/**
 * @author Ryan Johnson <http://syntacticx.com/>
 * @copyright 2008 PersonalGrid Corporation <http://personalgrid.com/>
 * @package LivePipe UI
 * @license MIT
 * @url http://livepipe.net/control/tabs
 * @require prototype.js, livepipe.js
 */

/*global window, document, Prototype, $, $A, $H, $break, Class, Element, Event, Control */

if (typeof(Prototype) == "undefined") {
    throw "Control.Tabs requires Prototype to be loaded.";
}
if (typeof(Object.Event) == "undefined") {
    throw "Control.Tabs requires Object.Event to be loaded.";
}

Control.Tabs = Class.create({
    initialize: function(tab_list_container, options) {
        if (!$(tab_list_container)) {
            throw "Control.Tabs could not find the element: " + tab_list_container;
        }
        this.activeContainer = false;
        this.activeLink = false;
        this.containers = $H({});
        this.links = [];
        this.options = {
            beforeChange: Prototype.emptyFunction,
            afterChange: Prototype.emptyFunction,
            hover: false,
            tracked: true,
            linkSelector: 'li a',
            linkAttribute: 'href',
            setClassOnContainer: false,
            activeClassName: 'active',
            disabledClassName: 'disabled',
            defaultTab: 'first',
            autoLinkExternal: true,
            targetRegExp: /#(.+)$/,
            showFunction: Element.show,
            hideFunction: Element.hide
        };
        Object.extend(this.options, options || {});
        if (this.options.tracked) {
            Control.Tabs.instances.push(this);
        }
        var filterLinks;
        switch (this.options.linkAttribute) {
        case 'href':
        case 'src':
            filterLinks = function(link) {
                return (/^#/).test(link.getAttribute(this.options.linkAttribute).replace(
                window.location.href.split('#')[0], ''));
            };
            break;

        default:
            if (typeof(this.options.linkAttribute) == 'function') {
                filterLinks = this.options.linkAttribute;
            } else {
                filterLinks = function(link) {
                    return link.hasAttribute(this.options.linkAttribute);
                };
            }
        }

        (typeof(this.options.linkSelector) == 'string' ? $(tab_list_container).select(this.options.linkSelector) : this.options.linkSelector($(tab_list_container))).findAll(filterLinks.bind(this)).each(function(link) {
            this.addTab(link);
        }.bind(this));
        this.containers.values().each(Element.hide);
        if (this.options.defaultTab == 'first') {
            this.setActiveTab(this.links.first());
        } else if (this.options.defaultTab == 'last') {
            this.setActiveTab(this.links.last());
        } else {
            this.setActiveTab(this.options.defaultTab);
        }
        var targets = this.options.targetRegExp.exec(window.location);
        if (targets && targets[1]) {
            targets[1].split(',').each(function(target) {
                this.setActiveTab(this.links.find(function(link) {
                    return link.key == target;
                }));
            }.bind(this));
        }
        if (this.options.autoLinkExternal) {
            $A(document.getElementsByTagName('a')).each(function(a) {
                if (!this.links.include(a)) {
                    var clean_href = a.href.replace(window.location.href.split('#')[0], '');
                    if (clean_href.substring(0, 1) == '#') {
                        if (this.containers.keys().include(clean_href.substring(1))) {
                            $(a).observe('click', function(event, clean_href) {
                                this.setActiveTab(clean_href.substring(1));
                            }.bindAsEventListener(this, clean_href));
                        }
                    }
                }
            }.bind(this));
        }
    },
    addTab: function(link) {
        this.links.push(link);

        switch (this.options.linkAttribute) {
        case 'href':
        case 'src':
            link.key = link.getAttribute(this.options.linkAttribute).replace(
            window.location.href.split('#')[0], '').split('#').last().replace(/#/, '');
            break;

