/* valainterface.vala
 *
 * Copyright (C) 2006-2010  Jürg Billeter
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.

 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.

 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 *
 * Author:
 * 	Jürg Billeter <j@bitron.ch>
 */

using GLib;

/**
 * Represents a class declaration in the source code.
 */
public class Vala.Interface : ObjectTypeSymbol {
	private List<DataType> prerequisites = new ArrayList<DataType> ();

	private List<Method> methods = new ArrayList<Method> ();
	private List<Field> fields = new ArrayList<Field> ();
	private List<Constant> constants = new ArrayList<Constant> ();
	private List<Property> properties = new ArrayList<Property> ();
	private List<Signal> signals = new ArrayList<Signal> ();
	private List<Symbol> virtuals = new ArrayList<Symbol> ();

	// inner types
	private List<Class> classes = new ArrayList<Class> ();
	private List<Struct> structs = new ArrayList<Struct> ();
	private List<Enum> enums = new ArrayList<Enum> ();
	private List<Delegate> delegates = new ArrayList<Delegate> ();

	/**
	 * Returns a copy of the list of classes.
	 *
	 * @return list of classes
	 */
	public List<Class> get_classes () {
		return classes;
	}

	/**
	 * Returns a copy of the list of structs.
	 *
	 * @return list of structs
	 */
	public List<Struct> get_structs () {
		return structs;
	}

	/**
	 * Returns a copy of the list of enums.
	 *
	 * @return list of enums
	 */
	public List<Enum> get_enums () {
		return enums;
	}

	/**
	 * Returns a copy of the list of delegates.
	 *
	 * @return list of delegates
	 */
	public List<Delegate> get_delegates () {
		return delegates;
	}

	/**
	 * Creates a new interface.
	 *
	 * @param name              type name
	 * @param source_reference  reference to source code
	 * @return                  newly created interface
	 */
	public Interface (string name, SourceReference? source_reference = null, Comment? comment = null) {
		base (name, source_reference, comment);
	}

	/**
	 * Adds the specified interface or class to the list of prerequisites of
	 * this interface.
	 *
	 * @param type an interface or class reference
	 */
	public void add_prerequisite (DataType type) {
		prerequisites.add (type);
		type.parent_node = this;
	}

	/**
	 * Prepends the specified interface or class to the list of
	 * prerequisites of this interface.
	 *
	 * @param type an interface or class reference
	 */
	public void prepend_prerequisite (DataType type) {
		prerequisites.insert (0, type);
	}

	/**
	 * Returns a copy of the base type list.
	 *
	 * @return list of base types
	 */
	public List<DataType> get_prerequisites () {
		return prerequisites;
	}
	
	/**
	 * Adds the specified method as a member to this interface.
	 *
	 * @param m a method
	 */
	public override void add_method (Method m) {
		if (m is CreationMethod) {
			Report.error (m.source_reference, "construction methods may only be declared within classes and structs");
		
			m.error = true;
			return;
		}
		if (m.binding == MemberBinding.INSTANCE) {
			m.this_parameter = new Parameter ("this", get_this_type ());
			m.scope.add (m.this_parameter.name, m.this_parameter);
		}
		if (!(m.return_type is VoidType) && m.get_postconditions ().size > 0) {
			m.result_var = new LocalVariable (m.return_type.copy (), "result", null, source_reference);
			m.result_var.is_result = true;
		}

		methods.add (m);
		scope.add (m.name, m);
	}
	
	/**
	 * Returns a copy of the list of methods.
	 *
	 * @return list of methods
	 */
	public override List<Method> get_methods () {
		return methods;
	}
	
	/**
	 * Adds the specified field as a member to this interface. The field
	 * must be private and static.
	 *
	 * @param f a field
	 */
	public override void add_field (Field f) {
		fields.add (f);
		scope.add (f.name, f);
	}

	/**
	 * Returns a copy of the list of fields.
	 *
	 * @return list of fields
	 */
	public List<Field> get_fields () {
		return fields;
	}

	/**
	 * Adds the specified constant as a member to this interface.
	 *
	 * @param c a constant
	 */
	public override void add_constant (Constant c) {
		constants.add (c);
		scope.add (c.name, c);
	}

