#include "CrushCompiler.h"

#ifndef EBADE
#define EBADE EFTYPE
#endif

#include <iostream>
#include <stack>
#include <functional>
#include <string>
#include <stdexcept>
#include <map>
#include <cctype>

#include <typeinfo>

// -------------

static void print_type_name(ostream& out, int t, CrushWrapper &crush)
{
  const char *name = crush.get_type_name(t);
  if (name)
    out << name;
  else if (t == 0)
    out << "device";
  else
    out << "type" << t;
}

static void print_item_name(ostream& out, int t, CrushWrapper &crush)
{
  const char *name = crush.get_item_name(t);
  if (name)
    out << name;
  else if (t >= 0)
    out << "device" << t;
  else
    out << "bucket" << (-1-t);
}

static void print_rule_name(ostream& out, int t, CrushWrapper &crush)
{
  const char *name = crush.get_rule_name(t);
  if (name)
    out << name;
  else
    out << "rule" << t;
}

static void print_fixedpoint(ostream& out, int i)
{
  char s[20];
  snprintf(s, sizeof(s), "%.3f", (float)i / (float)0x10000);
  out << s;
}

int CrushCompiler::decompile_bucket_impl(int i, ostream &out)
{
  int type = crush.get_bucket_type(i);
  print_type_name(out, type, crush);
  out << " ";
  print_item_name(out, i, crush);
  out << " {\n";
  out << "\tid " << i << "\t\t# do not change unnecessarily\n";

  out << "\t# weight ";
  print_fixedpoint(out, crush.get_bucket_weight(i));
  out << "\n";

  int n = crush.get_bucket_size(i);

  int alg = crush.get_bucket_alg(i);
  out << "\talg " << crush_bucket_alg_name(alg);

  // notate based on alg type
  bool dopos = false;
  switch (alg) {
  case CRUSH_BUCKET_UNIFORM:
    out << "\t# do not change bucket size (" << n << ") unnecessarily";
    dopos = true;
    break;
  case CRUSH_BUCKET_LIST:
    out << "\t# add new items at the end; do not change order unnecessarily";
    break;
  case CRUSH_BUCKET_TREE:
    out << "\t# do not change pos for existing items unnecessarily";
    dopos = true;
    break;
  }
  out << "\n";

  int hash = crush.get_bucket_hash(i);
  out << "\thash " << hash << "\t# " << crush_hash_name(hash) << "\n";

  for (int j=0; j<n; j++) {
    int item = crush.get_bucket_item(i, j);
    int w = crush.get_bucket_item_weight(i, j);
    out << "\titem ";
    print_item_name(out, item, crush);
    out << " weight ";
    print_fixedpoint(out, w);
    if (dopos) 
      out << " pos " << j;
    
    out << "\n";
  }
  out << "}\n";
  return 0;
}

/* Basically, we just descend recursively into all of the buckets,
 * executing a depth-first traversal of the graph. Since the buckets form a
 * directed acyclic graph, this should work just fine. The graph isn't
 * necessarily a tree, so we have to keep track of what buckets we already
 * outputted. We don't want to output anything twice. We also keep track of
 * what buckets are in progress so that we can detect cycles. These can
 * arise through user error.
 */
int CrushCompiler::decompile_bucket(int cur,
				    std::map<int, dcb_state_t>& dcb_states,
				    ostream &out)
{
  if ((cur == 0) || (!crush.bucket_exists(cur)))
    return 0;

  std::map<int, dcb_state_t>::iterator c = dcb_states.find(cur);
  if (c == dcb_states.end()) {
    // Mark this bucket as "in progress."
    std::map<int, dcb_state_t>::value_type val(cur, DCB_STATE_IN_PROGRESS);
    std::pair <std::map<int, dcb_state_t>::iterator, bool> rval
      (dcb_states.insert(val));
    assert(rval.second);
    c = rval.first;
  }
  else if (c->second == DCB_STATE_DONE) {
    // We already did this bucket.
    return 0;
  }
  else if (c->second == DCB_STATE_IN_PROGRESS) {
    err << "decompile_crush_bucket: logic error: tried to decompile "
	"a bucket that is already being decompiled" << std::endl;
    return -EBADE;
  }
  else {
    err << "decompile_crush_bucket: logic error: illegal bucket state! "
	 << c->second << std::endl;
    return -EBADE;
  }

