<?
  class student {

    var $student, $fields, $fields_conditions, $query_order, $num_records, $records_view, $config, $ref, $exercise;

    function student() {

      global $CONF, $EXERCISE;

      $this->config        = &$CONF;
      $this->exercise      = &$EXERCISE;
      $this->fields        = array( '1' => 'a.id',
                                    '2' => 'a.nombre',
                                    '3' => 'a.apellidos',
                                    '4' => 'a.nif',
                                    '5' => 'a.telefono',
                                    '6' => 'a.email',
                                    '7' => 'a.id_empresa',
                                    '8' => 'e.nombre' );

      $this->query_order   = array( 'a' => 'ASC',
                                    'd' => 'DESC' );

      $this->records_view  = array('order'   => array('1','3','2', '8','4','5','6'),
                                   'width'   => array('25', '180', '90', '130', '70', '70', '150'),
                                   'orderby' => array(true, true, true, true, true, true, true),
                                   'search'  => array(true, true, true, true, true, true, false) );

      $this->ref_tables    = array( 'student_role'  => 'ref_colectivos' );

      $this->getReferenceValues();
    }

    //-----------------------------------------------------------------------------------
    // getReferenceValues
    // Obtiene el listado de los datos de las tablas de referencia.

    function getReferenceValues() {
      if ( count($this->ref_tables) > 0 ) {
        while ( list($field) = each($this->ref_tables) ) {
          $SQL_query = db_query('SELECT id, nombre FROM ' . $this->ref_tables[$field] . ' ORDER BY nombre');
          if ( db_num_rows($SQL_query) > 0 ) {
            while ( $SQL_values = db_fetch_array($SQL_query) ) $this->ref[$field][$SQL_values['id']] = $SQL_values['nombre'];
          }
        }
        reset($this->ref_tables);
      }
    }

    //-----------------------------------------------------------------------------------
    // getRecordList
    // Obtiene un listado de registros de la BBDD.

    function getRecordList(&$page, $order_field = 1, $order_type = 'd', $SQL_records_filter = '' ) {

      $records_list = array();

      if ( !isset( $this->fields[$order_field] ) )     $order_field = 1;
      if ( !isset( $this->query_order[$order_type] ) ) $order_type  = 'd';
      if ( empty($SQL_records_filter) ) $this->generateFilterQuery();

      $SQL_records_query  = db_query('SELECT COUNT(*) AS total FROM alumnos a LEFT JOIN empresas e ON a.id_empresa = e.id ' . $SQL_records_filter);
      $SQL_records        = db_fetch_array($SQL_records_query);

      if ( $SQL_records['total'] > 0 ) {

        $page              = check_records_page($page, $SQL_records['total']);
        $this->num_records = $SQL_records['total'];
        $SQL_records_order = ' ORDER BY ' . $this->fields[$order_field] . ' ' . $this->query_order[$order_type] . ', ' . $this->fields[2];
        $SQL_records_limit = ' LIMIT ' . ( ( $page - 1 ) * $this->config['max_num_regs_list'] ) . ', ' . $this->config['max_num_regs_list'];
        $SQL_query         = db_query('SELECT a.id, a.id_empresa, e.nombre AS nombre_empresa, a.nombre, a.apellidos, a.nif, a.telefono, a.email FROM alumnos a LEFT JOIN empresas e ON a.id_empresa = e.id ' . $SQL_records_filter . $SQL_records_order . $SQL_records_limit);

        while ( $SQL_record = db_fetch_array($SQL_query) ) {
          $records_list[$SQL_record['id']]['1'] = $SQL_record['id'];
          $records_list[$SQL_record['id']]['2'] = stripslashes($SQL_record['nombre']);
          $records_list[$SQL_record['id']]['3'] = stripslashes($SQL_record['apellidos']);
          $records_list[$SQL_record['id']]['4'] = $SQL_record['nif'];
          $records_list[$SQL_record['id']]['5'] = ( !empty($SQL_record['telefono']) ? $SQL_record['telefono'] : '');
          $records_list[$SQL_record['id']]['6'] = stripslashes($SQL_record['email']);
          $records_list[$SQL_record['id']]['8'] = stripslashes($SQL_record['nombre_empresa']);
        }
      }

      return $records_list;
    }

    //-----------------------------------------------------------------------------------
    // generateFilterQuery
    
    function generateFilterQuery( $filter_field = '', $filter_values = '', $exactSearch = false ) {

