<?php

/*
    Copyright 2012-2020 OpenBroadcaster, Inc.

    This file is part of OpenBroadcaster Server.

    OpenBroadcaster Server is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenBroadcaster Server 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 Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with OpenBroadcaster Server.  If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * Secondary model for managing media metadata.
 *
 * @package Model
 */
class MediaMetadataModel extends OBFModel
{

  /**
   * Get all metadata columns.
   *
   * @return metadata_columns
   */
  public function get_all()
  {
    $this->db->orderby('order_id');
    $fields = $this->db->get('media_metadata_columns');
    foreach($fields as &$field)
    {
      if(!$field['settings']) $field['settings'] = '{}';
      $field['settings'] = json_decode($field['settings']);

      // attach all available tags to tag settings
      if($field['type']=='tags')
      {
        $field['settings']->all = $this('tag_search',['id'=>$field['id'],'search'=>'']);
      }
    }
    return $fields;
  }

  /**
   * Get a metadata column.
   *
   * @param id
   *
   * @param metadata_column
   */
  public function get_one($id)
  {
    $this->db->where('id',$id);
    $field = $this->db->get_one('media_metadata_columns');
    if($field['settings']) $field['settings'] = json_decode($field['settings']);
    return $field;
  }

  /**
   * Get a metadata column by name.
   *
   * @param name
   *
   * @param metadata_column
   */
  public function get_by_name($name)
  {
    $this->db->where('name',$name);
    $field = $this->db->get_one('media_metadata_columns');
    if($field['settings']) $field['settings'] = json_decode($field['settings']);
    return $field;
  }

  /**
   * Save a new order for metadata fields.
   *
   * @param order An array of metadata column IDs in the preferred order.
   *
   * @return is_valid_order
   */
  public function save_field_order($order)
  {
    if(!is_array($order)) return false;

    // make sure all valid before saving
    $expected_order_id = 0;
    foreach($order as $order_id=>$field_id)
    {
      if(!$this->get_one($field_id) || $order_id!=$expected_order_id) return false;
      $expected_order_id++;
    }

    // save
    foreach($order as $order_id=>$field_id)
    {
      $this->db->where('id',$field_id);
      $this->db->update('media_metadata_columns',['order_id'=>$order_id]);
    }

    return true;
  }

  /**
   * Validate metadata field before updating.
   *
   * @param data
   * @param id Optional. Specified when updating an existing metadata field.
   *
   * @return [is_valid, msg]
   */
  public function validate($data, $id)
  {
    // if editing, use name/type from existing field.
    if($id)
    {
      $existing_field = $this->get_one($id);
      $data['name'] = $existing_field['name'];
      $data['type'] = $existing_field['type'];
    }

    //T All fields are required.
    if(!$data['name'] || !$data['description'] || !$data['type'] || ($data['type']=='select' && !$data['select_options'])) return [false,'All fields are required.'];
    //T Field name must contain only letters, numbers, and underscores.
    if(!preg_match('/^[0-9a-z_]+$/',$data['name'])) return [false,'Field name must contain only letters, numbers, and underscores.'];
    //T Field name maximum length is 32 characters.
    if(strlen($data['name'])>32) return [false,'Field name maximum length is 32 characters.'];
    //T This field name is reserved and cannot be used.
    if($data['name']=='media_id') return [false,'This field name is reserved and cannot be used.'];

    if(!$id)
    {
      $this->db->where('name',$data['name']);
      //T This field name is already in use.
      if($this->db->get_one('media_metadata_columns')) return [false,'This field name is already in use'];
    }

    //T The field type is not valid.
    if(array_search($data['type'], ['select','bool','text','textarea','integer','tags','hidden'])===false) return [false,'The field type is not valid.'];

    return [true,'Valid.'];
  }

  /**
   * Save a metadata field.
   *
   * @param data
   * @param id Optional. Specified when updating an existing metadata field.
   *
   * @return id
   */
  public function save($data, $id)
  {
    $save = [];
    $save['settings'] = [];
    $save['description'] = $data['description'];

    // if editing, use name/type from existing field.
    if($id)
    {
      $existing_field = $this->get_one($id);
      $data['name'] = $existing_field['name'];
      $data['type'] = $existing_field['type'];
    }

    // some extra things for select field
    if($data['type']=='select')
    {
      $options = explode(PHP_EOL,$data['select_options']);
      $save_options = [];
      foreach($options as $option)
      {
        $option = trim($option);
        if($option!='') $save_options[] = $option;
      }
      $save['settings']['options'] = $save_options;
    }

    // default
    $save['settings']['default'] = $data['default'];

    // tag suggestions
    if($data['type']=='tags')
    {
      $save['settings']['suggestions'] = [];
      foreach($data['tag_suggestions'] as $tag)
      {
        $tag = trim($tag);
        if($tag!='') $save['settings']['suggestions'][] = $tag;
      }
      if(is_array($save['settings']['default'])) $save['settings']['suggestions'] = array_values(array_unique(array_merge($save['settings']['suggestions'], $save['settings']['default'])));
    }

    $save['settings'] = json_encode($save['settings']);

    if($id)
    {
      $this->db->where('id',$id);
      return $this->db->update('media_metadata_columns',$save);
    }

    else
    {
      $save['name'] = $data['name'];
      $save['type'] = $data['type'];