  int bsize = crush.get_bucket_size(cur);
  for (int i = 0; i < bsize; ++i) {
    int item = crush.get_bucket_item(cur, i);
    std::map<int, dcb_state_t>::iterator d = dcb_states.find(item);
    if (d == dcb_states.end()) {
      int ret = decompile_bucket(item, dcb_states, out);
      if (ret)
	return ret;
    }
    else if (d->second == DCB_STATE_IN_PROGRESS) {
      err << "decompile_crush_bucket: error: while trying to output bucket "
	   << cur << ", we found out that it contains one of the buckets that "
	   << "contain it. This is not allowed. The buckets must form a "
	   <<  "directed acyclic graph." << std::endl;
      return -EINVAL;
    }
    else if (d->second != DCB_STATE_DONE) {
      err << "decompile_crush_bucket: logic error: illegal bucket state "
	   << d->second << std::endl;
      return -EBADE;
    }
  }
  decompile_bucket_impl(cur, out);
  c->second = DCB_STATE_DONE;
  return 0;
}

int CrushCompiler::decompile(ostream &out)
{
  out << "# begin crush map\n";

  // only dump tunables if they differ from the defaults
  if (crush.get_choose_local_tries() != 2)
    out << "tunable choose_local_tries " << crush.get_choose_local_tries() << "\n";
  if (crush.get_choose_local_fallback_tries() != 5)
    out << "tunable choose_local_fallback_tries " << crush.get_choose_local_fallback_tries() << "\n";
  if (crush.get_choose_total_tries() != 19)
    out << "tunable choose_total_tries " << crush.get_choose_total_tries() << "\n";
  if (crush.get_chooseleaf_descend_once() != 0)
    out << "tunable chooseleaf_descend_once " << crush.get_chooseleaf_descend_once() << "\n";

  out << "\n# devices\n";
  for (int i=0; i<crush.get_max_devices(); i++) {
    out << "device " << i << " ";
    print_item_name(out, i, crush);
    out << "\n";
  }
  
  out << "\n# types\n";
  int n = crush.get_num_type_names();
  for (int i=0; n; i++) {
    const char *name = crush.get_type_name(i);
    if (!name) {
      if (i == 0) out << "type 0 device\n";
      continue;
    }
    n--;
    out << "type " << i << " " << name << "\n";
  }

  out << "\n# buckets\n";
  std::map<int, dcb_state_t> dcb_states;
  for (int bucket = -1; bucket > -1-crush.get_max_buckets(); --bucket) {
    int ret = decompile_bucket(bucket, dcb_states, out);
    if (ret)
      return ret;
  }

  out << "\n# rules\n";
  for (int i=0; i<crush.get_max_rules(); i++) {
    if (!crush.rule_exists(i))
      continue;
    out << "rule ";
    if (crush.get_rule_name(i))
      print_rule_name(out, i, crush);
    out << " {\n";
    out << "\truleset " << crush.get_rule_mask_ruleset(i) << "\n";

    switch (crush.get_rule_mask_type(i)) {
    case CEPH_PG_TYPE_REP:
      out << "\ttype replicated\n";
      break;
    case CEPH_PG_TYPE_RAID4:
      out << "\ttype raid4\n";
      break;
    default:
      out << "\ttype " << crush.get_rule_mask_type(i) << "\n";
    }

    out << "\tmin_size " << crush.get_rule_mask_min_size(i) << "\n";
    out << "\tmax_size " << crush.get_rule_mask_max_size(i) << "\n";

