/**
 * Copyright 2005-2007 Xue Yong Zhi, Ye Zheng
 * Distributed under the GNU General Public License 2.0
 */

package com.xruby.runtime.lang;

import com.xruby.runtime.value.RubyString;
import com.xruby.runtime.value.RubyArray;

public class RubyModule extends MethodCollection {

    private RubyModule owner_ = null;//owner is where is the module is defined under.
    protected RubyClass superclass_;

    public RubyModule(String name, RubyModule owner) {
        super(null);
        super.name_ = name;
        owner_ = owner;
    }

    public boolean isRealModule() {
        return true;
    }

    public boolean isRealClass() {
        return false;
    }

    public RubyValue defineMethod(String name, RubyMethod m) {
        m.setOwner(this);
        RubyID mid = StringMap.intern(name);
        return addMethod(mid, m);
    }

    /// This method is only used by java classes in package 'com.xruby.runtime.builtin'.
    /// It has less overhead than 'defineClass' (no hash table lookup).
    /// This method is NOT used by classes compiled from ruby script.
    public RubyClass defineNewClass(String name, RubyClass parent) {
        if (parent == null) {
            parent = RubyRuntime.ObjectClass;
        }

        RubyClass c = new RubyClass(name, parent, this);
        c.setName(name);
        c.setRubyClass(RubyRuntime.ClassClass);
        new RubySingletonClass(c, parent.getRubyClass());

        constants_.put(name, c);
        return c;
    }

    private RubyClass defineClass(String name, RubyClass parent) {
        RubyValue v = constants_.get(name);
        if (null == v) {
            return defineNewClass(name, (null == parent) ? RubyRuntime.ObjectClass : parent);
        }

        if (!(v instanceof RubyClass)) {
            throw new RubyException(RubyRuntime.TypeErrorClass, name + " is not a class");
        }

        RubyClass c = (RubyClass)v;

        if (null != parent) {
            if (!c.isMyParent(parent)){
                throw new RubyException(RubyRuntime.TypeErrorClass, "superclass mismatch for class "+ name);
            }
        }

        c.setAccessPublic();
        return c;
    }

    /// define a new class or get a old one
    public RubyClass defineClass(String name, RubyValue parent) {
        if (null != parent && !(parent instanceof RubyClass)) {
            throw new RubyException(RubyRuntime.TypeErrorClass, "superclass must be a Class (" + parent.getRubyClass().getName() + " given)");
        }

        return defineClass(name, null == parent ? null : (RubyClass)parent);
    }

    /// For compile-time recognizable builtin class, just do sanity checks...
    public RubyClass defineBuiltInClass(RubyClass c, RubyValue parent) {
        if (null != parent) {
            if (!(parent instanceof RubyClass)) {
                throw new RubyException(RubyRuntime.TypeErrorClass, "superclass must be a Class (" + parent.getRubyClass().getName() + " given)");
            }

            if (!c.isMyParent((RubyClass)parent)){
                throw new RubyException(RubyRuntime.TypeErrorClass, "superclass mismatch for class "+ c.getName());
            }
        }

        c.setAccessPublic();
        return c;
    }

    public RubyModule defineNewModule(String name) {
        RubyModule m = new RubyModule(name, this);
        m.setName(name);
        m.setRubyClass(RubyRuntime.ModuleClass);
        constants_.put(name, m);//NOTE, do not use ObjectFactory.createClass, it will cause initialization issue
        return m;
    }

    public RubyModule defineModule(String name) {
        RubyValue v = constants_.get(name);
        if (null == v) {
            return defineNewModule(name);
        }

        if (!(v instanceof RubyModule) || (v instanceof RubyClass)) {
            throw new RubyException(RubyRuntime.TypeErrorClass, name + " is not a module");
        }

        return (RubyModule)v;
    }

    public RubyValue getConstant(String name) {
        RubyValue v = super.getOwnConstant(name);
        if (null != v) {
            return v;
        }

        if (null != this.superclass_) {
            v = this.superclass_.getConstant(name);
            if (null != v) {
                return v;
            }
        }

        if (null != owner_) {
            v = this.owner_.getConstant(name);
            if (null != v) {
                return v;
            }
        }

        return null;
    }

    public void to_s(RubyString s) {
        if (null != owner_) {
            owner_.to_s(s);
            if (s.length() > 0) {
                s.appendString("::");
            }
        }

        String name = this.getName();
        if (name != null) {
            s.appendString(getName());
        }
    }

    /*
     * Include Module
     */
    public void includeModule(RubyModule module) {
        if (module == null) {
            return;
        }
        RubyModule c = this;
        boolean changed = false;
        while (module != null) {
            boolean superclassSeen = false;
            if (c.methods_ == module.methods_) {
                throw new RubyException(RubyRuntime.ArgumentErrorClass, "cyclic include detected");
            }

            boolean skip = false;

            for (RubyClass p = this.superclass_; p != null; p = p.superclass_) {
                if (p instanceof RubyIncludeClass) {
                    if (p.methods_ == module.methods_) {
                        if (!superclassSeen) {
                            c = p;
                            skip = true;
                            break;
                        }
                    }
                } else if (p.isRealClass()) {
                    superclassSeen = true;
                    break;
                }
            }

            if (!skip) {
                c.superclass_ = new RubyIncludeClass(module, c.superclass_);
                c = c.superclass_;
                changed = true;
            }

            module = module.superclass_;
        }

        if (changed) {
            RubyClass.resetCache();
        }
    }

    public final void collectIncludedModuleNames(RubyArray a) {
        for (RubyModule m = this; m != null; m = m.superclass_) {
            if (m.isRealModule()) {
                a.add(m);
            } else if (m instanceof RubyIncludeClass) {
                a.add(((RubyIncludeClass)m).getIncludedModule());
            }
        }
    }

    public void module_function(String method_name) {
        RubyID mid = StringMap.intern(method_name);
        RubyMethod m = findOwnMethod(mid);
        if (null == m || UndefMethod.isUndef(m)) {
            throw new RubyException(RubyRuntime.NoMethodErrorClass, "undefined method '" +  method_name + "' for " + getName());
        }
        getSingletonClass().defineMethod(method_name, m);
    }

}

@@ -1491,24 +1491,53 @@
 (name, c);%0D%0A
+        ObjectSpace.add(c);%0D%0A
         retu

add more to ObjectSpace