<?php
// $Id$

/******************************************************************************/
/***************************** EDIT EXAMPLE ***********************************/
/******************************************************************************/

function upload_examples_edit_form($form_state)
{
  global $user;
  $example_id = arg(3);

  /* get example details */
  $example_q = db_query("SELECT * FROM {textbook_companion_example} WHERE id = %d LIMIT 1", $example_id);
  $example_data = db_fetch_object($example_q);
  if (!$example_q)
  {
    drupal_set_message(t("Invalid example selected."), 'error');
    drupal_goto('');
    return;
  }
  if ($example_data->approval_status != 0)
  {
    drupal_set_message(t("You cannot edit an example after it has been approved or dis-approved. Please contact site administrator if you want to edit this example."), 'error');
    drupal_goto('');
    return;
  }

  /* get examples files */
  $source_file = ""; $source_id = 0;
  $result1_file = ""; $result1_id = 0;
  $result2_file = ""; $result2_id = 0;
  $xcos1_file = ""; $xcos1_id = 0;
  $xcos2_file = ""; $xcos2_id = 0;

  $example_files_q = db_query("SELECT * FROM {textbook_companion_example_files} WHERE example_id = %d", $example_id);
  while ($example_files_data = db_fetch_object($example_files_q))
  {
    if ($example_files_data->filetype == "S")
    {
      $source_file = l($example_files_data->filename, 'download/file/' . $example_files_data->id);
      $source_file_id = $example_files_data->id;
    }
    if ($example_files_data->filetype == "R")
    {
      if (strlen($result1_file) == 0)
      {
        $result1_file = l($example_files_data->filename, 'download/file/' . $example_files_data->id);
        $result1_file_id = $example_files_data->id;
      } else {
        $result2_file = l($example_files_data->filename, 'download/file/' . $example_files_data->id);
        $result2_file_id = $example_files_data->id;
      }
    }
    if ($example_files_data->filetype == "X")
    {
      if (strlen($xcos1_file) <= 0)
      {
        $xcos1_file = l($example_files_data->filename, 'download/file/' . $example_files_data->id);
        $xcos1_file_id = $example_files_data->id;
      } else {
        $xcos2_file = l($example_files_data->filename, 'download/file/' . $example_files_data->id);
        $xcos2_file_id = $example_files_data->id;
      }
    }
   }

  /* get chapter details */
  $chapter_q = db_query("SELECT * FROM {textbook_companion_chapter} WHERE id = %d", $example_data->chapter_id);
  $chapter_data = db_fetch_object($chapter_q);
  if (!$chapter_data)
  {
    drupal_set_message(t("Invalid chapter selected."), 'error');
    drupal_goto('');
    return;
  }

  /* get preference details */
  $preference_q = db_query("SELECT * FROM {textbook_companion_preference} WHERE id = %d", $chapter_data->preference_id);
  $preference_data = db_fetch_object($preference_q);
  if (!$preference_data)
  {
    drupal_set_message(t("Invalid book selected."), 'error');
    drupal_goto('');
    return;
  }
  if ($preference_data->approval_status != 1)
  {
    drupal_set_message(t("Cannot edit example. Either the book proposal has not been approved or it has been rejected."), 'error');
    drupal_goto('');
    return;
  }

  /* get proposal details */
  $proposal_q = db_query("SELECT * FROM {textbook_companion_proposal} WHERE id = %d", $preference_data->proposal_id);
  $proposal_data = db_fetch_object($proposal_q);
  if (!$proposal_data)
  {
    drupal_set_message(t("Invalid proposal selected."), 'error');
    drupal_goto('');
    return;
  }
  if ($proposal_data->uid != $user->uid)
  {
    drupal_set_message(t("You do not have permissions to edit this example."), 'error');
    drupal_goto('');
    return;
  }

  $user_data = user_load($proposal_data->uid);

  /* add javascript for automatic book title, check if example uploaded, dependency selection effects */
  $chapter_name_js = " $(document).ready(function() {
    $('#edit-existing-depfile-dep-book-title').change(function() {
      var dep_selected = ''; 
      /* showing and hiding relevant files */
      $('.form-checkboxes .option').hide();
      $('.form-checkboxes .option').each(function(index) {
        var activeClass = $('#edit-existing-depfile-dep-book-title').val();
        if ($(this).children().hasClass(activeClass)) {
          $(this).show();
        }
        if ($(this).children().attr('checked') == true) {
          dep_selected += $(this).children().next().text() + '<br />';
        }
      });
      /* showing list of already existing dependencies */
      $('#existing_depfile_selected').html(dep_selected);
    });

    $('.form-checkboxes .option').change(function() {
      $('#edit-existing-depfile-dep-book-title').trigger('change');
    });
    $('#edit-existing-depfile-dep-book-title').trigger('change');
  });";
  drupal_add_js($chapter_name_js, 'inline', 'header');

  $form['#redirect'] = 'textbook_companion/code';
  $form['#attributes'] = array('enctype' => "multipart/form-data");

