<?php
// +-----------------------------------------------------------------------+
// | This file is part of Piwigo.                                          |
// |                                                                       |
// | For copyright and license information, please view the COPYING.txt    |
// | file that was distributed with this source code.                      |
// +-----------------------------------------------------------------------+

/**
 * @package functions\mysql
 */

define('DB_ENGINE', 'MySQL');
define('REQUIRED_MYSQL_VERSION', '5.0.0');

define('DB_REGEX_OPERATOR', 'REGEXP');
define('DB_RANDOM_FUNCTION', 'RAND');


/**
 * Connect to database and store MySQLi resource in __$mysqli__ global variable.
 *
 * @param string $host
 *    - localhost
 *    - 1.2.3.4:3405
 *    - /path/to/socket
 * @param string $user
 * @param string $password
 * @param string $database
 *
 * @throws Exception
 */
function pwg_db_connect($host, $user, $password, $database)
{
  global $mysqli;

  $port = null;
  $socket = null;
  
  if (strpos($host, '/') === 0)
  {
    $socket = $host;
    $host = null;
  }
  elseif (strpos($host, ':') !== false)
  {
    list($host, $port) = explode(':', $host);
  }

  $dbname = null;
  
  $mysqli = new mysqli($host, $user, $password, $dbname, $port, $socket);
  if (mysqli_connect_error())
  {
    throw new Exception("Can't connect to server");
  }
  if (!$mysqli->select_db($database))
  {
    throw new Exception('Connection to server succeed, but it was impossible to connect to database');
  }

  // MySQL 5.7 default settings forbid to select a colum that is not in the
  // group by. We've used that in Piwigo, for years. As an immediate solution
  // we can remove this constraint in the current MySQL session.
  list($sql_mode_current) = pwg_db_fetch_row(pwg_query('SELECT @@SESSION.sql_mode'));

  // remove ONLY_FULL_GROUP_BY from the list
  $sql_mode_altered = implode(',', array_diff(explode(',', $sql_mode_current), array('ONLY_FULL_GROUP_BY')));

  if ($sql_mode_altered != $sql_mode_current)
  {
    pwg_query("SET SESSION sql_mode='".$sql_mode_altered."'");
  }
}

/**
 * Set charset for database connection.
 */
function pwg_db_check_charset() 
{
  global $mysqli;

  $db_charset = 'utf8';
  if (defined('DB_CHARSET') and DB_CHARSET != '')
  {
    $db_charset = DB_CHARSET;
  }
  $mysqli->set_charset($db_charset);
}

/**
 * Check MySQL version. Can call fatal_error().
 */
function pwg_db_check_version()
{
  $current_mysql = pwg_get_db_version();
  if (version_compare($current_mysql, REQUIRED_MYSQL_VERSION, '<'))
  {
    fatal_error(
      sprintf(
        'your MySQL version is too old, you have "%s" and you need at least "%s"',
        $current_mysql,
        REQUIRED_MYSQL_VERSION
        )
      );
  }
}

/**
 * Get Mysql Version.
 *
 * @return string
 */
function pwg_get_db_version() 
{
  global $mysqli;
  
  return $mysqli->server_info;
}

/**
 * Execute a query
 *
 * @param string $query
 * @return mysqli_result|bool
 */
function pwg_query($query, $escape_reserved_words=true)
{
  global $mysqli, $conf, $page, $debug, $t2;

  // starting with MySQL 8, rank becomes a reserved keyword, we need to escape it
  if ($escape_reserved_words and preg_match('/\brank\b/', $query))
  {
    // first we unescape what's already escaped (to avoid double escaping)
    $query = preg_replace('/`rank`/', 'rank', $query);
    // then we escape the keyword
    $query = preg_replace('/\brank\b/', '`rank`', $query);
  }

  if ($escape_reserved_words and preg_match('/\bgroups\b/', $query))
  {
    // first we unescape what's already escaped (to avoid double escaping)
    $query = preg_replace('/`groups`/', 'groups', $query);
    // then we escape the keyword
    $query = preg_replace('/\bgroups\b/', '`groups`', $query);
  }

  $start = microtime(true);
  ($result = $mysqli->query($query)) or my_error($query, $conf['die_on_sql_error']);

  $time = microtime(true) - $start;

  if (!isset($page['count_queries']))
  {
    $page['count_queries'] = 0;
    $page['queries_time'] = 0;
  }

