<?php
// ----------------------------------------------------------------------------
// result_part.php
// Contains the Result_Sub_Part class definition.
// ----------------------------------------------------------------------------

require_once '/projects/lupp/2-1-devel//www/common/xml_handler.php';
require_once 'altered_tag.php';

// ----------------------------------------
// The Result_Sub_Part class (ex. Ada.O1, Ada.P2...) contains all the
// alteration tags and meta data for this particular sub part.
// ----------------------------------------
class Result_Sub_Part {

    // ----------------------------------------
    // Instance variables
    // ----------------------------------------
    // Attributes
    private $id;
    private $state; // failed, passed, autofail, autopass
    private $auto_state; // failed, passed, autofail, autopass, submitted
            
    // Sub tags
    private $altered_tags;

    // Variables to handle storing data on file 
    private $changes;
    private $is_new;
    
    // ----------------------------------------
    // Constructor
    //
    // The only "true" constructor which is always the one
    // called. Works as a filter, and checks the arg count to see
    // which "fake constructor" should be called.
    // ----------------------------------------
    public function __construct() {

        $args = func_get_args();
        $arg_count = func_num_args();

        if (method_exists($this, $function = '__construct'.$arg_count)) {
            call_user_func_array(array($this, $function), $args);
        }
    }
    
    // ----------------------------------------
    // Constructor
    //
    // Initiates instance variables and creates classes based
    // on the xml data received.
    //
    // Arguments:
    //   $xml_data is an xml data object supposed to contain relevant
    //   data retrieved from the char_students.year-semester file(s).
    // ----------------------------------------
    public function __construct1($xml_data) {

        $this->changes = array();
        $this->altered_tags = array();
        $this->id = $xml_data->getAttribute('id');
        $this->state = $xml_data->getAttribute('state');
        $this->auto_state = $xml_data->getAttribute('autostate');
        
        // ----------
        // Check if there are any altered tags, and if so extract
        // them.
        // ----------
        if ( $xml_data->hasChildNodes() ) {
            $altered_data = $xml_data->getElementsByTagName('altered');

            foreach ( $altered_data as $tag ) {
                $this->altered_tags[] = new Altered_Tag($tag);
            }
        }
    }

    // ----------------------------------------
    // Constructor
    //
    // Initiates instance variables and creates classes based
    // on the partially extracted data.
    //
    // Arguments:
    //   $id is the id of the sub part (ex: Ada.O1)
    //   $state is the state to set for the sub part
    //   $auto_state is the auto_state for the sub part
    // ----------------------------------------
    public function __construct3($id,
                                 $state,
                                 $auto_state) {

        $this->changes = array();
        $this->altered_tags = array();
        $this->is_new = true;
        $this->id = $id;
        $this->state = $state;
        $this->auto_state = $auto_state;
        
        if ( (! isset($state)) && isset($auto_state) ) {
            $this->state = $auto_state;
        }
    }
    
    // ----------------------------------------
    // get_id
    //
    // Returns the id of the result sub part.
    // ----------------------------------------
    public function get_id() {

        return $this->id;
    }
    
    // ----------------------------------------
    // get_state
    //
    // Returns the state set for the result part.
    // ----------------------------------------
    public function get_state() {

        return $this->state;
    }

    // ----------------------------------------
    // get_auto_state
    //
    // Returns the state set for the result part.
    // ----------------------------------------
    public function get_auto_state() {

        return $this->state;
    }

    // ----------------------------------------
    // set_auto_state
    //
    // Set auto state to a new value.
    //
    // Arguments:
    //   $new_auto_state - string containing the new auto state.
    // ----------------------------------------
    public function set_auto_state($new_auto_state) {

        $this->auto_state = $new_auto_state;
    }

    // ----------------------------------------
    // set_state
    //
    // Set a new state for this result part.
    //
    // Arguments:
    //   $new_state - string containing the new state.
    // ----------------------------------------
    public function set_state($new_state) {
        
        if ( strcasecmp($this->state, "passed") != 0) {
            $this->state = $new_state;
        }
    }

    // ----------------------------------------
    // set_state_unsafe
    //
    // Set a new state for this result part ignoring previous results
    // and thus permitting downgrade of previously passed results.
    //
    // Arguments:
    //   $new_state - string containing the new state.
    // ----------------------------------------
    public function set_state_unsafe($new_state) {
        
        $this->state = $new_state;
    }
    
    // ----------------------------------------
    // get_altered_tags
    //
    // Returns an array with all the sub parts to this.
    // ----------------------------------------
    public function get_altered_tags() {

        return $this->altered_tags;
    }

    // ----------------------------------------
    // is_new
    //
    // Returns a boolean indicating whether the sub part is new to
    // this student.
    // ----------------------------------------
    public function is_new() {

        return $this->is_new;
    }

    // ----------------------------------------
    // has_changes
    //
    // Returns true if there are stored changes, false otherwise.
    // ----------------------------------------
    public function has_changes() {

        return ( isset($this->changes) && ( ! empty($this->changes) ) ) ;
    }
    
    // ----------------------------------------
    // insert_altered_tag
    //
    // Add another altered tag to this result sub part 
    //
    // Arguments:
    //   $date is the date of the alteration.
    //   $by is the user making the alteration.
    //   $to_state is the new state for the result sub part, null if
    //   no modification is to be made.
    //   $to_auto_state is the new auto state, null if not modified.    
    // ----------------------------------------
    public function insert_altered_tag($date,
                                       $by,
                                       $to_state,
                                       $to_auto_state) {