  $form['book_details']['book'] = array(
    '#type' => 'item',
    '#value' => $preference_data->book,
    '#title' => t('Title of the Book'),
  );
  $form['contributor_name'] = array(
    '#type' => 'item',
    '#value' => $proposal_data->full_name,
    '#title' => t('Contributor Name'),
  );
  $form['number'] = array(
    '#type' => 'item',
    '#title' => t('Chapter No'),
    '#value' => $chapter_data->number,
  );
  $form['name'] = array(
    '#type' => 'item',
    '#title' => t('Title of the Chapter'),
    '#value' => $chapter_data->name,
  );
  $form['example_number'] = array(
    '#type' => 'item',
    '#title' => t('Example No'),
    '#value' => $example_data->number,
  );
  $form['example_caption'] = array(
    '#type' => 'textfield',
    '#title' => t('Caption'),
    '#size' => 40,
    '#maxlength' => 255,
    '#required' => TRUE,
    '#default_value' => $example_data->caption,
  );
  $form['example_warning'] = array(
    '#type' => 'item',
    '#title' => t('You should upload all the files (main or source files, result files, executable file if any)'),
    '#prefix' => '<div style="color:red">',
    '#suffix' => '</div>',
  );

  $form['sourcefile'] = array(
    '#type' => 'fieldset',
    '#title' => t('Main or Source Files'),
    '#collapsible' => FALSE,
    '#collapsed' => FALSE,
  );
  if ($source_file)
  {
    $form['sourcefile']['cur_source'] = array(
      '#type' => 'item',
      '#title' => t('Existing Main or Source File'),
      '#value' => $source_file,
    );
    $form['sourcefile']['cur_source_checkbox'] = array(
      '#type' => 'checkbox',
      '#title' => t('Delete Existing Main or Source File'),
      '#description' => 'Check to delete the existing Main or Source file.',
    );
    $form['sourcefile']['sourcefile1'] = array(
      '#type' => 'file',
      '#title' => t('Upload New Main or Source File'),
      '#size' => 48,
      '#description' => t("Upload new Main or Source file above if you want to replace the existing file. Leave blank if you want to keep using the existing file. <br />") .
      t('Allowed file extensions : ') . variable_get('textbook_companion_source_extensions', ''),
    );
    $form['sourcefile']['cur_source_file_id'] = array(
      '#type' => 'hidden',
      '#value' => $source_file_id,
    );
  } else {
    $form['sourcefile']['sourcefile1'] = array(
      '#type' => 'file',
      '#title' => t('Upload New Main or Source File'),
      '#size' => 48,
      '#description' => t('Allowed file extensions : ') . variable_get('textbook_companion_source_extensions', ''),
    );
  }

  $form['dep_files'] = array(
    '#type' => 'item',
    '#title' => t('Dependency Files'),
  );
  
  /************ START OF EXISTING DEPENDENCIES **************/
  
  $dependency_files = array();
  $dependency_q = db_query("SELECT * FROM {textbook_companion_example_dependency} WHERE example_id = %d", $example_data->id);
  while ($dependency_data = db_fetch_object($dependency_q))
  {
    $dependency_files[] = $dependency_data->dependency_id;
  }
  
  /* existing dependencies */
  $form['existing_depfile'] = array(
    '#type' => 'fieldset',
    '#title' => t('Use Already Existing Dependency Files'),
    '#collapsible' => FALSE,
    '#collapsed' => FALSE,
    '#prefix' => '<div id="existing-depfile-wrapper">',
    '#suffix' => '</div>',
    '#tree' => TRUE,
  );
  
  /* existing dependencies */
  $form['existing_depfile']['selected'] = array(
    '#type' => 'item',
    '#title' => t('Existing Dependency Files Selected'),
    '#value' => '<div id="existing_depfile_selected"></div>',
  );
  
  $form['existing_depfile']['dep_book_title'] = array(
    '#type' => 'select',
    '#title' => t('Title of the Book'),
    '#options' => _list_of_book_titles(),
  );

  list($files_options, $files_options_class) = _list_of_book_dependency_files();
  $form['existing_depfile']['dep_chapter_example_files'] = array(
    '#type' => 'checkboxes',
    '#title' => t('Dependency Files'),
    '#options' => $files_options,
    '#options_class' => $files_options_class,
    '#multiple' => TRUE,
    '#default_value' => $dependency_files,
  );

  $form['existing_depfile']['dep_upload'] = array(
    '#type' => 'item',
    '#value' => l('Upload New Depedency Files', 'textbook_companion/code/upload_dep'),
  );
  /************ END OF EXISTING DEPENDENCIES **************/
  
  $form['result'] = array(
    '#type' => 'fieldset',
    '#title' => t('Result Files'),
    '#collapsible' => FALSE,
    '#collapsed' => FALSE,
  );
  if ($result1_file)
  {
    $form['result']['cur_result1'] = array(
      '#type' => 'item',
      '#title' => t('Existing Result File 1'),
      '#value' => $result1_file,
    );
    $form['result']['cur_result1_checkbox'] = array(
      '#type' => 'checkbox',
      '#title' => t('Delete Existing Result File 1'),
      '#description' => 'Check to delete the existing Result file.',
    );
    $form['result']['result1'] = array(
      '#type' => 'file',
      '#title' => t('Upload New Result File 1'),
      '#size' => 48,
      '#description' => t("Upload new Result file above if you want to replace the existing file, leave blank if you want to keep using the existing file. <br />") .
        t('Allowed file extensions : ') . variable_get('textbook_companion_result_extensions', ''),
    );
    $form['result']['cur_result1_file_id'] = array(
      '#type' => 'hidden',
      '#value' => $result1_file_id,
    );
  } else {
    $form['result']['result1'] = array(
      '#type' => 'file',
      '#title' => t('Upload New Result File 1'),
      '#size' => 48,
      '#description' => t('Allowed file extensions : ') . variable_get('textbook_companion_result_extensions', ''),
    );
  }
  
