/* 
 * Copyright (c) 2009, 2015, Oracle and/or its affiliates. All rights reserved.
 *
 * 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; version 2 of the
 * License.
 * 
 * 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 <fstream>
#include <glib/gstdio.h>
#include <stdlib.h>
#include <fstream>

#include "tinyxml.h"
#include <boost/foreach.hpp>
#include <pcre.h>

#include "db_sql_editor_history_be.h"
#include "sqlide/recordset_data_storage.h"

#include "base/threading.h"
#include "base/string_utilities.h"
#include "base/util_functions.h"
#include "base/log.h"
#include "base/file_utilities.h"

#include "mforms/utilities.h"

DEFAULT_LOG_DOMAIN("sqlide-history")

using namespace bec;
using namespace grt;
using namespace base;

const char *SQL_HISTORY_DIR_NAME= "sql_history";


DbSqlEditorHistory::DbSqlEditorHistory(GRTManager *grtm)
:
_grtm(grtm), _current_entry_index(-1)
{
  _entries_model= EntriesModel::create(this, _grtm);
  _details_model= DetailsModel::create(_grtm);
  _write_only_details_model= DetailsModel::create(_grtm);
  load();
}


DbSqlEditorHistory::~DbSqlEditorHistory()
{
}


void DbSqlEditorHistory::reset()
{
  _details_model->reset();
  _entries_model->reset();
  _current_entry_index= -1;
}


void DbSqlEditorHistory::load()
{
  _entries_model->load();
}


void DbSqlEditorHistory::add_entry(const std::list<std::string> &statements)
{
  size_t old_date_count = _details_model->count();
  _entries_model->add_statements(statements);

  if (_entries_model->get_ui_usage())
  {
    _entries_model->refresh_ui();
    if (old_date_count < _details_model->count())
      _details_model->refresh_ui();
  }
}

void DbSqlEditorHistory::current_entry(int index)
{
  if (index < 0)
    _details_model->reset();
  else
  {
    update_timestamp(_entries_model->entry_date(index));
    _details_model->load(_entries_model->entry_path(index));
  }

  _current_entry_index= index;

  // Indicates to the entries model if its changes affect UI or not
  // UI is affected only in the first entry ( where the new statements are appended )
  _entries_model->set_ui_usage(_current_entry_index == 0);
  _entries_model->refresh();
  _details_model->refresh();
}


std::string DbSqlEditorHistory::restore_sql_from_history(int entry_index, std::list<int> &detail_indexes)
{
  std::string sql;
  if (entry_index >= 0)
  {
    DetailsModel::Ref details_model;
    if (entry_index == _current_entry_index)
      details_model = _details_model;
    else
    {
      details_model = DetailsModel::create(_grtm);
      details_model->load(_entries_model->entry_path(entry_index));
    }
    std::string statement;
    BOOST_FOREACH (int row, detail_indexes)
    {
      details_model->get_field(row, 1, statement);
      sql+= statement + ";\n";
    }
  }
  return sql;
}

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

DbSqlEditorHistory::EntriesModel::EntriesModel(DbSqlEditorHistory *owner, bec::GRTManager *grtm)
: VarGridModel(grtm), _ui_usage(false), _owner(owner)
{
  reset();
}


void DbSqlEditorHistory::EntriesModel::reset()
{
  VarGridModel::reset();
  
  _readonly = true;
  add_column("Date", std::string());
  
  boost::shared_ptr<sqlite::connection> data_swap_db= this->data_swap_db();
  Recordset_data_storage::create_data_swap_tables(data_swap_db.get(), _column_names, _column_types);

  refresh_ui();  
}


void DbSqlEditorHistory::EntriesModel::load()
{
  std::string sql_history_dir= make_path(_grtm->get_user_datadir(), SQL_HISTORY_DIR_NAME);
  g_mkdir_with_parents(sql_history_dir.c_str(), 0700);
  {
    GError *error= NULL;
    GDir *dir= g_dir_open(sql_history_dir.c_str(), 0, &error);
    if (!dir)
    {
      _grtm->get_grt()->send_error(_("Can't open SQL history directory"), (error ? error->message : sql_history_dir.c_str()));
      return;
    }
    // files are not read in alpha-order, so we need to sort them before inserting
    std::set<std::string> entries;
    ScopeExitTrigger on_scope_exit(boost::bind(&g_dir_close, dir));
    while (const char *name_= g_dir_read_name(dir))
    {
      // file name is expected in "YYYY-MM-DD" format
      std::string name(name_);
      if (name.size() != 10)
        continue;
      name[4]= '\0';
      name[7]= '\0';
      entries.insert(name);
    }

