<?php

class Entity_Base
{

    /**
     * this function check if a field is in the data sent in the constructor
     * you can specify an array, and this function will use like alias
     */
    protected function validateField ($field, $default = false)
    {
        $fieldIsEmpty = true;

        // this is a trick, if $fields is a string, $fields will be an array with
        // one element
        if (is_array( $field )) {
            $fields = $field;
        } else {
            $fields = array ();
            $fields[] = $field;
        }

        // if there are aliases for this field, evaluate all aliases and take the
        // first occurence
        foreach ($fields as $k => $f) {
            if (isset( $this->temp[$f] )) {
                $fieldIsEmpty = false;
                return $this->temp[$f];
            }
        }

        // field empty means the user has not sent a value for this Field, so we are
        // using the default value
        if ($fieldIsEmpty) {
            if ($default !== false) {
                return $default;
            }
        }
    }

    protected function validateRequiredFields ($requiredFields = array())
    {
        foreach ($requiredFields as $k => $field) {
            if ($this->{$field} === null) {
                throw (new Exception( "Field $field is required in " . get_class( $this ) ));
                die();
            }
        }
    }

    /**
     *
     *
     *
     *
     * Copy the values of the Entity to the array of aliases
     * The array of aliases must be defined.
     *
     * @return Array of alias with the Entity values
     */
    public function getAliasDataArray ()
    {
        $aAlias = array ();
        // get aliases from class
        $className = get_class( $this );
        if (method_exists( $className, 'GetAliases' )) {
            $aliases = call_user_func( array ($className,'GetAliases'
            ) );
            // $aliases = $className::GetAliases ();
            foreach ($this as $field => $value) {
                if (isset( $aliases[$field] )) {
                    // echo "Field exists in Aliases: " . $field . "\n";
                    // echo "Alias Name:" . $aliases[$field] . "\n";
                    // echo "Alias value:" . $value . "\n";
                    $aAlias[$aliases[$field]] = $value;
                }
            }
        }

        return $aAlias;
    }

    /**
     *
     *
     *
     *
     * Set the data from array of alias to Entity
     *
     * @param $aAliasData array of data of aliases
     */
    public function setAliasDataArray ($aAliasData)
    {
        // get aliases from class
        $className = get_class( $this );
        if (method_exists( $className, 'GetAliases' )) {
            $aliases = call_user_func( array ($className,'GetAliases'
            ) );
            // $aliases = $className::GetAliases ();
            foreach ($this as $field => $value) {
                if (isset( $aliases[$field] )) {
                    $this->{$field} = $aAliasData[$aliases[$field]];
                }
            }
        }
    }

    /**
     *
     *
     *
     *
     * Initialize object with values from $data.
     * The values from data use properties or alias array.
     *
     * @param $data
     */
    protected function initializeObject ($data)
    {
        // get aliases from class
        $className = get_class( $this );
        $aliases = array ();
        $swAliases = false;
        if (method_exists( $className, 'GetAliases' )) {
            $aliases = call_user_func( array ($className,'GetAliases'
            ) );
            // $aliases = $className::GetAliases ();
            $swAliases = true;
        }
        // use object properties or aliases to initialize
        foreach ($this as $field => $value) {
            if (isset( $data[$field] )) {
                $this->$field = $data[$field];
            } elseif ($swAliases && isset( $aliases[$field] ) && isset( $data[$aliases[$field]] )) {
                $this->$field = $data[$aliases[$field]];
            }
        }
    }

    public function serialize ()
    {
        if (isset( $this->temp )) {
            unset( $this->temp );
        }
        return serialize( $this );
    }

    public function unserialize ($str)
    {
        $className = get_class( $this );
        $data = unserialize( $str );
        return new $className( $data );
    }
}