      $filterQuery   = ' WHERE 1 AND a.estado != \'2\'';
      $filter_values = ( $exactSearch ? '\'' . addslashes($filter_values) . '\'' : '\'%' . addslashes($filter_values) . '%\'' );

      if ( !empty($filter_values) && isset( $this->fields[$filter_field] ) ) $filterQuery .= ' AND ' . $this->fields[$filter_field] . ' LIKE ' . $filter_values;

      return $filterQuery;
    }

    //-----------------------------------------------------------------------------------
    // deleteRecord
    // Elimina un registro de la BBDD.

    function deleteRecord($record) {

      $error .= '';

      if ( $this->checkRecord($record) ) {

        $SQL_query  = db_query('SELECT count(*) AS total FROM alumnos_grupos WHERE id_alumno = \'' . $record . '\'');
        $SQL_values = db_fetch_array($SQL_query);
	
        if ( $SQL_values['total'] > 0 ) {
	  if ( @db_query('UPDATE alumnos SET estado = \'2\', apellidos = \'\', nif = \'\', email = \'\', telefono = \'\', telefono_2 = \'\' WHERE id = \'' . $record . '\'') ) $error .= 0;
          else $error .= 2;
        }
        else {	
          if ( @db_query('DELETE FROM alumnos WHERE id = \'' . $record . '\'') ) $error .= '0';
          else $error .= 2;
        }
      }
      else $error .= '1';

      return $error;
    }

    //-----------------------------------------------------------------------------------
    // checkRecord
    // Comprueba si existe o no un registro

    function checkRecord(&$record) {

      settype($record, "integer");

      $SQL_check_record = db_query('SELECT count(*) AS total FROM alumnos WHERE id = \'' . $record . '\'');
      $SQL_num_records  = db_fetch_array($SQL_check_record);

      if ( $SQL_num_records['total'] == 1 ) return true;
      else return false;
    }

    //-----------------------------------------------------------------------------------
    // getRecordValues
    // Obtiene los valores para el registro indicado.

    function getRecordValues($record) {

      if ( $this->checkRecord($record) ) {

        $SQL_check_record = db_query('SELECT id, id_empresa AS company_id, nombre AS student_name, apellidos AS student_surname, nif AS student_nif, email AS student_email, IF(telefono, telefono, \'\') AS student_phone, IF(telefono_2, telefono_2, \'\') AS student_phone_2, observaciones AS student_comments, id_colectivo AS student_role FROM alumnos WHERE id = \'' . $record . '\'');
        if ( db_num_rows($SQL_check_record) == 1 ) {

          $this->student = db_fetch_array($SQL_check_record);
          return $this->student;
        }
        else return false;
      }
      else return false;
    }

    //-----------------------------------------------------------------------------------
    // manageRecord
    // - Recibe los parametros enviados desde el formulario mediante metodo POST.
    // - Determina el tipo de accion a realizar (INSERT o UPDATE).
    // - Trata los valores recibidos.
    // - Genera un codigo de error correspondiente a las acciones realizadas.
    //
    //     [1] > Tipo de accion
    //     [2] > Campo nombre
    //     [3] > Codigo Empresa
    //     [4] > Campo NIF
    //     [5] > Resultado de la accion sobre la BBDD.

    function manageRecord(&$params) {

      $action = '';
      $error  = '';

      // Chequeo y tratamiento de los valores recibidos

      if ( isset($params['record_id']) ) {
        if ( ereg("^[0-9]+$", $params['record_id'] ) && $params['record_id'] > 0 ) { if ( $this->checkRecord($params['record_id']) ) $action = 'update'; }
      }
      else $action = 'insert';

      $params['student_nif'] = eregi_replace("[^0-9a-z]", '', $params['student_nif']);

