// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
// vim: ts=8 sw=2 smarttab
/*
 * Ceph - scalable distributed file system
 *
 * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
 *
 * This is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 2.1, as published by the Free Software 
 * Foundation.  See file COPYING.
 * 
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include <sys/stat.h>
#include <iostream>
#include <string>
using namespace std;

#include "config.h"

#include "mon/MonMap.h"
#include "mon/Monitor.h"
#include "mon/MonitorStore.h"

#include "msg/SimpleMessenger.h"

#include "include/CompatSet.h"

#include "common/Timer.h"
#include "common/common_init.h"

extern const CompatSet::Feature ceph_mon_feature_compat[];
extern const CompatSet::Feature ceph_mon_feature_ro_compat[];
extern const CompatSet::Feature ceph_mon_feature_incompat[];

void usage()
{
  cerr << "usage: cmon -i monid [--mon-data=pathtodata] [flags]" << std::endl;
  cerr << "  --debug_mon n\n";
  cerr << "        debug monitor level (e.g. 10)\n";
  cerr << "  --mkfs\n";
  cerr << "        build fresh monitor fs\n";
  generic_server_usage();
}

int main(int argc, const char **argv) 
{
  int err;
  DEFINE_CONF_VARS(usage);

  bool mkfs = false;
  const char *osdmapfn = 0;

  vector<const char*> args;
  argv_to_vec(argc, argv, args);
  env_to_vec(args);

  common_set_defaults(true);
  common_init(args, "mon", true);

  FOR_EACH_ARG(args) {
    if (CONF_ARG_EQ("mkfs", '\0')) {
      mkfs = true;
    } else if (CONF_ARG_EQ("osdmap", '\0')) {
      CONF_SAFE_SET_ARG_VAL(&osdmapfn, OPT_STR);
    } else
      usage();
  }

  // whoami
  string name = g_conf.id;
  if (name.length() == 0) {
    cerr << "must specify '-i id' where id is the mon name" << std::endl;
    usage();
  }

  if (!g_conf.mon_data) {
    cerr << "must specify '--mon-data=foo' data path" << std::endl;
    usage();
  }

  // -- mkfs --
  if (mkfs) {
    if (!g_conf.monmap || !osdmapfn)
      usage();

    // make sure it doesn't already exist
        /*
    struct stat st;
    if (::lstat(g_conf.mon_data, &st) == 0) {
      cerr << "monfs dir " << g_conf.mon_data << " already exists; remove it first" << std::endl;
      usage();
    }
	*/

    // load monmap
    bufferlist monmapbl, osdmapbl;
    int err = monmapbl.read_file(g_conf.monmap);
    if (err < 0)
      exit(1);
    MonMap monmap;
    monmap.decode(monmapbl);
    
    err = osdmapbl.read_file(osdmapfn);
    if (err < 0)
      exit(1);

    // go
    MonitorStore store(g_conf.mon_data);
    Monitor mon(name, &store, 0, &monmap);
    mon.mkfs(osdmapbl);
    cout << argv[0] << ": created monfs at " << g_conf.mon_data 
	 << " for mon." << name
	 << std::endl;
    return 0;
  }

  if (g_conf.clock_tare) g_clock.tare();

  CompatSet mon_features(ceph_mon_feature_compat,
			 ceph_mon_feature_ro_compat,
			 ceph_mon_feature_incompat);
  CompatSet ondisk_features;