      $id = $this->db->insert('media_metadata_columns',$save);

      if($save['type']=='bool')
      {
        $this->db->query('ALTER TABLE '.$this->db->format_backticks('media_metadata').' ADD '.$this->db->format_backticks($data['name']).' BOOLEAN NULL DEFAULT NULL');
      }

      elseif($save['type']=='select' || $save['type']=='text')
      {
        $this->db->query('ALTER TABLE '.$this->db->format_backticks('media_metadata').' ADD '.$this->db->format_backticks($data['name']).' VARCHAR(255) NULL DEFAULT NULL');
      }

      elseif($save['type']=='textarea' || $save['type']=='tags')
      {
        $this->db->query('ALTER TABLE '.$this->db->format_backticks('media_metadata').' ADD '.$this->db->format_backticks($data['name']).' TEXT NULL DEFAULT NULL');
      }
      
      elseif($save['type']=='integer')
      {
        $this->db->query('ALTER TABLE '.$this->db->format_backticks('media_metadata').' ADD '.$this->db->format_backticks($data['name']).' BIGINT NULL DEFAULT NULL');
      }
      
      elseif($save['type']=='hidden')
      {
        $this->db->query('ALTER TABLE '.$this->db->format_backticks('media_metadata').' ADD '.$this->db->format_backticks($data['name']).' LONGTEXT NULL DEFAULT NULL');
      }

      return $id;
    }
  }

  /**
   * Delete a metadata field.
   *
   * @param id
   *
   * @return was_deleted
   */
  public function delete($id)
  {
    $field = $this->get_one($id);
    if(!$field) return false;

    $this->db->where('id',$id);
    $this->db->delete('media_metadata_columns');
    $this->db->query('ALTER TABLE '.$this->db->format_backticks('media_metadata').' DROP COLUMN '.$this->db->format_backticks($field['name']));

    return true;
  }

  /**
   * Validate metadata fields. Making sure that all the mandatory fields are set,
   * and that metadata has no invalid associated values.
   *
   * @param data
   */
  public function validate_fields ($data) {
    if (!array_key_exists('artist', $data) ||
        !array_key_exists('album', $data) ||
        !array_key_exists('year', $data) ||
        !array_key_exists('category_id', $data) ||
        !array_key_exists('country_id', $data) ||
        !array_key_exists('language_id', $data) ||
        !array_key_exists('comments', $data) ||
        !array_key_exists('dynamic_content_default', $data) ||
        !array_key_exists('dynamic_content_hidden', $data)) {
      return [false, 'Not all values set in field settings.'];
    }

    foreach ($data as $key=>$item) {
      if ($key != 'dynamic_content_hidden' && $item != 'required' && $item != 'enabled' && $item != 'disabled') {
        return [false, 'Invalid value in field settings.'];
      }
    }

    return [true, 'Field settings validated.'];
  }

  /**
   * Get metadata field settings, which fields are required/enabled/disabled, and
   * dynamic content field settings.
   *
   * @return field_settings
   */
  public function get_fields () {
    $this->db->where('name', 'core_metadata');
    $data = $this->db->get_one('settings');

    if (!$data) {
      return [false, 'Failed to load field settings from database.'];
    }

    $data = json_decode($data['value'], true);

    $this->db->where('name', 'dynamic_content_field');
    $dynamic_content = $this->db->get_one('settings');
    if($dynamic_content)
    {
      $dynamic_content = json_decode($dynamic_content['value'], true);
      $data['dynamic_content_default'] = $dynamic_content['default'];
      $data['dynamic_content_hidden'] = $dynamic_content['hidden'];
    }
    else
    {
      $data['dynamic_content_default'] = 'enabled';
      $data['dynamic_content_hidden'] = false;
    }

    return [true, 'Successfully loaded field settings', $data];
  }

  /**
   * Update required field settings.
   *
   * @param data
   */
  public function required_fields ($data) {

    // handle dynamic content settings first
    $dynamic_content = [];
    $dynamic_content['default'] = $data['dynamic_content_default'];
    $dynamic_content['hidden'] = (bool) $data['dynamic_content_hidden'];
    unset($data['dynamic_content_default']);
    unset($data['dynamic_content_hidden']);
    $this->db->where('name', 'dynamic_content_field');
    $this->db->delete('settings');
    $this->db->insert('settings', [
      'name'  => 'dynamic_content_field',
      'value' => json_encode($dynamic_content)]);

    // handle core metadata
    $this->db->where('name', 'core_metadata');
    $this->db->delete('settings');
    $this->db->insert('settings', [
      'name'  => 'core_metadata',
      'value' => json_encode($data)]);

    return [true, 'Successfully updated field settings.'];
  }

  /**
   * Search tags in a metadata field of the tag type. Maximum 25 tags returned
   * by query.
   *
   * @param data
   *
   * @return results
   */
  public function tag_search($data)
  {
    $results = [];

    $data['search'] = trim($data['search']);
    $data['id'] = trim($data['id']);

    $this->db->where('id',$data['id'] ?? 0);
    $this->db->where('type','tags');
    $this->db->what('settings');
    $tag = $this->db->get_one('media_metadata_columns');

    if($tag)
    {
      $settings = json_decode($tag['settings'],true);

      foreach($settings['suggestions'] as $suggestion)
      {
        if($data['search']==='' || stripos($suggestion, $data['search'])!==false) $results[] = $suggestion;
      }
    }

    // query is weird without search ("%%") but fine.
    $this->db->query('SELECT DISTINCT(tag) AS `tag` FROM `media_metadata_tags` WHERE `media_metadata_column_id`="'.$this->db->escape($data['id']).'" AND `tag` LIKE "%'.$this->db->escape($data['search']).'%"');
    $rows = $this->db->assoc_list();

    foreach($rows as $row) $results[] = $row['tag'];

    // unique, sort
    $results = array_unique($results);
    sort($results);

    // return max 25 results
    return array_splice($results,0,25);
  }

}