	/**
	 * Returns a copy of the list of constants.
	 *
	 * @return list of constants
	 */
	public List<Constant> get_constants () {
		return constants;
	}

	/**
	 * Adds the specified property as a member to this interface.
	 *
	 * @param prop a property
	 */
	public override void add_property (Property prop) {
		if (prop.field != null) {
			Report.error (prop.source_reference, "automatic properties are not allowed in interfaces");

			prop.error = true;
			return;
		}

		properties.add (prop);
		scope.add (prop.name, prop);

		prop.this_parameter = new Parameter ("this", new ObjectType (this));
		prop.scope.add (prop.this_parameter.name, prop.this_parameter);
	}
	
	/**
	 * Returns a copy of the list of properties.
	 *
	 * @return list of properties
	 */
	public override List<Property> get_properties () {
		return properties;
	}
	
	/**
	 * Adds the specified signal as a member to this interface.
	 *
	 * @param sig a signal
	 */
	public override void add_signal (Signal sig) {
		signals.add (sig);
		scope.add (sig.name, sig);
	}
	
	/**
	 * Returns a copy of the list of signals.
	 *
	 * @return list of signals
	 */
	public override List<Signal> get_signals () {
		return signals;
	}

	public virtual List<Symbol> get_virtuals () {
		return virtuals;
	}

	/**
	 * Adds the specified class as an inner class.
	 *
	 * @param cl a class
	 */
	public override void add_class (Class cl) {
		classes.add (cl);
		scope.add (cl.name, cl);
	}

	/**
	 * Adds the specified struct as an inner struct.
	 *
	 * @param st a struct
	 */
	public override void add_struct (Struct st) {
		structs.add (st);
		scope.add (st.name, st);
	}

	/**
	 * Adds the specified enum as an inner enum.
	 *
	 * @param en an enum
	 */
	public override void add_enum (Enum en) {
		enums.add (en);
		scope.add (en.name, en);
	}

	/**
	 * Adds the specified delegate as an inner delegate.
	 *
	 * @param d a delegate
	 */
	public override void add_delegate (Delegate d) {
		delegates.add (d);
		scope.add (d.name, d);
	}

	public override void accept (CodeVisitor visitor) {
		visitor.visit_interface (this);
	}

	public override void accept_children (CodeVisitor visitor) {
		foreach (DataType type in prerequisites) {
			type.accept (visitor);
		}

		foreach (TypeParameter p in get_type_parameters ()) {
			p.accept (visitor);
		}

		/* process enums first to avoid order problems in C code */
		foreach (Enum en in enums) {
			en.accept (visitor);
		}

		foreach (Method m in methods) {
			m.accept (visitor);
		}
		
		foreach (Field f in fields) {
			f.accept (visitor);
		}

		foreach (Constant c in constants) {
			c.accept (visitor);
		}

		foreach (Property prop in properties) {
			prop.accept (visitor);
		}
		
		foreach (Signal sig in signals) {
			sig.accept (visitor);
		}
		
		foreach (Class cl in classes) {
			cl.accept (visitor);
		}
		
		foreach (Struct st in structs) {
			st.accept (visitor);
		}

		foreach (Delegate d in delegates) {
			d.accept (visitor);
		}
	}

	public override bool is_reference_type () {
		return true;
	}
	
	public override bool is_subtype_of (TypeSymbol t) {
		if (this == t) {
			return true;
		}

		foreach (DataType prerequisite in prerequisites) {
			if (prerequisite.data_type != null && prerequisite.data_type.is_subtype_of (t)) {
				return true;
			}
		}
		
		return false;
	}
	
	public override void replace_type (DataType old_type, DataType new_type) {
		for (int i = 0; i < prerequisites.size; i++) {
			if (prerequisites[i] == old_type) {
				prerequisites[i] = new_type;
				new_type.parent_node = this;
				return;
			}
		}
	}

	public override bool check (CodeContext context) {
		if (checked) {
			return !error;
		}

		checked = true;

		var old_source_file = context.analyzer.current_source_file;
		var old_symbol = context.analyzer.current_symbol;

		if (source_reference != null) {
			context.analyzer.current_source_file = source_reference.file;
		}
		context.analyzer.current_symbol = this;

		foreach (DataType prerequisite_reference in get_prerequisites ()) {
			// check whether prerequisite is at least as accessible as the interface
			if (!context.analyzer.is_type_accessible (this, prerequisite_reference)) {
				error = true;
				Report.error (source_reference, "prerequisite `%s` is less accessible than interface `%s`".printf (prerequisite_reference.to_string (), get_full_name ()));
				return false;
			}
		}

