<?php

if(!defined('ABSPATH'))
    exit;

/**
 * Field Setting
 */
add_action('acf/render_field_settings/type=relationship', 'acfe_bidirectional_settings');
add_action('acf/render_field_settings/type=post_object', 'acfe_bidirectional_settings');
add_action('acf/render_field_settings/type=user', 'acfe_bidirectional_settings');
add_action('acf/render_field_settings/type=taxonomy', 'acfe_bidirectional_settings');
function acfe_bidirectional_settings($field){
    
    // Settings
    acf_render_field_setting($field, array(
        'label'             => __('Bidirectional'),
        'key'               => 'acfe_bidirectional',
        'name'              => 'acfe_bidirectional',
        'instructions'      => __('Set the field as bidirectional'),
        'type'              => 'group',
        'required'          => false,
        'conditional_logic' => false,
        'wrapper' => array(
            'width' => '',
            'class' => '',
            'id'    => '',
        ),
        'layout' => 'block',
        'sub_fields' => array(
            array(
                'label'             => false,
                'key'               => 'acfe_bidirectional_enabled',
                'name'              => 'acfe_bidirectional_enabled',
                'type'              => 'true_false',
                'instructions'      => '',
                'required'          => false,
                'wrapper' => array(
                    'width' => '15',
                    'class' => 'acfe_width_auto',
                    'id'    => '',
                ),
                'message'           => '',
                'default_value'     => false,
                'ui'                => true,
                'ui_on_text'        => '',
                'ui_off_text'       => '',
                'conditional_logic' => false,
            ),
            array(
                'label'             => false,
                'key'               => 'acfe_bidirectional_related',
                'name'              => 'acfe_bidirectional_related',
                'type'              => 'select',
                'instructions'      => '',
                'required'          => false,
                'wrapper' => array(
                    'width' => 50,
                    'class' => '',
                    'id'    => '',
                ),
                'choices'       => array(),
                'default_value' => array(),
                'allow_null'    => 1,
                'multiple'      => 0,
                'ui'            => 1,
                'ajax'          => 1,
                'return_format' => 'value',
                'placeholder'   => '',
                'conditional_logic' => array(
                    array(
                        array(
                            'field'     => 'acfe_bidirectional_enabled',
                            'operator'  => '==',
                            'value'     => '1',
                        ),
                    ),
                ),
            ),
        ),
    ));
    
}

/**
 * Field Setting: Ajax Handler
 */
add_action('wp_ajax_acf/fields/select/query', 'acfe_bidirectional_ajax', 0);
add_action('wp_ajax_nopriv_acf/fields/select/query', 'acfe_bidirectional_ajax', 0);
function acfe_bidirectional_ajax(){
    
    // Do not die to let ACF handle others ajax requests
    if(!acf_verify_ajax())
        return;
    
    $options = acf_parse_args($_POST, array(
        'post_id'   => 0,
        's'         => '',
        'field_key' => '',
        'paged'     => 1
    ));
    
    // Not our field setting. Stop
    if($options['field_key'] != 'acfe_bidirectional_related')
        return;
    
    $response = acfe_bidirectional_ajax_query($options);
    
    acf_send_ajax_results($response);
    
}

/**
 * Field Setting: Ajax Query
 */
function acfe_bidirectional_ajax_query($options = array()){
    
    // Current field group
    $field_group = acf_get_field_group($options['post_id']);
    
    // Get field groups
    $r_field_groups = acf_get_field_groups();
    if(empty($r_field_groups))
        return false;
    
    $choices = array();
    
    foreach($r_field_groups as $r_field_group){
        
        // Bypass current field group
        if($r_field_group['key'] == $field_group['key'])
            continue;
        
        // Bypass ACFE native groups
        if(in_array($r_field_group['key'], array('group_acfe_author', 'group_acfe_dynamic_post_type', 'group_acfe_dynamic_taxonomy')))
            continue;
        
        // Get related fields
        $r_fields = acf_get_fields($r_field_group['key']);
        if(empty($r_fields))
            continue;
        