    for (int j=0; j<crush.get_rule_len(i); j++) {
      switch (crush.get_rule_op(i, j)) {
      case CRUSH_RULE_NOOP:
	out << "\tstep noop\n";
	break;
      case CRUSH_RULE_TAKE:
	out << "\tstep take ";
	print_item_name(out, crush.get_rule_arg1(i, j), crush);
	out << "\n";
	break;
      case CRUSH_RULE_EMIT:
	out << "\tstep emit\n";
	break;
      case CRUSH_RULE_CHOOSE_FIRSTN:
	out << "\tstep choose firstn "
	    << crush.get_rule_arg1(i, j) 
	    << " type ";
	print_type_name(out, crush.get_rule_arg2(i, j), crush);
	out << "\n";
	break;
      case CRUSH_RULE_CHOOSE_INDEP:
	out << "\tstep choose indep "
	    << crush.get_rule_arg1(i, j) 
	    << " type ";
	print_type_name(out, crush.get_rule_arg2(i, j), crush);
	out << "\n";
	break;
      case CRUSH_RULE_CHOOSE_LEAF_FIRSTN:
	out << "\tstep chooseleaf firstn "
	    << crush.get_rule_arg1(i, j) 
	    << " type ";
	print_type_name(out, crush.get_rule_arg2(i, j), crush);
	out << "\n";
	break;
      case CRUSH_RULE_CHOOSE_LEAF_INDEP:
	out << "\tstep chooseleaf indep "
	    << crush.get_rule_arg1(i, j) 
	    << " type ";
	print_type_name(out, crush.get_rule_arg2(i, j), crush);
	out << "\n";
	break;
      }
    }
    out << "}\n";
  }
  out << "\n# end crush map" << std::endl;
  return 0;
}


// ================================================================

string CrushCompiler::string_node(node_t &node)
{
  string s = string(node.value.begin(), node.value.end());
  while (s.length() > 0 &&
	 s[0] == ' ')
    s = string(s.begin() + 1, s.end());
  return s;
}

int CrushCompiler::int_node(node_t &node) 
{
  string str = string_node(node);
  return strtol(str.c_str(), 0, 10);
}

float CrushCompiler::float_node(node_t &node)
{
  string s = string_node(node);
  return strtof(s.c_str(), 0);
}

int CrushCompiler::parse_device(iter_t const& i)
{
  int id = int_node(i->children[1]);

  string name = string_node(i->children[2]);
  crush.set_item_name(id, name.c_str());
  if (item_id.count(name)) {
    err << "item " << name << " defined twice" << std::endl;
    return -1;
  }    
  item_id[name] = id;
  id_item[id] = name;

  if (verbose) err << "device " << id << " '" << name << "'" << std::endl;
  return 0;
}

int CrushCompiler::parse_tunable(iter_t const& i)
{
  string name = string_node(i->children[1]);
  int val = int_node(i->children[2]);

  if (name == "choose_local_tries")
    crush.set_choose_local_tries(val);
  else if (name == "choose_local_fallback_tries")
    crush.set_choose_local_fallback_tries(val);
  else if (name == "choose_total_tries")
    crush.set_choose_total_tries(val);
  else if (name == "chooseleaf_descend_once")
    crush.set_chooseleaf_descend_once(val);
  else {
    err << "tunable " << name << " not recognized" << std::endl;
    return -1;
  }

  if (!unsafe_tunables) {
    err << "tunables are NOT FULLY IMPLEMENTED; enable with --enable-unsafe-tunables to enable this feature" << std::endl;
    return -1;
  }

  if (verbose) err << "tunable " << name << " " << val << std::endl;
  return 0;
}

int CrushCompiler::parse_bucket_type(iter_t const& i)
{
  int id = int_node(i->children[1]);
  string name = string_node(i->children[2]);
  if (verbose) err << "type " << id << " '" << name << "'" << std::endl;
  type_id[name] = id;
  crush.set_type_name(id, name.c_str());
  return 0;
}

int CrushCompiler::parse_bucket(iter_t const& i)
{
  string tname = string_node(i->children[0]);
  if (!type_id.count(tname)) {
    err << "bucket type '" << tname << "' is not defined" << std::endl;
    return -1;
  }
  int type = type_id[tname];

  string name = string_node(i->children[1]);
  if (item_id.count(name)) {
    err << "bucket or device '" << name << "' is already defined" << std::endl;
    return -1;
  }

  int id = 0;  // none, yet!
  int alg = -1;
  int hash = 0;
  set<int> used_items;
  int size = 0;
  
