  char buf[1024];
  FILE* fp;

  snprintf(buf,
           sizeof(buf),
           "/sys/devices/system/cpu/cpu%u/cpufreq/scaling_cur_freq",
           cpunum);

  fp = fopen(buf, "r");
  if (fp == NULL)
    return 0;

  if (fscanf(fp, "%lu", &val) != 1)
    val = 0;

  fclose(fp);

  return val;
}


void uv_free_cpu_info(uv_cpu_info_t* cpu_infos, int count) {
  int i;

  for (i = 0; i < count; i++) {
    free(cpu_infos[i].model);
  }

  free(cpu_infos);
}


uv_err_t uv_interface_addresses(uv_interface_address_t** addresses,
  int* count) {
#ifndef HAVE_IFADDRS_H
  return uv__new_artificial_error(UV_ENOSYS);
#else
  struct ifaddrs *addrs, *ent;
  char ip[INET6_ADDRSTRLEN];
  uv_interface_address_t* address;

  if (getifaddrs(&addrs) != 0) {
    return uv__new_sys_error(errno);
  }

  *count = 0;

  /* Count the number of interfaces */
  for (ent = addrs; ent != NULL; ent = ent->ifa_next) {
    if (!(ent->ifa_flags & IFF_UP && ent->ifa_flags & IFF_RUNNING) ||
        (ent->ifa_addr == NULL) ||
        (ent->ifa_addr->sa_family == PF_PACKET)) {
      continue;
    }

    (*count)++;
  }

  *addresses = (uv_interface_address_t*)
    malloc(*count * sizeof(uv_interface_address_t));
  if (!(*addresses)) {
    return uv__new_artificial_error(UV_ENOMEM);
  }

  address = *addresses;

  for (ent = addrs; ent != NULL; ent = ent->ifa_next) {
    bzero(&ip, sizeof (ip));
    if (!(ent->ifa_flags & IFF_UP && ent->ifa_flags & IFF_RUNNING)) {
      continue;
    }

    if (ent->ifa_addr == NULL) {
      continue;
    }

    /*
     * On Linux getifaddrs returns information related to the raw underlying
     * devices. We're not interested in this information.
     */
    if (ent->ifa_addr->sa_family == PF_PACKET) {
      continue;
    }

    address->name = strdup(ent->ifa_name);

    if (ent->ifa_addr->sa_family == AF_INET6) {
      address->address.address6 = *((struct sockaddr_in6 *)ent->ifa_addr);
    } else {
      address->address.address4 = *((struct sockaddr_in *)ent->ifa_addr);
    }

    address->is_internal = ent->ifa_flags & IFF_LOOPBACK ? 1 : 0;

    address++;
  }

  freeifaddrs(addrs);

  return uv_ok_;
#endif
}


void uv_free_interface_addresses(uv_interface_address_t* addresses,
  int count) {
  int i;

  for (i = 0; i < count; i++) {
    free(addresses[i].name);
  }

  free(addresses);
}