<?php namespace ProcessWire;

/**
 * Base for selection form inputs, which by default behaves as a regular <select>
 *
 * Serves as the base for Inputfields that provide selection of options (whether single or multi).
 * As a result, this class includes functionality for, and checks for both single-and-multi selection values. 
 * Sublcasses will want to override the render method, but it's not necessary to override processInput().
 * Subclasses that select multiple values should implement the InputfieldHasArrayValue interface. 
 * 
 * @property string|int $defaultValue
 *
 */
class InputfieldSelect extends Inputfield {

	/**
	 * Options specific to this Select
	 *
	 */
	protected $options = array();

	/**
	 * Attributes for options specific to this select (if applicable)
	 *
	 */
	protected $optionAttributes = array();

	/**
	 * Return information about this module
	 *
	 */
	public static function getModuleInfo() {
		return array(
			'title' => __('Select', __FILE__), // Module Title
			'summary' => __('Selection of a single value from a select pulldown', __FILE__), // Module Summary
			'version' => 102,
			'permanent' => true, 
			);
	}

	public function __construct() {
		parent::__construct();
		$this->set('defaultValue', ''); 
	}

	/**
	 * Add an option that may be selected
	 *
	 * If you want to add an optgroup, use the $value param as the label, and the label param as an array of options. 
	 * Note that optgroups may not be applicable to other Inputfields that descend from InputfieldSelect.
	 *
	 * @param string $value Value that the option submits
	 * @param string $label|array Optional label associated with the value (if null, value will be used as the label)
	 * @param array $attributes Optional attributes to be associated with this option (i.e. a 'selected' attribute for
	 *     an <option> tag)
	 * @return $this
	 *
	 */
	public function addOption($value, $label = null, array $attributes = null) {
		if(is_null($label) || (is_string($label) && !strlen($label))) $label = $value; 
		$this->options[$value] = $label; 	
		if(!is_null($attributes)) $this->optionAttributes[$value] = $attributes; 
		return $this; 
	}

	/**
	 * Add multiple options at once
	 *
 	 * @param array $options May be associative or regular array. If associative, use $value => $label. If regular,
 	 *     use just array($value, ...)
	 * @return $this
	 *
	 */
	public function addOptions(array $options) {
		foreach($options as $k => $v) {
			$this->addOption($k, $v); 
		}
		return $this; 
	}

	/**
	 * Given a multi-line string, convert it to options, one per line
	 *
	 * Lines preceded with a plus "+" are assumed selected, i.e. +option
	 * Lines with an equals sign are split into separate value and label, i.e. value=label
	 *
	 * @param string $value 
	 * @return $this
	 *
	 */
	public function addOptionsString($value) {

		$value = (string) $value; 
		$options = explode("\n", $value);
		$lastOption = '';
		$optgroup = array();
		$optgroupLabel = '';

		foreach($options as $option) {

			// in an optgroup when line starts with 3 or more spaces
			if(strpos($option, '   ') === 0 && !empty($lastOption)) {
				// if no optgroupLabel, we're starting a new option group
				if(empty($optgroupLabel)) $optgroupLabel = $lastOption; 
				$option = trim($option);
			} else {
				if($optgroupLabel) $this->addOption($optgroupLabel, $optgroup); 
				$optgroup = array();
				$optgroupLabel = '';
			}

			$option = trim($option); 
			$attrs = array(); 
			$label = null;

			// if option starts with a plus then make it selected
			if(substr($option, 0, 1) == '+') $attrs['selected'] = 'selected';

			// option option has an equals "=", but not "==", then assume it's a: value=label
			if(strpos($option, '=') !== false && strpos($option, '==') === false) list($option, $label) = explode('=', $option); 	

			// convert double equals "==" to single equals "=", as a means of allowing escaped equals sign
			if(strpos($option, '==') !== false) $option = str_replace('==', '=', $option);

			$option = trim($option, '+ '); 
	
			if($optgroupLabel) {
				// add option to optgroup
				$optgroup[$option] = is_null($label) ? $option : $label;
				if(count($attrs)) $this->optionAttributes[$option] = $attrs; 
			} else {	
				// add the option
				$this->addOption($option, $label, $attrs);
			}