        // Filter & find possible related fields
        foreach($r_fields as $r_field){
            
            acfe_bidirectional_setting_find_related($r_field, $r_field_group, $choices);
            
        }
        
    }
    
    // vars
    $results = array();
    $s = null;
    
    if(!empty($choices)){
    
        // search
        if($options['s'] !== ''){
            
            // strip slashes (search may be integer)
            $s = strval($options['s']);
            $s = wp_unslash($s);
            
        }
        
        foreach($choices as $field_group_title => $childs){
            
            $field_group_title = strval($field_group_title);
            
            $childrens = array();
            foreach($childs as $child_key => $child_label){
                
                $child_label = strval($child_label);
                
                // if searching, but doesn't exist
                if(is_string($s) && stripos($child_label, $s) === false && stripos($field_group_title, $s) === false)
                    continue(2);
                
                $childrens[] = array(
                    'id' => $child_key,
                    'text' => $child_label,
                );
                
            }
            
            $results[] = array(
                'text' => $field_group_title,
                'children' => $childrens
            );
            
        }
    
    }
    
    return array(
        'results' => $results
    );
    
}

function acfe_bidirectional_setting_find_related($r_field, $r_field_group, &$choices){
    
    if(in_array($r_field['type'], array('repeater', 'flexible_content')))
        return;
    
    // Recursive search for sub_fields (groups & clones)
    if(isset($r_field['sub_fields']) && !empty($r_field['sub_fields'])){
        
        foreach($r_field['sub_fields'] as $r_sub_field){
            
            // Recursive call
            return acfe_bidirectional_setting_find_related($r_sub_field, $r_field_group, $choices);
            
        }
        
    }
    
    // Allow only specific fields
    $allowed_fields_types = array('relationship', 'post_object', 'user', 'taxonomy');
    if(!in_array($r_field['type'], $allowed_fields_types))
        return false;
    
    $choices[$r_field_group['title']][$r_field['key']] = (!empty($r_field['label']) ? $r_field['label'] : $r_field['name']) . ' (' . $r_field['key'] . ')';
    
}

/**
 * Field Setting: Default Value
 */
add_filter('acf/prepare_field/name=acfe_bidirectional_related', 'acfe_bidirectional_setting_value');
function acfe_bidirectional_setting_value($field){
    
    if(!isset($field['value']) || empty($field['value']))
        return $field;
    
    // Get related field
    $r_field = acf_get_field($field['value']);
    
    // Related field not found
    if(!$r_field){
        
        // Unset & updatevalue
        $field['value'] = false;
        acf_update_field($field);
        
        return $field;
        
    }
    
    $r_field_group = acfe_get_field_group_from_field($r_field);
    
    $field['choices'] = array($r_field['key'] => (!empty($r_field['label']) ? $r_field['label'] : $r_field['name']) . ' (' . $r_field['key'] . ')');
    
    return $field;
    
}

/**
 * Field Setting Update
 */
add_filter('acf/update_field/type=relationship', 'acfe_bidirectional_setting_update');
add_filter('acf/update_field/type=post_object', 'acfe_bidirectional_setting_update');
add_filter('acf/update_field/type=user', 'acfe_bidirectional_setting_update');
add_filter('acf/update_field/type=taxonomy', 'acfe_bidirectional_setting_update');
function acfe_bidirectional_setting_update($field){
    
    $do_update = apply_filters('acfe/bidirectional/setting/update', true);
    if(!$do_update)
        return $field;
    
    // Previous setting values
    $_field = acf_get_field($field['key']);
    
    // Turning off - Remove related field
    if(acfe_has_field_bidirectional($_field) && !acfe_has_field_bidirectional($field)){
        
        // Get related bidirectional related
        $r_field = acf_get_field($_field['acfe_bidirectional']['acfe_bidirectional_related']);
        
        // Reset related bidirectional related
        $r_field['acfe_bidirectional']['acfe_bidirectional_enabled'] = false;
        $r_field['acfe_bidirectional']['acfe_bidirectional_related'] = false;
        
        add_filter('acfe/bidirectional/setting/update', '__return_false');
        