        $new_tag = new Altered_Tag($date, $by, $to_state, $to_auto_state);
        $this->altered_tags[] = $new_tag;
        $this->changes[] = $new_tag;
    }

    // ----------------------------------------
    // print_dump
    //
    // Print function for debugging / testing.
    // ----------------------------------------
    public function print_dump() {

        print "\t\t\tCoures sub part id: " . $this->id
                                         . ", state: " . $this->state
                                         . ", auto-state: " . $this->auto_state
                                         . "\n";
        
        foreach ( $this->altered_tags as $tag ) {
            $tag->print_dump();
        }
    }

    // ----------------------------------------
    // to_json
    //
    // Creates a json string representation of the student result.
    //
    // Arguments:
    //   $indentation is the count of tabs to indent the json data,
    //   default 0. Used for when the json data should be nested
    //   inside another json object.
    //
    // Returns a string containing the json representation of the
    // student result
    // ----------------------------------------
    public function to_json($indentation = 0) {

        // Extract and "jsonify" attributes that are always present.
        $res = str_repeat("\t", $indentation) . "{\n" 
             . str_repeat("\t", $indentation) . "\t\"id\": \"" . $this->id . "\",\n"
             . str_repeat("\t", $indentation) . "\t\"state\": \"" . $this->state . "\"";

        // ----------
        // Check if the attributes the can be empty contain data, if
        // so "jsonify" and add them.
        // ----------
        if ( isset($this->auto_state) ) {
            $res .= ",\n" . str_repeat("\t", $indentation) . "\t\"autostate\": \"" . $this->auto_state . "\"";
        }

        $res .= "\n" . str_repeat("\t", $indentation) . "}";
        // We do not want to include altered tags in the json-report,
        // so we stop here.
        return $res;
    }

    // ----------------------------------------
    // save_results_to_file
    //
    // Stores the results for this student result part on the given
    // file. We know the student exists in active students for this
    // course
    //
    // Arguments:
    //   $xml_path is the DOMDXpath for the xml_handler document.
    //   $xml_document is the DOMDocument in which to store the changes.
    //   $deadlines is an array of deadlines fetched from course info.
    //   $part_elem the part xml element to append results to.
    //   $uid is the uid of the student, needed to extract xml data.
    //   $part_name is the name of the parent part, needed to locate
    //   xml data.
    //
    // Returns true if successfully saved, false otherwise, to handle
    // errors outside.
    // ----------------------------------------
    public function save_results_to_file($xml_path,
                                         $xml_document,
                                         $deadlines,
                                         $part_elem,
                                         $uid,
                                         $part_name) {

        // Extract the student xml part from the xml document.
        $xml_element = $xml_path->query("//student[@uid='{$uid}']"
                                        ."/part[@name='{$part_name}']"
                                        ."/lab[@id='{$this->id}']");

        if ( ! $xml_element->length || ( ! isset($xml_element) ) ) {
            // The student / part / subpart combination did not
            // previously exist in the results document, so we create
            // it and append the attributes.
            $sub_elem = $xml_document->createElement('lab');
           
            $sub_elem->setAttribute('id', $this->id);
            
            $part_elem->appendChild($sub_elem);
        }
        else if ( $xml_element->length > 1 ) {
            $this->errors[] = "Student with uid: " . $uid . " has multiple entries of sub part: "
                          . $part_name . ":" .  $this->id . " in the results xml file.";
            return false;
        }
        else {
            // Only one entry of this student / course part / subpart
            // combination existed previously.
            $sub_elem = $xml_element->item(0);
        }
        
        // ----------
        // Check the optional attributes and store them if they
        // have a value.
        // ----------
        if ( isset($this->state) and ! empty($this->state) ) {
            $sub_elem->setAttribute('state', $this->state);
        }
        
        if ( isset($this->auto_state) and ! empty($this->auto_state) ) {
            $sub_elem->setAttribute('autostate', $this->auto_state);
        }

        // ----------
        // Check if there are any changes (new tags), if so store
        // them.
        // ----------
        if ( isset($this->changes) and (! empty($this->changes) ) ) { 
            foreach ( $this->changes as $tag ) {
                $tag->save_results_to_file($xml_document, $sub_elem);
            }
        }

        return true;
    }
    
    // ----------------------------------------
    // End of Result_Sub_Part class definition
    // ----------------------------------------
}

// ----------------------------------------------------------------------------
?>