      // Generacion del codigo de error

      $error  = ( $action == '' ? 1 : 0 );
      $error .= ( empty($params['student_name']) ? 1 : 0 );
      $error .= ( !$this->checkCompany($params['company_id']) ? 1 : 0 );
      $error .= ( !empty($params['student_nif']) && !$this->checkNif($params['student_nif'], $params['record_id']) ? 1 : 0 );

      // Acciones sobre la BBDD

      if ( ereg("^0+$", $error) ) {

        format_record($params);

        if ( $action == 'insert' ) {
          if ( db_query('INSERT INTO alumnos (id_empresa, nombre, apellidos, nif, email, telefono, telefono_2, observaciones, id_colectivo) VALUES (\'' . $params['company_id'] . '\', \'' . $params['student_name'] . '\', \'' . $params['student_surname'] . '\', \'' . $params['student_nif'] . '\', \'' . $params['student_email'] . '\', \'' . $params['student_phone'] . '\', \'' . $params['student_phone_2'] . '\', \'' . $params['student_comments'] . '\', \'' . $params['student_role'] . '\')') ) { 
            $params['record_id'] = db_insert_id(); $error .= 0;
          }
          else $error .= 1;
        }
        elseif ( $action == 'update' ) {
          if ( db_query('UPDATE alumnos SET nombre = \'' . $params['student_name'] . '\', apellidos = \'' . $params['student_surname'] . '\', nif = \'' . $params['student_nif'] . '\', email = \'' . $params['student_email'] . '\', telefono = \'' . $params['student_phone'] . '\', telefono_2 = \'' . $params['student_phone_2'] . '\', observaciones = \'' . $params['student_comments'] . '\', id_colectivo = \'' . $params['student_role'] . '\' WHERE id = \'' . $params['record_id'] . '\'') ) $error .= 0;
          else $error .= 2;
        }
      }
      
      strip_slashes($params);
      return $error;
    }

    //-----------------------------------------------------------------------------------
    // manageStudentsToGroup

    function manageStudentsToGroup( $group_id, $params, $group_level = '0' ) {

      $error = '';

      if ( is_array($params['students']) && count($params['students']) > 0 ) {

        $error           .= 0;
        $reg_errors       = array();
        $students         = array();
        $studentsToGroup  = array();
        $studentsInGroup  = array();

        // Comprobacion alumnos que ya estan asignados al grupo

        while ( list($id) = each($params['students']) ) {
          if ( ereg("^([0-9]+)$", $params['students'][$id]) ) $studentsToGroup[] = $params['students'][$id];
        }

        reset($params['students']);

        $SQL_query = db_query('SELECT ag.id_alumno, CONCAT(a.apellidos, \' \', a.nombre) AS nombre FROM alumnos_grupos ag LEFT JOIN alumnos a ON ag.id_alumno = a.id WHERE ag.id_grupo = \'' . $group_id . '\' AND ag.id_alumno IN (' . implode(',', $studentsToGroup) . ')');

        if ( db_num_rows($SQL_query) ) {
          while ( $SQL_values = db_fetch_array($SQL_query) ) $studentsInGroup[$SQL_values['id_alumno']] = $SQL_values['nombre'];
        }

        // Asignacion alumnos a grupo

        while ( list($id) = each($params['students']) ) {
          if ( ereg("^([0-9]+)$", $params['students'][$id]) ) {
            if ( $studentsInGroup[$params['students'][$id]] ) $reg_errors[] = array( 'name' => $studentsInGroup[$params['students'][$id]], 'code' => 1 );
            elseif ( $this->checkRecord($params['students'][$id]) ) {
              @db_query('INSERT INTO alumnos_grupos (id_alumno, id_grupo, id_nivel) VALUES (\'' . $params['students'][$id] . '\', \'' . $group_id . '\', \'' . $group_level . '\')');
              $students[] = $params['students'][$id];
            }
          }
        }