			$lastOption = $option;
		}

		if($optgroupLabel && count($optgroup)) $this->addOption($optgroupLabel, $optgroup);

		return $this; 
	}

	/**
	 * Remove the option with the given value
	 * 
	 * @param string|int $value
	 * @return $this
	 *
	 */
	public function removeOption($value) {
		unset($this->options[$value]); 
		return $this; 
	}
		
	/**
	 * Get all options for this Select
	 *
	 * @return array
	 *
	 */
	public function getOptions() {
		return $this->options; 
	}

	/**
	 * Returns whether the provided value is one of the available options
	 *
	 * @param string|int $value
	 * @param array $options Array of options to check, or omit if using this classes options. 
	 * @return bool
	 *
	 */
	public function isOption($value, array $options = null) {

		if(is_null($options)) $options = $this->options; 
		$is = false;
		
		foreach($options as $key => $option) {
			if(is_array($option)) {
				// fieldgroup
				if($this->isOption($value, $option)) {
					$is = true;
					break;
				}
			} else {
				if("$value" === "$key") {
					$is = true;
					break;
				}
			}
		}
		
		return $is; 
	}

	/**
	 * Returns whether the provided value is selected
	 * 
	 * @param string|int $value
	 * @return bool
	 *
	 */
	public function isOptionSelected($value) {

		$valueAttr = $this->attr('value'); 
		if(empty($valueAttr)) {
			// no value set yet, check if it's set in any of the option attributes
			$selected = false;
			if(isset($this->optionAttributes[$value])) {
				$attrs = $this->optionAttributes[$value]; 
				if(!empty($attrs['selected']) || !empty($attrs['checked'])) $selected = true; 
				
			}
			if($selected) return true; 
		}

		if($this instanceof InputfieldHasArrayValue) { 
			// multiple selection
			/** @var InputfieldSelect $this */
			return in_array($value, $this->attr('value')); 
		}

		return "$value" == (string) $this->value; 
	}

	/**
	 * Is the given option value disabled?
	 * 
	 * @param $value
	 * @return bool
	 * 
	 */
	public function isOptionDisabled($value) {
		$disabled = false;
		if(isset($this->optionAttributes[$value])) {
			$attrs = $this->optionAttributes[$value];
			if(!empty($attrs['disabled'])) $disabled = true; 
		}
		return $disabled;
	}

	/**
	 * Render the given options
	 * 
	 * @param array $options
	 * @param bool $allowBlank
	 * @return string
	 * 
	 */
	protected function renderOptions($options, $allowBlank = true) {

		$out = '';
		reset($options); 
		$key = key($options); 
		$hasBlankOption = empty($key); 
		if($allowBlank && !$this->required && !$this->attr('multiple') && !$hasBlankOption) {
			$out .= "<option value=''>&nbsp;</option>";
		}

		foreach($options as $value => $label) {

			if(is_array($label)) {
				$out .= 
					"<optgroup label='" . htmlspecialchars($value, ENT_QUOTES, 'UTF-8') . "'>" . 
					$this->renderOptions($label, false) . 
					"</optgroup>";
				continue; 
			}

			$selected = $this->isOptionSelected($value) ? " selected='selected'" : '';
			$attrs = $this->getOptionAttributesString($value);
			$out .= 
				"<option$selected $attrs value='" . htmlspecialchars($value, ENT_QUOTES, "UTF-8") . "'>" . 
				$this->entityEncode($label) . 
				"</option>";
		}

		return $out; 
	}

	/**
	 * Check for default value and populate when appropriate
	 *
	 * This should be called at the beginning of render() and at the end of processInput()
	 *
	 */
	protected function checkDefaultValue() {

		if(!$this->required || !$this->defaultValue || !$this->isEmpty()) return;

