/**
 * Represents an evaluation (e.g., a "CMS evaluation").
 * @param type {String} Ex: "CMS" or "ATMS" ...
 * @param data Array(label1, text1, label2, text2, ...)
 */
function Evaluation(type, evttime, data)
{
    //========== private static members ==========//
    Evaluation.id = (typeof Evaluation.id == 'undefined') ? 0 : ++Evaluation.id;
    
    //========== public constants ==========//
    this.ratingQualities = ["", "Worst","Poor","Average","Good","Best"];
    this.id = Evaluation.id;
    this.ratingGroupName = "evaluationGroup" + this.id;    
    this.textID = "evaluationText" + this.id;
    this.type = type;
    this.data = data;
    this.evttime = evttime;
    
    //========== public read-only members ==========//
    this.text = "";
    this.rating = -1;
    
    //========== public methods ==========//
    this.html = html;
    this.recordText = recordText; 
    this.writeRating = writeRating;
    
    //========== private methods ==========//
    this.smallScaleForm = smallScaleForm;
    this.evaluationForm = evaluationForm;
    
    //========== function definitions ==========//
    /**
     * @return The html representation of this evaluation.
     */
    function html()
    {
        var text = "<table class='evaluation'>" +
                         "<tr>" +
                         "<th class='evaluationType' colspan='2'>" + type + " Evaluation</th>" +
                         "</tr>" +
                         "<tr>" +
                         "<td><table class='evaluationInner2'>";
        
        for (i = 0; i < this.data.length; i += 2)
        {
            text += "<tr>" +
                   "<td class='evaluationLabel'>" + this.data[i] + "</td>" +
                   "<td class='evaluationCriteria'>" + this.data[i+1] + "</td>" +
                   "</tr>";
        }
        /*  Displays the comment input field 
        text += "<tr><td colspan='2' class='evaluationResponse'>" +
            "<input onchange='events.getEvaluation(" + this.id + ").recordText();'" +
            " id='" + this.textID + "' type='text' value='" + this.text + "'" +
            " class='evaluationResponseText' />" 
            + "</td>";
        */
        text += "<tr>"
        /*  Displays the ranking bubbles  */
        text += "</td>" 
             + "<td class='evaluationScale'>" + this.evaluationForm()
             + "</td>" 
        text += "<td colspan='2' class='evaluationResponse'>" 
            + "<input id='" + this.textID + "' type='text' value='" + this.text + "'" 
            + " class='evaluationResponseText' "
            + " onchange='events.getEvaluation(" + this.id + ").recordText();' />" 
            + "</td>";
        text += "</tr>";
        text +=    "</table>";
        
        text += "</table>";

                
        return text;
    }
    

    /**
     * Write an individual rating to a log file
     */
    function writeRating(givenRating)
    {
        // Build a string for the log in this format:
        //03:01:00, Evaluation, CMS, Poor
        logString = this.evttime.format() + ", Evaluation, " + this.type + ", " 
        + this.ratingQualities[givenRating] + "\n"
        postMessage(logString)
    }

    /**
     * Stores the text in the written response text box.
     */
    function recordText() 
    { 
        this.text = events.doc.getElementById(this.textID).value; 
        // Build a string for the log in this format:
        //03:01:00, Evaluation, CMS, 'comment'
        logString = this.evttime.format() + ", Evaluation, " + this.type + ", '" 
        + this.text + "'\n"
        postMessage(logString)
        // Change the text color as feedback to user
        // events.doc.getElementById(this.textID).style.color = "lightgrey"; 
    }
    
    function postMessage(logString)
    {
        // Using POST to send the data 
        var xhr = new XMLHttpRequest();
        xhr.open("POST", "/cgi-bin/appendRatingToLog.py", true);
        xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8');
        // send the collected data
        xhr.send("msg="+logString);
    }

    /**
     * @return The html for appropriate evaluation form for grading.
     */
    function evaluationForm()
    {
        return this.smallScaleForm();
    }
    
    /**
     * @return The html for a 1-5 grading scale.
     */
    function smallScaleForm()
    {
        return "<form>" +
               "<table align='right' class='evaluationScale'>" +
               "<tr>" +
               "<td class='eventRadioButtonSmallScale'>"+this.ratingQualities[5]+"</td>" +
               "<td class='eventRadioButtonSmallScale'>"+this.ratingQualities[4]+"</td>" +
               "<td class='eventRadioButtonSmallScale'>"+this.ratingQualities[3]+"</td>" +
               "<td class='eventRadioButtonSmallScale'>"+this.ratingQualities[2]+"</td>" +
               "<td class='eventRadioButtonSmallScale'>"+this.ratingQualities[1]+"</td>" +
               "</tr>" +
               "<tr>" +
               "<td align='center'><input type='radio' " + 
                       (this.rating == 5 ? "checked='true'" : "") + 
                       " onchange='events.getEvaluation(" + this.id + 
                       ").writeRating(5)' name='" + this.ratingGroupName + 
                       "' value='5'></td>" +
               "<td align='center'><input type='radio' " + 
                       (this.rating == 4 ? "checked='true'" : "") + 
                       " onchange='events.getEvaluation(" + this.id + 
                       ").writeRating(4)' name='" + this.ratingGroupName + 
                       "' value='4'></td>" +
               "<td align='center'><input type='radio' " + 
                       (this.rating == 3 ? "checked='true'" : "") + 
                       " onchange='events.getEvaluation(" + this.id + 
                       ").writeRating(3)' name='" + this.ratingGroupName + 
                       "' value='3'></td>" +
               "<td align='center'><input type='radio' " + 
                       (this.rating == 2 ? "checked='true'" : "") + 
                       " onchange='events.getEvaluation(" + this.id + 
                       ").writeRating(2)' name='" + this.ratingGroupName + 
                       "' value='2'></td>" +
               "<td align='center'><input type='radio' " + 
                       (this.rating == 1 ? "checked='true'" : "") + 
                       " onchange='events.getEvaluation(" + this.id + 
                       ").writeRating(1)' name='" + this.ratingGroupName + 
                       "' value='1'></td>" +
               "</tr>" +
               "</table>"  +
               "</form>";
    }
}