        $error .= ( count($studentsInGroup) ? 1 : 0 );

        if ( count($students) > 0 ) {

          $SQL_query = db_query('SELECT id, id_colectivo FROM alumnos WHERE id IN (' . implode(',', $students) . ')');
          if ( db_num_rows($SQL_query) ) {
            while ( $SQL_record = db_fetch_array($SQL_query) ) @db_query('UPDATE alumnos_grupos SET id_colectivo = \'' . $SQL_record['id_colectivo'] . '\' WHERE id_grupo = \'' . $group_id . '\' AND id_alumno = \'' . $SQL_record['id'] . '\'');
          }
        }
      }
      else $error .= 1;

      return array( $error, $reg_errors );
    }

    //-----------------------------------------------------------------------------------
    // checkCompany

    function checkCompany( $record ) {

      settype($record, "integer");

      $SQL_query  = db_query('SELECT count(*) AS total FROM empresas WHERE id = \'' . $record . '\'');
      $SQL_values = db_fetch_array($SQL_query);

      if ( $SQL_values['total'] == 1 ) return true;
      else return false;
    }

    //-----------------------------------------------------------------------------------
    // checkNif

    function checkNif( $nif, $record = '' ) {

      $SQL_query  = db_query('SELECT count(*) AS total FROM alumnos WHERE nif = \'' . $nif . '\'' . ( !empty($record) ? ' AND id != \'' . $record . '\'' : '' ) );
      $SQL_values = db_fetch_array($SQL_query);

      if ( $SQL_values['total'] > 0 ) return false;
      else return true;
    }

    //-----------------------------------------------------------------------------------
    // getStudentsNoGroup

    function getStudentsNoGroup( $company_id ) {

      $SQL_query = db_query('SELECT count(*) AS total FROM alumnos a LEFT JOIN alumnos_grupos ag ON a.id = ag.id_alumno LEFT JOIN grupos g ON ag.id_grupo = g.id WHERE a.id_empresa = \'' . $company_id . '\' AND a.estado != \'2\' AND ag.id_grupo IS NULL AND ( g.id_periodo != \'' . $this->exercise->exercise['id'] . '\' OR g.id_periodo IS NULL )');

      $SQL_values = db_fetch_array($SQL_query);

      if ( $SQL_values['total'] > 0 ) return true;
      else return false;
    }

    //-----------------------------------------------------------------------------------
    // getCompanyStudents

    function getCompanyStudents( $company ) {

      $SQL_query = db_query('SELECT id, CONCAT(apellidos, \' \', nombre) AS alumno FROM alumnos WHERE id_empresa = \'' . $company . '\' AND estado != \'2\' ORDER BY alumno' );

      if ( db_num_rows($SQL_query) > 0 ) {

        $company_students = array();

        while ( $SQL_values = db_fetch_array($SQL_query) ) $company_students[$SQL_values['id']] = stripslashes($SQL_values['alumno']);
        return $company_students;
      }
      else return false;
    }

    //-----------------------------------------------------------------------------------
    // checkStudentToGroup

    function checkStudentToGroup( &$record, $group ) {

      settype($record, "integer");

      $SQL_query  = db_query('SELECT count(*) AS total FROM alumnos_grupos WHERE id = \'' . $record . '\' AND id_grupo = \'' . $group . '\'');
      $SQL_values = db_fetch_array($SQL_query);
      if ( $SQL_values['total'] > 0 ) return true;
      else return false;
    }

    //-----------------------------------------------------------------------------------
    // getStudentToGroupValues

    function getStudentToGroupValues( $record ) {

      $SQL_query = db_query('SELECT ag.id, id_alumno AS student_id, ag.id_grupo AS group_id, IF( ag.id_nivel > 0, ag.id_nivel, \'\' ) AS student_level, ag.id_colectivo AS student_role, ag.observaciones AS student_comments, IF( ag.fecha_inicio, UNIX_TIMESTAMP(ag.fecha_inicio), UNIX_TIMESTAMP(g.fecha_inicio) ) AS date_start, IF( ag.fecha_fin, UNIX_TIMESTAMP(ag.fecha_fin), IF(g.fecha_fin, UNIX_TIMESTAMP(g.fecha_fin), UNIX_TIMESTAMP(e.fecha_fin) ) ) AS date_end, CONCAT(a.apellidos, \' \', a.nombre) AS student_name, estado as student_status FROM alumnos_grupos ag LEFT JOIN grupos g ON ag.id_grupo = g.id LEFT JOIN ejercicios_lectivos e ON g.id_periodo = e.id LEFT JOIN alumnos a ON ag.id_alumno = a.id WHERE ag.id = \'' . $record . '\'');

      if ( db_num_rows($SQL_query) == 1 ) {

        $SQL_values = db_fetch_array($SQL_query);
        strip_slashes($SQL_values);