  $form['result']['br'] = array(
  '#type' => 'item',
  '#value' => "<br />",
  );
  
  if ($result2_file)
  {
    $form['result']['cur_result2'] = array(
      '#type' => 'item',
      '#title' => t('Existing Result File 2'),
      '#value' => $result2_file,
    );
    $form['result']['cur_result2_checkbox'] = array(
      '#type' => 'checkbox',
      '#title' => t('Delete Existing Result File 2'),
      '#description' => 'Check to delete the existing Result file.',
    );
    $form['result']['result2'] = array(
      '#type' => 'file',
      '#title' => t('Upload New Result file 2'),
      '#size' => 48,
      '#description' => t("Upload new Result file above if you want to replace the existing file. Leave blank if you want to keep using the existing file. <br />") . 
        t('Allowed file extensions : ') . variable_get('textbook_companion_result_extensions', ''),
    );
    $form['result']['cur_result2_file_id'] = array(
      '#type' => 'hidden',
      '#value' => $result2_file_id,
    );
  } else {
    $form['result']['result2'] = array(
      '#type' => 'file',
      '#title' => t('Upload New Result file 2'),
      '#size' => 48,
      '#description' => t('Allowed file extensions : ') . variable_get('textbook_companion_result_extensions', ''),
    );
  }
  $form['xcos'] = array(
    '#type' => 'fieldset',
    '#title' => t('XCOS Files'),
    '#collapsible' => FALSE,
    '#collapsed' => FALSE,
  );
  if ($xcos1_file)
  {
    $form['xcos']['cur_xcos1'] = array(
      '#type' => 'item',
      '#title' => t('Existing xcos File 1'),
      '#value' => $xcos1_file,
    );
    $form['xcos']['cur_xcos1_checkbox'] = array(
      '#type' => 'checkbox',
      '#title' => t('Delete Existing xcos File 1'),
      '#description' => 'Check to delete the existing xcos file.',
    );
    $form['xcos']['xcos1'] = array(
      '#type' => 'file',
      '#title' => t('Upload New xcos file 1'),
      '#size' => 48,
      '#description' => t("Upload new xcos file above if you want to replace the existing file. Leave blank if you want to keep using the existing file. <br />") .
        t('Allowed file extensions : ') . variable_get('textbook_companion_xcos_extensions', ''),
    );
    $form['sourcefile']['cur_xcos1_file_id'] = array(
      '#type' => 'hidden',
      '#value' => $xcos1_file_id,
    );
  } else {
    $form['xcos']['xcos1'] = array(
      '#type' => 'file',
      '#title' => t('Upload New xcos file 1'),
      '#size' => 48,
      '#description' => t('Allowed file extensions : ') . variable_get('textbook_companion_xcos_extensions', ''),
    );
  }

  $form['xcos']['br'] = array(
    '#type' => 'item',
    '#value' => "<br />",
  );

  if ($xcos2_file)
  {
    $form['xcos']['cur_xcos2'] = array(
      '#type' => 'item',
      '#title' => t('Existing xcos File 2'),
      '#value' => $xcos2_file,
    );
    $form['xcos']['cur_xcos2_checkbox'] = array(
      '#type' => 'checkbox',
      '#title' => t('Delete Existing xcos File 2'),
      '#description' => 'Check to delete the existing xcos file.',
    );
    $form['xcos']['xcos2'] = array(
      '#type' => 'file',
      '#title' => t('Upload New xcos file 2'),
      '#size' => 48,
      '#description' =>  t("Upload new xcos file above if you want to replace the existing file. Leave blank if you want to keep using the existing file. <br />") . 
        t('Allowed file extensions : ') . variable_get('textbook_companion_xcos_extensions', ''),
    );
    $form['xcos']['cur_xcos2_file_id'] = array(
      '#type' => 'hidden',
      '#value' => $xcos2_file_id,
    );
  } else {
    $form['xcos']['xcos2'] = array(
      '#type' => 'file',
      '#title' => t('Upload New xcos file 2'),
      '#size' => 48,
      '#description' => t('Allowed file extensions : ') . variable_get('textbook_companion_xcos_extensions', ''),
    );
  }

  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Submit')
  );

  $form['cancel'] = array(
    '#type' => 'markup',
    '#value' => l(t('Cancel'), 'textbook_companion/code'),
  );
  return $form;
}

function upload_examples_edit_form_validate($form, &$form_state)
{
  if (!check_name($form_state['values']['example_caption']))
    form_set_error('example_caption', t('Example Caption can contain only alphabets, numbers and spaces.'));

  if (isset($_FILES['files']))
  {
    /* check for valid filename extensions */  
    foreach ($_FILES['files']['name'] as $file_form_name => $file_name)
    {
      if ($file_name)
      {
        /* checking file type */
        if (strstr($file_form_name, 'source'))
          $file_type = 'S';
        else if (strstr($file_form_name, 'result'))
          $file_type = 'R';
        else if (strstr($file_form_name, 'xcos'))
          $file_type = 'X';
        else
          $file_type = 'U';