        default:
            if (typeof(this.options.linkAttribute) == 'function') {
                link.key = this.options.linkAttribute(link);
            } else {
                link.key = link.getAttribute(this.options.linkAttribute);
            }
        }
        var container = this.options.tabs_container ? this.options.tabs_container.down('#' + link.key) : $(link.key);
        if (!container) {
            throw "Control.Tabs: #" + link.key + " was not found on the page.";
        }
        this.containers.set(link.key, container);
        link[this.options.hover ? 'onmouseover' : 'onclick'] = function(link) {
            if (window.event) {
                Event.stop(window.event);
            }
            this.setActiveTab(link);
            return false;
        }.bind(this, link);
    },
    getTab: function(link) {
        if (!link && typeof(link) == 'undefined') {
            return null;
        }
        if (typeof(link) == 'string') {
            return this.getTab(this.links.find(function(_link) {
                return _link.key == link;
            }));
        } else if (typeof(link) == 'number') {
            return this.getTab(this.links[link]);
        } else {
            return this.containers.get(link.key);
        }
    },
    setActiveTab: function(link) {
        if (!link && typeof(link) == 'undefined') {
            return;
        }
        if (typeof(link) == 'string') {
            this.setActiveTab(this.links.find(function(_link) {
                return _link.key == link;
            }));
        } else if (typeof(link) == 'number') {
            this.setActiveTab(this.links[link]);
        } else if (!(this.options.setClassOnContainer ? $(link.parentNode) : link).hasClassName(this.options.disabledClassName)) {
            if (link == this.activeLink) {
                return;
            }
            if (this.notify('beforeChange', this.activeContainer, this.containers.get(link.key)) === false) {
                return;
            }
            if (this.activeContainer) {
                this.options.hideFunction(this.activeContainer);
            }
            this.links.each(function(item) {
                (this.options.setClassOnContainer ? $(item.parentNode) : item).removeClassName(this.options.activeClassName);
            }.bind(this));
            (this.options.setClassOnContainer ? $(link.parentNode) : link).addClassName(this.options.activeClassName);
            this.activeContainer = this.containers.get(link.key);
            this.activeLink = link;
            this.options.showFunction(this.containers.get(link.key));
            this.notify('afterChange', this.containers.get(link.key));
        }
    },
    disableTab: function(link) {
        if (!link && typeof(link) == 'undefined') {
            return;
        }
        if (typeof(link) == 'string') {
            this.disableTab(this.links.find(function(_link) {
                return _link.key == link;
            }));
        } else if (typeof(link) == 'number') {
            this.disableTab(this.links[link]);
        } else {
            if ({
                'INPUT': true,
                'BUTTON': true,
                'SELECT': true,
                'TEXTAREA': true
            }[link.nodeName]) {
                link.disabled = true;
            }(this.options.setClassOnContainer ? $(link.parentNode) : link).addClassName(this.options.disabledClassName);
        }
    },
    enableTab: function(link) {
        if (!link && typeof(link) == 'undefined') {
            return;
        }
        if (typeof(link) == 'string') {
            this.enableTab(this.links.find(function(_link) {
                return _link.key == link;
            }));
        } else if (typeof(link) == 'number') {
            this.enableTab(this.links[link]);
        } else {
            if ({
                'INPUT': true,
                'BUTTON': true,
                'SELECT': true,
                'TEXTAREA': true
            }[link.nodeName]) {
                link.disabled = false;
            }(this.options.setClassOnContainer ? $(link.parentNode) : link).removeClassName(this.options.disabledClassName);
        }
    },
    next: function() {
        this.links.each(function(link, i) {
            if (this.activeLink == link && this.links[i + 1]) {
                this.setActiveTab(this.links[i + 1]);
                throw $break;
            }
        }.bind(this));
    },
    previous: function() {
        this.links.each(function(link, i) {
            if (this.activeLink == link && this.links[i - 1]) {
                this.setActiveTab(this.links[i - 1]);
                throw $break;
            }
        }.bind(this));
    },
    first: function() {
        this.setActiveTab(this.links.first());
    },
    last: function() {
        this.setActiveTab(this.links.last());
    }
});
Object.extend(Control.Tabs, {
    instances: [],
    findByTabId: function(id) {
        return Control.Tabs.instances.find(function(tab) {
            return tab.links.find(function(link) {
                return link.key == id;
            });
        });
    }
});
Object.Event.extend(Control.Tabs);