  $page['count_queries']++;
  $page['queries_time']+= $time;

  if ($conf['show_queries'])
  {
    $output = '';
    $output.= '<pre>['.$page['count_queries'].'] ';
    $output.= "\n".$query;
    $output.= "\n".'(this query time : ';
    $output.= '<b>'.number_format($time, 3, '.', ' ').' s)</b>';
    $output.= "\n".'(total SQL time  : ';
    $output.= number_format($page['queries_time'], 3, '.', ' ').' s)';
    $output.= "\n".'(total time      : ';
    $output.= number_format( ($time+$start-$t2), 3, '.', ' ').' s)';
    if ( $result!=null and preg_match('/\s*SELECT\s+/i',$query) )
    {
      $output.= "\n".'(num rows        : ';
      $output.= pwg_db_num_rows($result).' )';
    }
    elseif ( $result!=null
      and preg_match('/\s*INSERT|UPDATE|REPLACE|DELETE\s+/i',$query) )
    {
      $output.= "\n".'(affected rows   : ';
      $output.= pwg_db_changes().' )';
    }
    $output.= "</pre>\n";

    $debug .= $output;
  }

  return $result;
}

/**
 * Get max value plus one of a particular column.
 *
 * @param string $column
 * @param string $table
 * @param int
 */
function pwg_db_nextval($column, $table)
{
  $query = '
SELECT IF(MAX('.$column.')+1 IS NULL, 1, MAX('.$column.')+1)
  FROM '.$table;
  list($next) = pwg_db_fetch_row(pwg_query($query));

  return $next;
}

function pwg_db_changes() 
{
  global $mysqli;
  
  return $mysqli->affected_rows;
}

function pwg_db_num_rows($result) 
{
  return $result->num_rows;
}

function pwg_db_fetch_array($result)
{
  return $result->fetch_array();
}

function pwg_db_fetch_assoc($result)
{
  return $result->fetch_assoc();
}

function pwg_db_fetch_row($result)
{
  return $result->fetch_row();
}

function pwg_db_fetch_object($result)
{
  return $result->fetch_object();
}

function pwg_db_free_result($result) 
{
  return $result->free_result();
}

function pwg_db_real_escape_string($s)
{
  global $mysqli;
  
  return $mysqli->real_escape_string($s);
}

function pwg_db_insert_id()
{
  global $mysqli;
  
  return $mysqli->insert_id;
}

function pwg_db_errno()
{
  global $mysqli;
  
  return $mysqli->errno;
}

function pwg_db_error()
{
  global $mysqli;
  
  return $mysqli->error;
}

function pwg_db_close()
{
  global $mysqli;
  
  return $mysqli->close();
}


define('MASS_UPDATES_SKIP_EMPTY', 1);

/**
 * Updates multiple lines in a table.
 *
 * @param string $tablename
 * @param array $dbfields - contains 'primary' and 'update' arrays
 * @param array $datas - indexed by column names
 * @param int $flags - if MASS_UPDATES_SKIP_EMPTY, empty values do not overwrite existing ones
 */
function mass_updates($tablename, $dbfields, $datas, $flags=0)
{
  if (count($datas) == 0)
  {
    return;
  }

  // we use the multi table update or N update queries
  if (count($datas) < 10)
  {
    foreach ($datas as $data)
    {
      $is_first = true;

      $query = '
UPDATE '.protect_column_name($tablename).'
  SET ';

      foreach ($dbfields['update'] as $key)
      {
        $separator = $is_first ? '' : ",\n    ";

        if (isset($data[$key]) and $data[$key] != '')
        {
          $query.= $separator.protect_column_name($key).' = \''.$data[$key].'\'';
        }
        else
        {
          if ($flags & MASS_UPDATES_SKIP_EMPTY)
          {
            continue; // next field
          }
          $query.= $separator.protect_column_name($key).' = NULL';
        }
        $is_first = false;
      }

      if (!$is_first)
      {// only if one field at least updated
        $is_first = true;

        $query.= '
  WHERE ';
        foreach ($dbfields['primary'] as $key)
        {
          if (!$is_first)
          {
            $query.= ' AND ';
          }
          if (isset($data[$key]))
          {
            $query.= protect_column_name($key).' = \''.$data[$key].'\'';
          }
          else
          {
            $query.= protect_column_name($key).' IS NULL';
          }
          $is_first = false;
        }

        pwg_query($query);
      }
    } // foreach update
  } // if count<X
  else
  {
    // creation of the temporary table
    $result = pwg_query('SHOW FULL COLUMNS FROM '.protect_column_name($tablename));
    $columns = array();
    $all_fields = array_merge($dbfields['primary'], $dbfields['update']);

    while ($row = pwg_db_fetch_assoc($result))
    {
      if (in_array($row['Field'], $all_fields))
      {
        $column = '`'.$row['Field'].'`';
        $column.= ' '.$row['Type'];