		/* check prerequisites */
		Class prereq_class = null;
		foreach (DataType prereq in get_prerequisites ()) {
			TypeSymbol class_or_interface = prereq.data_type;
			/* skip on previous errors */
			if (class_or_interface == null) {
				error = true;
				continue;
			}

			if (!(class_or_interface is ObjectTypeSymbol)) {
				error = true;
				Report.error (source_reference, "Prerequisite `%s` of interface `%s` is not a class or interface".printf (get_full_name (), class_or_interface.to_string ()));
				return false;
			}

			/* interfaces are not allowed to have multiple instantiable prerequisites */
			if (class_or_interface is Class) {
				if (prereq_class != null) {
					error = true;
					Report.error (source_reference, "%s: Interfaces cannot have multiple instantiable prerequisites (`%s' and `%s')".printf (get_full_name (), class_or_interface.get_full_name (), prereq_class.get_full_name ()));
					return false;
				}

				prereq_class = (Class) class_or_interface;
			}
		}

		foreach (DataType type in prerequisites) {
			type.check (context);
		}

		foreach (TypeParameter p in get_type_parameters ()) {
			p.check (context);
		}

		foreach (Enum en in enums) {
			en.check (context);
		}

		foreach (Method m in methods) {
			m.check (context);
			if (m.is_virtual || m.is_abstract) {
				virtuals.add (m);
			}
		}

		foreach (Field f in fields) {
			f.check (context);
		}

		foreach (Constant c in constants) {
			c.check (context);
		}

		foreach (Signal sig in signals) {
			sig.check (context);
			if (sig.is_virtual) {
				virtuals.add (sig);
			}
		}

		foreach (Property prop in properties) {
			prop.check (context);
			if (prop.is_virtual || prop.is_abstract) {
				virtuals.add (prop);
			}
		}

		foreach (Class cl in classes) {
			cl.check (context);
		}

		foreach (Struct st in structs) {
			st.check (context);
		}

		foreach (Delegate d in delegates) {
			d.check (context);
		}

		Map<int, Symbol>? positions = new HashMap<int, Symbol> ();
		bool ordered_seen = false;
		bool unordered_seen = false;
		foreach (Symbol sym in virtuals) {
			int ordering = sym.get_attribute_integer ("CCode", "ordering", -1);
			if (ordering < -1) {
				Report.error (sym.source_reference, "%s: Invalid ordering".printf (sym.get_full_name ()));
				// Mark state as invalid
				error = true;
				ordered_seen = true;
				unordered_seen = true;
				continue;
			}
			bool ordered = ordering != -1;
			if (ordered && unordered_seen && !ordered_seen) {
				Report.error (sym.source_reference, "%s: Cannot mix ordered and unordered virtuals".printf (sym.get_full_name ()));
				error = true;
			}
			ordered_seen = ordered_seen || ordered;
			if (!ordered && !unordered_seen && ordered_seen) {
				Report.error (sym.source_reference, "%s: Cannot mix ordered and unordered virtuals".printf (sym.get_full_name ()));
				error = true;
			}
			unordered_seen = unordered_seen || !ordered;
			if (!ordered_seen || !unordered_seen) {
				if (ordered) {
					Symbol? prev = positions[ordering];
					if (prev != null) {
						Report.error (sym.source_reference, "%s: Duplicate ordering (previous virtual with the same position is %s)".printf (sym.get_full_name (), prev.name));
						error = true;
					}
					positions[ordering] = sym;
				}
			}
		}
		if (ordered_seen) {
			for (int i = 0; i < virtuals.size; i++) {
				Symbol? sym = positions[i];
				if (sym == null) {
					Report.error (source_reference, "%s: Gap in ordering in position %d".printf (get_full_name (), i));
					error = true;
				}
				if (!error) {
					virtuals[i] = sym;
				}
			}
		}

		context.analyzer.current_source_file = old_source_file;
		context.analyzer.current_symbol = old_symbol;

		return !error;
	}
}