/* ****************************************************************************

 *

 * Copyright (c) Microsoft Corporation. 

 *

 * This source code is subject to terms and conditions of the Microsoft Public License. A 

 * copy of the license can be found in the License.html file at the root of this distribution. If 

 * you cannot locate the  Microsoft Public License, please send an email to 

 * dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound 

 * by the terms of the Microsoft Public License.

 *

 * You must not remove this notice, or any other, from this software.

 *

 *

 * ***************************************************************************/



using System; using Microsoft;

using System.Collections;

using System.Collections.Generic;

using System.Diagnostics;

using System.Reflection;

using System.Runtime.InteropServices;

using Microsoft.Scripting.Actions;



using Microsoft.Scripting;

using Microsoft.Scripting.Generation;

using Microsoft.Scripting.Runtime;

using Microsoft.Scripting.Utils;



using IronPython.Runtime.Types;



namespace IronPython.Runtime.Operations {

    /// <summary>

    /// InstanceOps contains methods that get added to CLS types depending on what

    /// methods and constructors they define. These have not been added directly to

    /// PythonType since they need to be added conditionally.

    /// 

    /// Possibilities include:

    /// 

    ///     __new__, one of 3 __new__ sets can be added:

    ///         DefaultNew - This is the __new__ used for a PythonType (list, dict, object, etc...) that

    ///             has only 1 default public constructor that takes no parameters.  These types are 

    ///             mutable types, and __new__ returns a new instance of the type, and __init__ can be used

    ///             to re-initialize the types.  This __new__ allows an unlimited number of arguments to

    ///             be passed if a non-default __init__ is also defined.

    ///

    ///         NonDefaultNew - This is used when a type has more than one constructor, or only has one

    ///             that takes more than zero parameters.  This __new__ does not allow an arbitrary # of

    ///             extra arguments.

    /// 

    ///         DefaultNewCls - This is the default new used for CLS types that have only a single ctor

    ///             w/ an arbitray number of arguments.  This constructor allows setting of properties

    ///             based upon an extra set of kw-args, e.g.: System.Windows.Forms.Button(Text='abc').  It

    ///             is only used on non-Python types.

    /// 

    ///     __init__:

    ///         For types that do not define __init__ we have an __init__ function that takes an

    ///         unlimited number of arguments and does nothing.  All types share the same reference

    ///         to 1 instance of this.

    /// 

    ///     next: Defined when a type is an enumerator to expose the Python iter protocol.

    /// 

    /// 

    ///     repr: Added for types that override ToString

    /// 

    ///     get: added for types that implement IDescriptor

    /// </summary>

    public static class InstanceOps {

        [MultiRuntimeAware]

        private static BuiltinFunction _New;

        internal static readonly BuiltinFunction NewCls = CreateFunction("__new__", "DefaultNew", "DefaultNewClsKW");

        internal static readonly BuiltinFunction OverloadedNew = CreateFunction("__new__", "OverloadedNewBasic", "OverloadedNewKW", "OverloadedNewClsKW");

        internal static readonly BuiltinFunction NonDefaultNewInst = CreateNonDefaultNew();

        [MultiRuntimeAware]

        internal static BuiltinMethodDescriptor _Init;



        internal static BuiltinMethodDescriptor Init {

            get {

                if (_Init == null) {

                    _Init = GetInitMethod();

                }

                return _Init;

            }

        }

        



        internal static BuiltinFunction New {

            get {

                if (_New == null) {

                    _New = (BuiltinFunction)PythonTypeOps.GetSlot(

                        TypeInfo.GetExtensionMemberGroup(typeof(object), typeof(ObjectOps).GetMember("__new__")),

                        "__new__",

                        false // privateBinding

                    );

                }

                return _New;

            }

        }



        internal static BuiltinFunction CreateNonDefaultNew() {

            return CreateFunction("__new__", "NonDefaultNew", "NonDefaultNewKW", "NonDefaultNewKWNoParams");

        }



        public static object DefaultNew(CodeContext context, PythonType type\u00F8, params object[] args\u00F8) {

            if (type\u00F8 == null) throw PythonOps.TypeError("__new__ expected type object, got {0}", PythonOps.Repr(context, DynamicHelpers.GetPythonType(type\u00F8)));



            CheckInitArgs(context, null, args\u00F8, type\u00F8);



            return type\u00F8.CreateInstance(context);

