// -*- 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) 2013 Inktank Storage, Inc.
 *
 * This is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License version 2, as published by the Free Software
 * Foundation.  See file COPYING.
 *
 */

#include "json_spirit/json_spirit.h"
#include "common/debug.h"

using namespace std;

/**
 * Given a cmddesc like "foo baz name=bar,type=CephString",
 * return the prefix "foo baz".
 */
std::string cmddesc_get_prefix(const std::string &cmddesc)
{
  stringstream ss(cmddesc);
  std::string word;
  std::ostringstream result;
  bool first = true;
  while (std::getline(ss, word, ' ')) {
    if (word.find_first_of(",=") != string::npos) {
      break;
    }

    if (!first) {
      result << " ";
    }
    result << word;
    first = false;
  }

  return result.str();
}

/**
 * Read a command description list out of cmd, and dump it to f.
 * A signature description is a set of space-separated words;
 * see MonCommands.h for more info.
 */

void
dump_cmd_to_json(Formatter *f, const string& cmd)
{
  // put whole command signature in an already-opened container
  // elements are: "name", meaning "the typeless name that means a literal"
  // an object {} with key:value pairs representing an argument

  stringstream ss(cmd);
  std::string word;

  while (std::getline(ss, word, ' ')) {
    // if no , or =, must be a plain word to put out
    if (word.find_first_of(",=") == string::npos) {
      f->dump_string("arg", word);
      continue;
    }
    // Snarf up all the key=val,key=val pairs, put 'em in a dict.
    // no '=val' implies '=True'.
    std::stringstream argdesc(word);
    std::string keyval;
    std::map<std::string, std::string>desckv;
    // accumulate descriptor keywords in desckv

    while (std::getline(argdesc, keyval, ',')) {
      // key=value; key by itself implies value is bool true
      // name="name" means arg dict will be titled 'name'
      size_t pos = keyval.find('=');
      std::string key, val;
      if (pos != std::string::npos) {
	key = keyval.substr(0, pos);
	val = keyval.substr(pos+1);
      } else {
        key = keyval;
        val = true;
      }
      desckv.insert(std::pair<std::string, std::string> (key, val));
    }
    // name the individual desc object based on the name key
    f->open_object_section(desckv["name"].c_str());
    // dump all the keys including name into the array
    for (std::map<std::string, std::string>::iterator it = desckv.begin();
	 it != desckv.end(); ++it) {
      f->dump_string(it->first.c_str(), it->second);
    }
    f->close_section(); // attribute object for individual desc
  }
}

void
dump_cmd_and_help_to_json(Formatter *jf,
			  const string& secname,
			  const string& cmdsig,
			  const string& helptext)
{
      jf->open_object_section(secname.c_str());
      jf->open_array_section("sig");
      dump_cmd_to_json(jf, cmdsig);
      jf->close_section(); // sig array
      jf->dump_string("help", helptext.c_str());
      jf->close_section(); // cmd
}

void
dump_cmddesc_to_json(Formatter *jf,
		     const string& secname,
		     const string& cmdsig,
		     const string& helptext,
		     const string& module,
		     const string& perm,
		     const string& avail,
		     uint64_t flags)
{
      jf->open_object_section(secname.c_str());
      jf->open_array_section("sig");
      dump_cmd_to_json(jf, cmdsig);
      jf->close_section(); // sig array
      jf->dump_string("help", helptext.c_str());
      jf->dump_string("module", module.c_str());
      jf->dump_string("perm", perm.c_str());
      jf->dump_string("avail", avail.c_str());
      jf->dump_int("flags", flags);
      jf->close_section(); // cmd
}

void cmdmap_dump(const cmdmap_t &cmdmap, Formatter *f)
{
  assert(f != nullptr);

  class dump_visitor : public boost::static_visitor<void>
  {
    Formatter *f;
    std::string const &key;
    public:
    dump_visitor(Formatter *f_, std::string const &key_)
      : f(f_), key(key_)
    {
    }

    void operator()(const std::string &operand) const
    {
      f->dump_string(key.c_str(), operand);
    }

    void operator()(const bool &operand) const
    {
      f->dump_bool(key.c_str(), operand);
    }

    void operator()(const int64_t &operand) const
    {
      f->dump_int(key.c_str(), operand);
    }

    void operator()(const double &operand) const
    {
      f->dump_float(key.c_str(), operand);
    }

    void operator()(const std::vector<std::string> &operand) const
    {
      f->open_array_section(key.c_str());
      for (const auto i : operand) {
        f->dump_string("item", i);
      }
      f->close_section();
    }

    void operator()(const std::vector<int64_t> &operand) const
    {
      f->open_array_section(key.c_str());
      for (const auto i : operand) {
        f->dump_int("item", i);
      }
      f->close_section();
    }

    void operator()(const std::vector<double> &operand) const
    {
      f->open_array_section(key.c_str());
      for (const auto i : operand) {
        f->dump_float("item", i);
      }
      f->close_section();
    }
  };

  //f->open_object_section("cmdmap");
  for (const auto &i : cmdmap) {
    boost::apply_visitor(dump_visitor(f, i.first), i.second);
  }
  //f->close_section();
}