		// when a value is required and the value is empty and a default value is specified, we use it.
		if($this instanceof InputfieldHasArrayValue) {
			/** @var InputfieldSelect $this */
			$value = explode("\n", $this->defaultValue); 
			foreach($value as $k => $v) {
				$value[$k] = trim($v); // remove possible extra LF
			}
		} else {
			$value = $this->defaultValue; 
			$pos = strpos($value, "\n"); 
			if($pos) $value = substr($value, 0, $pos); 
			$value = trim($value); 
		}
		$this->attr('value', $value); 
	}

	/**
	 * Render and return the output for this Select
	 * 
	 * @return string
	 *
	 */
	public function ___render() {
		$this->checkDefaultValue();
		$attrs = $this->getAttributes();
		unset($attrs['value']); 

		$out =	
			"<select " . $this->getAttributesString($attrs) . ">" . 
			$this->renderOptions($this->options) . 
			"</select>";

		return $out; 
	}

	/**
	 * Render non-editable value
	 * 
	 * @return string
	 * 
	 */
	public function ___renderValue() {
		
		$out = '';
		
		foreach($this->options as $value => $label) {
			
			$o = '';
			
			if(is_array($label)) {
				foreach($label as $k => $v) {
					if($this->isOptionSelected($k)) {
						$o = trim($value, ' :') . ": $v";
					}
				}
			} else {
				if($this->isOptionSelected($value)) $o = $label;
			}
			
			if(strlen($o)) {
				$out .= "<li>" . $this->wire('sanitizer')->entities($o) . "</li>";
			}
		}
	
		if(strlen($out)) $out = "<ul class='pw-bullets'>$out</ul>";
		
		return $out; 
	}

	/**
	 * Get an attributes array intended for the <option> element
	 *
	 * @param string $key
	 * @return array
	 *
	 */
	public function getOptionAttributes($key) {
		if(!isset($this->optionAttributes[$key])) return array();
		return $this->optionAttributes[$key]; 
	}

	/**
	 * Get an attributes string intended for the <option> element
	 *
	 * @param string|array $key If an array, it will be assumed to the attributes you want rendered. If a key for an
	 *     existing option, then  the attributes for that option will be rendered. 
	 * @return string
	 *
	 */
	protected function getOptionAttributesString($key) {

		if(is_array($key)) $attrs = $key; 
			else if(!isset($this->optionAttributes[$key])) return '';
			else $attrs = $this->optionAttributes[$key]; 

		return $this->getAttributesString($attrs); 
	}

	/**
	 * Process input from the provided array
	 *
	 * In this case we're having the Inputfield base process the input and we're going back and validating the value.
	 * If the value(s) that were set aren't in our specific list of options, we remove them. This is a security measure.
	 *
	 * @param WireInputData $input
	 * @return $this
	 *
	 */
	public function ___processInput(WireInputData $input) {

		parent::___processInput($input); 	

		$name = $this->attr('name');
		if(!isset($input[$name])) {
			$value = $this instanceof InputfieldHasArrayValue ? array() : null;
			$this->setAttribute('value', $value); 
			return $this;
		}

		// validate that the selected posted option(s) are those from our options list 
		// removing any that aren't

		$value = $this->attr('value'); 

		if($this instanceof InputfieldHasArrayValue) {
			/** @var InputfieldSelect $this */
			foreach($value as $k => $v) {
				if(!$this->isOption($v)) {
					// $this->message("Removing invalid option: " . wire('sanitizer')->entities($value[$k]), Notice::debug); 
					unset($value[$k]); 
				}
			}

		} else if($value && !$this->isOption($value)) {
			$value = null;
		}

		$this->setAttribute('value', $value); 
		$this->checkDefaultValue();

		return $this; 
	}

	/**
	 * Get property
	 * 
	 * @param string $key
	 * @return array|mixed|null
	 * 
	 */
	public function get($key) {
		if($key == 'options') return $this->options; 
		if($key == 'optionAttributes') return $this->optionAttributes;
		return parent::get($key); 
	}