        }



        public static object DefaultNewClsKW(CodeContext context, PythonType type\u00F8, [ParamDictionary] IAttributesCollection kwargs\u00F8, params object[] args\u00F8) {

            object res = DefaultNew(context, type\u00F8, args\u00F8);



            if (kwargs\u00F8.Count > 0) {

                foreach (KeyValuePair<object, object> kvp in (IDictionary<object, object>)kwargs\u00F8) {

                    PythonOps.SetAttr(context,

                        res,

                        SymbolTable.StringToId(kvp.Key.ToString()),

                        kvp.Value);

                }

            }

            return res;

        }



        public static object OverloadedNewBasic(CodeContext context, SiteLocalStorage<CallSite<Func<CallSite, CodeContext, object, object[], object>>> storage, BuiltinFunction overloads\u00F8, PythonType type\u00F8, params object[] args\u00F8) {

            if (type\u00F8 == null) throw PythonOps.TypeError("__new__ expected type object, got {0}", PythonOps.Repr(context, DynamicHelpers.GetPythonType(type\u00F8)));

            if (args\u00F8 == null) args\u00F8 = new object[1];

            return overloads\u00F8.Call(context, storage, null, args\u00F8);

        }



        public static object OverloadedNewKW(CodeContext context, BuiltinFunction overloads\u00F8, PythonType type\u00F8, [ParamDictionary] IAttributesCollection kwargs\u00F8) {

            if (type\u00F8 == null) throw PythonOps.TypeError("__new__ expected type object, got {0}", PythonOps.Repr(context, DynamicHelpers.GetPythonType(type\u00F8)));

            

            return overloads\u00F8.Call(context, null, null, ArrayUtils.EmptyObjects, kwargs\u00F8);

        }



        public static object OverloadedNewClsKW(CodeContext context, BuiltinFunction overloads\u00F8, PythonType type\u00F8, [ParamDictionary] IAttributesCollection kwargs\u00F8, params object[] args\u00F8) {

            if (type\u00F8 == null) throw PythonOps.TypeError("__new__ expected type object, got {0}", PythonOps.Repr(context, DynamicHelpers.GetPythonType(type\u00F8)));

            if (args\u00F8 == null) args\u00F8 = new object[1];



            return overloads\u00F8.Call(context, null, null, args\u00F8, kwargs\u00F8);

        }



        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA1801:ReviewUnusedParameters", MessageId = "self"), System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA1801:ReviewUnusedParameters", MessageId = "context"), System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA1801:ReviewUnusedParameters", MessageId = "args\u00F8")]

        public static void DefaultInit(CodeContext context, object self, params object[] args\u00F8) {

        }



        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA1801:ReviewUnusedParameters", MessageId = "self"), System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA1801:ReviewUnusedParameters", MessageId = "kwargs\u00F8"), System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA1801:ReviewUnusedParameters", MessageId = "context"), System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA1801:ReviewUnusedParameters", MessageId = "args\u00F8")]

        public static void DefaultInitKW(CodeContext context, object self, [ParamDictionary] IAttributesCollection kwargs\u00F8, params object[] args\u00F8) {

        }



        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA1801:ReviewUnusedParameters", MessageId = "context")]

        [StaticExtensionMethod]

        public static object NonDefaultNew(CodeContext context, PythonType type\u00F8, params object[] args\u00F8) {

            if (type\u00F8 == null) throw PythonOps.TypeError("__new__ expected type object, got {0}", PythonOps.Repr(context, DynamicHelpers.GetPythonType(type\u00F8)));

            if (args\u00F8 == null) args\u00F8 = new object[1];

            return type\u00F8.CreateInstance(context, args\u00F8);

        }



        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA1801:ReviewUnusedParameters", MessageId = "context")]

        [StaticExtensionMethod]

        public static object NonDefaultNewKW(CodeContext context, PythonType type\u00F8, [ParamDictionary] IAttributesCollection kwargs\u00F8, params object[] args\u00F8) {

            if (type\u00F8 == null) throw PythonOps.TypeError("__new__ expected type object, got {0}", PythonOps.Repr(context, DynamicHelpers.GetPythonType(type\u00F8)));

            if (args\u00F8 == null) args\u00F8 = new object[1];



            string []names;

