/*
 * Module of utility functions for working with "classes"
 */

// create/check the global symbol "com"
var com;
if (!com) {
    com = {};
} else if (typeof com != "object") {
    throw new Error("com already exists and is not an object");
}

// create/check com.archstoneapartments
if (!com.archstoneapartments) {
    com.archstoneapartments = {}
} else if (typeof com.archstoneapartments != object) {
    throw new Error ("com.archstoneapartments already exists and is not an object");
}

// throw an error if com.archstoneapartments.Class already exists
if (com.archstoneapartments.Class) {
    throw new Error("com.archstoneapartments.Class already exists");
}

// Otherwise, create and populate the namespace with one big object literal
com.archstoneapartments.Class = {
    define: function(data) {
        var classname = data.name;
        var superclass = data.extend || Object;
        var constructor = data.construct || function() {};
        var methods = data.methods || {};
        var statics = data.statics || {};
        var borrows;
        var provides;
        
        if (!data.borrows) borrows = [];
        else if (data.borrows instanceof Array) borrows = data.borrows;
        else borrows = [data.borrows];
        
        if (!data.provides) provides = [];
        else if (data.provides instanceof Array) provides = data.provides;
        else provides = [data.provides];
        
        var proto = new superclass();
        
        for (var p in proto) if (proto.hasOwnProperty(p)) delete proto[p];
            
        for (var i = 0; i < borrows.length; i++) {
            var c = data.borrows[i];
            borrows[i] = c;
            for (var p in c.prototype) {
                if (typeof c.prototype != "function") continue;
                proto[p] = c.prototype[p];
            }
        }
        
        for (var p in methods) proto[p] = methods[p];
        
        proto.constructor = constructor;
        proto.superclass = superclass;
        if (classname) proto.classname = classname;
        
        for (var i = 0; i < provides.length; i++) {
            var c = provides[i];
            for (var p in c.prototype) {
                if (typeof c.prototype[p] != "function") continue;
                if (p == "constructor" || p == "superclass") continue;
                if (p in proto && typeof proto[p] == "function" && proto[p].length == c.prototype[p].length) continue;
                throw new Error("Class " + classname + " does not provide method " + c.classname + "." + p);
            }
        }
        
        constructor.prototype = proto;
        
        for (var p in statics) constructor[p] = data.statics[p];
        
        return constructor;
    },
    provides: function(o, c) { /* code here */ }
};