    for (std::set<std::string>::const_iterator name= entries.begin(); name != entries.end(); ++name)
    {
      tm t;
      memset(&t, 0, sizeof(t));
      t.tm_year= base::atoi<int>(&(*name)[0], 0)-1900;
      t.tm_mon= base::atoi<int>(&(*name)[5], 0)-1;
      t.tm_mday= base::atoi<int>(&(*name)[8], 0);
      if (t.tm_year != 0)
        insert_entry(t);
    }
  }
}


void DbSqlEditorHistory::EntriesModel::add_statements(const std::list<std::string> &statements)
{
  if (statements.empty())
    return;

  std::tm timestamp = local_timestamp();
  bool new_date = insert_entry(timestamp);

  std::string time= format_time(timestamp, "%X");
  std::list<std::string> timed_statements;

  BOOST_FOREACH(std::string statement, statements)
  {
    timed_statements.push_back(time);
    timed_statements.push_back(base::strip_text(statement));
  }

  if (new_date)
  {
    refresh_ui();
    _owner->current_entry((int)_row_count - 1);
    _owner->update_timestamp(timestamp);
  }

  if(_ui_usage)
    _owner->details_model()->add_entries(timed_statements);
  else
    _owner->write_only_details_model()->add_entries(timed_statements);
}


bool DbSqlEditorHistory::EntriesModel::insert_entry(const std::tm &t)
{
  std::string newest_date;
  if (_row_count > 0)
    get_field(NodeId(0), 0, newest_date);
  std::string date= format_time(t, "%Y-%m-%d");
  if (date != newest_date)
  {
    base::RecMutexLock data_mutex(_data_mutex);
    _data.insert(_data.begin(), date);
    ++_row_count;
    ++_data_frame_end;
    return true;
  }
  return false;
}


bec::MenuItemList DbSqlEditorHistory::EntriesModel::get_popup_items_for_nodes(const std::vector<bec::NodeId> &nodes)
{
  bec::MenuItemList items;
  bec::MenuItem item;

  item.name = "delete_selection";
  item.caption = "Delete Selected Date Log";
  item.enabled = nodes.size() > 0;
  items.push_back(item);
  
  item.name = "delete_all";
  item.caption = "Delete All Logs";
  item.enabled = true;
  items.push_back(item);
  
  return items;
}


bool DbSqlEditorHistory::EntriesModel::activate_popup_item_for_nodes(const std::string &action, const std::vector<bec::NodeId> &orig_nodes)
{
  if (action == "delete_selection")
  {
    std::vector<size_t> rows;
    rows.reserve(orig_nodes.size());
    BOOST_FOREACH (const bec::NodeId &node, orig_nodes)
      rows.push_back(node[0]);
    delete_entries(rows);

    return true;
  }
  else if (action == "delete_all")
  {
    delete_all_entries();
    return true;
  }

  return false;
}


void DbSqlEditorHistory::EntriesModel::delete_all_entries()
{
  if (mforms::Utilities::show_message("Clear History",
                                      "Do you really want to delete the entire query history?\nThis operation cannot be undone.",
                                      "Delete All", "Cancel", "") == mforms::ResultCancel)
    return;
  
  std::vector<size_t> rows;
  rows.reserve(_row_count);
  for (RowId row= 0; row < _row_count; ++row)
    rows.push_back(row);
  delete_entries(rows);  
}