  MonitorStore store(g_conf.mon_data);
  err = store.mount();
  if (err < 0) {
    char buf[80];
    cerr << "problem opening monitor store in " << g_conf.mon_data << ": " << strerror_r(-err, buf, sizeof(buf)) << std::endl;
    exit(1);
  }

  bufferlist magicbl;
  store.get_bl_ss(magicbl, "magic", 0);
  string magic(magicbl.c_str(), magicbl.length()-1);  // ignore trailing \n
  if (strcmp(magic.c_str(), CEPH_MON_ONDISK_MAGIC)) {
    cerr << "mon fs magic '" << magic << "' != current '" << CEPH_MON_ONDISK_MAGIC << "'" << std::endl;
    exit(1);
  }

  bufferlist features;
  store.get_bl_ss(features, COMPAT_SET_LOC, 0);
  if (features.length() == 0) {
    cerr << "WARNING: mon fs missing feature list.\n"
	 << "Assuming it is old-style and introducing one." << std::endl;
    //we only want the baseline ~v.18 features assumed to be on disk.
    //If new features are introduced this code needs to disappear or
    //be made smarter.
    ondisk_features = CompatSet(ceph_mon_feature_compat,
				ceph_mon_feature_ro_compat,
				ceph_mon_feature_incompat);
  } else {
    bufferlist::iterator it = features.begin();
    ondisk_features.decode(it);
  }
  
  if (!mon_features.writeable(ondisk_features)) {
    cerr << "monitor executable cannot read disk! Missing features: "
	 << std::endl;
    CompatSet diff = mon_features.unsupported(ondisk_features);
    //NEEDS_COMPATSET_ITER
    exit(1);
  }


  // monmap?
  MonMap monmap;
  {
    bufferlist latest;
    store.get_bl_ss(latest, "monmap/latest", 0);
    if (latest.length() == 0) {
      cerr << "mon fs missing 'monmap'" << std::endl;
      exit(1);
    }
    bufferlist::iterator p = latest.begin();
    version_t v;
    ::decode(v, p);
    bufferlist mapbl;
    ::decode(mapbl, p);
    monmap.decode(mapbl);
    assert(v == monmap.get_epoch());
  }

  if (!monmap.contains(name)) {
    cerr << "mon." << name << " does not exist in monmap" << std::endl;
    exit(1);
  }

  entity_addr_t ipaddr = monmap.get_addr(name);
  entity_addr_t conf_addr;
  char *mon_addr_str;

  if (conf_read_key(NULL, "mon addr", OPT_STR, &mon_addr_str, NULL) &&
      conf_addr.parse(mon_addr_str) &&
      ipaddr != conf_addr)
    cerr << "WARNING: 'mon addr' config option " << conf_addr << " does not match monmap file" << std::endl
	 << "         continuing with monmap configuration" << std::endl;

  // bind
  SimpleMessenger *messenger = new SimpleMessenger();

  int rank = monmap.get_rank(name);

  cout << "starting mon." << name << " rank " << rank
       << " at " << monmap.get_addr(name)
       << " mon_data " << g_conf.mon_data
       << " fsid " << monmap.get_fsid()
       << std::endl;
  g_conf.public_addr = monmap.get_addr(name);
  err = messenger->bind();
  if (err < 0)
    return 1;

  // start monitor
  messenger->register_entity(entity_name_t::MON(rank));
  messenger->set_default_send_priority(CEPH_MSG_PRIO_HIGH);
  Monitor *mon = new Monitor(name, &store, messenger, &monmap);

  messenger->start();  // may daemonize

  uint64_t supported =
    CEPH_FEATURE_UID |
    CEPH_FEATURE_NOSRCADDR |
    CEPH_FEATURE_MONCLOCKCHECK;
  messenger->set_default_policy(SimpleMessenger::Policy::stateless_server(supported, 0));
  messenger->set_policy(entity_name_t::TYPE_MON,
			SimpleMessenger::Policy::lossless_peer(supported,
							       CEPH_FEATURE_UID));
  mon->init();
  messenger->wait();

  store.umount();
  delete mon;
  messenger->destroy();

  // cd on exit, so that gmon.out (if any) goes into a separate directory for each node.
  char s[20];
  snprintf(s, sizeof(s), "gmon/%d", getpid());
  if (mkdir(s, 0755) == 0)
    chdir(s);

  return 0;
}