        $nullable = true;
        if (!isset($row['Null']) or $row['Null'] == '' or $row['Null']=='NO')
        {
          $column.= ' NOT NULL';
          $nullable = false;
        }
        if (isset($row['Default']))
        {
          $column.= " default '".$row['Default']."'";
        }
        elseif ($nullable)
        {
          $column.= " default NULL";
        }
        if (isset($row['Collation']) and $row['Collation'] != 'NULL')
        {
          $column.= " collate '".$row['Collation']."'";
        }
        $columns[] = $column;
      }
    }

    $temporary_tablename = $tablename.'_'.micro_seconds();

    $query = '
CREATE TABLE '.$temporary_tablename.'
(
  '.implode(",\n  ", $columns).',
  UNIQUE KEY the_key ('.implode(',', $dbfields['primary']).')
)';

    pwg_query($query);
    mass_inserts($temporary_tablename, $all_fields, $datas);

    if ($flags & MASS_UPDATES_SKIP_EMPTY)
      $func_set = function($s) { return "t1.$s = IFNULL(t2.$s, t1.$s)"; };
    else
      $func_set = function($s) { return "t1.$s = t2.$s"; };

    // update of table by joining with temporary table
    $query = '
UPDATE '.protect_column_name($tablename).' AS t1, '.$temporary_tablename.' AS t2
  SET '.
      implode(
        "\n    , ",
        array_map($func_set,$dbfields['update'])
        ).'
  WHERE '.
      implode(
        "\n    AND ",
        array_map(
          function($s) { return "t1.$s = t2.$s"; },
          $dbfields['primary']
          )
        );
    pwg_query($query);

    pwg_query('DROP TABLE '.$temporary_tablename);
  }
}

/**
 * Updates one line in a table.
 *
 * @param string $tablename
 * @param array $datas
 * @param array $where
 * @param int $flags - if MASS_UPDATES_SKIP_EMPTY, empty values do not overwrite existing ones
 */
function single_update($tablename, $datas, $where, $flags=0)
{
  if (count($datas) == 0)
  {
    return;
  }

  $is_first = true;

  $query = '
UPDATE '.protect_column_name($tablename).'
  SET ';

  foreach ($datas as $key => $value)
  {
    $separator = $is_first ? '' : ",\n    ";

    if (isset($value) and $value !== '')
    {
      $query.= $separator.protect_column_name($key).' = \''.$value.'\'';
    }
    else
    {
      if ($flags & MASS_UPDATES_SKIP_EMPTY)
      {
        continue; // next field
      }
      $query.= $separator.protect_column_name($key).' = NULL';
    }
    $is_first = false;
  }

  if (!$is_first)
  {// only if one field at least updated
    $is_first = true;

    $query.= '
  WHERE ';

    foreach ($where as $key => $value)
    {
      if (!$is_first)
      {
        $query.= ' AND ';
      }
      if (isset($value))
      {
        $query.= protect_column_name($key).' = \''.$value.'\'';
      }
      else
      {
        $query.= protect_column_name($key).' IS NULL';
      }
      $is_first = false;
    }

    pwg_query($query);
  }
}

/**
 * Inserts multiple lines in a table.
 *
 * @param string $table_name
 * @param array $dbfields - fields from $datas which will be used
 * @param array $datas
 * @param array $options
 *    - boolean ignore - use "INSERT IGNORE"
 */
function mass_inserts($table_name, $dbfields, $datas, $options=array())
{
  $ignore = '';
  if (isset($options['ignore']) and $options['ignore'])
  {
    $ignore = 'IGNORE';
  }
  
  if (count($datas) != 0)
  {
    $first = true;

    $query = 'SHOW VARIABLES LIKE \'max_allowed_packet\'';
    list(, $packet_size) = pwg_db_fetch_row(pwg_query($query));
    $packet_size = $packet_size - 2000; // The last list of values MUST not exceed 2000 character*/
    $query = '';

    foreach ($datas as $insert)
    {
      if (strlen($query) >= $packet_size)
      {
        pwg_query($query);
        $first = true;
      }

      if ($first)
      {
        $query = '
INSERT '.$ignore.' INTO '.protect_column_name($table_name).'
  ('.implode(',', array_map('protect_column_name', $dbfields)).')
  VALUES';
        $first = false;
      }
      else
      {
        $query .= '
  , ';
      }