  for (unsigned p=3; p<i->children.size()-1; p++) {
    iter_t sub = i->children.begin() + p;
    string tag = string_node(sub->children[0]);
    //err << "tag " << tag << std::endl;
    if (tag == "id") 
      id = int_node(sub->children[1]);
    else if (tag == "alg") {
      string a = string_node(sub->children[1]);
      if (a == "uniform")
	alg = CRUSH_BUCKET_UNIFORM;
      else if (a == "list")
	alg = CRUSH_BUCKET_LIST;
      else if (a == "tree")
	alg = CRUSH_BUCKET_TREE;
      else if (a == "straw")
	alg = CRUSH_BUCKET_STRAW;
      else {
	err << "unknown bucket alg '" << a << "'" << std::endl << std::endl;
	return -EINVAL;
      }
    }
    else if (tag == "hash") {
      string a = string_node(sub->children[1]);
      if (a == "rjenkins1")
	hash = CRUSH_HASH_RJENKINS1;
      else
	hash = atoi(a.c_str());
    }
    else if (tag == "item") {
      // first, just determine which item pos's are already used
      size++;
      for (unsigned q = 2; q < sub->children.size(); q++) {
	string tag = string_node(sub->children[q++]);
	if (tag == "pos") {
	  int pos = int_node(sub->children[q]);
	  if (used_items.count(pos)) {
	    err << "item '" << string_node(sub->children[1]) << "' in bucket '" << name << "' has explicit pos " << pos << ", which is occupied" << std::endl;
	    return -1;
	  }
	  used_items.insert(pos);
	}
      }
    }
    else assert(0);
  }

  // now do the items.
  if (!used_items.empty())
    size = MAX(size, *used_items.rbegin());
  vector<int> items(size);
  vector<int> weights(size);

  int curpos = 0;
  unsigned bucketweight = 0;
  bool have_uniform_weight = false;
  unsigned uniform_weight = 0;
  for (unsigned p=3; p<i->children.size()-1; p++) {
    iter_t sub = i->children.begin() + p;
    string tag = string_node(sub->children[0]);
    if (tag == "item") {

      string iname = string_node(sub->children[1]);
      if (!item_id.count(iname)) {
	err << "item '" << iname << "' in bucket '" << name << "' is not defined" << std::endl;
	return -1;
      }
      int itemid = item_id[iname];

      unsigned weight = 0x10000;
      if (item_weight.count(itemid))
	weight = item_weight[itemid];

      int pos = -1;
      for (unsigned q = 2; q < sub->children.size(); q++) {
	string tag = string_node(sub->children[q++]);
	if (tag == "weight") {
	  weight = float_node(sub->children[q]) * (float)0x10000;
	  if (weight > CRUSH_MAX_DEVICE_WEIGHT && itemid >= 0) {
	    err << "device weight limited to " << CRUSH_MAX_DEVICE_WEIGHT / 0x10000 << std::endl;
	    return -ERANGE;
	  }
	  else if (weight > CRUSH_MAX_BUCKET_WEIGHT && itemid < 0) {
	    err << "bucket weight limited to " << CRUSH_MAX_BUCKET_WEIGHT / 0x10000
	        << " to prevent overflow" << std::endl;
	    return -ERANGE;
	  }
	}
	else if (tag == "pos") 
	  pos = int_node(sub->children[q]);
	else
	  assert(0);

      }
      if (alg == CRUSH_BUCKET_UNIFORM) {
	if (!have_uniform_weight) {
	  have_uniform_weight = true;
	  uniform_weight = weight;
	} else {
	  if (uniform_weight != weight) {
	    err << "item '" << iname << "' in uniform bucket '" << name << "' has weight " << weight
		<< " but previous item(s) have weight " << (float)uniform_weight/(float)0x10000
		<< "; uniform bucket items must all have identical weights." << std::endl;
	    return -1;
	  }
	}
      }

      if (pos >= size) {
	err << "item '" << iname << "' in bucket '" << name << "' has pos " << pos << " >= size " << size << std::endl;
	return -1;
      }
      if (pos < 0) {
	while (used_items.count(curpos)) curpos++;
	pos = curpos++;
      }
      //err << " item " << iname << " (" << itemid << ") pos " << pos << " weight " << weight << std::endl;
      items[pos] = itemid;
      weights[pos] = weight;

