<?php

namespace dokuwiki\plugin\bez\mdl;

use dokuwiki\plugin\bez\meta\ValidationException;

class Validator {
	private $rules=array(), $errors=array(), $model;
	public function __construct($model) {
		$this->model = $model;
	}

	public function add_rule($field, $rule) {
        $this->rules[$field] = $rule;
    }

    public function delete_rule($field) {
	    if (isset($this->rules[$field])) {
            unset($this->rules[$field]);
        }
    }
	
	public function set_rules($rules) {
		$this->rules = array_merge($this->rules, $rules);
	}
	
	public function get_rules() {
		return $this->rules;
	}

	public function get_rule($field) {
	    if (!isset($this->rules[$field])) {
            throw new \Exception("no rule exists for $field");
        }
        return $this->rules[$field];
    }
	
	public function get_errors() {
		return $this->errors;
	}
	
	public function set_error($field, $code) {
		$this->errors[$field] = $code;
	}
	
	protected function check_against_val_method($value, $method, $args) {
		$validator = 'validate_'.$method;
		if (!method_exists($this, $validator)) {
			throw new \Exception("there is no validation function $validator");
		}
		
		array_unshift($args, $value);
		$result = call_user_func_array(array($this, $validator), $args);
		return array($result, $method);
	}
	
	protected function validate_one($value, $method, $args, $null) {
			if ($null === 'NOT NULL' && $value == '') {
				return array(false, 'is_null');
			} else if ($null === 'NULL' && $value == '') {
				return array(true, 'is_null');
			}

			return $this->check_against_val_method($value, $method, $args);
	}
    
    public function validate_field($field, $value) {
        if (!isset($this->rules[$field])) {
            throw new \Exception('no validation rule for '.$field);
        }
            
        $args = $this->rules[$field][0];
        $null = $this->rules[$field][1];

        $method = array_shift($args);
        list($result, $code) = $this->validate_one($value, $method, $args, $null);
        if ($result === false) {
            throw new ValidationException('-unknown', array($field => $code));
        }
        
        /*by convention all values as passed as strings*/
        return (string) $value;
    }
	
	public function validate($data, $fields=null) {
		$val_data = array();

		if (is_null($fields)) {
		    $fields = array_keys($this->rules);
        }

		foreach ($data as $key => $value) {
			if (!in_array($key, $fields)) {
				continue;
			}
			try {
                $val_data[$key] = $this->validate_field($key, $value);
                
            } catch (ValidationException $e) {
				$this->errors[$key] = $e->get_errors()[$key];
			}
		}
		if (count($this->errors) > 0) {
			return false;
		}

		return $val_data;
	}
	
	public function validate_array_of($array, $args) {
		
		$method = array_shift($args);
		
		foreach ($array as $value) {
			$result = $this->check_against_val_method($value, $method, $args);
			if ($result === false) {
				return false;
			}
		}
		return true;
	}
	
	public function validate_select($value, $options) {
		if (in_array($value, $options)) {
			return true;
		}
		return false;
	}
	
	public function validate_dw_user($user, $addtitional_values=array()) {
		$wiki_users = $this->model->userFactory->get_all();
		if (array_key_exists($user, $wiki_users) ||
			in_array($user, $addtitional_values)) {
			return true;
		}
		return false;
	}
	
	public function validate_unix_timestamp($stamp) {
		if (is_numeric($stamp)) {
			return true;
		}
		return false;
	}
	
	public function validate_numeric($value) {
		if (is_numeric($value)) {
			return true;
		}
		return false;
	}
	
	public function validate_length($value, $max_length) {
		if (strlen($value) <= $max_length) {
			return true;
		}
		return false;
	}
	
	public function validate_iso_date($date) {
		if (preg_match('/^(\d{4})-(\d{2})-(\d{2})$/', $date, $parts)) {
			$year  = $parts[1];
			$month = $parts[2];
			$day   = $parts[3];
			if (mktime(0, 0, 0, $month, $day, $year)) {
				return true;
			}
			return false;
		}
		return false;
	}
    
    public function validate_sqlite_datetime($date) {
        $strtotime = strtotime($date);
        if ($strtotime === false) {
            return false;
        }
        
        $datetime = date('Y-m-d H:i:s', $strtotime);
        if ($datetime !== $date) {
            return false;
        }
        
		return true;
	}
	
	public function validate_time($time) {
		if (preg_match('/^(\d{1,2}):(\d{1,2})$/', $time, $parts)) {
			$hours  = $parts[1];
			$minutes = $parts[2];
			
			if (mktime($hours, $minutes, 0)) {
				return true;
			}
			return false;
		}
		return false;
	}
	
	public function validate_must_be_empty($value) {
		if ($value == '') {
			return true;
		}
		return false;
	}
}