class-settings.php

<?php

namespace WPCT_ABSTRACT;

if (!class_exists('\WPCT_ABSTRACT\Settings')) :

    class Undefined
    {
    };

    abstract class Settings extends Singleton
    {
        protected $group_name;
        protected $_default = [];

        abstract public function register();

        public function __construct($textdomain)
        {
            $this->group_name = $textdomain;
        }

        public function get_name()
        {
            return $this->group_name;
        }

        public function register_setting($name)
        {
            $default = $this->get_default($name);
            $default = $this->get_default($name, $default);
            register_setting(
                $this->group_name,
                $name,
                [
                    'type' => 'array',
                    'show_in_rest' => false,
                    'default' => $default,
                ],
            );

            add_settings_section(
                $name . '_section',
                __($name . '--title', 'wpct'),
                function () use ($name) {
                    $title = __($name . '--description', 'wpct');
                    echo "<p>{$title}</p>";
                },
                $this->group_name,
            );

            $this->_default[$name] = $default;

            foreach (array_keys($default) as $field) {
                $this->register_field($field, $name);
            }
        }

        public function register_field($field_name, $setting_name)
        {
            $field_id = $setting_name . '__' . $field_name;
            add_settings_field(
                $field_name,
                __($field_id . '--label', 'wpct'),
                function () use ($setting_name, $field_name) {
                    echo $this->field_render($setting_name, $field_name);
                },
                $this->group_name,
                $setting_name . '_section',
                [
                    'class' => $field_id,
                ]
            );
        }

        public function field_render()
        {
            $args = func_get_args();
            $setting = $args[0];
            $field = $args[1];
            if (count($args) >= 3) {
                $value = $args[2];
            } else {
                $value = new Undefined();
            }

            return $this->_field_render($setting, $field, $value);
        }

        private function _field_render($setting, $field, $value)
        {
            $is_root = false;
            if ($value instanceof Undefined) {
                $value = $this->option_getter($setting, $field);
                $is_root = true;
            }

            if (!is_array($value)) {
                return $this->input_render($setting, $field, $value);
            } else {
                $fieldset = $this->fieldset_render($setting, $field, $value);
                if ($is_root) {
                    $fieldset = $this->control_style($setting, $field)
                        . $fieldset . $this->control_render($setting, $field);
                }

                return $fieldset;
            }
        }

        public function input_render($setting, $field, $value)
        {
            $default_value = $this->get_default($setting);
            $keys = explode('][', $field);
            $is_list = is_list($default_value);
            for ($i = 0; $i < count($keys); $i++) {
                $key = $keys[$i];
                if ($is_list) {
                    $key = (int) $key;
                }
                $default_value = isset($default_value[$key]) ? $default_value[$key] : $default_value[0];
                $is_list = is_list($default_value);
            }
            $is_bool = is_bool($default_value);
            if ($is_bool) {
                $is_bool = true;
                $value = 'on' === $value;
            }

            if ($is_bool) {
                return "<input type='checkbox' name='{$setting}[$field]' " . ($value ? 'checked' : '') . " />";
            } else {
                return "<input type='text' name='{$setting}[{$field}]' value='{$value}' />";
            }
        }

        public function fieldset_render($setting, $field, $data)
        {
            $table_id = $setting . '__' . str_replace('][', '_', $field);
            $fieldset = "<table id='{$table_id}'>";
            $is_list = is_list($data);
            foreach (array_keys($data) as $key) {
                $fieldset .= '<tr>';
                if (!$is_list) {
                    $fieldset .= "<th>{$key}</th>";
                }
                $_field = $field . '][' . $key;
                $fieldset .= "<td>{$this->field_render($setting, $_field, $data[$key])}</td>";
                $fieldset .= '</tr>';
            }
            $fieldset .= '</table>';

            return $fieldset;
        }

        public function control_render($setting, $field)
        {
            $default = $this->get_default($setting);
            ob_start();
            ?>
        <div class="<?= $setting; ?>__<?= $field ?>--controls">
            <button class="button button-primary" data-action="add">Add</button>
            <button class="button button-secondary" data-action="remove">Remove</button>
        </div>
        <?php include 'fieldset-control-js.php' ?>
<?php
            return ob_get_clean();
        }

        public function control_style($setting, $field)
        {
            return "<style>#{$setting}__{$field} td td,#{$setting}__{$field} td th{padding:0}#{$setting}__{$field} table table{margin-bottom:1rem}</style>";
        }

        public function option_getter($setting, $option)
        {
            $default = $this->get_default($setting, $option);
            $setting = get_option($setting) ?: [];
            if (!key_exists($option, $setting)) {
                return null;
            }

            if (empty($setting[$option])) {
                return $default;
            } elseif (is_list($setting[$option])) {
                // $setting[$option] = array_map($setting[$option]);
            }

            return $setting[$option];
        }

        public function get_default($setting_name, $field = null)
        {
            $default = usset($this->_default[$setting_name]) ?: [];
            $default = apply_filters($setting_name . '_default', $default);

            if ($field && isset($default[$field])) {
                return $default[$field];
            }

            return $default;
        }
    }

endif;

if (!function_exists('\WPCT_ABSTRACT\is_list')) :

    function is_list($arr)
    {
        if (!is_array($arr)) {
            return false;
        }
        if (sizeof($arr) === 0) {
            return true;
        }
        return array_keys($arr) === range(0, count($arr) - 1);
    }

endif;