void DbSqlEditorHistory::EntriesModel::delete_entries(const std::vector<size_t> &rows)
{
  if (rows.empty())
    return;
  {
    std::vector<size_t> sorted_rows = rows;
    std::sort(sorted_rows.begin(), sorted_rows.end());
    BOOST_REVERSE_FOREACH (size_t row, sorted_rows)
    {
      try
      {
        base::remove(entry_path(row));
      }
      catch (const std::exception &exc)
      {
        log_error("Error deleting log entry %s: %s\n", entry_path(row).c_str(), exc.what());
      }
      Cell row_begin = _data.begin() + row * _column_count;
      _data.erase(row_begin, row_begin + _column_count);
      --_row_count;
    }
  }
  refresh_ui();
  _owner->current_entry(-1);
}

std::string DbSqlEditorHistory::EntriesModel::entry_path(size_t index)
{
  std::string name;
  get_field(index, 0, name);
  std::string storage_file_path= make_path(_grtm->get_user_datadir(), SQL_HISTORY_DIR_NAME);
  storage_file_path= make_path(storage_file_path, name);
  return storage_file_path;
}

std::tm DbSqlEditorHistory::EntriesModel::entry_date(size_t index)
{
  tm t;
  std::string name;
  get_field(index, 0, name);

  memset(&t, 0, sizeof(t));
  t.tm_year = base::atoi<int>(&name[0], 0) - 1900;
  t.tm_mon = base::atoi<int>(&name[5], 0) - 1;
  t.tm_mday = base::atoi<int>(&name[8], 0);

  return t;
}


//--------------------------------------------------------------------------------------------------
DbSqlEditorHistory::DetailsModel::DetailsModel(bec::GRTManager *grtm) 
                   : VarGridModel(grtm)
{
  reset();

  _context_menu.add_item(_("Copy Row To Clipboard"), "copy_row");
  _context_menu.add_separator();
  _context_menu.add_item(_("Append Selected Items to SQL script"), "append_selected_items");
  _context_menu.add_item(_("Replace SQL Script With Selected Items"), "replace_sql_script");
}

void DbSqlEditorHistory::DetailsModel::reset()
{
  VarGridModel::reset();

  _last_loaded_row= -1;
  _last_timestamp = std::string("");
  _last_statement = std::string("");
  _datestamp= local_timestamp();

  _readonly= true;

  add_column("Time", std::string());
  add_column("SQL", std::string());

  boost::shared_ptr<sqlite::connection> data_swap_db= this->data_swap_db();
  Recordset_data_storage::create_data_swap_tables(data_swap_db.get(), _column_names, _column_types);

  refresh_ui();
}


void DbSqlEditorHistory::DetailsModel::load(const std::string &storage_file_path)
{
  if (base::file_exists(storage_file_path))
  {
    std::ifstream history_xml(base::path_from_utf8(storage_file_path).c_str());

    if (history_xml.is_open())
    {
      base::RecMutexLock data_mutex(_data_mutex);
      _data.clear();
      _data.reserve(_data.size() + _column_count);

      std::string line;

      // Skips the first line in the file as is the xml header
      std::getline(history_xml, line);

      const char *errptr;
      int erroffs=0;
      const char *pattern = "<ENTRY( timestamp\\=\'(.*)\')?>(.*)<\\/ENTRY>";
      int patres[64];

      pcre *patre= pcre_compile(pattern, 0, &errptr, &erroffs, NULL);
      if (!patre)
        throw std::logic_error("error compiling regex "+std::string(errptr));

      // process the file
      _row_count = 0;
      while (history_xml.good())
      {
        std::string timestamp;
        std::string statement;
        const char *value;

        std::getline(history_xml, line);

        // executes the regexp against the new line
        int rc = pcre_exec(patre, NULL, line.c_str(), (int)line.length(), 0, 0, patres,
          sizeof(patres) / sizeof(int));

        if ( rc > 0 )
        {
          // gets the values timestamp and 
          pcre_get_substring(line.c_str(), patres, rc, 2, &value);
          timestamp = value ? std::string(value) : "";
          if (value)
            pcre_free_substring(value);

          TiXmlText sql_text("");
          pcre_get_substring(line.c_str(), patres, rc, 3, &value);
           
          if (value && *value)
            sql_text.Parse(value, 0, /*TiXmlEncoding::*/TIXML_ENCODING_UTF8);

          if (value)
            pcre_free_substring(value);
 
          statement = sql_text.ValueStr();