      $query .= '(';
      foreach ($dbfields as $field_id => $dbfield)
      {
        if ($field_id > 0)
        {
          $query .= ',';
        }

        if (!isset($insert[$dbfield]) or $insert[$dbfield] === '')
        {
          $query .= 'NULL';
        }
        else
        {
          $query .= "'".$insert[$dbfield]."'";
        }
      }
      $query .= ')';
    }

    pwg_query($query);
  }
}

/**
 * Inserts one line in a table.
 *
 * @param string $table_name
 * @param array $data
 * @param array $options
 *    - boolean ignore - use "INSERT IGNORE"
 */
function single_insert($table_name, $data, $options=array())
{
  $ignore = '';
  if (isset($options['ignore']) and $options['ignore'])
  {
    $ignore = 'IGNORE';
  }

  if (count($data) != 0)
  {
    $query = '
INSERT '.$ignore.' INTO '.protect_column_name($table_name).'
  ('.implode(',', array_map('protect_column_name', array_keys($data))).')
  VALUES';

    $query .= '(';
    $is_first = true;
    foreach ($data as $key => $value)
    {
      if (!$is_first)
      {
        $query .= ',';
      }
      else
      {
        $is_first = false;
      }
      
      if ($value === '' || is_null($value))
      {
        $query .= 'NULL';
      }
      else
      {
        $query .= "'".$value."'";
      }
    }
    $query .= ')';
    
    pwg_query($query);
  }
}

function protect_column_name($column_name)
{
  if ('`' != $column_name[0])
  {
    $column_name = '`'.$column_name.'`';
  }

  return $column_name;
}

/**
 * Do maintenance on all Piwigo tables
 */
function do_maintenance_all_tables()
{
  global $prefixeTable, $page;

  $all_tables = array();

  // List all tables
  $query = 'SHOW TABLES LIKE \''.$prefixeTable.'%\'';
  $result = pwg_query($query);
  while ($row = pwg_db_fetch_row($result))
  {
    $all_tables[] = $row[0];
  }

  // Repair all tables
  $query = 'REPAIR TABLE '.implode(', ', $all_tables);
  $mysqli_rc = pwg_query($query);

  // Re-Order all tables
  foreach ($all_tables as $table_name)
  {
    $all_primary_key = array();

    $query = 'DESC '.$table_name.';';
    $result = pwg_query($query);
    while ($row = pwg_db_fetch_assoc($result))
    {
      if ($row['Key'] == 'PRI')
      {
        $all_primary_key[] = $row['Field'];
      }
    }

    if (count($all_primary_key) != 0)
    {
      $query = 'ALTER TABLE '.$table_name.' ORDER BY '.implode(', ', $all_primary_key).';';
      $mysqli_rc = $mysqli_rc && pwg_query($query);
    }
  }

  // Optimize all tables
  $query = 'OPTIMIZE TABLE '.implode(', ', $all_tables);
  $mysqli_rc = $mysqli_rc && pwg_query($query);
  if ($mysqli_rc)
  {
    $page['infos'][] = l10n('All optimizations have been successfully completed.');
  }
  else
  {
    $page['errors'][] = l10n('Optimizations have been completed with some errors.');
  }
}

function pwg_db_concat($array)
{
  $string = implode(',', $array);
  return 'CONCAT('. $string.')';
}

function pwg_db_concat_ws($array, $separator)
{
  $string = implode(',', $array);
  return 'CONCAT_WS(\''.$separator.'\','. $string.')';
}

function pwg_db_cast_to_text($string)
{
  return $string;
}

/**
 * Returns an array containing the possible values of an enum field.
 *
 * @param string $table
 * @param string $field
 * @return string[]
 */
function get_enums($table, $field)
{
  $result = pwg_query('DESC '.$table);
  while ($row = pwg_db_fetch_assoc($result))
  {
    if ($row['Field'] == $field)
    {
      // parse enum('blue','green','black')
      $options = explode(',', substr($row['Type'], 5, -1));
      foreach ($options as $i => $option)
      {
        $options[$i] = str_replace("'", '',$option);
      }
    }
  }

  pwg_db_free_result($result);
  return $options;
}

/**
 * Checks if a variable is equivalent to true or false.
 *
 * @param mixed $input
 * @return bool
 */
function get_boolean($input)
{
  if ('false' === strtolower($input))
  {
    return false;
  }