        $SQL_values['student_date_start'] = date('d/m/Y', $SQL_values['date_start']);
        $SQL_values['student_date_end']   = date('d/m/Y', $SQL_values['date_end']);

        return $SQL_values;
      }
      else return false;
    }

    //-----------------------------------------------------------------------------------
    // manageStudentToGroup

    function manageStudentToGroup(&$params, $groupValues, &$record) {

      $error       = '';

      // Chequeo y tratamiento de los valores recibidos

      $error .= ( !is_array($groupValues) || count($groupValues) == 0 ? 1 : 0 );

      if ( empty($record) && empty($params['search_student_id']) ) $error .= 6;
      elseif ( !empty($record) && !$this->checkStudentToGroup( $record, $groupValues['id']) ) $error .= 1;
      elseif ( !empty($params['search_student_id']) && !$this->checkRecord($params['search_student_id']) ) $error .= 4;
      elseif ( !empty($params['search_student_id']) ) {
        $recordValues = $this->getRecordValues($params['search_student_id']);
        $error .= ( $recordValues['company_id'] == $groupValues['company_id'] ? 0 : 2 );
      }
      else $error .= 0;

      if ( !$this->ref['student_role'][$params['student_role']] ) $params['student_role'] = '0';

      if     ( empty($params['search_student_id'])  && !empty($record) ) $action = 'update';
      elseif ( !empty($params['search_student_id']) && empty($record)  ) $action = 'insert';

      $error .= ( !$action ? 1 : 0 );

      // Fechas recibidas

      if ( ereg("^([0-9]{2})\/([0-9]{2})\/([0-9]{4})$", $params['student_date_start'], $s_date ) && checkdate($s_date[2], $s_date[1], $s_date[3]) ) $student_date_start = mktime(0,0,0,$s_date[2], $s_date[1], $s_date[3]);
      if ( !empty($params['student_date_end']) ) {
        if ( ereg("^([0-9]{2})\/([0-9]{2})\/([0-9]{4})$", $params['student_date_end'], $e_date ) && checkdate($e_date[2], $e_date[1], $e_date[3]) ) $student_date_end = mktime(0,0,0,$e_date[2], $e_date[1], $e_date[3]);
      }
      else $student_date_end = $groupValues['date_end'];

      // Codigo error fechas

      if ( empty($student_date_start) ) $error .= 1;
      elseif ( empty($student_date_end) ) $error .= 2;
      elseif ( ( $student_date_start < $groupValues['date_start'] ) || ( $student_date_start >= $groupValues['date_end'] ) || ( $student_date_start >= $student_date_end ) ) $error .= 3;
      elseif ( ( $student_date_end <= $groupValues['date_start'] ) || ( $student_date_end > $groupValues['date_end'] ) || ( $student_date_end < $student_date_start ) ) $error .= 4;
      else $error .= 0;

      // Nivel del alumno

      $params['student_level'] = ereg_replace("[^0-9\.,]", '', $params['student_level']);
      $params['student_level'] = ereg_replace(',', '.', $params['student_level']);

      $error .= ( $params['student_level'] < '0' || $params['student_level'] > '10' ? '1' : '0' );

      // Preparacion de los datos

      if ( ereg("^0+$", $error) ) {

        if ( $action == 'insert' ) {

          // INSERTAR ALUMNO
          //   * Se comprueba que no se repita el alumno en el grupo

          if ( $this->checkStudentNoGroup( $params['search_student_id'], $groupValues['id'], $student_date_start, $student_date_end) ) {

            if ( empty($params['student_role']) && $params['student_automatic_role'] == '1' ) $params['student_role'] = $recordValues['student_role'];

            if ( @db_query('INSERT INTO alumnos_grupos (id_alumno, id_grupo, id_nivel, id_colectivo, observaciones, fecha_inicio, fecha_fin) VALUES (\'' . $params['search_student_id'] . '\', \'' . $groupValues['id'] . '\', \'' . $params['student_level'] . '\', \'' . $params['student_role'] . '\', \'' . addslashes($params['student_comments']) . '\', ' . ( $student_date_start > $groupValues['date_start'] ? '\'' . date('Y-m-d', $student_date_start) . '\'' : 'NULL' ) . ', ' . ( $student_date_end < $groupValues['date_end'] ? '\'' . date('Y-m-d', $student_date_end) . '\'' : 'NULL' ) . ')' ) ) {