/** Parse JSON in vector cmd into a map from field to map of values
 * (use mValue/mObject)
 * 'cmd' should not disappear over lifetime of map
 * 'mapp' points to the caller's map
 * 'ss' captures any errors during JSON parsing; if function returns
 * false, ss is valid */

bool
cmdmap_from_json(vector<string> cmd, map<string, cmd_vartype> *mapp, stringstream &ss)
{
  json_spirit::mValue v;

  string fullcmd;
  // First, join all cmd strings
  for (vector<string>::iterator it = cmd.begin();
       it != cmd.end(); ++it)
    fullcmd += *it;

  try {
    if (!json_spirit::read(fullcmd, v))
      throw runtime_error("unparseable JSON " + fullcmd);
    if (v.type() != json_spirit::obj_type)
      throw(runtime_error("not JSON object " + fullcmd));

    // allocate new mObject (map) to return
    // make sure all contents are simple types (not arrays or objects)
    json_spirit::mObject o = v.get_obj();
    for (map<string, json_spirit::mValue>::iterator it = o.begin();
	 it != o.end(); ++it) {

      // ok, marshal it into our string->cmd_vartype map, or throw an
      // exception if it's not a simple datatype.  This is kind of
      // annoying, since json_spirit has a boost::variant inside it
      // already, but it's not public.  Oh well.

      switch (it->second.type()) {

      case json_spirit::obj_type:
      default:
	throw(runtime_error("JSON array/object not allowed " + fullcmd));
        break;

      case json_spirit::array_type:
	{
	  // array is a vector of values.  Unpack it to a vector
	  // of strings, doubles, or int64_t, the only types we handle.
	  const vector<json_spirit::mValue>& spvals = it->second.get_array();
	  if (spvals.empty()) {
	    // if an empty array is acceptable, the caller should always check for
	    // vector<string> if the expected value of "vector<int64_t>" in the
	    // cmdmap is missing.
	    (*mapp)[it->first] = vector<string>();
	  } else if (spvals.front().type() == json_spirit::str_type) {
	    vector<string> outv;
	    for (const auto& sv : spvals) {
	      if (sv.type() != json_spirit::str_type) {
		throw(runtime_error("Can't handle arrays of multiple types"));
	      }
	      outv.push_back(sv.get_str());
	    }
	    (*mapp)[it->first] = std::move(outv);
	  } else if (spvals.front().type() == json_spirit::int_type) {
	    vector<int64_t> outv;
	    for (const auto& sv : spvals) {
	      if (spvals.front().type() != json_spirit::int_type) {
		throw(runtime_error("Can't handle arrays of multiple types"));
	      }
	      outv.push_back(sv.get_int64());
	    }
	    (*mapp)[it->first] = std::move(outv);
	  } else if (spvals.front().type() == json_spirit::real_type) {
	    vector<double> outv;
	    for (const auto& sv : spvals) {
	      if (spvals.front().type() != json_spirit::real_type) {
		throw(runtime_error("Can't handle arrays of multiple types"));
	      }
	      outv.push_back(sv.get_real());
	    }
	    (*mapp)[it->first] = std::move(outv);
	  } else {
	    throw(runtime_error("Can't handle arrays of types other than "
				"int, string, or double"));
	  }
	}
	break;
      case json_spirit::str_type:
	(*mapp)[it->first] = it->second.get_str();
	break;

      case json_spirit::bool_type:
	(*mapp)[it->first] = it->second.get_bool();
	break;

      case json_spirit::int_type:
	(*mapp)[it->first] = it->second.get_int64();
	break;

      case json_spirit::real_type:
	(*mapp)[it->first] = it->second.get_real();
	break;
      }
    }
    return true;
  } catch (runtime_error &e) {
    ss << e.what();
    return false;
  }
}

class stringify_visitor : public boost::static_visitor<string>
{
  public:
    template <typename T>
    string operator()(T &operand) const
      {
	ostringstream oss;
	oss << operand;
	return oss.str();
      }
};

string 
cmd_vartype_stringify(const cmd_vartype &v)
{
  return boost::apply_visitor(stringify_visitor(), v);
}


void
handle_bad_get(CephContext *cct, const string& k, const char *tname)
{
  ostringstream errstr;
  int status;
  const char *typestr = abi::__cxa_demangle(tname, 0, 0, &status);
  if (status != 0) 
    typestr = tname;
  errstr << "bad boost::get: key " << k << " is not type " << typestr;
  lderr(cct) << errstr.str() << dendl;

  ostringstream oss;
  oss << BackTrace(1);
  lderr(cct) << oss.rdbuf() << dendl;
  if (status == 0)
    free((char *)typestr);
}

long parse_pos_long(const char *s, std::ostream *pss)
{
  if (*s == '-' || *s == '+') {
    if (pss)
      *pss << "expected numerical value, got: " << s;
    return -EINVAL;
  }

  string err;
  long r = strict_strtol(s, 10, &err);
  if ((r == 0) && !err.empty()) {
    if (pss)
      *pss << err;
    return -1;
  }
  if (r < 0) {
    if (pss)
      *pss << "unable to parse positive integer '" << s << "'";
    return -1;
  }
  return r;
}

int parse_osd_id(const char *s, std::ostream *pss)
{
  // osd.NNN?
  if (strncmp(s, "osd.", 4) == 0) {
    s += 4;
  }

  // NNN?
  ostringstream ss;
  long id = parse_pos_long(s, &ss);
  if (id < 0) {
    *pss << ss.str();
    return id;
  }
  if (id > 0xffff) {
    *pss << "osd id " << id << " is too large";
    return -ERANGE;
  }
  return id;
}