        $allowed_extensions_str = '';
        switch ($file_type)
        {
        case 'S':
          $allowed_extensions_str = variable_get('textbook_companion_source_extensions', '');
          break;
        case 'R':
          $allowed_extensions_str = variable_get('textbook_companion_result_extensions', '');
          break;
        case 'X':
          $allowed_extensions_str = variable_get('textbook_companion_xcos_extensions', '');
          break;
        }

        $allowed_extensions = explode(',' , $allowed_extensions_str);
        $temp_extension = end(explode('.', strtolower($_FILES['files']['name'][$file_form_name])));
        if (!in_array($temp_extension, $allowed_extensions))
          form_set_error($file_form_name, t('Only file with ' . $allowed_extensions_str . ' extensions can be uploaded.'));
        if ($_FILES['files']['size'][$file_form_name] <= 0)
          form_set_error($file_form_name, t('File size cannot be zero.'));

        /* check if valid file name */
        if (!textbook_companion_check_valid_filename($_FILES['files']['name'][$file_form_name]))
         form_set_error($file_form_name, t('Invalid file name specified. Only alphabets, numbers and underscore is allowed as a valid filename.'));
      }
    }
  }

  /* add javascript again for automatic book title, check if example uploaded, dependency selection effects */
  $chapter_name_js = " $(document).ready(function() {
    $('#edit-number').change(function() {
      $.get('" . base_path() . "textbook_companion/ajax/chapter_title/' + $('#edit-number').val() + '/' + " . $row->pre_id . ", function(data) {
        $('#edit-name').val(data);
      });
    });
    $('#edit-example-number').change(function() {
      $.get('" . base_path() . "textbook_companion/ajax/example_exists/' + $('#edit-number').val() + '/' + $('#edit-example-number').val(), function(data) {
        if (data) {
          alert(data);
        }
      });
    });
    $('#edit-existing-depfile-dep-book-title').change(function() {
      var dep_selected = ''; 
      /* showing and hiding relevant files */
      $('.form-checkboxes .option').hide();
      $('.form-checkboxes .option').each(function(index) {
        var activeClass = $('#edit-existing-depfile-dep-book-title').val();
        if ($(this).children().hasClass(activeClass)) {
          $(this).show();
        }
        if ($(this).children().attr('checked') == true) {
          dep_selected += $(this).children().next().text() + '<br />';
        }
      });
      /* showing list of already existing dependencies */
      $('#existing_depfile_selected').html(dep_selected);
    });

    $('.form-checkboxes .option').change(function() {
      $('#edit-existing-depfile-dep-book-title').trigger('change');
    });
    $('#edit-existing-depfile-dep-book-title').trigger('change');
  });";
  drupal_add_js($chapter_name_js, 'inline', 'header');
}

function upload_examples_edit_form_submit($form, &$form_state)
{
  global $user;
  $example_id = arg(3);

  /* get example details */
  $example_q = db_query("SELECT * FROM {textbook_companion_example} WHERE id = %d LIMIT 1", $example_id);
  $example_data = db_fetch_object($example_q);
  if (!$example_q)
  {
    drupal_set_message(t("Invalid example selected."), 'error');
    drupal_goto('');
    return;
  }
  if ($example_data->approval_status != 0)
  {
    drupal_set_message(t("You cannot edit an example after it has been approved or dis-approved. Please contact site administrator if you want to edit this example."), 'error');
    drupal_goto('');
    return;
  }

  /* get chapter details */
  $chapter_q = db_query("SELECT * FROM {textbook_companion_chapter} WHERE id = %d", $example_data->chapter_id);
  $chapter_data = db_fetch_object($chapter_q);
  if (!$chapter_data)
  {
    drupal_set_message(t("Invalid chapter selected."), 'error');
    drupal_goto('');
    return;
  }

  /* get preference details */
  $preference_q = db_query("SELECT * FROM {textbook_companion_preference} WHERE id = %d", $chapter_data->preference_id);
  $preference_data = db_fetch_object($preference_q);
  if (!$preference_data)
  {
    drupal_set_message(t("Invalid book selected."), 'error');
    drupal_goto('');
    return;
  }
  if ($preference_data->approval_status != 1)
  {
    drupal_set_message(t("Cannot edit example. Either the book proposal has not been approved or it has been rejected."), 'error');
    drupal_goto('');
    return;
  }

  /* get proposal details */
  $proposal_q = db_query("SELECT * FROM {textbook_companion_proposal} WHERE id = %d", $preference_data->proposal_id);
  $proposal_data = db_fetch_object($proposal_q);
  if (!$proposal_data)
  {
    drupal_set_message(t("Invalid proposal selected."), 'error');
    drupal_goto('');
    return;
  }
  if ($proposal_data->uid != $user->uid)
  {
    drupal_set_message(t("You do not have permissions to edit this example."), 'error');
    drupal_goto('');
    return;
  }