            // Update related bidirectional
            acf_update_field($r_field);
        
        remove_filter('acfe/bidirectional/setting/update', '__return_false');
        
        return $field;
        
    }
    
    // Turning on - Add related field
    elseif(!acfe_has_field_bidirectional($_field) && acfe_has_field_bidirectional($field)){
            
        // Get related bidirectional related
        $r_field = acf_get_field($field['acfe_bidirectional']['acfe_bidirectional_related']);
            
        // Reset related bidirectional related
        $r_field['acfe_bidirectional']['acfe_bidirectional_enabled'] = true;
        $r_field['acfe_bidirectional']['acfe_bidirectional_related'] = $field['key'];
        
        add_filter('acfe/bidirectional/setting/update', '__return_false');
        
            // Update related bidirectional
            acf_update_field($r_field);
        
        remove_filter('acfe/bidirectional/setting/update', '__return_false');
        
        return $field;
        
    }
    
    // Return
    return $field;
    
}

/**
 * Field Setting Deleted
 */
add_action('acf/delete_field/type=relationship', 'acfe_bidirectional_setting_delete');
add_filter('acf/delete_field/type=post_object', 'acfe_bidirectional_setting_delete');
add_filter('acf/delete_field/type=user', 'acfe_bidirectional_setting_delete');
add_filter('acf/delete_field/type=taxonomy', 'acfe_bidirectional_setting_delete');
function acfe_bidirectional_setting_delete($field){
    
    if(!acfe_has_field_bidirectional($field))
        return;
    
    // Get related bidirectional related
    $r_field = acf_get_field($field['acfe_bidirectional']['acfe_bidirectional_related']);
    
    // Reset related bidirectional related
    $r_field['acfe_bidirectional']['acfe_bidirectional_related'] = false;
    
    // Update related bidirectional
    acf_update_field($r_field);
    
}

/**
 * Update Value
 */
add_filter('acf/update_value/type=relationship', 'acfe_bidirectional_update_value', 11, 3);
add_filter('acf/update_value/type=post_object', 'acfe_bidirectional_update_value', 11, 3);
add_filter('acf/update_value/type=user', 'acfe_bidirectional_update_value', 11, 3);
add_filter('acf/update_value/type=taxonomy', 'acfe_bidirectional_update_value', 11, 3);
function acfe_bidirectional_update_value($value, $post_id, $field){
    
    $ignore = apply_filters('acfe/bidirectional/ignore', false, $value, $post_id, $field);
    if($ignore)
        return $value;
    
    // Check if bidirectional
    if(!acfe_get_field_bidirectional($field))
        return $value;
    
    // Decode current post_id (ie: user_1)
    $request = acf_decode_post_id($post_id);
    
    // Values
    $old_values = acf_get_array(acf_get_metadata($post_id, $field['name']));
    $new_values = acf_get_array($value);
    
    // Bail early if no difference
    if($old_values == $new_values)
        return $value;
        
    // Values have been removed
    if(!empty($old_values)){
        foreach($old_values as $r_id){
            
            if(in_array($r_id, $new_values))
                continue;
            
            acfe_bidirectional_relationship('remove', $r_id, $field, $request['id']);
            
        }
    }
    
    // Values have been added
    if(!empty($new_values)){
        foreach($new_values as $r_id){
            
            if(in_array($r_id, $old_values))
                continue;
            
            acfe_bidirectional_relationship('add', $r_id, $field, $request['id']);
            
        }
    }
    
    return $value;
    
}

/**
 * Establish Relationship
 *
 * $type: add|remove
 * $r_id: the post_id to add the relationship to
 * $p_field: the parent field
 * $p_id: the relationship to add
 */
function acfe_bidirectional_relationship($type = 'add', $r_id, $p_field, $p_value){
    
    // Get Related Field Configuration
    $r_field = acf_get_field($p_field['acfe_bidirectional']['acfe_bidirectional_related']);
    
    // Get if bidirectional is active
    if(!acfe_get_field_bidirectional($r_field))
        return;
    