            GetKeywordArgs(kwargs\u00F8, args\u00F8, out args\u00F8, out names);

            return type\u00F8.CreateInstance(context, args\u00F8, names);

        }



        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA1801:ReviewUnusedParameters", MessageId = "context")]

        [StaticExtensionMethod]

        public static object NonDefaultNewKWNoParams(CodeContext context, PythonType type\u00F8, [ParamDictionary] IAttributesCollection kwargs\u00F8) {

            if (type\u00F8 == null) throw PythonOps.TypeError("__new__ expected type object, got {0}", PythonOps.Repr(context, DynamicHelpers.GetPythonType(type\u00F8)));



            string[] names;

            object[] args;

            GetKeywordArgs(kwargs\u00F8, ArrayUtils.EmptyObjects, out args, out names);

            return type\u00F8.CreateInstance(context, args, names);

        }



        public static object IterMethod(CodeContext/*!*/ context, object self) {

            return self;

        }



        public static object NextMethod(object self) {

            IEnumerator i = (IEnumerator)self;

            if (i.MoveNext()) return i.Current;

            throw PythonOps.StopIteration();

        }



        public static int LengthMethod(ICollection self) {

            return self.Count;

        }



        public static int GenericLengthMethod<T>(ICollection<T> self) {

            return self.Count;

        }



        public static string SimpleRepr(object self) {

            return String.Format("<{0} object at {1}>",

                PythonTypeOps.GetName(self),

                PythonOps.HexId(self));

        }



        public static string FancyRepr(object self) {

            PythonType pt = (PythonType)DynamicHelpers.GetPythonType(self);

            // we can't call ToString on a UserType because we'll stack overflow, so

            // only do FancyRepr for reflected types.

            if (pt.IsSystemType) {

                string toStr = self.ToString();

                if (toStr == null) toStr = String.Empty;



                // get the type name to display (CLI name or Python name)

                Type type = pt.UnderlyingSystemType;

                string typeName = type.FullName;



                // Get the underlying .ToString() representation.  Truncate multiple

                // lines, and don't display it if it's object's default representation (type name)



                // skip initial empty lines:

                int i = 0;

                while (i < toStr.Length && (toStr[i] == '\r' || toStr[i] == '\n')) i++;



                // read the first non-empty line:

                int j = i;

                while (j < toStr.Length && toStr[j] != '\r' && toStr[j] != '\n') j++;



                // skip following empty lines:

                int k = j;

                while (k < toStr.Length && (toStr[k] == '\r' || toStr[k] == '\n')) k++;



                if (j > i) {

                    string first_non_empty_line = toStr.Substring(i, j - i);

                    bool has_multiple_non_empty_lines = k < toStr.Length;



                    return String.Format("<{0} object at {1} [{2}{3}]>",

                        typeName,

                        PythonOps.HexId(self),

                        first_non_empty_line,

                        has_multiple_non_empty_lines ? "..." : String.Empty);



                } else {

                    return String.Format("<{0} object at {1}>",

                             typeName,

                             PythonOps.HexId(self));

                }

            }

            return SimpleRepr(self);

        }



        public static object ReprHelper(CodeContext context, object self) {

            return ((ICodeFormattable)self).__repr__(context);

        }



        public static string ToStringMethod(object self) {

            string res = self.ToString();

            if (res == null) return String.Empty;

            return res;

        }



        // Value equality helpers:  These are the default implementation for classes that implement

        // IValueEquality.  We promote the ReflectedType to having these helper methods which will

        // automatically test the type and return NotImplemented for mixed comparisons.  For non-mixed

        // comparisons we have a fully optimized version which returns bool.



        public static bool ValueEqualsMethod<T>(T x, [NotNull]T y) 

            where T : IValueEquality {

            return x.ValueEquals(y);

        }



        public static bool ValueNotEqualsMethod<T>(T x, [NotNull]T y)

            where T : IValueEquality {

            return !x.ValueEquals(y);

        }



        [return: MaybeNotImplemented]

        public static object ValueEqualsMethod<T>([NotNull]T x, object y) 

            where T : IValueEquality {

            if (!(y is T)) return NotImplementedType.Value;



            return RuntimeHelpers.BooleanToObject(x.ValueEquals(y));