  /* creating directories */
  $root_path = textbook_companion_path();

  $dest_path = $preference_data->id . '/';
  if (!is_dir($root_path . $dest_path))
    mkdir($root_path . $dest_path);

  $dest_path .= 'CH' . $chapter_data->number . '/';
  if (!is_dir($root_path . $dest_path))
    mkdir($root_path . $dest_path);

  $dest_path .= 'EX' . $example_data->number . '/';
  if (!is_dir($root_path . $dest_path))
    mkdir($root_path . $dest_path);

  /* updating example caption */
  db_query("UPDATE {textbook_companion_example} SET caption = '%s' WHERE id = %d", $form_state['values']['example_caption'], $example_id);

  /* handling dependencies */
  db_query("DELETE FROM {textbook_companion_example_dependency} WHERE example_id = %d", $example_data->id);
  foreach ($form_state['values']['existing_depfile']['dep_chapter_example_files'] as $row)
  {
    if ($row > 0)
    {
      /* insterting into database */
      db_query("INSERT INTO {textbook_companion_example_dependency} (example_id, dependency_id, approval_status, timestamp)
        VALUES (%d, %d, %d, %d)",
        $example_data->id,
        $row,
        0,
        time()
      );
    }
  }

  /* handle source file */
  $cur_file_id = $form_state['values']['cur_source_file_id'];
  if ($cur_file_id > 0)
  {
    $file_q = db_query("SELECT * FROM  {textbook_companion_example_files} WHERE id = %d AND example_id = %d", $cur_file_id, $example_data->id);
    $file_data = db_fetch_object($file_q);
    if (!$file_data)
    {
        drupal_set_message("Error deleting example source file. File not present in database.", 'error');
        return;
    }
    if (($form_state['values']['cur_source_checkbox'] == 1) && (!$_FILES['files']['name']['sourcefile1']))
    {
      if (!delete_file($cur_file_id))
      {
        drupal_set_message("Error deleting example source file.", 'error');
        return;
      }
    }
  }
  if ($_FILES['files']['name']['sourcefile1'])
  {
    if ($cur_file_id > 0)
    {
      if (!delete_file($cur_file_id))
      {
        drupal_set_message("Error removing previous example source file.", 'error');
        return;
      }
    }
    if (file_exists($root_path . $dest_path . $_FILES['files']['name']['sourcefile1']))
    {
      drupal_set_message(t("Error uploading source file. File !filename already exists.", array('!filename' => $_FILES['files']['name']['sourcefile1'])), 'error');
      return;
    }
    /* uploading file */
    if (move_uploaded_file($_FILES['files']['tmp_name']['sourcefile1'], $root_path . $dest_path . $_FILES['files']['name']['sourcefile1']))
    {
      /* for uploaded files making an entry in the database */
      db_query("INSERT INTO {textbook_companion_example_files} (example_id, filename, filepath, filemime, filesize, filetype, timestamp)
        VALUES (%d, '%s', '%s', '%s', %d, '%s', %d)",
        $example_data->id,
        $_FILES['files']['name']['sourcefile1'],
        $dest_path . $_FILES['files']['name']['sourcefile1'],
        $_FILES['files']['type']['sourcefile1'],
        $_FILES['files']['size']['sourcefile1'],
        'S',
        time()
        );
      drupal_set_message($_FILES['files']['name']['sourcefile1'] . ' uploaded successfully.', 'status');
    } else {
      drupal_set_message('Error uploading file : ' . $dest_path . '/' . $_FILES['files']['name']['sourcefile1'], 'error');
    }
  }

  /* handle result1 file */
  $cur_file_id = $form_state['values']['cur_result1_file_id'];
  if ($cur_file_id > 0)
  {
    $file_q = db_query("SELECT * FROM  {textbook_companion_example_files} WHERE id = %d AND example_id = %d", $cur_file_id, $example_data->id);
    $file_data = db_fetch_object($file_q);
    if (!$file_data)
    {
        drupal_set_message("Error deleting example result 1 file. File not present in database.", 'error');
        return;
    }
    if (($form_state['values']['cur_result1_checkbox'] == 1) && (!$_FILES['files']['name']['result1']))
    {
      if (!delete_file($cur_file_id))
      {
        drupal_set_message("Error deleting example result 1 file.", 'error');
        return;
      }
    }
  }
  if ($_FILES['files']['name']['result1'])
  {
    if ($cur_file_id > 0)
    {
      if (!delete_file($cur_file_id))
      {
        drupal_set_message("Error removing previous example result 1 file.", 'error');
        return;
      }
    }
    if (file_exists($root_path . $dest_path . $_FILES['files']['name']['result1']))
    {
      drupal_set_message(t("Error uploading result 1 file. File !filename already exists.", array('!filename' => $_FILES['files']['name']['result1'])), 'error');
      return;
    }
    /* uploading file */
    if (move_uploaded_file($_FILES['files']['tmp_name']['result1'], $root_path . $dest_path . $_FILES['files']['name']['result1']))
    {
      /* for uploaded files making an entry in the database */
      db_query("INSERT INTO {textbook_companion_example_files} (example_id, filename, filepath, filemime, filesize, filetype, timestamp)
        VALUES (%d, '%s', '%s', '%s', %d, '%s', %d)",
        $example_data->id,
        $_FILES['files']['name']['result1'],
        $dest_path . $_FILES['files']['name']['result1'],
        $_FILES['files']['type']['result1'],
        $_FILES['files']['size']['result1'],
        'R',
        time()
        );
      drupal_set_message($_FILES['files']['name']['result1'] . ' uploaded successfully.', 'status');
    } else {
      drupal_set_message('Error uploading file : ' . $dest_path . '/' . $_FILES['files']['name']['result1'], 'error');
    }
  }

