/*
 * nghttp2 - HTTP/2 C Library
 *
 * Copyright (c) 2012 Tatsuhiro Tsujikawa
 *
 * 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 "shrpx_log.h"

#include <syslog.h>
#include <unistd.h>
#include <inttypes.h>

#include <cerrno>
#include <cstdio>
#include <cstring>
#include <ctime>
#include <iostream>

#include "shrpx_config.h"
#include "shrpx_downstream.h"
#include "shrpx_worker_config.h"
#include "util.h"

using namespace nghttp2;

namespace shrpx {

namespace {
const char *SEVERITY_STR[] = {
  "INFO", "NOTICE", "WARN", "ERROR", "FATAL"
};
} // namespace

namespace {
const char *SEVERITY_COLOR[] = {
  "\033[1;32m", // INFO
  "\033[1;36m", // NOTICE
  "\033[1;33m", // WARN
  "\033[1;31m", // ERROR
  "\033[1;35m", // FATAL
};
} // namespace

int Log::severity_thres_ = NOTICE;

void Log::set_severity_level(int severity)
{
  severity_thres_ = severity;
}

int Log::set_severity_level_by_name(const char *name)
{
  for(size_t i = 0, max = util::array_size(SEVERITY_STR); i < max;  ++i) {
    if(strcmp(SEVERITY_STR[i], name) == 0) {
      severity_thres_ = i;
      return 0;
    }
  }
  return -1;
}

int severity_to_syslog_level(int severity)
{
  switch(severity) {
  case(INFO):
    return LOG_INFO;
  case(NOTICE):
    return LOG_NOTICE;
  case(WARN):
    return LOG_WARNING;
  case(ERROR):
    return LOG_ERR;
  case(FATAL):
    return LOG_CRIT;
  default:
    return -1;
  }
}

Log::Log(int severity, const char *filename, int linenum)
  : filename_(filename),
    severity_(severity),
    linenum_(linenum)
{}

Log::~Log()
{
  int rv;

  if(!get_config()) {
    return;
  }

  auto wconf = worker_config;

  if(!log_enabled(severity_) ||
     (wconf->errorlog_fd == -1 && !get_config()->errorlog_syslog)) {
    return;
  }

  if(get_config()->errorlog_syslog) {
    if (severity_ == NOTICE) {
      syslog(severity_to_syslog_level(severity_), "[%s] %s",
             SEVERITY_STR[severity_], stream_.str().c_str());
    } else {
      syslog(severity_to_syslog_level(severity_), "[%s] %s (%s:%d)",
             SEVERITY_STR[severity_], stream_.str().c_str(),
             filename_, linenum_);
    }

    return;
  }

  char buf[4096];
  auto tty = wconf->errorlog_tty;

  auto cached_time = get_config()->cached_time;

  if (severity_ == NOTICE) {
    rv = snprintf(buf, sizeof(buf),
                  "%s PID%d [%s%s%s] %s\n",
                  cached_time->c_str(),
                  getpid(),
                  tty ? SEVERITY_COLOR[severity_] : "",
                  SEVERITY_STR[severity_],
                  tty ? "\033[0m" : "",
                  stream_.str().c_str());
  } else {
    rv = snprintf(buf, sizeof(buf),
                  "%s PID%d [%s%s%s] %s%s:%d%s %s\n",
                  cached_time->c_str(),
                  getpid(),
                  tty ? SEVERITY_COLOR[severity_] : "",
                  SEVERITY_STR[severity_],
                  tty ? "\033[0m" : "",
                  tty ? "\033[1;30m" : "",
                  filename_, linenum_,
                  tty ? "\033[0m" : "",
                  stream_.str().c_str());
  }

  if(rv < 0) {
    return;
  }

  auto nwrite = std::min(static_cast<size_t>(rv), sizeof(buf) - 1);

  while(write(wconf->errorlog_fd, buf, nwrite) == -1 && errno == EINTR);
}

namespace {
template<typename OutputIterator>
std::pair<OutputIterator, size_t>
copy(const char *src, size_t avail, OutputIterator oitr)
{
  auto nwrite = std::min(strlen(src), avail);
  auto noitr = std::copy_n(src, nwrite, oitr);
  return std::make_pair(noitr, avail - nwrite);
}
} // namespace