	/**
	 * Set property
	 * 
	 * @param string $key
	 * @param mixed $value
	 * @return Inputfield|InputfieldSelect
	 * 
	 */
	public function set($key, $value) {

		if($key == 'options') {
			if(is_string($value)) return $this->addOptionsString($value); 
			if(is_array($value)) $this->options = $value; 	
			return $this;
		} 

		return parent::set($key, $value); 
	}

	/**
	 * Set attribute
	 * 
	 * @param array|string $key
	 * @param array|int|string $value
	 * @return Inputfield|InputfieldSelect
	 * 
	 */
	public function setAttribute($key, $value) {
		if($key == 'value') {
			if(is_object($value) || (is_string($value) && strpos($value, '|'))) {
				$value = (string) $value;
				if($this instanceof InputfieldHasArrayValue) {
					$value = explode('|', $value);
				}
			} else if(is_array($value)) {
				if($this instanceof InputfieldHasArrayValue) {
					// ok
				} else {
					$value = reset($value); 
				}
			}
		}
		return parent::setAttribute($key, $value);
	}

	/**
	 * Is the value empty?
	 * 
	 * @return bool
	 * 
	 */
	public function isEmpty() {
		$value = $this->attr('value');

		if(is_array($value)) {
			$cnt = count($value);
			if(!$cnt) return true; 
			if($cnt === 1) return strlen(reset($value)) === 0; 
			return false; // $cnt > 1

		} else if($value === null || $value === false) {
			return true; 

		} else if($value == "0") {
			if(!array_key_exists("$value", $this->options)) return true; 

		} else {
			return strlen($value) === 0; 
		}
		
		return false;
	}

	/**
	 * Field configuration
	 * 
	 * @return InputfieldWrapper
	 * 
	 */
	public function ___getConfigInputfields() {

		$inputfields = parent::___getConfigInputfields();

		if($this instanceof InputfieldHasArrayValue) {
			$f = $this->wire('modules')->get('InputfieldTextarea');
			$f->description = $this->_('To have pre-selected default value(s), enter the option values (one per line) below.'); 
		} else {
			$f = $this->wire('modules')->get('InputfieldText');
			$f->description = $this->_('To have a pre-selected default value, enter the option value below.'); 
		}
		$f->attr('name', 'defaultValue'); 
		$f->label = $this->_('Default value'); 
		$f->attr('value', $this->defaultValue);
		$f->description .= ' ' . $this->_('For default page selection, the value would be the page ID number.'); 
		$f->notes = $this->_('IMPORTANT: The default value is not used unless the field is required (see the “required” checkbox on this screen).'); 
		$f->collapsed = $this->hasFieldtype === false ? Inputfield::collapsedBlank : Inputfield::collapsedNo;
		
		$inputfields->add($f); 

		// if dealing with an inputfield that has an associated fieldtype, 
		// we don't need to perform the remaining configuration
		if($this->hasFieldtype === false) {

			$isInputfieldSelect = $this->className() == 'InputfieldSelect';

			$f = $this->wire('modules')->get('InputfieldTextarea'); 
			$f->attr('name', 'options'); 
			$value = '';
			foreach($this->options as $key => $option) {
				if(is_array($option)) {
					$value .= "$key\n";
					foreach($option as $o) {
						$value .= "   $o\n";
					}
				} else {
					$value .= "$option\n";
				}
			}
			$value = trim($value);
			if(empty($value)) {
				$value = "=\nOption 1\nOption 2\nOption 3";
				if(!$isInputfieldSelect) $value = ltrim($value, '='); 
			}
			$f->attr('value', $value); 
			$f->attr('rows', 10); 
			$f->label = $this->_('Options');
			$f->description = $this->_('Enter the options that may be selected, one per line.');
			$f->notes = 
				($isInputfieldSelect ? $this->_('To precede your list with a blank option, enter just a equals sign "=" as the first option.') . "\n" : '') . 
				$this->_('To make an option selected, precede it with a plus sign. Example: +My Option') . "\n" . 
				$this->_('To keep a separate value and label, separate them with an equals sign. Example: value=My Option') . "\n" . 
				($isInputfieldSelect ? $this->_('To create an optgroup (option group) indent the options in the group with 3 or more spaces.') : ''); 
				
			$inputfields->add($f); 
		}

		return $inputfields; 
	}

	
}