  /* handle result2 file */
  $cur_file_id = $form_state['values']['cur_result2_file_id'];
  if ($cur_file_id > 0)
  {
    $file_q = db_query("SELECT * FROM  {textbook_companion_example_files} WHERE id = %d AND example_id = %d", $cur_file_id, $example_data->id);
    $file_data = db_fetch_object($file_q);
    if (!$file_data)
    {
        drupal_set_message("Error deleting example result 2 file. File not present in database.", 'error');
        return;
    }
    if (($form_state['values']['cur_result2_checkbox'] == 1) && (!$_FILES['files']['name']['result2']))
    {
      if (!delete_file($cur_file_id))
      {
        drupal_set_message("Error deleting example result 2 file.", 'error');
        return;
      }
    }
  }
  if ($_FILES['files']['name']['result2'])
  {
    if ($cur_file_id > 0)
    {
      if (!delete_file($cur_file_id))
      {
        drupal_set_message("Error removing previous example result 2 file.", 'error');
        return;
      }
    }
    if (file_exists($root_path . $dest_path . $_FILES['files']['name']['result2']))
    {
      drupal_set_message(t("Error uploading result 2 file. File !filename already exists.", array('!filename' => $_FILES['files']['name']['result2'])), 'error');
      return;
    }
    /* uploading file */
    if (move_uploaded_file($_FILES['files']['tmp_name']['result2'], $root_path . $dest_path . $_FILES['files']['name']['result2']))
    {
      /* for uploaded files making an entry in the database */
      db_query("INSERT INTO {textbook_companion_example_files} (example_id, filename, filepath, filemime, filesize, filetype, timestamp)
        VALUES (%d, '%s', '%s', '%s', %d, '%s', %d)",
        $example_data->id,
        $_FILES['files']['name']['result2'],
        $dest_path . $_FILES['files']['name']['result2'],
        $_FILES['files']['type']['result2'],
        $_FILES['files']['size']['result2'],
        'R',
        time()
        );
      drupal_set_message($_FILES['files']['name']['result2'] . ' uploaded successfully.', 'status');
    } else {
      drupal_set_message('Error uploading file : ' . $dest_path . '/' . $_FILES['files']['name']['result2'], 'error');
    }
  }

  /* handle xcos1 file */
  $cur_file_id = $form_state['values']['cur_xcos1_file_id'];
  if ($cur_file_id > 0)
  {
    $file_q = db_query("SELECT * FROM  {textbook_companion_example_files} WHERE id = %d AND example_id = %d", $cur_file_id, $example_data->id);
    $file_data = db_fetch_object($file_q);
    if (!$file_data)
    {
        drupal_set_message("Error deleting example xcos 1 file. File not present in database.", 'error');
        return;
    }
    if (($form_state['values']['cur_xcos1_checkbox'] == 1) && (!$_FILES['files']['name']['xcos1']))
    {
      if (!delete_file($cur_file_id))
      {
        drupal_set_message("Error deleting example xcos 1 file.", 'error');
        return;
      }
    }
  }
  if ($_FILES['files']['name']['xcos1'])
  {
    if ($cur_file_id > 0)
    {
      if (!delete_file($cur_file_id))
      {
        drupal_set_message("Error removing previous example xcos 1 file.", 'error');
        return;
      }
    }
    if (file_exists($root_path . $dest_path . $_FILES['files']['name']['xcos1']))
    {
      drupal_set_message(t("Error uploading xcos 1 file. File !filename already exists.", array('!filename' => $_FILES['files']['name']['xcos1'])), 'error');
      return;
    }
    /* uploading file */
    if (move_uploaded_file($_FILES['files']['tmp_name']['xcos1'], $root_path . $dest_path . $_FILES['files']['name']['xcos1']))
    {
      /* for uploaded files making an entry in the database */
      db_query("INSERT INTO {textbook_companion_example_files} (example_id, filename, filepath, filemime, filesize, filetype, timestamp)
        VALUES (%d, '%s', '%s', '%s', %d, '%s', %d)",
        $example_data->id,
        $_FILES['files']['name']['xcos1'],
        $dest_path . $_FILES['files']['name']['xcos1'],
        $_FILES['files']['type']['xcos1'],
        $_FILES['files']['size']['xcos1'],
        'X',
        time()
        );
      drupal_set_message($_FILES['files']['name']['xcos1'] . ' uploaded successfully.', 'status');
    } else {
      drupal_set_message('Error uploading file : ' . $dest_path . '/' . $_FILES['files']['name']['xcos1'], 'error');
    }
  }