  return (bool)$input;
}

/**
 * Returns string 'true' or 'false' if the given var is boolean.
 * If the input is another type, it is not changed.
 *
 * @param mixed $var
 * @return mixed
 */
function boolean_to_string($var)
{
  if (is_bool($var))
  {
    return $var ? 'true' : 'false';
  }
  else
  {
    return $var;
  }
}

function pwg_db_get_recent_period_expression($period, $date='CURRENT_DATE')
{
  if ($date!='CURRENT_DATE')
  {
    $date = '\''.$date.'\'';
  }

  return 'SUBDATE('.$date.',INTERVAL '.$period.' DAY)';
}

function pwg_db_get_recent_period($period, $date='CURRENT_DATE')
{
  $query = '
SELECT '.pwg_db_get_recent_period_expression($period);
  list($d) = pwg_db_fetch_row(pwg_query($query));

  return $d;
}

function pwg_db_get_flood_period_expression($seconds)
{
  return 'SUBDATE(NOW(), INTERVAL '.$seconds.' SECOND)';
}

function pwg_db_get_hour($date) 
{
  return 'HOUR('.$date.')';
}

function pwg_db_get_date_YYYYMM($date)
{
  return 'DATE_FORMAT('.$date.', \'%Y%m\')';
}

function pwg_db_get_date_MMDD($date)
{
  return 'DATE_FORMAT('.$date.', \'%m%d\')';
}

function pwg_db_get_year($date)
{
  return 'YEAR('.$date.')';
}

function pwg_db_get_month($date)
{
  return 'MONTH('.$date.')';
}

function pwg_db_get_week($date, $mode=null)
{
  if ($mode)
  {
    return 'WEEK('.$date.', '.$mode.')';
  }
  else
  {
    return 'WEEK('.$date.')';
  }
}

function pwg_db_get_dayofmonth($date)
{
  return 'DAYOFMONTH('.$date.')';
}

function pwg_db_get_dayofweek($date)
{
  return 'DAYOFWEEK('.$date.')';
}

function pwg_db_get_weekday($date)
{
  return 'WEEKDAY('.$date.')';
}

function pwg_db_date_to_ts($date) 
{
  return 'UNIX_TIMESTAMP('.$date.')';
}

/**
 * Returns (or send to standard output) the message concerning the 
 * error occured for the last mysql query.
 */
function my_error($header, $die)
{
  global $mysqli;
  
  $error = "[mysql error ".$mysqli->errno.'] '.$mysqli->error."\n";
  $error .= $header;

  if ($die)
  {
    fatal_error($error);
  }
  echo("<pre>");
  trigger_error($error, E_USER_WARNING);
  echo("</pre>");
}

/**
 * Builds an data array from a SQL query.
 * Depending on $key_name and $value_name it can return :
 *
 *    - an array of arrays of all fields (key=null, value=null)
 *        array(
 *          array('id'=>1, 'name'=>'DSC8956', ...),
 *          array('id'=>2, 'name'=>'DSC8957', ...),
 *          ...
 *          )
 *
 *    - an array of a single field (key=null, value='...')
 *        array('DSC8956', 'DSC8957', ...)
 *
 *    - an associative array of array of all fields (key='...', value=null)
 *        array(
 *          'DSC8956' => array('id'=>1, 'name'=>'DSC8956', ...),
 *          'DSC8957' => array('id'=>2, 'name'=>'DSC8957', ...),
 *          ...
 *          )
 *
 *    - an associative array of a single field (key='...', value='...')
 *        array(
 *          'DSC8956' => 1,
 *          'DSC8957' => 2,
 *          ...
 *          )
 *
 * @since 2.6
 *
 * @param string $query
 * @param string $key_name
 * @param string $value_name
 * @return array
 */
function query2array($query, $key_name=null, $value_name=null)
{
  $result = pwg_query($query);
  $data = array();

  if (isset($key_name))
  {
    if (isset($value_name))
    {
      while ($row = $result->fetch_assoc())
        $data[ $row[$key_name] ] = $row[$value_name];
    }
    else
    {
      while ($row = $result->fetch_assoc())
        $data[ $row[$key_name] ] = $row;
    }
  }
  else
  {
    if (isset($value_name))
    {
      while ($row = $result->fetch_assoc())
        $data[] = $row[$value_name];
    }
    else
    {
      while ($row = $result->fetch_assoc())
        $data[] = $row;
    }
  }

  return $data;
}

?>
