<?php namespace Backend\Classes;

use Str;

/**
 * Form Field definition
 * A translation of the form field configuration
 *
 * @package october\backend
 * @author Alexey Bobkov, Samuel Georges
 */
class FormField
{
    /**
     * @var string Form field name.
     */
    public $fieldName;

    /**
     * @var string If the field element names should be contained in an array.
     * Eg: <input name="nameArray[fieldName]" />
     */
    public $arrayName;

    /**
     * @var string A prefix to the field identifier so it can be totally unique.
     */
    public $idPrefix;

    /**
     * @var string Form field label.
     */
    public $label;

    /**
     * @var string Form field value.
     */
    public $value;

    /**
     * @var string Model attribute to use for the display value.
     */
    public $valueFrom;

    /**
     * @var string Specifies if this field belongs to a tab.
     */
    public $tab;

    /**
     * @var string Display mode. Text, textarea
     */
    public $type = 'text';

    /**
     * @var string Field options.
     */
    public $options;

    /**
     * @var string Specifies a side. Possible values: auto, left, right, full.
     */
    public $span = 'full';

    /**
     * @var string Specifies a size. Possible values: tiny, small, large, huge, giant.
     */
    public $size = 'large';

    /**
     * @var string Specifies contextual visibility of this form field.
     */
    public $context = null;

    /**
     * @var bool Specifies if this field is mandatory.
     */
    public $required = false;

    /**
     * @var bool Specify if the field is disabled or not.
     */
    public $disabled = false;

    /**
     * @var bool Specifies if this field stretch to fit the page height.
     */
    public $stretch = false;

    /**
     * @var string Specifies a comment to accompany the field
     */
    public $comment;
    
    /**
     * @var string Specifies the comment position.
     */
    public $commentPosition = 'below';

    /**
     * @var string Specifies if the comment is in HTML format.
     */
    public $commentHtml = false;

    /**
     * @var string Specifies a default value for supported fields.
     */
    public $defaults;

    /**
     * @var string Specifies a message to display when there is no value supplied (placeholder).
     */
    public $placeholder;

    /**
     * @var array Contains a list of attributes specified in the field configuration.
     */
    public $attributes;

    /**
     * @var string Specifies a CSS class to attach to the field container.
     */
    public $cssClass;

    /**
     * @var string Specifies a path for partial-type fields.
     */
    public $path;

    /**
     * @var array Raw field configuration.
     */
    public $config;

    /**
     * @var array Other field names this field depends on, when the other fields are modified, this field will update.
     */
    public $depends;

    /**
     * Constructor.
     * @param string $fieldName
     * @param string $label
     */
    public function __construct($fieldName, $label)
    {
        $this->fieldName = $fieldName;
        $this->label = $label;
    }

    /**
     * If this field belongs to a tab.
     */
    public function tab($value)
    {
        $this->tab = $value;
        return $this;
    }

    /**
     * Sets a side of the field on a form.
     * @param string $value Specifies a side. Possible values: left, right, full
     */
    public function span($value = 'full')
    {
        $this->span = $value;
        return $this;
    }

    /**
     * Sets a side of the field on a form.
     * @param string $value Specifies a size. Possible values: tiny, small, large, huge, giant
     */
    public function size($value = 'large')
    {
        $this->size = $value;
        return $this;
    }

    /**
     * Sets field options, for dropdowns, radio lists and checkbox lists.
     * @param  array $value
     * @return self
     */
    public function options($value = null)
    {
        if ($value === null) {
            if (is_array($this->options)) {
                return $this->options;
            }
            elseif (is_callable($this->options)) {
                $callable = $this->options;
                return $callable();
            }

            return [];
        }
        else {
            $this->options = $value;
        }

        return $this;
    }

    /**
     * Specifies a field control rendering mode. Supported modes are:
     * - text - creates a text field. Default for varchar column types.
     * - textarea - creates a textarea control. Default for text column types.
     * - dropdown - creates a drop-down list. Default for reference-based columns.
     * - radio - creates a set of radio buttons.
     * - checkbox - creates a single checkbox.
     * - checkboxlist - creates a checkbox list.
     * @param string $type Specifies a render mode as described above
     * @param array $config A list of render mode specific config.
     */
    public function displayAs($type, $config = [])
    {
        $this->type = strtolower($type) ?: $this->type;
        $this->config = $this->evalConfig($config);
        return $this;
    }

    /**
     * Process options and apply them to this object.
     * @param array $config
     * @return array
     */
    protected function evalConfig($config)
    {
        if (isset($config['options'])) $this->options($config['options']);
        if (isset($config['span'])) $this->span($config['span']);
        if (isset($config['context'])) $this->context = $config['context'];
        if (isset($config['size'])) $this->size($config['size']);
        if (isset($config['tab'])) $this->tab($config['tab']);
        if (isset($config['commentAbove'])) $this->comment($config['commentAbove'], 'above');
        if (isset($config['comment'])) $this->comment($config['comment']);
        if (isset($config['placeholder'])) $this->placeholder = $config['placeholder'];
        if (isset($config['default'])) $this->defaults = $config['default'];
        if (isset($config['cssClass'])) $this->cssClass = $config['cssClass'];
        if (isset($config['attributes'])) $this->attributes = $config['attributes'];
        if (isset($config['depends'])) $this->depends = $config['depends'];
        if (isset($config['path'])) $this->path = $config['path'];

        if (array_key_exists('required', $config)) $this->required = $config['required'];
        if (array_key_exists('disabled', $config)) $this->disabled = $config['disabled'];
        if (array_key_exists('stretch', $config)) $this->stretch = $config['stretch'];

        if (isset($config['valueFrom'])) $this->valueFrom = $config['valueFrom'];
        else $this->valueFrom = $this->fieldName;

        return $config;
    }

    /**
     * Adds a text comment above or below the field.
     * @param string $text Specifies a comment text.
     * @param string $position Specifies a comment position.
     * @param bool $isHtml Set to true if you use HTML formatting in the comment
     * Supported values are 'below' and 'above'
     */
    public function comment($text, $position = 'below', $isHtml = false)
    {
        $this->comment = $text;
        $this->commentPosition = $position;
        $this->commentHtml = $isHtml;
        return $this;
    }

    /**
     * Returns a value suitable for the field name property.
     * @param  string $arrayName Specify a custom array name
     * @return string
     */
    public function getName($arrayName = null)
    {
        if ($arrayName === null)
            $arrayName = $this->arrayName;

        if ($arrayName)
            return $arrayName.'['.implode('][', Str::evalHtmlArray($this->fieldName)).']';
        else
            return $this->fieldName;
    }

    /**
     * Returns a value suitable for the field id property.
     */
    public function getId($suffix = null)
    {
        $id = 'field';
        if ($this->arrayName)
            $id .= '-'.$this->arrayName;

        $id .= '-'.$this->fieldName;

        if ($suffix)
            $id .= '-'.$suffix;

        if ($this->idPrefix)
            $id = $this->idPrefix . '-' . $id;

        return Str::evalHtmlId($id);
    }
}