              $error .= 0;
              $record = db_insert_id();

              $SQL_query = db_query('SELECT id_nivel, id_colectivo FROM alumnos_grupos WHERE id_alumno = \'' . $params['search_student_id'] . '\' AND id_grupo = \'' . $groupValues['id'] . '\' LIMIT 1');

              if ( db_num_rows($SQL_query) ) {

                $student = db_fetch_array($SQL_query);

                if ( empty( $params['student_role'] ) && !empty($student['id_colectivo']) ) { db_query('UPDATE alumnos_grupos SET id_colectivo = \'' . $student['id_colectivo'] . '\' WHERE id = \'' . $record . '\''); $params['student_role'] = $student['id_colectivo']; }
                else db_query('UPDATE alumnos_grupos SET id_colectivo = \'' . $params['student_role'] . '\' WHERE id_alumno = \'' . $params['search_student_id'] . '\' AND id_grupo = \'' . $groupValues['id'] . '\' AND id != \'' . $record . '\'');

                if ( $student['id_nivel'] != $params['student_level'] ) db_query('UPDATE alumnos_grupos SET id_nivel = \'' . $params['student_level'] . '\' WHERE id_alumno = \'' . $params['search_student_id'] . '\' AND id_grupo = \'' . $groupValues['id'] . '\' AND id != \'' . $record . '\'');
              }
            }
            else $error .= 1;
          }
          else $error .= 9;
        }
        elseif ( $action == 'update' ) {

          // ACTUALIZAR ALUMNO

          $SQL_query = @db_query('SELECT id_alumno FROM alumnos_grupos WHERE id = \'' . $record . '\'');

          if ( db_num_rows($SQL_query) ) {

            $student = db_fetch_array($SQL_query);

              if ($this->checkStudentNoGroup( $student['id_alumno'], $groupValues['id'], $student_date_start, $student_date_end, $record) ) {

                if ( @db_query('UPDATE alumnos_grupos SET fecha_inicio = ' . ( $groupValues['date_start'] == $student_date_start ? 'NULL' : '\'' . date('Y-m-d', $student_date_start) . '\'' ) . ', fecha_fin = ' . ( $groupValues['date_end'] != $student_date_end ? '\'' . date('Y-m-d', $student_date_end) . '\'' : 'NULL' ) . ', id_nivel = \'' . $params['student_level'] . '\', id_colectivo = \'' . $params['student_role'] . '\', observaciones = \'' . addslashes($params['student_comments']) . '\' WHERE id = \'' . $record . '\'') ) {
                $error .= 0;

                @db_query('UPDATE alumnos_grupos SET id_nivel = \'' . $params['student_level'] . '\' WHERE id_alumno = \'' . $student['id_alumno'] . '\' AND id_grupo = \'' .  $groupValues['id'] . '\'');

                @db_query('UPDATE alumnos_grupos SET id_colectivo = \'' . $params['student_role'] . '\' WHERE id_alumno = \'' . $student['id_alumno'] . '\' AND id_grupo = \'' .  $groupValues['id'] . '\'');
              }
              else $error .= 1;
            }
            else $error .= 9;
          }
          else $error .= 9;
        }
        return $error;
      }
      else return $error;
    }

    function checkStudentNoGroup( $student_id, $group_id, $student_date_start, $student_date_end, $record = '' ) {

      $SQL_student_date_start = date('Y-m-d', $student_date_start);
      $SQL_student_date_end   = date('Y-m-d', $student_date_end);