        }



        [return: MaybeNotImplemented]

        public static object ValueNotEqualsMethod<T>([NotNull]T x, object y) 

            where T : IValueEquality {

            if (!(y is T)) return NotImplementedType.Value;



            return RuntimeHelpers.BooleanToObject(!x.ValueEquals(y));

        }



        [return: MaybeNotImplemented]

        public static object ValueEqualsMethod<T>(object y, [NotNull]T x)

            where T : IValueEquality {

            if (!(y is T)) return NotImplementedType.Value;



            return RuntimeHelpers.BooleanToObject(x.ValueEquals(y));

        }



        [return: MaybeNotImplemented]

        public static object ValueNotEqualsMethod<T>(object y, [NotNull]T x)

            where T : IValueEquality {

            if (!(y is T)) return NotImplementedType.Value;



            return RuntimeHelpers.BooleanToObject(x.ValueEquals(y));

        }



        // TODO: Remove me

        public static object ValueHashMethod(object x) {

            return ((IValueEquality)x).GetValueHashCode();

        }



        public static int GetHashCodeMethod(object x) {

            return x.GetHashCode();

        }



        public static bool EqualsMethod(object x, object y) {

            return x.Equals(y);

        }



        public static bool NotEqualsMethod(object x, object y) {

            return !x.Equals(y);

        }



        /// <summary>

        /// Provides the implementation of __enter__ for objects which implement IDisposable.

        /// </summary>

        public static object EnterMethod(IDisposable/*!*/ self) {

            return self;

        }



        /// <summary>

        /// Provides the implementation of __exit__ for objects which implement IDisposable.

        /// </summary>

        public static void ExitMethod(IDisposable/*!*/ self, object exc_type, object exc_value, object exc_back) {

            self.Dispose();

        }



        [PropertyMethod, StaticExtensionMethod]

        public static List/*!*/ Get__all__<T>(CodeContext/*!*/ context) {

            Debug.Assert(typeof(T).IsSealed && typeof(T).IsAbstract, "__all__ should only be produced for static members"); 



            PythonType pt = DynamicHelpers.GetPythonTypeFromType(typeof(T));



            List names = new List();

            foreach (string name in pt.GetMemberNames(context)) {

                object res;

                if (IsStaticTypeMemberInAll(context, pt, SymbolTable.StringToId(name), out res)) {

                    names.AddNoLock(name);

                }

            }



            return names;

        }



        /// <summary>

        /// Determines if a type member can be imported.  This is used to treat static types like modules.

        /// </summary>

        private static bool IsStaticTypeMemberInAll(CodeContext/*!*/ context, PythonType/*!*/ pt, SymbolId name, out object res) {

            PythonTypeSlot pts;

            res = null;

            if (pt.TryResolveSlot(context, name, out pts)) {

                if (name == Symbols.Doc || name == Symbols.Class) {

                    // these exist but we don't want to clobber __doc__ on import * or bring in __class__

                    return false;

                } else if (pts is ReflectedGetterSetter) {

                    // property or indexer, these fetch the value at runtime, the user needs to explicitly

                    // import them using from type import property

                    return false;

                }



                ReflectedField rf = pts as ReflectedField;

                if (rf != null && !rf.info.IsInitOnly && !rf.info.IsLiteral) {

                    // only bring in read-only fields, if the value can change the user needs to explicitly

                    // import by name

                    return false;

                }



                BuiltinMethodDescriptor method = pts as BuiltinMethodDescriptor;

                if (method != null && (!method.DeclaringType.IsSealed || !method.DeclaringType.IsAbstract)) {

                    // inherited object member on a static class (GetHashCode, Equals, etc...)

                    return false;

                }



                BuiltinFunction bf = pts as BuiltinFunction;

                if (bf != null && (!bf.DeclaringType.IsSealed || !bf.DeclaringType.IsAbstract)) {

                    // __new__/ReferenceEquals inherited from object

                    return false;

                }



                if (pts.TryGetValue(context, null, pt, out res)) {

                    return true;

                }

            }



            res = null;

            return false;

        }



        /// <summary>

        /// Implements __contains__ for types implementing IEnumerable of T.

