// Marty Stepp's CSE 14x course web site script
// Sets up various things on my course web site pages,
// such as zebra striping for some table rows,
// links to files, email addresses and campus buildings.

// max number of files that will be shown before initially collapsing
var MAX_FILES_LENGTH = 99;

document.observe("dom:loaded", function() {
    if ($("maximizelink")) {
        $("maximizelink").href = "#";
        $("maximizelink").observe("click", maximizeClick);
    }
    
    var rows = $$("table.color_alternating_rows tr");
    for (var i = 0; i < rows.length; i += 2) {
        // color every other row gray
        rows[i].addClassName("evenrow");
    }

    // place links around email addresses
    var cells = $$(".ema");
    for (var i = 0; i < cells.length; i++) {
        var addr = cells[i].textContent ? cells[i].textContent : cells[i].innerText;
        var linkText = addr;
        if (cells[i].hasClassName("showema")) {
            linkText += "@cs.washington.edu";
        }
        cells[i].update("<a href=\"mailto:" + addr + "@cs.washington.edu\">" + linkText + "</a>");
    }

    cells = $$(".building");
    for (var i = 0; i < cells.length; i++) {
        var addr = cells[i].innerHTML;
        var tokens = addr.split(/[ ]+/);
        if (tokens.length < 2) {
            continue;
        }
        var building = tokens[0];
        var roomNumber = tokens[1];
        
        var area = "southcentral";
        if (cells[i].hasClassName("north")) {
            area = "northcentral";
        }
        
        cells[i].update("<a href=\"http://www.washington.edu/home/maps/" + area + ".html?" + building + "\">" + building + "</a> " + roomNumber);
    }
    
    $$(".plusicon").each(function(el) {
        var a = el.up("a");
        a.href = "#";

        if (!a || a.id == "expandall") { return; }
        a.observe("click", collapseableClick);
        
        var collapse = el.up(".collapseable");
        if (collapse && collapse.select("li").length > MAX_FILES_LENGTH) {
            collapseableClick(null, el);   // initially collapsed
        }
    });
    
    if ($("expandall")) {
        $("expandall").observe("click", expandAllClick);
    }
    
    // inject each date's month/day into "date" spans sequentially
    //                    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    var daysInMonth = [-1, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
    var month = 0;
    var day = 0;
    var year = 2010;
    if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0)) {
        daysInMonth[2]++;  // leap years
    }
    
    var today = new Date();
    var tomorrow = new Date();
    tomorrow.setDate(today.getDate() + 1);
    var yesterday = new Date();
    yesterday.setDate(today.getDate() - 1);
    
    $$(".date").each(function(element) {
        if (element.innerHTML) {
            var tokens = element.innerHTML.split(/\//);
            month = parseInt(tokens[0]);
            day = parseInt(tokens[1]);
        } else if (month > 0 && day > 0) {
            day++;
            if (day > daysInMonth[month]) {
                day = 1;
                month = (month % 12) + 1;
            }
            element.innerHTML = month + "/" + day;
        }
        
        var td = element.up("td");
        if (td) {
            var thisDate = new Date(year, month - 1, day);
            if (thisDate > yesterday && thisDate <= today) {
                td.addClassName("today");
                if (typeof(td.id) === "undefined" || !td.id) {
                    td.id = "today";
                    location.hash = "today";
                }
            }
        }
    });
});

function expandAllClick(event) {
    if (event) {
        event.stop();
    }

    var img = this.select("img.plusicon")[0];
    if (!img) { return; }
    
    var expand = !!img.src.match(/plus/);
    swapPlusMinus(img);

    $$(".collapseable").each(function(collapse) {
        // .select("ul").each(Element.toggle);
        var img = collapse.select("img.plusicon")[0];
        if (!!isExpanded(img) !== expand) {
            toggleCollapsed(collapse);
        }
    });
}

function maximizeClick() {
    this.siblings().each(Element.toggle);
}

// handles click on a link around a plusicon image
function collapseableClick(event, element) {
    if (event) {
        event.stop();
    }
    if (!element) {
        element = this;
    }
    var collapse = element.up(".collapseable");
    if (!collapse) { return; }
    
    toggleCollapsed(collapse);
}

function toggleCollapsed(collapse) {
    collapse.select("ul").each(Element.toggle);
    var img = collapse.select("img.plusicon")[0];
    swapPlusMinus(img);
}

function isExpanded(img) {
    return img.src.match(/minus/);
}

function swapPlusMinus(img) {
    if (isExpanded(img)) {
        img.src = img.src.replace(/minus/, "plus");
    } else {
        img.src = img.src.replace(/plus/, "minus");
    }
}


/*
// old functions I used before Prototype
getElementsByClassName = function(tagName, className, root) {
    var elements;
    if (!root) {
        root = document;
    }
    elements = root.getElementsByTagName(tagName);
    
    if (!(className instanceof Array)) {
        className = [className];
    }

    var result = [];
    for (var i = 0; i < elements.length; i++) {
        for (var j = 0; j < className.length; j++) {
            if (hasClass(elements[i], className[j])) {
                result.push(elements[i]);
            }
        }
    }
    return result;
};

hasClass = function(element, className) {
    if (!element) {
        return false;
    } else if (!className || className == "*") {
        return true;
    } else if (!element.className) {
        return false;
    }
    
    var classes = getClasses(element);
    for (var i = 0; i < classes.length; i++) {
        if (classes[i] == className) {
            return true;
        }
    }
    return false;
};

getClasses = function(element) {
    return element.className.split(/\s+/);
};
*/