      $SQL_query = db_query('SELECT IF( ag.fecha_inicio, ag.fecha_inicio, g.fecha_inicio ) AS fecha_inicio, IF( ag.fecha_fin, ag.fecha_fin, IF( g.fecha_fin, g.fecha_fin, e.fecha_fin ) ) AS fecha_fin FROM alumnos_grupos ag LEFT JOIN grupos g ON ag.id_grupo = g.id LEFT JOIN ejercicios_lectivos e ON g.id_periodo = e.id WHERE ag.id_alumno = \'' . $student_id . '\' AND ag.id_grupo = \'' . $group_id . '\'' . ( !empty($record) ? ' AND ag.id != \'' . $record . '\'' : '' ) . ' HAVING ( ( fecha_inicio <= "' . $SQL_student_date_end . '" AND fecha_fin >= "' . $SQL_student_date_end . '" ) OR ( fecha_inicio <= "' . $SQL_student_date_start . '" AND fecha_fin >= "' . $SQL_student_date_start . '" ) OR ( fecha_inicio = "' . $SQL_student_date_start . '" AND fecha_fin = "' . $SQL_student_date_end . '" ) )');

      if ( db_num_rows($SQL_query) == 0 ) return true;
      else return false;
    }
 
    //-----------------------------------------------------------------------------------
    // deleteStudentToGroup

    function deleteStudentToGroup( $record, $group = '' ) {

      $error  = '';

      if ( !empty($group) ) $error .= ( $this->checkStudentToGroup($record, $group) ? 0 : 1 );
      else $error .= 0;

      if ( ereg("^0+$", $error) ) {

        $recordValues = $this->getStudentToGroupValues($record);

        if ( @db_query('DELETE FROM alumnos_grupos WHERE id = \'' . $record . '\'') ) {

          $delDateStart = '';
          $delDateStop  = '';

          // INFORMES
          // Registros anteriores

          $SQL_query_start_date = db_query('SELECT UNIX_TIMESTAMP(fecha_fin) AS fecha_fin FROM alumnos_grupos WHERE id_grupo = \'' . $recordValues['group_id'] .'\' AND id_alumno = \'' . $recordValues['student_id'] . '\' AND fecha_fin IS NOT NULL AND fecha_fin < "' . date('Y-m-d', $recordValues['date_start']) . '" ORDER BY fecha_fin DESC LIMIT 1');

          if ( db_num_rows($SQL_query_start_date) ) {
            $startDate    = db_fech_array($SQL_query_start_date);
            $delDateStart = date('Y-m-d', $startDate['fecha_fin']);
          }
          else $delDateStart = date('Y-m-d', mktime(0, 0, 0, date('m', $recordValues['date_start']), -1, date('Y', $recordValues['date_start']) ) );

          // Registros anteriores

          $SQL_query_end_date = db_query('SELECT fecha_inicio FROM alumnos_grupos WHERE id_grupo = \'' . $recordValues['group_id'] .'\' AND id_alumno = \'' . $recordValues['student_id'] . '\' AND fecha_inicio IS NOT NULL AND fecha_inicio > "' . $recordValues['date_end'] . '" ORDER BY fecha_inicio ASC LIMIT 1');

          if ( db_num_rows($SQL_query_end_date) ) {
            $endDate     = db_fetch_array($SQL_query_end_date);
            $delDateStop = date('Y-m-d', mktime(0, 0, 0, date('m', $endDate['fecha_inicio']), -1, date('Y', $endDate['fecha_inicio']) ));
          }
          else $delDateStop = ( date('j', $recordValues['date_end'] ) > 1 ? date('Y-m-d', $recordValues['date_end']) : date('Y-m-', $recordValues['date_end']) . '02');

          @db_query('DELETE FROM informe_global WHERE id_grupo = \'' . $recordValues['group_id'] . '\' AND id_alumno = \'' . $recordValues['student_id'] . '\' AND ( fecha > "' . $delDateStart . '" AND fecha < "' . $delDateStop . '" )');

	  if ( $recordValues['student_status'] == '2' ) $this->deleteRecord($recordValues['student_id']);
          $error .= 0;
        }
        else $error .= 1;
      }
      else return $error;
    }
  }
?>