      if (crush_addition_is_unsafe(bucketweight, weight)) {
        err << "oh no! our bucket weights are overflowing all over the place, better lower the item weights" << std::endl;
        return -ERANGE;
      }

      bucketweight += weight;
    }
  }

  if (id == 0) {
    for (id=-1; id_item.count(id); id--) ;
    //err << "assigned id " << id << std::endl;
  }

  if (verbose) err << "bucket " << name << " (" << id << ") " << size << " items and weight "
		   << (float)bucketweight / (float)0x10000 << std::endl;
  id_item[id] = name;
  item_id[name] = id;
  item_weight[id] = bucketweight;
  
  crush.add_bucket(id, alg, hash, type, size, &items[0], &weights[0]);
  crush.set_item_name(id, name.c_str());
  return 0;
}

int CrushCompiler::parse_rule(iter_t const& i)
{
  int start;  // rule name is optional!
 
  string rname = string_node(i->children[1]);
  if (rname != "{") {
    if (rule_id.count(rname)) {
      err << "rule name '" << rname << "' already defined\n" << std::endl;
      return -1;
    }
    start = 4;
  } else {
    rname = string();
    start = 3;
  }

  int ruleset = int_node(i->children[start]);

  string tname = string_node(i->children[start+2]);
  int type;
  if (tname == "replicated")
    type = CEPH_PG_TYPE_REP;
  else if (tname == "raid4") 
    type = CEPH_PG_TYPE_RAID4;
  else 
    assert(0);    

  int minsize = int_node(i->children[start+4]);
  int maxsize = int_node(i->children[start+6]);
  
  int steps = i->children.size() - start - 8;
  //err << "num steps " << steps << std::endl;
  
  int ruleno = crush.add_rule(steps, ruleset, type, minsize, maxsize, -1);
  if (rname.length()) {
    crush.set_rule_name(ruleno, rname.c_str());
    rule_id[rname] = ruleno;
  }

  int step = 0;
  for (iter_t p = i->children.begin() + start + 7; step < steps; p++) {
    iter_t s = p->children.begin() + 1;
    int stepid = s->value.id().to_long();
    switch (stepid) {
    case crush_grammar::_step_take: 
      {
	string item = string_node(s->children[1]);
	if (!item_id.count(item)) {
	  err << "in rule '" << rname << "' item '" << item << "' not defined" << std::endl;
	  return -1;
	}
	crush.set_rule_step_take(ruleno, step++, item_id[item]);
      }
      break;

    case crush_grammar::_step_choose:
    case crush_grammar::_step_chooseleaf:
      {
	string type = string_node(s->children[4]);
	if (!type_id.count(type)) {
	  err << "in rule '" << rname << "' type '" << type << "' not defined" << std::endl;
	  return -1;
	}
	string choose = string_node(s->children[0]);
	string mode = string_node(s->children[1]);
	if (choose == "choose") {
	  if (mode == "firstn")
	    crush.set_rule_step_choose_firstn(ruleno, step++, int_node(s->children[2]), type_id[type]);
	  else if (mode == "indep")
	    crush.set_rule_step_choose_indep(ruleno, step++, int_node(s->children[2]), type_id[type]);
	  else assert(0);
	} else if (choose == "chooseleaf") {
	  if (mode == "firstn") 
	    crush.set_rule_step_choose_leaf_firstn(ruleno, step++, int_node(s->children[2]), type_id[type]);
	  else if (mode == "indep")
	    crush.set_rule_step_choose_leaf_indep(ruleno, step++, int_node(s->children[2]), type_id[type]);
	  else assert(0);
	} else assert(0);
      }
      break;

    case crush_grammar::_step_emit:
      crush.set_rule_step_emit(ruleno, step++);
      break;

    default:
      err << "bad crush step " << stepid << std::endl;
      return -1;
    }
  }
  assert(step == steps);
  return 0;
}

void CrushCompiler::find_used_bucket_ids(iter_t const& i)
{
  for (iter_t p = i->children.begin(); p != i->children.end(); p++) {
    if ((int)p->value.id().to_long() == crush_grammar::_bucket) {
      iter_t firstline = p->children.begin() + 3;
      string tag = string_node(firstline->children[0]);
      if (tag == "id") {
	int id = int_node(firstline->children[1]);
	//err << "saw bucket id " << id << std::endl;
	id_item[id] = string();
      }
    }
  }
}