  /* handle xcos2 file */
  $cur_file_id = $form_state['values']['cur_xcos2_file_id'];
  if ($cur_file_id > 0)
  {
    $file_q = db_query("SELECT * FROM  {textbook_companion_example_files} WHERE id = %d AND example_id = %d", $cur_file_id, $example_data->id);
    $file_data = db_fetch_object($file_q);
    if (!$file_data)
    {
        drupal_set_message("Error deleting example xcos 2 file. File not present in database.", 'error');
        return;
    }
    if (($form_state['values']['cur_xcos2_checkbox'] == 1) && (!$_FILES['files']['name']['xcos2']))
    {
      if (!delete_file($cur_file_id))
      {
        drupal_set_message("Error deleting example xcos 2 file.", 'error');
        return;
      }
    }
  }
  if ($_FILES['files']['name']['xcos2'])
  {
    if ($cur_file_id > 0)
    {
      if (!delete_file($cur_file_id))
      {
        drupal_set_message("Error removing previous example xcos 2 file.", 'error');
        return;
      }
    }
    if (file_exists($root_path . $dest_path . $_FILES['files']['name']['xcos2']))
    {
      drupal_set_message(t("Error uploading xcos 2 file. File !filename already exists.", array('!filename' => $_FILES['files']['name']['xcos2'])), 'error');
      return;
    }
    /* uploading file */
    if (move_uploaded_file($_FILES['files']['tmp_name']['xcos2'], $root_path . $dest_path . $_FILES['files']['name']['xcos2']))
    {
      /* for uploaded files making an entry in the database */
      db_query("INSERT INTO {textbook_companion_example_files} (example_id, filename, filepath, filemime, filesize, filetype, timestamp)
        VALUES (%d, '%s', '%s', '%s', %d, '%s', %d)",
        $example_data->id,
        $_FILES['files']['name']['xcos2'],
        $dest_path . $_FILES['files']['name']['xcos2'],
        $_FILES['files']['type']['xcos2'],
        $_FILES['files']['size']['xcos2'],
        'X',
        time()
        );
      drupal_set_message($_FILES['files']['name']['xcos2'] . ' uploaded successfully.', 'status');
    } else {
      drupal_set_message('Error uploading file : ' . $dest_path . '/' . $_FILES['files']['name']['xcos2'], 'error');
    }
  }

  /* sending email */
  $email_to = $user->mail;
  $param['example_updated']['example_id'] = $example_id;
  $param['example_updated']['user_id'] = $user->uid;
  if (!drupal_mail('textbook_companion', 'example_updated', $email_to, language_default(), $param, variable_get('textbook_companion_from_email', NULL), TRUE))
    drupal_set_message('Error sending email message.', 'error');

  drupal_set_message(t("Example successfully udpated."), 'status');
}


/******************************************************************************/
/**************************** EDIT CHAPTER TITLE ******************************/
/******************************************************************************/

function edit_chapter_title_form($form_state)
{
  global $user;

  /************************ start approve book details ************************/
  $proposal_q = db_query("SELECT * FROM {textbook_companion_proposal} WHERE uid = %d ORDER BY id DESC LIMIT 1", $user->uid);
  $proposal_data = db_fetch_object($proposal_q);
  if (!$proposal_data)
  {
    drupal_set_message("Please submit a " . l('proposal', 'proposal') . ".", 'error');
    drupal_goto('textbook_companion/code');
  }
  if ($proposal_data->proposal_status  != 1 && $proposal_data->proposal_status  != 4)
  {
    switch ($proposal_data->proposal_status )
    {
    case 0:
      drupal_set_message(t('We have already received your proposal. We will get back to you soon.'), 'status');
      drupal_goto('textbook_companion/code');
      return;
      break;
    case 2:
      drupal_set_message(t('Your proposal has been dis-approved. Please create another proposal ' . l('here', 'proposal') . '.'), 'error');
      drupal_goto('textbook_companion/code');
      return;
      break;
    case 3:
      drupal_set_message(t('Congratulations! You have completed your last book proposal. You have to create another proposal ' . l('here', 'proposal') . '.'), 'status');
      drupal_goto('textbook_companion/code');
      return;
      break;
    default:
       drupal_set_message(t('Invalid proposal state. Please contact site administrator for further information.'), 'error');
       drupal_goto('textbook_companion/code');
       return;
       break;
    }
  }

  $preference_q = db_query("SELECT * FROM {textbook_companion_preference} WHERE proposal_id = %d AND approval_status = 1 LIMIT 1", $proposal_data->id);
  $preference_data = db_fetch_object($preference_q);
  if (!$preference_data)
  {
    drupal_set_message(t('Invalid Book Preference status. Please contact site administrator for further information.'), 'error');
    drupal_goto('textbook_companion/code');
    return;
  }
  /************************ end approve book details **************************/

  $chapter_id = arg(4);

  $chapter_q = db_query("SELECT * FROM {textbook_companion_chapter} WHERE id = %d AND preference_id = %d", $chapter_id, $preference_data->id);
  $chapter_data = db_fetch_object($chapter_q);
  if (!$chapter_data)
  {
    drupal_set_message(t('Invalid chapter.'), 'error');
    drupal_goto('textbook_companion/code');
    return;
  }

  $form['#redirect'] = 'textbook_companion/code';