          // decides whether to use or not the existing data
          if (timestamp != _last_timestamp.toString() && timestamp != "~")
            _last_timestamp = timestamp;

          if (statement != _last_statement.toString() && statement != "~")
            _last_statement = statement;

          _data.push_back(_last_statement);
          _data.push_back(_last_timestamp);
        
          _row_count++;
        }
      }

      std::reverse(_data.begin(),_data.end());

      pcre_free(patre);

      history_xml.close();

      _data_frame_end= _row_count;

      _last_loaded_row = (int)_row_count - 1;
    }
    else
      log_error("Can't open SQL history file %s\n", storage_file_path.c_str());
  }
}

std::string DbSqlEditorHistory::DetailsModel::storage_file_path() const
{
  std::string storage_file_path= make_path(_grtm->get_user_datadir(), SQL_HISTORY_DIR_NAME);
  storage_file_path= make_path(storage_file_path, format_time(_datestamp, "%Y-%m-%d"));
  return storage_file_path;
}

void DbSqlEditorHistory::DetailsModel::save()
{
  std::string storage_file_path= this->storage_file_path();
  std::ofstream ofs;
  {
    std::string storage_file_dir= make_path(_grtm->get_user_datadir(), SQL_HISTORY_DIR_NAME);
    if (g_mkdir_with_parents(storage_file_dir.c_str(), 0700) != -1)
    {
      bool is_file_new= (g_file_test(storage_file_path.c_str(), G_FILE_TEST_EXISTS) == 0);
      if (is_file_new || g_file_test(storage_file_path.c_str(), G_FILE_TEST_IS_REGULAR))
      {
        ofs.open(base::path_from_utf8(storage_file_path).c_str(), std::ios_base::app);
        if (is_file_new)
          ofs << "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n";
      }
    }
  }

  if (!ofs.is_open() || !ofs)
  {
    _grtm->get_grt()->send_error("Can't write to SQL history file", storage_file_path);
    return;
  }

  {
    base::RecMutexLock data_mutex(_data_mutex);
    std::string last_saved_timestamp;
    std::string last_saved_statement;
    get_field(NodeId(_last_loaded_row), 0, last_saved_timestamp);
    get_field(NodeId(_last_loaded_row), 1, last_saved_statement);

    for (RowId row = _last_loaded_row+1; row < _row_count; ++row)
    {
      std::string time, sql;
      get_field(NodeId((int)row), 0, time);
      get_field(NodeId((int)row), 1, sql);

      if (time == last_saved_timestamp)
        time = "~";
      else
        last_saved_timestamp = time;

      if (sql == last_saved_statement)
        sql = "~";
      else
        last_saved_statement = sql;

      std::string xml_time, xml_sql;
      TiXmlBase::EncodeString(time, &xml_time); 
      TiXmlBase::EncodeString(sql, &xml_sql); 
      ofs << "<ENTRY timestamp=\'" << xml_time << "\'>" << xml_sql << "</ENTRY>\n";
    }
    _last_loaded_row = (int)_row_count - 1;
  }
  ofs.flush();
}


void DbSqlEditorHistory::DetailsModel::add_entries(const std::list<std::string> &statements)
{
  if (statements.empty())
    return;

  {

    base::RecMutexLock data_mutex(_data_mutex);

    _data.reserve(_data.size() + _column_count);

    try
    {
      int index=0;
      BOOST_FOREACH (std::string statement, statements)
      {
        if (index % 2)
        {
          // decides whether to use or not the existing data
          if (statement != _last_statement.toString())
            _last_statement = statement;
        
          _data.push_back(_last_statement);
        }
        else
        {
          if (statement != _last_timestamp.toString())
            _last_timestamp = statement;

          _data.push_back(_last_timestamp);
        }
      }

      index++;
    }
    catch(...)
    {
      _data.resize(_row_count * _column_count);
      throw;
    }

    _row_count+= statements.size()/2;
    _data_frame_end= _row_count;
  }

  save();
  
  //refresh_ui();
}

void DbSqlEditorHistory::update_timestamp(std::tm timestamp)
{
  details_model()->datestamp(timestamp);
  write_only_details_model()->datestamp(timestamp);
}
//--------------------------------------------------------------------------------------------------