int CrushCompiler::parse_crush(iter_t const& i) 
{ 
  find_used_bucket_ids(i);

  int r = 0;
  for (iter_t p = i->children.begin(); p != i->children.end(); p++) {
    switch (p->value.id().to_long()) {
    case crush_grammar::_tunable:
      r = parse_tunable(p);
      break;
    case crush_grammar::_device: 
      r = parse_device(p);
      break;
    case crush_grammar::_bucket_type: 
      r = parse_bucket_type(p);
      break;
    case crush_grammar::_bucket: 
      r = parse_bucket(p);
      break;
    case crush_grammar::_crushrule: 
      r = parse_rule(p);
      break;
    default:
      assert(0);
    }
  }

  if (r < 0)
    return r;

  //err << "max_devices " << crush.get_max_devices() << std::endl;
  crush.finalize();
  
  return 0;
} 

// squash runs of whitespace to one space, excepting newlines
string CrushCompiler::consolidate_whitespace(string in)
{
  string out;

  bool white = false;
  for (unsigned p=0; p<in.length(); p++) {
    if (isspace(in[p]) && in[p] != '\n') {
      if (white)
	continue;
      white = true;
    } else {
      if (white) {
	if (out.length()) out += " ";
	white = false;
      }
      out += in[p];
    }
  }
  if (verbose > 3)
    err << " \"" << in << "\" -> \"" << out << "\"" << std::endl;
  return out;
}

void CrushCompiler::dump(iter_t const& i, int ind) 
{
  err << "dump"; 
  for (int j=0; j<ind; j++)
    cout << "\t"; 
  long id = i->value.id().to_long();
  err << id << "\t"; 
  err << "'" << string(i->value.begin(), i->value.end())  
      << "' " << i->children.size() << " children" << std::endl; 
  for (unsigned int j = 0; j < i->children.size(); j++)  
    dump(i->children.begin() + j, ind+1); 
}


int CrushCompiler::compile(istream& in, const char *infn)
{
  if (!infn)
    infn = "<input>";

  string big;
  string str;
  int line = 1;
  map<int,int> line_pos;  // pos -> line
  map<int,string> line_val;
  while (getline(in, str)) {
    // remove newline
    int l = str.length();
    if (l && str[l] == '\n')
      str.erase(l-1, 1);

    line_val[line] = str;

    // strip comment
    int n = str.find("#");
    if (n >= 0)
      str.erase(n, str.length()-n);
    
    if (verbose>1) err << line << ": " << str << std::endl;

    // work around spirit crankiness by removing extraneous
    // whitespace.  there is probably a more elegant solution, but
    // this only broke with the latest spirit (with the switchover to
    // "classic"), i don't want to spend too much time figuring it
    // out.
    string stripped = consolidate_whitespace(str);
    if (stripped.length() && big.length() && big[big.length()-1] != ' ') big += " ";

    line_pos[big.length()] = line;
    line++;
    big += stripped;
  }
  
  if (verbose > 2) err << "whole file is: \"" << big << "\"" << std::endl;
  
  crush_grammar crushg;
  const char *start = big.c_str();
  //tree_parse_info<const char *> info = ast_parse(start, crushg, space_p);
  tree_parse_info<> info = ast_parse(start, crushg, space_p);
  
  // parse error?
  if (!info.full) {
    int cpos = info.stop - start;
    //out << "cpos " << cpos << std::endl;
    //out << " linemap " << line_pos << std::endl;
    assert(!line_pos.empty());
    map<int,int>::iterator p = line_pos.upper_bound(cpos);
    if (p != line_pos.begin())
      --p;
    int line = p->second;
    int pos = cpos - p->first;
    err << infn << ":" << line //<< ":" << (pos+1)
	<< " error: parse error at '" << line_val[line].substr(pos) << "'" << std::endl;
    return -1;
  }

  //out << "parsing succeeded\n";
  //dump(info.trees.begin());
  return parse_crush(info.trees.begin());
}