  $form['book_details']['book'] = array(
    '#type' => 'item',
    '#value' => $preference_data->book,
    '#title' => t('Title of the Book'),
  );
  $form['contributor_name'] = array(
    '#type' => 'item',
    '#value' => $proposal_data->full_name,
    '#title' => t('Contributor Name'),
  );
  $form['number'] = array(
    '#type' => 'item',
    '#title' => t('Chapter No'),
    '#value' => $chapter_data->number,
  );

  $form['chapter_title'] = array(
    '#type' => 'textfield',
    '#title' => t('Title of the Chapter'),
    '#size' => 40,
    '#maxlength' => 255,
    '#required' => TRUE,
    '#default_value' => $chapter_data->name,
  );

  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Submit')
  );
  $form['cancel'] = array(
    '#type' => 'markup',
    '#value' => l(t('Cancel'), 'textbook_companion/code'),
  );
  return $form;
}

function edit_chapter_title_form_validate($form, &$form_state)
{
  if (!check_name($form_state['values']['chapter_title']))
    form_set_error('chapter_title', t('Title of the Chapter can contain only alphabets, numbers and spaces.'));
}

function edit_chapter_title_form_submit($form, &$form_state)
{
  global $user;

  /************************ start approve book details ************************/
  $proposal_q = db_query("SELECT * FROM {textbook_companion_proposal} WHERE uid = %d ORDER BY id DESC LIMIT 1", $user->uid);
  $proposal_data = db_fetch_object($proposal_q);
  if (!$proposal_data)
  {
    drupal_set_message("Please submit a " . l('proposal', 'proposal') . ".", 'error');
    drupal_goto('textbook_companion/code');
  }
  if ($proposal_data->proposal_status  != 1 && $proposal_data->proposal_status  != 4)
  {
    switch ($proposal_data->proposal_status )
    {
    case 0:
      drupal_set_message(t('We have already received your proposal. We will get back to you soon.'), 'status');
      drupal_goto('textbook_companion/code');
      return;
      break;
    case 2:
      drupal_set_message(t('Your proposal has been dis-approved. Please create another proposal ' . l('here', 'proposal') . '.'), 'error');
      drupal_goto('textbook_companion/code');
      return;
      break;
    case 3:
      drupal_set_message(t('Congratulations! You have completed your last book proposal. You have to create another proposal ' . l('here', 'proposal') . '.'), 'status');
      drupal_goto('textbook_companion/code');
      return;
      break;
    default:
       drupal_set_message(t('Invalid proposal state. Please contact site administrator for further information.'), 'error');
       drupal_goto('textbook_companion/code');
       return;
       break;
    }
  }

  $preference_q = db_query("SELECT * FROM {textbook_companion_preference} WHERE proposal_id = %d AND approval_status = 1 LIMIT 1", $proposal_data->id);
  $preference_data = db_fetch_object($preference_q);
  if (!$preference_data)
  {
    drupal_set_message(t('Invalid Book Preference status. Please contact site administrator for further information.'), 'error');
    drupal_goto('textbook_companion/code');
    return;
  }
  /************************ end approve book details **************************/

  $chapter_id = arg(4);

  $chapter_q = db_query("SELECT * FROM {textbook_companion_chapter} WHERE id = %d AND preference_id = %d", $chapter_id, $preference_data->id);
  $chapter_data = db_fetch_object($chapter_q);
  if (!$chapter_data)
  {
    drupal_set_message(t('Invalid chapter.'), 'error');
    drupal_goto('textbook_companion/code');
    return;
  }
  db_query("UPDATE {textbook_companion_chapter} SET name = '%s' WHERE id = %d", $form_state['values']['chapter_title'], $chapter_id);
  drupal_set_message(t('Title of the Chapter updated.'), 'status');
}


/******************************************************************************/
/************************** GENERAL FUNCTIONS *********************************/
/******************************************************************************/

function _list_of_book_titles()
{
  $book_titles = array('0' => 'Please select...');
  $book_titles_q = db_query("SELECT * FROM {textbook_companion_preference} WHERE approval_status = 1 OR approval_status = 3 ORDER BY book ASC");
  while ($book_titles_data = db_fetch_object($book_titles_q))
  {
    $book_titles[$book_titles_data->id] = $book_titles_data->book . ' (Written by ' . $book_titles_data->author . ')';
  }
  return $book_titles;
}

function _list_of_book_dependency_files()
{
  $book_dependency_files = array();
  $book_dependency_files_class = array();
  $book_dependency_files_q = db_query("SELECT * FROM {textbook_companion_dependency_files} ORDER BY filename ASC");

  while ($book_dependency_files_data = db_fetch_object($book_dependency_files_q))
  {
    $temp_caption = '';
    if ($book_dependency_files_data->caption)
      $temp_caption .= ' (' . $book_dependency_files_data->caption . ')';
    $book_dependency_files[$book_dependency_files_data->id] = l($book_dependency_files_data->filename . $temp_caption, 'download/dependency/' . $book_dependency_files_data->id, array('attributes' => array('class' => $book_dependency_files_data->preference_id)));
    $book_dependency_files_class[$book_dependency_files_data->id] = $book_dependency_files_data->preference_id;
  }
  return array($book_dependency_files, $book_dependency_files_class);
}