void upstream_accesslog(const std::vector<LogFragment>& lfv, LogSpec *lgsp)
{
  auto wconf = worker_config;

  if(wconf->accesslog_fd == -1 && !get_config()->accesslog_syslog) {
    return;
  }

  char buf[4096];

  auto downstream = lgsp->downstream;

  auto p = buf;
  auto avail = sizeof(buf) - 2;

  auto cached_time = get_config()->cached_time;

  for(auto& lf : lfv) {
    switch(lf.type) {
    case SHRPX_LOGF_LITERAL:
      std::tie(p, avail) = copy(lf.value.get(), avail, p);
      break;
    case SHRPX_LOGF_REMOTE_ADDR:
      std::tie(p, avail) = copy(lgsp->remote_addr, avail, p);
      break;
    case SHRPX_LOGF_TIME_LOCAL:
      std::tie(p, avail) = copy(cached_time->c_str(), avail, p);
      break;
    case SHRPX_LOGF_REQUEST:
      std::tie(p, avail) = copy(lgsp->method, avail, p);
      std::tie(p, avail) = copy(" ", avail, p);
      std::tie(p, avail) = copy(lgsp->path, avail, p);
      std::tie(p, avail) = copy(" HTTP/", avail, p);
      std::tie(p, avail) = copy(util::utos(lgsp->major).c_str(), avail, p);
      std::tie(p, avail) = copy(".", avail, p);
      std::tie(p, avail) = copy(util::utos(lgsp->minor).c_str(), avail, p);
      break;
    case SHRPX_LOGF_STATUS:
      std::tie(p, avail) = copy(util::utos(lgsp->status).c_str(), avail, p);
      break;
    case SHRPX_LOGF_BODY_BYTES_SENT:
      std::tie(p, avail) = copy(util::utos(lgsp->body_bytes_sent).c_str(),
                                avail, p);
      break;
    case SHRPX_LOGF_HTTP:
      if(downstream) {
        auto hd = downstream->get_request_header(lf.value.get());
        if(hd != std::end(downstream->get_request_headers())) {
          std::tie(p, avail) = copy((*hd).value.c_str(), avail, p);
          break;
        }
      }

      std::tie(p, avail) = copy("-", avail, p);

      break;
    default:
      break;
    }
  }

  *p = '\0';

  if(get_config()->accesslog_syslog) {
    syslog(LOG_INFO, "%s", buf);

    return;
  }

  *p++ = '\n';

  auto nwrite = p - buf;
  while(write(wconf->accesslog_fd, buf, nwrite) == -1 && errno == EINTR);
}

int reopen_log_files()
{
  int res = 0;

  auto wconf = worker_config;

  if(wconf->accesslog_fd != -1) {
    close(wconf->accesslog_fd);
    wconf->accesslog_fd = -1;
  }

  if(!get_config()->accesslog_syslog && get_config()->accesslog_file) {

    wconf->accesslog_fd =
      util::reopen_log_file(get_config()->accesslog_file.get());

    if(wconf->accesslog_fd == -1) {
      LOG(ERROR) << "Failed to open accesslog file "
                 << get_config()->accesslog_file.get();
      res = -1;
    }
  }

  int new_errorlog_fd = -1;

  if(!get_config()->errorlog_syslog && get_config()->errorlog_file) {

    new_errorlog_fd = util::reopen_log_file(get_config()->errorlog_file.get());

    if(new_errorlog_fd == -1) {
      if(wconf->errorlog_fd != -1) {
        LOG(ERROR) << "Failed to open errorlog file "
                   << get_config()->errorlog_file.get();
      } else {
        std::cerr << "Failed to open errorlog file "
                  << get_config()->errorlog_file.get()
                  << std::endl;
      }

      res = -1;
    }
  }

  if(wconf->errorlog_fd != -1) {
    close(wconf->errorlog_fd);
    wconf->errorlog_fd = -1;
    wconf->errorlog_tty = false;
  }

  if(new_errorlog_fd != -1) {
    wconf->errorlog_fd = new_errorlog_fd;
    wconf->errorlog_tty = isatty(wconf->errorlog_fd);
  }

  return res;
}

} // namespace shrpx