/*************************************************************************
 *
 * HTCd - Copyright (C) 1998-2006 Henrik Rydberg
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <hdb/db.h>
#include <new>

filemap* dbmap::flist;
mutex_t dbmap::mutex;
opmap dbmap::M;

///////////////////////////////////////////////////////////////////////

dbmap::dbmap():
  wok(0),fatal(0),index(0),
  compname(),file(0),tmap(),recs()
{
  minor=0;
  major=0;
}

dbmap::~dbmap()
{
  Close();
}

///////////////////////////////////////////////////////////////////////

void dbmap::remap_tabs()
{
  fatal=head()->fatal.get();
  tmap.clear();
  for(int i=0;i<Tables();i++) tmap.add(sref(head()->tabs[i]),i);
}

void dbmap::remap_recs()
{
  major=head()->major.get();
  recs.clear();
  int p=file->recs();
  while(file->size(p)) {
    record_t* rec=(record_t*)file->at(p);
    if(rec->caps.get())
      recs.push_back(idx_t(rec->at(index),rec));
    p+=rec->mem.get();
  }
  recs.sort(CompOperator(compname));
}

int dbmap::remap()
{
  int state=0;
  if(fatal!=head()->fatal.get()) { remap_tabs(); state|=4; }
  if(major!=head()->major.get()) { remap_recs(); state|=2; }
  if(minor!=head()->minor.get()) { minor=head()->minor.get(); state|=1; }
  return state;
}

///////////////////////////////////////////////////////////////////////

void Open(const mstring& path,int update=0,int prot=0600) throw(merror_t);
void Saveas(const mstring& path,int prot=0600) throw(merror_t);
void Close();

void dbmap::Open(const mstring& path,int update,int prot) throw(merror_t)
{
  Close();
  wok=update?1:0;
  {
    MLOCK(mutex);
    for(filemap* p=flist;p;p=p->next)
      if(p->Pathname()==path&&p->writable()==wok) { (file=p)->pushref(); break; }
    if(!file) {
      filemap* fm=new filemap(flist);
      try { fm->open(path,wok,prot); fm->check(); file=flist=fm; }
      catch(...) { delete fm; wok=0; throw; }
    }
  }
  index=head()->index.get();
  compname=head()->compname;
  remap_tabs();
  remap_recs();
  minor=head()->minor.get();
}

void dbmap::Saveas(const mstring& path,int prot) throw(merror_t)
{
  file->save(path,prot);
}

void dbmap::Close()
{
  wok=0;
  minor=0;
  major=0;
  fatal=0;
  index=0;
  compname.clear();
  recs.clear();
  tmap.clear();
  if(file) {
    MLOCK(mutex);
    if(file->reference()) file->popref();
    else {
      if(flist==file) flist=file->next;
      else for(filemap* p=flist;p;p=p->next)
        if(p->next==file) { p->next=file->next; break; }
      delete file;
    }
    file=0;
  }
}

void dbmap::Sync()
{
  MLOCK(mutex);
  for(filemap* p=flist;p;p=p->next) {
    if(p->writable()) p->sync();
  }
}

///////////////////////////////////////////////////////////////////////

void dbmap::SetTable(int col,const sref& name) throw(merror_t)
{
  check();
  if(!wok) THROW("db: cannot set table - readonly");
  if(col<0||col>=Tables()) THROW("db: bad column");
  HEADLOCK(file);
  head()->set(col,name);
  remap();
}

void dbmap::InsertTable(int col,const sref& name) throw(merror_t)
{
  check();
  if(!wok) THROW("db: cannot insert table - readonly");
  if(Tables()+1>file->maxtabs) THROW("db: too many tables");
  if(col<0||col>Tables()) THROW("db: bad column");
  {
    HEADLOCK(file);
    head()->insert(col,name);
    int p=file->recs();
    while(file->size(p)) {
      record_t* rec=(record_t*)file->at(p);
      if(rec->caps.get()) rec->insert(col);
      p+=rec->mem.get();
    }
    head()->major.add(1);
  }
  index=head()->index.get();
  compname=head()->compname;
  remap();
}

void dbmap::RemTable(int col) throw(merror_t)
{
  check();
  if(!wok) THROW("db: cannot remove table - readonly");
  if(col<0||col>=Tables()) THROW("db: bad column");
  if(col==head()->index.get()) THROW("db: cannot remove index table");
  {
    HEADLOCK(file);
    head()->remove(col);
    int p=file->recs();
    while(file->size(p)) {
      record_t* rec=(record_t*)file->at(p);
      if(rec->caps.get()) rec->remove(col);
      p+=rec->mem.get();
    }
    head()->major.add(1);
  }
  index=head()->index.get();
  compname=head()->compname;
  remap();
}

///////////////////////////////////////////////////////////////////////

void dbmap::Get(int row,spile& list) throw(merror_t)
{
  check();
  if(row<0||row>=recs.size()) THROW("db: not a valid record");
  list.resize(Tables());
  recs[row].rec->get(list);
}

void dbmap::Set(int row,int col,const sref& s) throw(merror_t)
{
  check();
  if(!wok) THROW("db: cannot set - readonly");
  if(row<0||row>=recs.size()) THROW("db: not a valid record");
  if(col==index) THROW("db: cannot set index");
  HEADLOCK(file);
  record_t* rec=recs[row].rec;
  int dim=rec->setreq(col,s);
  if(dim>rec->caps.get()) {
    rec=new(file->add(dim)) record_t(*rec);
    file->rem(recs[row].rec);
    recs[row].rec=rec;
    head()->major.add(1);
    major++;
  }
  rec->set(col,s);
  head()->minor.add(1);
  minor++;
}

void dbmap::Set(int row,const spile& list) throw(merror_t)
{
  check();
  if(!wok) THROW("db: cannot set - readonly");
  if(row<0||row>=recs.size()) THROW("db: not a valid record");
  if(list.size()!=Tables())
    THROW("db: wrong number of tables - "<<list.size()<<" should be "<<Tables());
  HEADLOCK(file);
  record_t* rec=recs[row].rec;
  if(rec->at(index)!=list[index]) THROW("db: cannot set index");
  int dim=record_t::req(list);
  if(dim>rec->caps.get()) {
    rec=new(file->add(dim)) record_t(*rec);
    file->rem(recs[row].rec);
    recs[row].rec=rec;
    head()->major.add(1);
    major++;
  }
  rec->set(list);
  head()->minor.add(1);
  minor++;
}

///////////////////////////////////////////////////////////////////////

void dbmap::Rem(int row) throw(merror_t)
{
  if(!wok) THROW("db: cannot delete - readonly");
  if(row<0||row>=recs.size()) THROW("db: not a valid record");
  HEADLOCK(file);
  file->rem(recs[row].rec);
  recs.erase(recs.begin()+row);
  head()->major.add(1);
  major++;
}

int dbmap::Insert(const spile& list,int unique) throw(merror_t)
{
  check();
  if(!wok) THROW("db: cannot insert - readonly");
  if(index!=head()->index.get())
    THROW("db: can only insert under normal order");
  HEADLOCK(file);
  remap();
  int row=recs.get(list[index]);
  if(row<0) {
    record_t* rec=new(file->add(record_t::req(list))) record_t(list);
    row=recs.add(rec->at(index),rec);
    head()->major.add(1);
    major++;
  }
  return row;
}