    // Get Related Data Type ({post_id}, user_{id} ...)
    $r_mtype = '';
    if($p_field['type'] == 'user')
        $r_mtype = 'user_';
    elseif($p_field['type'] == 'taxonomy')
        $r_mtype = 'term_';
    
    // Get Related Field Ancestors
    $r_field_ancestors = acf_get_field_ancestors($r_field);
    
    // Ancestors - Complexe field (group|clone)
    if(!empty($r_field_ancestors)){
        
        // Get ancestors
        $r_field_ancestors = array_reverse($r_field_ancestors);
        $r_field_ancestors_fields = array_map('acf_get_field', $r_field_ancestors);
        
        // Get top ancestor
        $r_ref_field = $r_field_ancestors_fields[0];
        $r_ref_values = acf_get_array(acf_get_value($r_mtype.$r_id, $r_ref_field));
        
        // Get values
        $r_values = acf_get_array(acfe_get_value_from_ancestor($r_ref_values, $r_field));
        
        // Unset top ancestor for update (not needed)
        unset($r_field_ancestors_fields[0]);
        
        // Add related field to get
        $r_values_query = array($r_field['key']);
        
        // If > 1 ancestors, return ancestors keys only
        if(!empty($r_field_ancestors_fields)){
            
            $r_field_ancestors_keys = array_map(function($field){
                return $field['key'];
            }, $r_field_ancestors_fields);
            
            // Add ancestors to get
            $r_values_query = array_merge($r_field_ancestors_keys, $r_values_query);
            
        }
        
    }
    
    // No Ancestors - Simple field
    else{
        
        // Refence field
        $r_ref_field = $r_field;
        
        // Values
        $r_values = acf_get_array(acf_get_value($r_mtype.$r_id, $r_field));
        
    }
    
    // Add Value
    if($type == 'add'){
        
        if(!in_array($p_value, $r_values))
            $r_values[] = $p_value;
        
    }
    
    // Remove Value
    elseif($type == 'remove'){
            
        $r_new_values = array();
        foreach($r_values as $r_value){
            
            if($r_value == $p_value)
                continue;
            
            $r_new_values[] = $r_value;
            
        }
        
        $r_values = $r_new_values;
        
    }
    
    /*
     * Construct a value array in case of ancestors. ie:
     * $related_values = Array(
     *     [field_aaa] => Array(
     *         [field_bbb] => Array(
     *             [0] => xxxx
     *         )
     *     )
     * )
     */
    if(!empty($r_field_ancestors)){
        
        for($i = count($r_values_query)-1; $i>=0; $i--){
            $r_values = array($r_values_query[$i] => $r_values);
        }
        
    }
        
    // Filter acf_update_value (to avoid infinite loop)
    add_filter('acfe/bidirectional/ignore', '__return_true');
    
        // Update Related Field
        acf_update_value($r_values, $r_mtype.$r_id, $r_ref_field);
    
    // Remove acf_update_value filter
    remove_filter('acfe/bidirectional/ignore', '__return_true');
    
}

function acfe_get_value_from_ancestor($r_ref_values, $r_field){
    
    foreach($r_ref_values as $r_ref_key => $r_ref_value){
        
        if($r_ref_key != $r_field['key']){
            
            if(is_array($r_ref_value))
                return acfe_get_value_from_ancestor($r_ref_value, $r_field);
            
            return false;
            
        }
        
        return $r_ref_value;
        
    }
    
}

function acfe_is_field_bidirectional($field){
    
    return isset($field['acfe_bidirectional']['acfe_bidirectional_enabled']) && !empty($field['acfe_bidirectional']['acfe_bidirectional_enabled']);
    
}

function acfe_has_field_bidirectional($field){
    
    return isset($field['acfe_bidirectional']['acfe_bidirectional_related']) && !empty($field['acfe_bidirectional']['acfe_bidirectional_related']);
    
}

function acfe_get_field_bidirectional($field){
    
    if(!acfe_is_field_bidirectional($field) || !acfe_has_field_bidirectional($field))
        return false;
    
    return $field['acfe_bidirectional']['acfe_bidirectional_related'];
    
}