        /// </summary>

        public static bool ContainsGenericMethod<T>(CodeContext/*!*/ context, IEnumerable<T> enumerable, T value) {

            foreach(T item in enumerable) {

                if (PythonOps.EqualRetBool(context, item, value)) {

                    return true;

                }

            }



            return false;

        }



        /// <summary>

        /// Implements __contains__ for types implementing IEnumerable

        /// </summary>

        public static bool ContainsMethod(CodeContext/*!*/ context, IEnumerable enumerable, object value) {

            IEnumerator ie = enumerable.GetEnumerator();

            while (ie.MoveNext()) {

                if (PythonOps.EqualRetBool(context, ie.Current, value)) {

                    return true;

                }

            }



            return false;

        }



        /// <summary>

        /// Implements __contains__ for types implementing IEnumerable of T.

        /// </summary>

        public static bool ContainsGenericMethodIEnumerator<T>(CodeContext/*!*/ context, IEnumerator<T> enumerator, T value) {

            while (enumerator.MoveNext()) {

                if (PythonOps.EqualRetBool(context, enumerator.Current, value)) {

                    return true;

                }

            }



            return false;

        }



        /// <summary>

        /// Implements __contains__ for types implementing IEnumerable

        /// </summary>

        public static bool ContainsMethodIEnumerator(CodeContext/*!*/ context, IEnumerator enumerator, object value) {

            while (enumerator.MoveNext()) {

                if (PythonOps.EqualRetBool(context, enumerator.Current, value)) {

                    return true;

                }

            }



            return false;

        }



        public static object GetMethod(CodeContext context, object self, object instance, [Optional]object typeContext) {

            PythonTypeSlot dts = self as PythonTypeSlot;

            PythonType dt = typeContext as PythonType;



            Debug.Assert(dts != null);



            object res;

            if (dts.TryGetValue(context, instance, dt, out res))

                return res;



            // context is hiding __get__

            throw PythonOps.AttributeErrorForMissingAttribute(dt == null ? "?" : dt.Name, Symbols.GetDescriptor);

        }



#if !SILVERLIGHT

        /// <summary>

        /// Implements __reduce_ex__ for .NET types which are serializable.  This uses the .NET

        /// serializer to get a string of raw data which can be serialized.

        /// </summary>

        public static PythonTuple SerializeReduce(CodeContext/*!*/ context, object/*!*/ self, int protocol) {

            PythonTuple data = ClrModule.Serialize(self);



            object deserializeNew;

            bool res = PythonContext.GetContext(context).ClrModule.TryGetName(

                SymbolTable.StringToId("Deserialize"),

                out deserializeNew

            );

            Debug.Assert(res);



            return PythonTuple.MakeTuple(

                deserializeNew,                 // function to call, clr.DeserializeNew 

                data,                           // data to pass to it - our type & the raw data from the .NET serializer

                null                            // state, unused

            );

        }

#endif



        internal static void CheckInitArgs(CodeContext context, IAttributesCollection dict, object[] args, PythonType pt) {

            PythonTypeSlot dts;

            object initObj;

            if (((args != null && args.Length > 0) || (dict != null && dict.Count > 0)) &&

                (pt.TryResolveSlot(context, Symbols.Init, out dts)) && dts.TryGetValue(context, null, pt, out initObj) &&

                initObj == Init) {



                throw PythonOps.TypeError("default __new__ does not take parameters");

            }

        }



        private static BuiltinMethodDescriptor GetInitMethod() {

            PythonTypeSlot pts;

            TypeCache.Object.TryResolveSlot(DefaultContext.Default, Symbols.Init, out pts);



            Debug.Assert(pts != null);

            return (BuiltinMethodDescriptor)pts;

        }



        private static BuiltinFunction CreateFunction(string name, params string[] methodNames) {

            MethodBase[] methods = new MethodBase[methodNames.Length];

            for (int i = 0; i < methods.Length; i++) {

                methods[i] = typeof(InstanceOps).GetMethod(methodNames[i]);

            }

            return BuiltinFunction.MakeMethod(name, methods, typeof(object), FunctionType.Function | FunctionType.AlwaysVisible);

        }



        private static void GetKeywordArgs(IAttributesCollection dict, object[] args, out object[] finalArgs, out string[] names) {

            finalArgs = new object[args.Length + dict.Count];

            Array.Copy(args, finalArgs, args.Length);

            names = new string[dict.Count];

            int i = 0;

            foreach (KeyValuePair<object, object> kvp in (IDictionary<object, object>)dict) {

                names[i] = (string)kvp.Key;

                finalArgs[i + args.Length] = kvp.Value;

                i++;

            }

        }

    }

}